NCBI Conserved Domain Search

Third (or C-terminal) Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212851 [Multi-domain] Cd Length: 58 Bit Score: 136.63 E-value: 5.03e-39

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 503 WTPYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd11918     1 RTPYKAVYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAPV 58

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212714 [Multi-domain] Cd Length: 55 Bit Score: 126.26 E-value: 2.43e-35

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11780     1 RYRALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSERTGLFGTFPGNYVAR 55

Second Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212857 Cd Length: 56 Bit Score: 124.69 E-value: 1.16e-34

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 347 GDAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQI 402
Cdd:cd11924     1 GEAVAQYTFKGDLEVELSFRKGEHICLIRKVNENWYEGRITGTGRQGIFPASYVQV 56

First Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212854 Cd Length: 55 Bit Score: 120.41 E-value: 3.81e-33

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11921     1 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRVGIFPANYVEVL 55

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212849 [Multi-domain] Cd Length: 59 Bit Score: 113.16 E-value: 1.62e-30

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd11916     4 YQALYSYAPQNDDELELRDGDIVDVMEKCDDGWFVGTSRRTKQFGTFPGNYVKLL 58

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 109.35 E-value: 2.99e-29

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11781     1 KARALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGEHNGRVGIFPASYVEI 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212850 [Multi-domain] Cd Length: 61 Bit Score: 100.84 E-value: 4.77e-26

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11917     6 PFQALYNYMPRNEDELELREGDVIDVMEKCDDGWFVGTSRRTKFFGTFPGNYV 58

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212852 [Multi-domain] Cd Length: 55 Bit Score: 98.50 E-value: 2.79e-25

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11919     1 RPARAKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEGEHHGRVGIFPRSYIELL 55

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 96.27 E-value: 1.80e-24

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11782     2 ARAKYNFNADTGVELSFRKGDVITLTRRVDENWYEGRI--GGRQGIFPVSYVQV 53

Second Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212855 [Multi-domain] Cd Length: 58 Bit Score: 96.21 E-value: 2.07e-24

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 347 GDAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQI 402
Cdd:cd11922     1 GEAIAKFNFNGDTQVEMSFRKGERITLLRQVDENWYEGRIPGTSRQGIFPITYVDV 56

Second Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212856 [Multi-domain] Cd Length: 57 Bit Score: 90.36 E-value: 2.16e-22

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 347 GDAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQI 402
Cdd:cd11923     1 GEAVAKYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGKIPGTNRQGIFPVSYVEV 56

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 87.37 E-value: 2.33e-21

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11920     3 ARAVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGEHHGRVGIFPISYVEKL 55

Third Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212717 [Multi-domain] Cd Length: 55 Bit Score: 85.52 E-value: 9.15e-21

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11783     2 YVALYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTSLRTGQSGVFPGNYVQP 55

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 77.78 E-value: 5.79e-18

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11782     2 ARAKYNFNADTGVELSFRKGDVITLTRRVDENWYEGRIGGRQGIFPVSYVQV 53

Third Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212858 Cd Length: 57 Bit Score: 77.34 E-value: 1.00e-17

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd11925     3 YLALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSLRTGVSGVFPGNYVTPV 57

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 76.14 E-value: 1.95e-17

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11803     1 PCCRALYDFEPENEGELGFKEGDIITLTNQIDENWYEGMVNGQSGFFPVNYVEVL 55

Third Src Homology 3 domain of SH3 domain containing ring finger 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212859 [Multi-domain] Cd Length: 55 Bit Score: 75.39 E-value: 3.42e-17

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11926     2 YVAIYPYTPRKEDELELRKGEMFLVFERCQDGWFKGTSMHTSKIGVFPGNYVAP 55

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 74.50 E-value: 7.66e-17

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458  275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHH-GRLGIFPANYVE 325
Cdd:smart00326   5 VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGrGKEGLFPSNYVE 56

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 72.96 E-value: 3.12e-16

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458  349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItGTGRQGIFPASYVQ 401
Cdd:smart00326   5 VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRL-GRGKEGLFPSNYVE 56

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 69.80 E-value: 3.30e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGtGRQGIFPASY 399
Cdd:cd00174     2 ARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNG-GREGLFPANY 51

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 69.70 E-value: 3.81e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11786     2 AKALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNGKQGFFPASYVQV 53

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 69.19 E-value: 6.29e-15

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11805     2 VQALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGELRGRVGIFPANYVQP 53

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 67.87 E-value: 1.57e-14

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHH-GRLGIFPANY 323
Cdd:cd00174     6 YDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNgGREGLFPANY 51

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

Pssm-ID: 214620 [Multi-domain] Cd Length: 56 Bit Score: 66.41 E-value: 4.89e-14

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458  506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRtQKFGTFPGNYVA 558
Cdd:smart00326   5 VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGR-GKEGLFPSNYVE 56

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 66.52 E-value: 5.00e-14

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYVAP 559
Cdd:cd11766     1 PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRG--ECNGQVGWFPSNYVTE 53

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

Pssm-ID: 212690 [Multi-domain] Cd Length: 51 Bit Score: 66.33 E-value: 5.59e-14

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKfGTFPGNY 556
Cdd:cd00174     2 ARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNGGRE-GLFPANY 51

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 66.21 E-value: 6.11e-14

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11823     6 YSYTANREDELSLQPGDIIEVHEKQDDGWWLGELNGKKGIFPATYVEE 53

C-terminal Src Homology 3 domain of Nebulette and LIM-nebulette (or Lasp2); Nebulette is a cardiac-specific protein that localizes to the Z-disc. It interacts with tropomyosin and is important in stabilizing actin thin filaments in cardiac muscles. Polymorphisms in the nebulette gene are associated with dilated cardiomyopathy, with some mutations resulting in severe heart failure. Nebulette is a 107kD protein that contains an N-terminal acidic region, multiple nebulin repeats, and a C-terminal SH3 domain. LIM-nebulette, also called Lasp2 (LIM and SH3 domain protein 2), is an alternatively spliced variant of nebulette. Although it shares a gene with nebulette, Lasp2 is not transcribed from a muscle-specific promoter, giving rise to its multiple tissue expression pattern with highest amounts in the brain. It can crosslink actin filaments and it affects cell spreading. Lasp2 is a 34kD protein containing an N-terminal LIM domain, three nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212868 [Multi-domain] Cd Length: 58 Bit Score: 65.80 E-value: 9.55e-14

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 504 TPYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11935     1 RTYRAMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVQRTGRTGMLPANYI 54

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 65.06 E-value: 1.65e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEV--DKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11875     2 ARVLFDYEAENEDELTLREGDIVTILSKDceDKGWWKGELNGKRGVFPDNFVEP 55

C-terminal Src Homology 3 domain of the Nebulin family of proteins; Nebulin family proteins contain multiple nebulin repeats, and may contain an N-terminal LIM domain and/or a C-terminal SH3 domain. They have molecular weights ranging from 34 to 900 kD, depending on the number of nebulin repeats, and they all bind actin. They are involved in the regulation of actin filament architecture and function as stabilizers and scaffolds for cytoskeletal structures with which they associate, such as long actin filaments or focal adhesions. Nebulin family proteins that contain a C-terminal SH3 domain include the giant filamentous protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2, also called LIM-nebulette, is an alternatively spliced variant of nebulette. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212723 [Multi-domain] Cd Length: 55 Bit Score: 64.65 E-value: 2.19e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11789     2 YRAMYDYAAADDDEVSFQEGDVIINVEIIDDGWMEGTVQRTGQSGMLPANYVEL 55

Src homology 3 domain of Ubiquitin-associated and SH3 domain-containing proteins, also called TULA (T cell Ubiquitin LigAnd) family of proteins; UBASH3 or TULA proteins are also referred to as Suppressor of T cell receptor Signaling (STS) proteins. They contain an N-terminal UBA domain, a central SH3 domain, and a C-terminal histidine phosphatase domain. They bind c-Cbl through the SH3 domain and to ubiquitin via UBA. In some vertebrates, there are two TULA family proteins, called UBASH3A (also called TULA or STS-2) and UBASH3B (also called TULA-2 or STS-1), which show partly overlapping as well as distinct functions. UBASH3B is widely expressed while UBASH3A is only found in lymphoid cells. UBASH3A facilitates apoptosis induced in T cells through its interaction with the apoptosis-inducing factor AIF. UBASH3B is an active phosphatase while UBASH3A is not. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212725 [Multi-domain] Cd Length: 59 Bit Score: 64.63 E-value: 2.68e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRV----DVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11791     2 LRVLYPYTPQEEDELELVPGDYIyvspEELDSSSDGWVEGTSWLTGCSGLLPENYT 57

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 64.26 E-value: 3.48e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11877     2 VRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYVK 52

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 63.53 E-value: 5.09e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11796     2 ARVLQDLSAQLDEELDLREGDVVTITGILDKGWFRGELNGRRGIFPEGFV 51

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 63.60 E-value: 5.79e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEH--WYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11842     2 AVALYDFAGEQPGDLAFQKGDIITILKKSDSQndWWTGRI--GGREGIFPANYVEL 55

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 63.05 E-value: 7.47e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11873     2 VIVEFDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTLNGKRGMFPDNFVKV 53

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 63.15 E-value: 7.64e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11786     2 AKALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNGK--QGFFPASYVQV 53

Src homology 3 domain of JNK-interacting proteins 1 and 2, and similar domains; JNK-interacting proteins (JIPs) function as scaffolding proteins for c-Jun N-terminal kinase (JNK) signaling pathways. They bind to components of Mitogen-activated protein kinase (MAPK) pathways such as JNK, MKK, and several MAP3Ks such as MLK and DLK. There are four JIPs (JIP1-4); all contain a JNK binding domain. JIP1 and JIP2 also contain SH3 and Phosphotyrosine-binding (PTB) domains. Both are highly expressed in the brain and pancreatic beta-cells. JIP1 functions as an adaptor linking motor to cargo during axonal transport and also is involved in regulating insulin secretion. JIP2 form complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. The SH3 domain of JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212735 Cd Length: 55 Bit Score: 63.10 E-value: 8.00e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVA 558
Cdd:cd11801     2 HRALHKFIPRHEDEIELDIGDPVYVEQEADDLWCEGTNLRTGQRGIFPAAYVV 54

C-terminal (Fourth) Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the fourth SH3 domain, located at the C-terminus of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212719 Cd Length: 55 Bit Score: 62.87 E-value: 9.25e-13

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11785     2 YRVIVPYPPQSEAELELKEGDIVFVHKKREDGWFKGTLQRTGKTGLFPGSFVES 55

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 62.83 E-value: 1.15e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDK--NWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11842     2 AVALYDFAGEQPGDLAFQKGDIITILKKSDSqnDWWTGRIGGREGIFPANYVEL 55

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 62.36 E-value: 1.58e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRitGTGRQGIFPASYVQI 402
Cdd:cd11781     2 ARALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGE--HNGRVGIFPASYVEI 53

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212718 Cd Length: 55 Bit Score: 61.33 E-value: 3.16e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11784     2 CVALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLSLVTGRVGIFPSNYVSP 55

C-terminal Src Homology 3 domain of LIM and SH3 domain protein 1; Lasp1 is a cytoplasmic protein that binds focal adhesion proteins and is involved in cell signaling, migration, and proliferation. It is overexpressed in several cancer cells including breast, ovarian, bladder, and liver. In cancer cells, it can be found in the nucleus; its degree of nuclear localization correlates with tumor size and poor prognosis. Lasp1 is a 36kD protein containing an N-terminal LIM domain, two nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212867 [Multi-domain] Cd Length: 59 Bit Score: 61.17 E-value: 3.91e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11934     5 YRAVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGTVERTGDTGMLPANYV 56

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 60.71 E-value: 4.54e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYVA 558
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEESEDGWWEG--INTGRTGLVPANYVE 49

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 60.80 E-value: 4.90e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11826     3 VALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVT--GLFPGNYV 51

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 60.94 E-value: 4.97e-12

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIV-YIHKEV-DKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd12142     3 RVLFDYNPVAPDELALKKGDVIeVISKETeDEGWWEGELNGRRGFFPDNFVMP 55

Src Homology 3 domain of Mixed Lineage Kinase 4; MLK4 is a Serine/Threonine Kinase (STK), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The specific function of MLK4 is yet to be determined. Mutations in the kinase domain of MLK4 have been detected in colorectal cancers. MLK4 contains an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212991 [Multi-domain] Cd Length: 58 Bit Score: 59.95 E-value: 1.14e-11

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 503 WTpyrAMYQYRPQNEDELELREGDRVDVMQQ-----CDDGWFVGVSRRtqKFGTFPGNYVAP 559
Cdd:cd12058     2 WT---ALYDYEASGEDELSLRRGDVVEVLSQdaavsGDDGWWAGKIRH--RLGIFPANYVTR 58

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 59.62 E-value: 1.16e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11772     6 YDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYVE 52

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 59.59 E-value: 1.25e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11766     2 AVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYVT 52

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 59.26 E-value: 1.57e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11826     6 YDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYVE 52

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 58.93 E-value: 2.12e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12061     3 RAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYV 51

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 58.66 E-value: 2.59e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd12046     6 FSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCKGKIGIFPSAFVE 52

Second Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212856 [Multi-domain] Cd Length: 57 Bit Score: 58.77 E-value: 2.59e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG--RLGIFPANYVEVL 327
Cdd:cd11923     6 KYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGKIPGtnRQGIFPVSYVEVI 57

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 58.80 E-value: 2.77e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11929     3 AKALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGEINGVSGIFPASSVEV 54

C-terminal Src Homology 3 domain of Nebulin; Nebulin is a giant filamentous protein (600-900 kD) that is expressed abundantly in skeletal muscle. It binds to actin thin filaments and regulates its assembly and function. Nebulin was thought to be part of a molecular ruler complex that is critical in determining the lengths of actin thin filaments in skeletal muscle since its length, which varies due to alternative splicing, correlates with the length of thin filaments in various muscle types. Recent studies indicate that nebulin regulates thin filament length by stabilizing the filaments and preventing depolymerization. Mutations in nebulin can cause nemaline myopathy, characterized by muscle weakness which can be severe and can lead to neonatal lethality. Nebulin contains an N-terminal LIM domain, many nebulin repeats/super repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212866 [Multi-domain] Cd Length: 58 Bit Score: 58.87 E-value: 2.80e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd11933     4 FRAMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQRTGKTGMLPANYVEAI 58

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 58.40 E-value: 2.82e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:pfam14604   2 LYPYEPKDDDELSLQRGDVITVIEESEDGWWEGINTGRTGLVPANYVE 49

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 58.69 E-value: 2.96e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11870     6 HRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHSDGRVGIFPKCFVV 52

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 58.50 E-value: 3.25e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11874     3 KVLFSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKLN--GKVGVFPSNFV 51

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212987 [Multi-domain] Cd Length: 55 Bit Score: 58.44 E-value: 3.88e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSrrTQKFGTFPGNYV 557
Cdd:cd12054     4 KVLFEYVPQNEDELELKVGDIIDINEEVEEGWWSGTL--NGKSGLFPSNFV 52

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 58.09 E-value: 5.20e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkFGTFPGNYV 557
Cdd:cd11819     3 KALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVNAKGQ-KGLFPANYV 52

Src homology 3 domain of SH3 domain containing Ysc84-like 1 (SH3YL1) protein; SH3YL1 localizes to the plasma membrane and is required for dorsal ruffle formation. It binds phosphoinositides (PIs) with high affinity through its N-terminal SYLF domain (also called DUF500). In addition, SH3YL1 contains a C-terminal SH3 domain which has been reported to bind to N-WASP, dynamin 2, and SHIP2 (a PI 5-phosphatase). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212775 Cd Length: 54 Bit Score: 57.79 E-value: 5.87e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEH--WYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11841     2 VTALYSFEGQQPCDLSFQAGDRITVLTRTDSQfdWWEGRL--RGRVGIFPANYVS 54

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 57.92 E-value: 5.88e-11

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11961     2 AKALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGECHGSRGLFPSNYVE 52

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 57.21 E-value: 7.22e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGtGRQGIFPA 397
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRNKG-GKEGLIPS 47

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 57.52 E-value: 7.40e-11

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 503 WTpyrAMYQYRPQNEDELELREGDRVDVMQQ-----CDDGWFVGvsRRTQKFGTFPGNYVAP 559
Cdd:cd11876     2 WT---ALFDYDARGEDELTLRRGQPVEVLSKdaavsGDEGWWTG--KIGDKVGIFPSNYVAP 58

Src homology 3 domain of SH3 domain containing Ysc84-like 1 (SH3YL1) protein; SH3YL1 localizes to the plasma membrane and is required for dorsal ruffle formation. It binds phosphoinositides (PIs) with high affinity through its N-terminal SYLF domain (also called DUF500). In addition, SH3YL1 contains a C-terminal SH3 domain which has been reported to bind to N-WASP, dynamin 2, and SHIP2 (a PI 5-phosphatase). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212775 Cd Length: 54 Bit Score: 57.02 E-value: 9.86e-11

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDK--NWLEGEHHGRLGIFPANYV 324
Cdd:cd11841     6 YSFEGQQPCDLSFQAGDRITVLTRTDSqfDWWEGRLRGRVGIFPANYV 53

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 57.26 E-value: 1.02e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYI-HKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11976     1 TAKARYDFCARDRSELSLKEGDIIKIlNKKGQQGWWRGEIYGRVGWFPANYVE 53

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 56.75 E-value: 1.20e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12047     3 VAQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEGHCDGRIGIFPKCFA 51

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The N-terminal SH3 domain of GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212738 [Multi-domain] Cd Length: 52 Bit Score: 56.98 E-value: 1.20e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI-HKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11804     2 AVAKHDFKATAEDELSFKKGSILKVlNMEDDPNWYKAELDGKEGLIPKNYI 52

Src Homology 3 domain of the p40phox subunit of NADPH oxidase; p40phox, also called Neutrophil cytosol factor 4 (NCF-4), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p40phox positively regulates NADPH oxidase in both phosphatidylinositol-3-phosphate (PI3P)-dependent and PI3P-independent manner. It contains an N-terminal PX domain, a central SH3 domain, and a C-terminal PB1 domain that interacts with p67phox. The SH3 domain of p40phox binds to canonical polyproline and noncanonical motifs at the C-terminus of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212802 Cd Length: 54 Bit Score: 56.73 E-value: 1.51e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11869     6 FDFTGNSKLELNFKAGDVIFLLSRVNKDWLEGTVRGATGIFPLSFVKII 54

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 56.15 E-value: 2.09e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRtqKFGTFPGNYVAP 559
Cdd:cd11772     2 FRALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGG--KTGLIPSNYVEE 53

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 56.00 E-value: 2.28e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11949     1 YVQALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGACHGQTGMFPRNYVT 52

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 56.10 E-value: 2.45e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIH-KEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11830     2 AKARYDFCARDMRELSLKEGDVVKIYnKKGQQGWWRGEINGRIGWFPSTYVE 53

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 55.67 E-value: 2.60e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE-HHGRLGIFPA 321
Cdd:pfam00018   3 LYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRnKGGKEGLIPS 47

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 55.84 E-value: 2.78e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVgVSRRTQKfGTFPGNYV 557
Cdd:cd11824     2 YSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWT-VERNGQK-GLVPGTYL 51

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 55.73 E-value: 2.83e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQIN 403
Cdd:cd11803     3 CRALYDFEPENEGELGFKEGDIITLTNQIDENWYEGMV--NGQSGFFPVNYVEVL 55

Src homology 3 domain of Slit-Robo GTPase Activating Proteins; Slit-Robo GTPase Activating Proteins (srGAPs) are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. Vertebrates contain three isoforms of srGAPs (srGAP1-3), all of which are expressed during embryonic and early development in the nervous system but with different localization and timing. A fourth member has also been reported (srGAP4, also called ARHGAP4). srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212743 [Multi-domain] Cd Length: 53 Bit Score: 55.87 E-value: 2.86e-10

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11809     5 QFDYTGRSERELSFKKGDSLTLYRQVSDDWWRGQLNGQDGLVPHKYI 51

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 55.79 E-value: 2.88e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRitGTGRQGIFPASYVQ 401
Cdd:cd11920     3 ARAVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGE--HHGRVGIFPISYVE 53

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 55.83 E-value: 3.31e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKE--VDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11836     3 RALYAFEARNPDEISFQPGDIIQVDESqvAEPGWLAGELKGKTGWFPANYVE 54

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 55.81 E-value: 3.38e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGR-----LGIFPANYVEV 326
Cdd:cd11839     2 AQVIAPFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQARgkkrqIGWFPANYVKL 58

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 55.29 E-value: 3.95e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:pfam07653   2 GRVIFDYVGTDKNGLTLKKGDVVKVLGKDNDGWWEGETGGRVGLVPSTAVEEI 54

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 55.54 E-value: 3.97e-10

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                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 503 WTpyrAMYQYRPQNEDELELREGDRVDVMQQ-----CDDGWFVGvsRRTQKFGTFPGNYVAP 559
Cdd:cd12059     2 WT---AVFDYEASAEDELTLRRGDRVEVLSKdsavsGDEGWWTG--KINDRVGIFPSNYVTS 58

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 55.18 E-value: 4.19e-10

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASY 399
Cdd:cd11817     2 AVALYDFTGETEEDLSFQRGDRILVTEHLDAEWSRGRL--NGREGIFPRAF 50

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 55.18 E-value: 4.22e-10

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANY 323
Cdd:cd11818     2 ARALYDFTGENEDELSFKAGDIITELESIDEEWMSGELRGKSGIFPKNF 50

Src homology 3 domain of Signal Transducing Adaptor Molecule 2; STAM2, also called EAST (Epidermal growth factor receptor-associated protein with SH3 and TAM domain) or Hbp (Hrs binding protein), is part of the endosomal sorting complex required for transport (ESCRT-0). It plays a role in sorting mono-ubiquinated endosomal cargo for trafficking to the lysosome for degradation. It is also involved in the regulation of exocytosis. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212896 [Multi-domain] Cd Length: 57 Bit Score: 55.41 E-value: 5.30e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11963     2 RKVRALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHRGVGLFPSNFV 53

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 54.66 E-value: 6.38e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvSRRTQKfGTFPGNYV 557
Cdd:cd11823     3 KALYSYTANREDELSLQPGDIIEVHEKQDDGWWLG-ELNGKK-GIFPATYV 51

Sorbin homologous domain; First found in the peptide hormone sorbin and later in the ponsin/ArgBP2/vinexin family of proteins.

Pssm-ID: 128735 Cd Length: 50 Bit Score: 54.55 E-value: 7.31e-10

                           10        20        30
                   ....*....|....*....|....*....|..
gi 1958679458   10 QALGESVDSPRDWYRRMFQQIHRKMPDLQLDW 41
Cdd:smart00459  19 QAPRSSVERPKDWYRTMFKQIHRKGPDGDNDG 50

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 54.64 E-value: 7.93e-10

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKE-VDKNWLEGEH-HGRLGIFPANYVEV 326
Cdd:cd11763     2 VRALYDFDSQPSGELSLRAGEVLTITRQdVGDGWLEGRNsRGEVGLFPSSYVEI 55

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212911 [Multi-domain] Cd Length: 56 Bit Score: 54.26 E-value: 1.01e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKN-WLEGEHHGRLGIFPANYVE 325
Cdd:cd11978     6 RYDFCARDMRELSLLKGDVVKIYTKMSTNgWWRGEVNGRVGWFPSTYVE 54

Src Homology 3 domain of the p40phox subunit of NADPH oxidase; p40phox, also called Neutrophil cytosol factor 4 (NCF-4), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p40phox positively regulates NADPH oxidase in both phosphatidylinositol-3-phosphate (PI3P)-dependent and PI3P-independent manner. It contains an N-terminal PX domain, a central SH3 domain, and a C-terminal PB1 domain that interacts with p67phox. The SH3 domain of p40phox binds to canonical polyproline and noncanonical motifs at the C-terminus of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212802 Cd Length: 54 Bit Score: 54.42 E-value: 1.04e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQI 402
Cdd:cd11869     2 AEALFDFTGNSKLELNFKAGDVIFLLSRVNKDWLEG--TVRGATGIFPLSFVKI 53

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 54.13 E-value: 1.08e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12052     2 AIVEFDYKAQHEDELTITVGDIITKIKKDDGGWWEGEIKGRRGLFPDNFV 51

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 54.34 E-value: 1.09e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11840     6 FPYTAQNEDELSFQKGDIINVLSKDDPDWWRGELNGQTGLFPSNYVEP 53

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212897 [Multi-domain] Cd Length: 55 Bit Score: 54.18 E-value: 1.15e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11964     1 RKVRAIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGETPQGTGLFPSNFV 52

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 54.13 E-value: 1.17e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIV-YIHKE-VDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd12057     6 FPYEAQNEDELTIKEGDIVtLISKDcIDAGWWEGELNGRRGVFPDNFVKLL 56

First Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212861 Cd Length: 54 Bit Score: 54.16 E-value: 1.36e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQ 401
Cdd:cd11928     5 ALYSYEGKEPGDLKFNKGDIIILRRKVDENWYHGELNGC--HGFLPASYIQ 53

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 53.79 E-value: 1.48e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11805     4 ALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGEL--RGRVGIFPANYVQ 52

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 53.49 E-value: 1.69e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11874     2 CKVLFSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKLNGKVGVFPSNFVKE 53

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 53.57 E-value: 2.02e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11827     3 KALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTG--RLRGKEGLFPGNYV 51

Src homology 3 domain of Slit-Robo GTPase Activating Proteins; Slit-Robo GTPase Activating Proteins (srGAPs) are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. Vertebrates contain three isoforms of srGAPs (srGAP1-3), all of which are expressed during embryonic and early development in the nervous system but with different localization and timing. A fourth member has also been reported (srGAP4, also called ARHGAP4). srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212743 [Multi-domain] Cd Length: 53 Bit Score: 53.17 E-value: 2.44e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11809     2 ATAQFDYTGRSERELSFKKGDSLTLYRQVSDDWWRGQL--NGQDGLVPHKYI 51

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 53.17 E-value: 2.45e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKE----VDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11762     2 VRALYDYEAQSDEELSFPEGAIIRILRKddngVDDGWWEGEFNGRVGVFPSLVVE 56

Third Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212750 [Multi-domain] Cd Length: 51 Bit Score: 53.18 E-value: 2.52e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11816     2 CVARFDFEGEQEDELSFSEGDVITLKEYVGEEWAKGELNGKIGIFPLNFV 51

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 53.24 E-value: 2.58e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11820     4 RALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGEGLFPANFV 52

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 53.11 E-value: 2.68e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11793     4 CVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGERLRDGERGWFPSSYT 53

Src homology 3 domain of Slit-Robo GTPase Activating Protein 4; srGAP4, also called ARHGAP4, is highly expressed in hematopoietic cells and may play a role in lymphocyte differentiation. It is able to stimulate the GTPase activity of Rac1, Cdc42, and RhoA. In the nervous system, srGAP4 has been detected in differentiating neurites and may be involved in axon and dendritic growth. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212889 [Multi-domain] Cd Length: 55 Bit Score: 53.30 E-value: 2.68e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11956     8 FDYTGRTAQELSFKRGDVLLLHSKASSDWWRGEHNGMRGLIPHKYISV 55

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 53.08 E-value: 2.69e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd12060     5 KARFNFKQTNEDELSVCKGDIIYVTRVEEGGWWEGTLNGKTGWFPSNYVR 54

First Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212860 Cd Length: 54 Bit Score: 53.03 E-value: 2.72e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11927     3 AKALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGEVNGIHGFFPTNFVQI 54

Variant SH3 domain;

Pssm-ID: 434066 [Multi-domain] Cd Length: 49 Bit Score: 52.62 E-value: 3.30e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEESEDGWWEGIN--TGRTGLVPANYVE 49

Second Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212749 [Multi-domain] Cd Length: 52 Bit Score: 52.95 E-value: 3.43e-09

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11815     7 DFPAEHSDDLSLNSGEIVYLLEKIDTEWYRGKCKNTTGIFPANHVK 52

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 52.74 E-value: 3.63e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVM-QQCDD-GWFVG--VSRRtqkfGTFPGNYVAP 559
Cdd:cd11875     2 ARVLFDYEAENEDELTLREGDIVTILsKDCEDkGWWKGelNGKR----GVFPDNFVEP 55

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212988 [Multi-domain] Cd Length: 53 Bit Score: 52.69 E-value: 3.70e-09

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVsrRTQKFGTFPGNYV 557
Cdd:cd12055     3 QVAFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGV--LNGKTGMFPSNFI 51

Src homology 3 domain of Ubiquitin-associated and SH3 domain-containing protein A; UBASH3A is also called Cbl-Interacting Protein 4 (CLIP4), T cell Ubiquitin LigAnd (TULA), or T cell receptor Signaling (STS)-2. It is only found in lymphoid cells and exhibits weak phosphatase activity. UBASH3A facilitates T cell-induced apoptosis through interaction with the apoptosis-inducing factor AIF. It is involved in regulating the level of phosphorylation of the zeta-associated protein (ZAP)-70 tyrosine kinase. TULA proteins contain an N-terminal UBA domain, a central SH3 domain, and a C-terminal histidine phosphatase domain. They bind c-Cbl through the SH3 domain and to ubiquitin via UBA. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212870 [Multi-domain] Cd Length: 60 Bit Score: 52.71 E-value: 4.02e-09

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 507 RAMYQYRPQNEDELELREGDR--VDVMQQ--CDDGWFVGVSRRTQKFGTFPGNY 556
Cdd:cd11937     4 RALFQYKPQNIDELMLSPGDYifVDPTQQseASEGWVIGISHRTGCRGFLPENY 57

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. Its N-terminal SH3 domain binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212879 [Multi-domain] Cd Length: 56 Bit Score: 52.72 E-value: 4.31e-09

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI-HKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11946     3 AIAKYDFKATADDELSFKRGDILKVlNEECDQNWYKAELNGKDGFIPKNYIEM 55

First Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212861 Cd Length: 54 Bit Score: 52.62 E-value: 4.40e-09

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11928     7 YSYEGKEPGDLKFNKGDIIILRRKVDENWYHGELNGCHGFLPASYIQ 53

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 52.32 E-value: 4.92e-09

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE-HHGRLGIFPANYVE 325
Cdd:cd11819     2 AKALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVnAKGQKGLFPANYVE 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 52.11 E-value: 5.41e-09

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11951     2 VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGRISGRVGFFPRNYV 51

Src homology 3 domain of Abl Interactor proteins; Abl interactor (Abi) proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. They localize to sites of actin polymerization in epithelial adherens junction and immune synapses, as well as to the leading edge of lamellipodia. Vertebrates contain two Abi proteins, Abi1 and Abi2. Abi1 displays a wide expression pattern while Abi2 is highly expressed in the eye and brain. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212760 [Multi-domain] Cd Length: 52 Bit Score: 51.94 E-value: 7.23e-09

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11826     3 VALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVL--NGVTGLFPGNYVE 52

Second Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212721 [Multi-domain] Cd Length: 53 Bit Score: 51.57 E-value: 8.26e-09

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFK-GDLDVE--LSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASY 399
Cdd:cd11787     2 CKALYDFEmKDEDEKdcLTFKKGDVITVIRRVDENWAEGRL--GDKIGIFPISF 53

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 51.65 E-value: 8.60e-09

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11959     6 YDYQAADDDEISFDPDDIITNIEMIDEGWWRGVCRGKYGLFPANYVEL 53

Src homology 3 domain of Cortactin and related proteins; This subfamily includes cortactin, Abp1 (actin-binding protein 1), hematopoietic lineage cell-specific protein 1 (HS1), and similar proteins. These proteins are involved in regulating actin dynamics through direct or indirect interaction with the Arp2/3 complex, which is required to initiate actin polymerization. They all contain at least one C-terminal SH3 domain. Cortactin and HS1 bind Arp2/3 and actin through an N-terminal region that contains an acidic domain and several copies of a repeat domain found in cortactin and HS1. Abp1 binds actin via an N-terminal actin-depolymerizing factor (ADF) homology domain. Yeast Abp1 binds Arp2/3 directly through two acidic domains. Mammalian Abp1 does not directly interact with Arp2/3; instead, it regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. The C-terminal region of these proteins acts as an adaptor or scaffold that can connect membrane trafficking and signaling proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212753 [Multi-domain] Cd Length: 54 Bit Score: 51.55 E-value: 8.76e-09

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11819     2 AKALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGV-NAKGQKGLFPANYVEL 54

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212737 [Multi-domain] Cd Length: 55 Bit Score: 51.11 E-value: 1.26e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVG-VSRRTqkfGTFPGNYV 557
Cdd:cd11803     3 CRALYDFEPENEGELGFKEGDIITLTNQIDENWYEGmVNGQS---GFFPVNYV 52

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 50.71 E-value: 1.59e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDG-WFVgvsRRTQKFGTFPGNYVAP 559
Cdd:cd11856     2 YVAIADYEAQGDDEISLQEGEVVEVLEKNDSGwWYV---RKGDKEGWVPASYLEP 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 50.78 E-value: 1.70e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGT-GRQGIFPASY 399
Cdd:cd11821     4 ALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGHIEGDpSRRGVFPVSF 53

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 51.17 E-value: 1.71e-08

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYVAPV 560
Cdd:cd11971     4 AIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVCNGVT--GLFPGNYVESI 54

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 50.99 E-value: 1.75e-08

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd12073     3 AVALYDYQGEGDDEISFDPQETITDIEMVDEGWWKGTC--HGHRGLFPANYVEL 54

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 50.44 E-value: 2.05e-08

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERIcLIRKVNEHWYEGRITGtGRQGIFPASYVQI 402
Cdd:cd11837     2 ATALYPWRAKKENHLSFAKGDII-TVLEQQEMWWFGELEG-GEEGWFPKSYVKE 53

N-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212881 [Multi-domain] Cd Length: 54 Bit Score: 50.58 E-value: 2.12e-08

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11948     6 YSFQATESDELPFQKGDILKIlNMEDDQNWYKAELQGREGYIPKNYIKV 54

Second Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212855 [Multi-domain] Cd Length: 58 Bit Score: 50.37 E-value: 2.45e-08

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG--RLGIFPANYVEVL 327
Cdd:cd11922     6 KFNFNGDTQVEMSFRKGERITLLRQVDENWYEGRIPGtsRQGIFPITYVDVI 57

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 50.22 E-value: 2.54e-08

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd12073     7 YDYQGEGDDEISFDPQETITDIEMVDEGWWKGTCHGHRGLFPANYVELL 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 50.39 E-value: 2.61e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVG-VSRRTqkfGTFPGNYV 557
Cdd:cd11877     2 VRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGtLNGKT---GWFPSNYV 51

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212987 [Multi-domain] Cd Length: 55 Bit Score: 50.35 E-value: 2.65e-08

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd12054     1 RQCKVLFEYVPQNEDELELKVGDIIDINEEVEEGWWSGTLNGKSGLFPSNFVKEL 55

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 50.32 E-value: 2.77e-08

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11929     3 AKALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGEINGV--SGIFPASSVEV 54

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 50.11 E-value: 2.82e-08

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gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11827     6 YAYDAQDTDELSFNEGDIIEILKEDPSGWWTGRLRGKEGLFPGNYVE 52

Third Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. The third SH3 domain of Sla1p can bind ubiquitin while retaining the ability to bind proline-rich ligands; monoubiquitination of target proteins signals internalization and sorting through the endocytic pathway. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212709 [Multi-domain] Cd Length: 57 Bit Score: 50.39 E-value: 2.90e-08

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYI-HKEVDKNW--LEGEHHGRLGIFPANYVEV 326
Cdd:cd11775     1 KRGKVLYDFDAQSDDELTVKEGDVVYIlDDKKSKDWwmVENVSTGKEGVVPASYIEI 57

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212739 [Multi-domain] Cd Length: 53 Bit Score: 49.93 E-value: 2.91e-08

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gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVAP 559
Cdd:cd11805     3 QALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGELR--GRVGIFPANYVQP 53

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 50.16 E-value: 3.25e-08

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gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQC--DDGWFVG-VSRRTqkfGTFPGNYVAP 559
Cdd:cd12142     2 CRVLFDYNPVAPDELALKKGDVIEVISKEteDEGWWEGeLNGRR---GFFPDNFVMP 55

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 50.02 E-value: 3.27e-08

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gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQ-CDDGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11763     2 VRALYDFDSQPSGELSLRAGEVLTITRQdVGDGWLEGRNSRGEV-GLFPSSYV 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 49.82 E-value: 3.66e-08

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gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11950     2 VRALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHGKLGLFPANYVA 52

C-terminal (or second) Src homology 3 domain of VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212910 [Multi-domain] Cd Length: 58 Bit Score: 50.01 E-value: 4.10e-08

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gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEV--DKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11977     6 RYNFAARDMRELSLREGDVVRIYSRIggDQGWWKGETNGRIGWFPSTYVE 55

Src homology 3 domain of Ubiquitin-associated and SH3 domain-containing protein B; UBASH3B, also called Suppressor of T cell receptor Signaling (STS)-1 or T cell Ubiquitin LigAnd (TULA)-2 is an active phosphatase that is expressed ubiquitously. The phosphatase activity of UBASH3B is essential for its roles in the suppression of TCR signaling and the regulation of EGFR. It also interacts with Syk and functions as a negative regulator of platelet glycoprotein VI signaling. TULA proteins contain an N-terminal UBA domain, a central SH3 domain, and a C-terminal histidine phosphatase domain. They bind c-Cbl through the SH3 domain and to ubiquitin via UBA. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212869 Cd Length: 62 Bit Score: 50.04 E-value: 4.32e-08

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gi 1958679458 507 RAMYQYRPQNEDELELREGDRV--DVMQQ--CDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11936     5 QVIYPYTPQNDDELELVPGDYIfmSPMEQtsTSEGWIYGTSLTTGCSGLLPENYITK 61

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 49.65 E-value: 4.83e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11901     3 PAYVKFNYTAEREDELSLVKGTKVIVMEKCSDGWWRG--SYNGQVGWFPSNYV 53

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212703 [Multi-domain] Cd Length: 57 Bit Score: 49.61 E-value: 5.07e-08

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gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEV-DKNWLEGEHH-GRLGIFPANYVEV 326
Cdd:cd11769     7 KYNFNGASEEDLPFKKGDILTIVAVTkDPNWYKAKNKdGREGMIPANYVQK 57

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212830 [Multi-domain] Cd Length: 55 Bit Score: 49.60 E-value: 5.18e-08

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gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVD-KNWLEG-EHHGRLGIFPANYVEV 326
Cdd:cd11897     2 ARALYDFRSENPGEISLREHEVLSLCSEQDiEGWLEGvNSRGDRGLFPASYVEV 55

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212777 [Multi-domain] Cd Length: 53 Bit Score: 49.34 E-value: 5.36e-08

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVY-IHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11843     3 RALYDYEGQESDELSFKAGDILTkLEEEDEQGWCKGRLDGRVGLYPANYVE 53

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212852 [Multi-domain] Cd Length: 55 Bit Score: 49.58 E-value: 5.82e-08

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRitGTGRQGIFPASYVQI 402
Cdd:cd11919     3 ARAKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEGE--HHGRVGIFPRSYIEL 54

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 49.18 E-value: 5.83e-08

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11995     7 YDYTAQNDDELAFSKGQIINVLNKEDPDWWKGELNGQVGLFPSNYVKL 54

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 49.62 E-value: 6.12e-08

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11972     9 YDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGVTGLFPGNYVE 55

Third Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212750 [Multi-domain] Cd Length: 51 Bit Score: 48.94 E-value: 6.33e-08

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11816     2 CVARFDFEGEQEDELSFSEGDVITLKEYVGEEWAKGEL--NGKIGIFPLNFV 51

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 49.04 E-value: 6.66e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11833     1 TYVALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKG--KIEDRVGFFPANFV 51

Src homology 3 domain of Alpha1,6-fucosyltransferase (Fut8); Fut8 catalyzes the alpha1,6-linkage of a fucose residue from a donor substrate to N-linked oligosaccharides on glycoproteins in a process called core fucosylation, which is crucial for growth factor receptor-mediated biological functions. Fut8-deficient mice show severe growth retardation, early death, and a pulmonary emphysema-like phenotype. Fut8 is also implicated to play roles in aging and cancer metastasis. It contains an N-terminal coiled-coil domain, a catalytic domain, and a C-terminal SH3 domain. The SH3 domain of Fut8 is located in the lumen and its role in glycosyl transfer is unclear. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212726 Cd Length: 55 Bit Score: 48.74 E-value: 8.02e-08

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFP 553
Cdd:cd11792     3 VAIYPHKPRNHDEIELRVGDIIGVAGNHWDGYSKGRNRRTGKTGLYP 49

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 48.93 E-value: 8.42e-08

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH-HGRLGIFPANYVE 325
Cdd:cd11960     2 ARALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGTGpDGTYGLFPANYVE 53

Second Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212857 Cd Length: 56 Bit Score: 48.81 E-value: 8.57e-08

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG--RLGIFPANYVEV 326
Cdd:cd11924     6 QYTFKGDLEVELSFRKGEHICLIRKVNENWYEGRITGtgRQGIFPASYVQV 56

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 49.24 E-value: 8.62e-08

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYVAPV 560
Cdd:cd11972     7 AIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGVT--GLFPGNYVESI 57

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 48.87 E-value: 9.75e-08

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE--HHGRLGIFPANYVE 325
Cdd:cd11793     7 AYTAQQPDELTLEEGDVVNVLRKMPDGWYEGErlRDGERGWFPSSYTE 54

C-terminal (Fourth) Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the fourth SH3 domain, located at the C-terminus of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212719 Cd Length: 55 Bit Score: 48.62 E-value: 1.07e-07

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                  ....*....|....*....|....*....|....*....|....
gi 1958679458 284 QSPKELTLQKGDIVYIHKEVDKNWLEGEHH--GRLGIFPANYVE 325
Cdd:cd11785    11 QSEAELELKEGDIVFVHKKREDGWFKGTLQrtGKTGLFPGSFVE 54

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 48.22 E-value: 1.47e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 279 FDFQAQSPKELTLQKGDIVyihkEV---------DKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12059     6 FDYEASAEDELTLRRGDRV----EVlskdsavsgDEGWWTGKINDRVGIFPSNYV 56

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 48.08 E-value: 1.49e-07

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVsrRTQKFGTFPGNYV 557
Cdd:cd11902     2 PAFVKFAYVAEREDELSLVKGSRVTVMEKCSDGWWRGS--YNGQIGWFPSNYV 52

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 48.28 E-value: 1.52e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIV-YIHKEV----DKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11876     6 FDYDARGEDELTLRRGQPVeVLSKDAavsgDEGWWTGKIGDKVGIFPSNYV 56

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 48.25 E-value: 1.63e-07

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 510 YQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11962     6 YDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGTNSKGES-GLFPSNYV 52

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212770 [Multi-domain] Cd Length: 55 Bit Score: 48.12 E-value: 1.68e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 505 PYRAMYQYRPQNEDELELREGD--RVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11836     1 KYRALYAFEARNPDEISFQPGDiiQVDESQVAEPGWLAGELK--GKTGWFPANYV 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 47.87 E-value: 1.70e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11951     4 AQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGRI--SGRVGFFPRNYVH 52

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 47.80 E-value: 1.81e-07

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVAP 559
Cdd:cd11840     3 IALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGELN--GQTGLFPSNYVEP 53

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212940 [Multi-domain] Cd Length: 58 Bit Score: 47.72 E-value: 2.14e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd12007     4 VALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGKNGYIPSNYV 54

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 47.47 E-value: 2.14e-07

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                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANY 323
Cdd:cd11817     6 YDFTGETEEDLSFQRGDRILVTEHLDAEWSRGRLNGREGIFPRAF 50

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 47.48 E-value: 2.33e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH-HGRLGIFPANYVEV 326
Cdd:cd11962     1 RAVVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGTNsKGESGLFPSNYVEL 54

Src Homology 3 domain of Mixed Lineage Kinase 4; MLK4 is a Serine/Threonine Kinase (STK), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The specific function of MLK4 is yet to be determined. Mutations in the kinase domain of MLK4 have been detected in colorectal cancers. MLK4 contains an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212991 [Multi-domain] Cd Length: 58 Bit Score: 47.63 E-value: 2.35e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEV-----DKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12058     6 YDYEASGEDELSLRRGDVVEVLSQDaavsgDDGWWAGKIRHRLGIFPANYV 56

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 47.50 E-value: 2.36e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11833     3 VALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKGKI--EDRVGFFPANFVQ 52

N-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also have roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212880 [Multi-domain] Cd Length: 52 Bit Score: 47.48 E-value: 2.40e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEvDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11947     2 ARGKFDFTASGEDELSFKKGDVLKILSS-DDIWFKAELNGEEGYVPKNFVDI 52

First Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212860 Cd Length: 54 Bit Score: 47.64 E-value: 2.40e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11927     3 AKALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGEVNGI--HGFFPTNFVQI 54

C-terminal Src Homology 3 domain of the Nebulin family of proteins; Nebulin family proteins contain multiple nebulin repeats, and may contain an N-terminal LIM domain and/or a C-terminal SH3 domain. They have molecular weights ranging from 34 to 900 kD, depending on the number of nebulin repeats, and they all bind actin. They are involved in the regulation of actin filament architecture and function as stabilizers and scaffolds for cytoskeletal structures with which they associate, such as long actin filaments or focal adhesions. Nebulin family proteins that contain a C-terminal SH3 domain include the giant filamentous protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2, also called LIM-nebulette, is an alternatively spliced variant of nebulette. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212723 [Multi-domain] Cd Length: 55 Bit Score: 47.31 E-value: 2.79e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11789     3 RAMYDYAAADDDEVSFQEGDVIINVEIIDDGWMEGTVQRTGQSGMLPANYVE 54

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 47.34 E-value: 3.23e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11901     4 AYVKFNYTAEREDELSLVKGTKVIVMEKCSDGWWRGSYNGQVGWFPSNYV 53

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 47.10 E-value: 3.48e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd12046     3 VALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQC--KGKIGIFPSAFVE 52

Src homology 3 domain of JNK-interacting protein 1; JNK-interacting protein 1 (JIP1) is also called Islet-brain 1 (IB1) or Mitogen-activated protein kinase 8-interacting protein 1 (MAPK8IP1). It is highly expressed in neurons, where it functions as an adaptor linking motor to cargo during axonal transport. It also affects microtubule dynamics in neurons. JIP1 is also found in pancreatic beta-cells, where it is involved in regulating insulin secretion. In addition to a JNK binding domain, JIP1 also contains SH3 and Phosphotyrosine-binding (PTB) domains. Its SH3 domain homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212876 Cd Length: 55 Bit Score: 47.29 E-value: 3.55e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNY 556
Cdd:cd11943     2 HRAVFRFVPRHPDELELEVDDPLLVEVQAEDYWYEAYNMRTGARGIFPAYY 52

Third Src homology 3 domain (or SH3C) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. The SH3C of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212772 [Multi-domain] Cd Length: 52 Bit Score: 47.02 E-value: 3.62e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEhWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11838     3 IALYPYESNEPGDLTFNAGDVILVTKKDGE-WWTGTI--GDRTGIFPSNYVR 51

Src homology 3 domain of Blk Protein Tyrosine Kinase; Blk is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. It is expressed specifically in B-cells and is involved in pre-BCR (B-cell receptor) signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212942 [Multi-domain] Cd Length: 54 Bit Score: 47.12 E-value: 3.97e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMqqCDDG-WFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd12009     2 VIAQYDFVPSNERDLQLKKGEKLQVL--KSDGeWWLAKSLTTGKEGYIPSNYVAR 54

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 46.94 E-value: 4.57e-07

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11971     6 YDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVCNGVTGLFPGNYVE 52

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212988 [Multi-domain] Cd Length: 53 Bit Score: 46.91 E-value: 4.68e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd12055     3 QVAFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGVLNGKTGMFPSNFIK 52

C-terminal Src Homology 3 domain of LIM and SH3 domain protein 1; Lasp1 is a cytoplasmic protein that binds focal adhesion proteins and is involved in cell signaling, migration, and proliferation. It is overexpressed in several cancer cells including breast, ovarian, bladder, and liver. In cancer cells, it can be found in the nucleus; its degree of nuclear localization correlates with tumor size and poor prognosis. Lasp1 is a 36kD protein containing an N-terminal LIM domain, two nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212867 [Multi-domain] Cd Length: 59 Bit Score: 46.91 E-value: 4.73e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG--EHHGRLGIFPANYVEVL 327
Cdd:cd11934     3 KRYRAVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGtvERTGDTGMLPANYVEAI 59

First Src homology 3 domain (or SH3A) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212920 [Multi-domain] Cd Length: 55 Bit Score: 46.92 E-value: 4.76e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEV--DKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11987     3 RALYPFEARSHDEITIQPGDIVMVDESQtgEPGWLGGELKGKTGWFPANYAE 54

Second Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212708 [Multi-domain] Cd Length: 52 Bit Score: 46.69 E-value: 5.13e-07

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVgVSRRTQKFGTFPGNYV 557
Cdd:cd11774     3 KALYDYDKQTEEELSFNEGDTLDVYDDSDSDWIL-VGFNGTQFGFVPANYI 52

C-terminal Src Homology 3 domain of the Nebulin family of proteins; Nebulin family proteins contain multiple nebulin repeats, and may contain an N-terminal LIM domain and/or a C-terminal SH3 domain. They have molecular weights ranging from 34 to 900 kD, depending on the number of nebulin repeats, and they all bind actin. They are involved in the regulation of actin filament architecture and function as stabilizers and scaffolds for cytoskeletal structures with which they associate, such as long actin filaments or focal adhesions. Nebulin family proteins that contain a C-terminal SH3 domain include the giant filamentous protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2, also called LIM-nebulette, is an alternatively spliced variant of nebulette. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212723 [Multi-domain] Cd Length: 55 Bit Score: 46.54 E-value: 5.23e-07

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG--EHHGRLGIFPANYVE 325
Cdd:cd11789     6 YDYAAADDDEVSFQEGDVIINVEIIDDGWMEGtvQRTGQSGMLPANYVE 54

Src homology 3 domain of Slit-Robo GTPase Activating Proteins 1, 2, and 3; srGAP1, also called Rho GTPase-Activating Protein 13 (ARHGAP13), is a Cdc42- and RhoA-specific GAP and is expressed later in the development of central nervous system tissues. srGAP2 is expressed in zones of neuronal differentiation. It plays a role in the regeneration of neurons and axons. srGAP3, also called MEGAP (MEntal disorder associated GTPase-Activating Protein), is a Rho GAP with activity towards Rac1 and Cdc42. It impacts cell migration by regulating actin and microtubule cytoskeletal dynamics. The association between srGAP3 haploinsufficiency and mental retardation is under debate. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212888 [Multi-domain] Cd Length: 53 Bit Score: 46.48 E-value: 5.68e-07

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11955     5 KFDYVGRSARELSFKKGASLLLYHRASDDWWEGRHNGIDGLVPHQYIVV 53

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase and similar proteins; This subfamily is composed of Rho GTPase activating proteins (GAPs) with similarity to GRAF. Members contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. Although vertebrates harbor four Rho GAPs in the GRAF subfamily including GRAF, GRAF2, GRAF3, and Oligophrenin-1 (OPHN1), only three are included in this model. OPHN1 contains the BAR, PH and GAP domains, but not the C-terminal SH3 domain. GRAF and GRAF2 show GAP activity towards RhoA and Cdc42. GRAF influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase. GRAF2 regulates caspase-activated p21-activated protein kinase-2. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212815 [Multi-domain] Cd Length: 54 Bit Score: 46.52 E-value: 5.78e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVY-IHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11882     2 ARALYACKAEDESELSFEPGQIITnVQPSDEPGWLEGTLNGRTGLIPENYVE 53

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212940 [Multi-domain] Cd Length: 58 Bit Score: 46.57 E-value: 6.16e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 504 TPYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd12007     1 TIFVALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGKNGYIPSNYVAP 56

C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 2 (Stac2); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac2 contains a single SH3 domain at the C-terminus unlike Stac1 and Stac3, which contain two C-terminal SH3 domains. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212918 Cd Length: 53 Bit Score: 46.48 E-value: 6.19e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11985     2 YVALYKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGKSG--DRVGFFPANFV 51

Src homology 3 domain of Nitric Oxide Synthase TRaffic INducer; Nostrin is expressed in endothelial and epithelial cells and is involved in the regulation, trafficking and targeting of endothelial NOS (eNOS). It facilitates the endocytosis of eNOS by coordinating the functions of dynamin and the Wiskott-Aldrich syndrome protein (WASP). Increased expression of Nostrin may be correlated to preeclampsia. Nostrin contains an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212757 [Multi-domain] Cd Length: 53 Bit Score: 46.18 E-value: 6.63e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQ 401
Cdd:cd11823     3 KALYSYTANREDELSLQPGDIIEVHEKQDDGWWLGELNGK--KGIFPATYVE 52

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 46.11 E-value: 7.41e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11873     1 EVIVEFDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTL--NGKRGMFPDNFVKV 53

Second Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212749 [Multi-domain] Cd Length: 52 Bit Score: 46.02 E-value: 8.04e-07

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11815     2 AVVLHDFPAEHSDDLSLNSGEIVYLLEKIDTEWYRGKC--KNTTGIFPANHVK 52

Second Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212721 [Multi-domain] Cd Length: 53 Bit Score: 46.17 E-value: 8.27e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKE-LTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANY 323
Cdd:cd11787     4 ALYDFEMKDEDEKDcLTFKKGDVITVIRRVDENWAEGRLGDKIGIFPISF 53

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212703 [Multi-domain] Cd Length: 57 Bit Score: 46.14 E-value: 8.54e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERIcLIRKVNE--HWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11769     5 IAKYNFNGASEEDLPFKKGDIL-TIVAVTKdpNWYKAK-NKDGREGMIPANYVQK 57

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212939 [Multi-domain] Cd Length: 56 Bit Score: 46.20 E-value: 8.67e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 504 TPYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd12006     1 TLFVALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGETGYIPSNYVAP 56

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 45.81 E-value: 8.91e-07

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11796     2 ARVLQDLSAQLDEELDLREGDVVTITGILDKGWFRGEL--NGRRGIFPEGFV 51

C-terminal Src Homology 3 domain of LIM and SH3 domain protein 1; Lasp1 is a cytoplasmic protein that binds focal adhesion proteins and is involved in cell signaling, migration, and proliferation. It is overexpressed in several cancer cells including breast, ovarian, bladder, and liver. In cancer cells, it can be found in the nucleus; its degree of nuclear localization correlates with tumor size and poor prognosis. Lasp1 is a 36kD protein containing an N-terminal LIM domain, two nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212867 [Multi-domain] Cd Length: 59 Bit Score: 46.14 E-value: 9.69e-07

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTfKGDLDvELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11934     7 AVYDYN-AADED-EVSFQDGDTIVNVQQIDDGWMYGTVERTGDTGMLPANYVE 57

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 46.04 E-value: 9.70e-07

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKvNEHWYEG-RITGTGRQGIFPASYVQI 402
Cdd:cd11872     2 GVAIYNFQGDGEHQLSLQVGDTVQILEE-CEGWYRGfSLRNKSLKGIFPKSYVHI 55

First Src Homology 3 domain (SH3A) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present in c-Cbl and the cytoplasmic domain of cell adhesion protein CD2. Its interaction with CD2 anchors CD2 at sites of cell contact. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212986 Cd Length: 56 Bit Score: 45.99 E-value: 9.91e-07

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 277 LKFDFQAQSPKELTLQKGDIVY-IHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd12053     4 VEYDYDAVHEDELTIRVGEIIRnVKKLEEEGWLEGELNGRRGMFPDNFVK 53

Third Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. The third SH3 domain of Sla1p can bind ubiquitin while retaining the ability to bind proline-rich ligands; monoubiquitination of target proteins signals internalization and sorting through the endocytic pathway. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212709 [Multi-domain] Cd Length: 57 Bit Score: 45.77 E-value: 1.16e-06

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRITGTGRQGIFPASYVQI 402
Cdd:cd11775     3 GKVLYDFDAQSDDELTVKEGDVVYILDDKKSKdWWMVENVSTGKEGVVPASYIEI 57

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 45.58 E-value: 1.18e-06

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItGTGRQGIFPASYV 400
Cdd:cd11812     3 VALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFGSL-VNGQQGYFPANYV 52

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 45.83 E-value: 1.22e-06

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVsrRTQKFGTFPGNYVAPV 560
Cdd:cd12061     3 RAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGT--HNGRTGWFPSNYVREI 54

C-terminal Src Homology 3 domain of Nebulette and LIM-nebulette (or Lasp2); Nebulette is a cardiac-specific protein that localizes to the Z-disc. It interacts with tropomyosin and is important in stabilizing actin thin filaments in cardiac muscles. Polymorphisms in the nebulette gene are associated with dilated cardiomyopathy, with some mutations resulting in severe heart failure. Nebulette is a 107kD protein that contains an N-terminal acidic region, multiple nebulin repeats, and a C-terminal SH3 domain. LIM-nebulette, also called Lasp2 (LIM and SH3 domain protein 2), is an alternatively spliced variant of nebulette. Although it shares a gene with nebulette, Lasp2 is not transcribed from a muscle-specific promoter, giving rise to its multiple tissue expression pattern with highest amounts in the brain. It can crosslink actin filaments and it affects cell spreading. Lasp2 is a 34kD protein containing an N-terminal LIM domain, three nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212868 [Multi-domain] Cd Length: 58 Bit Score: 45.77 E-value: 1.25e-06

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG--EHHGRLGIFPANYVE 325
Cdd:cd11935     4 RAMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGtvQRTGRTGMLPANYIE 55

Src homology 3 domain of Abl Interactor 2; Abi2 is highly expressed in the brain and eye. It regulates actin cytoskeletal reorganization at adherens junctions and dendritic spines, which is important in cell morphogenesis, migration, and cognitive function. Mice deficient with Abi2 show defects in orientation and migration of lens fibers, neuronal migration, dendritic spine morphology, as well as deficits in learning and memory. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212905 [Multi-domain] Cd Length: 61 Bit Score: 45.77 E-value: 1.37e-06

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQ 401
Cdd:cd11972     6 VAIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGV--TGLFPGNYVE 55

Src Homology 3 domain of Pak Interactive eXchange factors; PIX proteins are Rho guanine nucleotide exchange factors (GEFs), which activate small GTPases by exchanging bound GDP for free GTP. They act as GEFs for both Cdc42 and Rac 1, and have been implicated in cell motility, adhesion, neurite outgrowth, and cell polarity. Vertebrates contain two proteins from the PIX subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also called ARHGEF6, is localized in dendritic spines where it regulates spine morphogenesis. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Beta-PIX play roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212810 [Multi-domain] Cd Length: 53 Bit Score: 45.38 E-value: 1.47e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQI 402
Cdd:cd11877     4 AKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEG--TLNGKTGWFPSNYVKE 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212714 [Multi-domain] Cd Length: 55 Bit Score: 45.37 E-value: 1.51e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHH--GRLGIFPANYVE 325
Cdd:cd11780     3 RALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSErtGLFGTFPGNYVA 54

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 45.17 E-value: 1.54e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNY 556
Cdd:cd11818     3 RALYDFTGENEDELSFKAGDIITELESIDEEWMSGELR--GKSGIFPKNF 50

Fifth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212752 [Multi-domain] Cd Length: 50 Bit Score: 45.17 E-value: 1.54e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASY 399
Cdd:cd11818     2 ARALYDFTGENEDELSFKAGDIITELESIDEEWMSGEL--RGKSGIFPKNF 50

C-terminal Src Homology 3 domain of Nebulin; Nebulin is a giant filamentous protein (600-900 kD) that is expressed abundantly in skeletal muscle. It binds to actin thin filaments and regulates its assembly and function. Nebulin was thought to be part of a molecular ruler complex that is critical in determining the lengths of actin thin filaments in skeletal muscle since its length, which varies due to alternative splicing, correlates with the length of thin filaments in various muscle types. Recent studies indicate that nebulin regulates thin filament length by stabilizing the filaments and preventing depolymerization. Mutations in nebulin can cause nemaline myopathy, characterized by muscle weakness which can be severe and can lead to neonatal lethality. Nebulin contains an N-terminal LIM domain, many nebulin repeats/super repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212866 [Multi-domain] Cd Length: 58 Bit Score: 45.38 E-value: 1.64e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11933     6 AMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQRTGKTGMLPANYVE 56

Src Homology 3 domain of fungal BOI-like proteins; This subfamily includes the Saccharomyces cerevisiae proteins BOI1 and BOI2, and similar proteins. They contain an N-terminal SH3 domain, a Sterile alpha motif (SAM), and a Pleckstrin homology (PH) domain at the C-terminus. BOI1 and BOI2 interact with the SH3 domain of Bem1p, a protein involved in bud formation. They promote polarized cell growth and participates in the NoCut signaling pathway, which is involved in the control of cytokinesis. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212819 Cd Length: 55 Bit Score: 45.40 E-value: 1.68e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCD---DGWFVGVSRRTQKFGTFPGNY 556
Cdd:cd11886     2 LIVIHDFNARSEDELTLKPGDKIELIEDDEefgDGWYLGRNLRTGETGLFPVVF 55

Third Src Homology 3 domain of Nck adaptor proteins; This group contains the third SH3 domain of Nck, the first SH3 domain of Caenorhabditis elegans Ced-2 (Cell death abnormality protein 2), and similar domains. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. Ced-2 is a cell corpse engulfment protein that interacts with Ced-5 in a pathway that regulates the activation of Ced-10, a Rac small GTPase.

Pssm-ID: 212701 [Multi-domain] Cd Length: 56 Bit Score: 45.38 E-value: 1.70e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKV--NEHWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11767     2 VVALYPFTGENDEELSFEKGERLEIIEKPedDPDWWKAR-NALGTTGLVPRNYVEV 56

Src Homology 3 domain of the p85beta regulatory subunit of Class IA Phosphatidylinositol 3-kinases; Class I PI3Ks convert PtdIns(4,5)P2 to the critical second messenger PtdIns(3,4,5)P3. They are heterodimers and exist in multiple isoforms consisting of one catalytic subunit (out of four isoforms) and one of several regulatory subunits. Class IA PI3Ks associate with the p85 regulatory subunit family, which contains SH3, RhoGAP, and SH2 domains. The p85 subunits recruit the PI3K p110 catalytic subunit to the membrane, where p110 phosphorylates inositol lipids. Vertebrates harbor two p85 isoforms, called alpha and beta. In addition to regulating the p110 subunit, p85beta binds CD28 and may be involved in the activation and differentiation of antigen-stimulated T cells. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212842 Cd Length: 74 Bit Score: 45.59 E-value: 1.88e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVM-------------QQCDD--GWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11909     3 YRALYPYRKEREEDIDLLPGDVLTVSraalqalgvkeggEQCPQsiGWILGLNERTKQRGDFPGTYV 69

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 45.02 E-value: 1.90e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRL-GIFPANYVE 325
Cdd:cd11825     1 TVKALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGKKqKWFPANYVE 53

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 45.10 E-value: 2.02e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11959     2 AVALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGVC--RGKYGLFPANYVEL 53

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212718 Cd Length: 55 Bit Score: 44.77 E-value: 2.15e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 281 FQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPANYV 324
Cdd:cd11784     8 YSAHRPEELELQKGEGVRVLGKFQEGWLRGLSlvTGRVGIFPSNYV 53

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 45.01 E-value: 2.19e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 280 DFQAQSPKELTLQKGDIVYI---HKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11884     7 AYITRDQTLLSFHKGDVIKLlpkEGPLDPGWLFGTLDGRSGAFPKEYVQ 55

Src homology 3 domain of JNK-interacting protein 2; JNK-interacting protein 2 (JIP2) is also called Mitogen-activated protein kinase 8-interacting protein 2 (MAPK8IP2) or Islet-brain-2 (IB2). It is widely expressed in the brain, where it forms complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. JIP2 is enriched in postsynaptic densities and may play a role in motor and cognitive function. In addition to a JNK binding domain, JIP2 also contains SH3 and Phosphotyrosine-binding (PTB) domains. The SH3 domain of the related protein JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212875 Cd Length: 55 Bit Score: 44.92 E-value: 2.23e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNY 556
Cdd:cd11942     2 HRAVFRFIPRHEDELELDVDDPLLVEAEEDDYWYRGYNMRTGERGIFPAFY 52

Src Homology 3 domain of Cytokinesis protein 3 and similar proteins; Cytokinesis protein 3 (Cyk3 or Cyk3p) is a component of the actomyosin ring independent cytokinesis pathway in yeast. It interacts with Inn1 and facilitates its recruitment to the bud neck, thereby promoting cytokinesis. Cyk3p contains an N-terminal SH3 domain and a C-terminal transglutaminase-like domain. The Cyk3p SH3 domain binds to the C-terminal proline-rich region of Inn1. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212822 Cd Length: 53 Bit Score: 44.80 E-value: 2.30e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11889     3 KAVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLRRNGAEGIFPSNFV 53

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 44.89 E-value: 2.32e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd12052     1 EAIVEFDYKAQHEDELTITVGDIITKIKKDDGGWWEGEI--KGRRGLFPDNFVR 52

Src homology 3 domain of High osmolarity signaling protein Sho1p; Sho1p (or Sho1), also called SSU81 (Suppressor of SUA8-1 mutation), is a yeast membrane protein that regulates adaptation to high salt conditions by activating the HOG (high-osmolarity glycerol) pathway. High salt concentrations lead to the localization to the membrane of the MAPKK Pbs2, which is then activated by the MAPKK Ste11 and in turn, activates the MAPK Hog1. Pbs2 is localized to the membrane though the interaction of its PxxP motif with the SH3 domain of Sho1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212789 [Multi-domain] Cd Length: 55 Bit Score: 44.72 E-value: 2.34e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQA--QSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11855     2 ARALYPYDAspDDPNELSFEKGEILEVSDTSGKWWQARKSNGETGICPSNYLQL 55

C-terminal Src Homology 3 domain of Nebulin; Nebulin is a giant filamentous protein (600-900 kD) that is expressed abundantly in skeletal muscle. It binds to actin thin filaments and regulates its assembly and function. Nebulin was thought to be part of a molecular ruler complex that is critical in determining the lengths of actin thin filaments in skeletal muscle since its length, which varies due to alternative splicing, correlates with the length of thin filaments in various muscle types. Recent studies indicate that nebulin regulates thin filament length by stabilizing the filaments and preventing depolymerization. Mutations in nebulin can cause nemaline myopathy, characterized by muscle weakness which can be severe and can lead to neonatal lethality. Nebulin contains an N-terminal LIM domain, many nebulin repeats/super repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212866 [Multi-domain] Cd Length: 58 Bit Score: 45.00 E-value: 2.38e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG--EHHGRLGIFPANYVEVL 327
Cdd:cd11933     2 KSFRAMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGtvQRTGKTGMLPANYVEAI 58

Second Src Homology 3 domain of Bud emergence protein 1 and similar domains; Members of this subfamily bear similarity to Saccharomyces cerevisiae Bem1p, containing two Src Homology 3 (SH3) domains at the N-terminus, a central PX domain, and a C-terminal PB1 domain. Bem1p is a scaffolding protein that is critical for proper Cdc42p activation during bud formation in yeast. During budding and mating, Bem1p migrates to the plasma membrane where it can serve as an adaptor for Cdc42p and some other proteins. Bem1p also functions as an effector of the G1 cyclin Cln3p and the cyclin-dependent kinase Cdc28p in promoting vacuolar fusion. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212812 [Multi-domain] Cd Length: 56 Bit Score: 44.63 E-value: 2.40e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLG---IFPANYVEV 326
Cdd:cd11879     2 GIVLYDFKAERPDELDAKAGDAIIICAHSNYEWFVAKPIGRLGgpgLIPVSFVEI 56

Src Homology 3 domain of Amphiphysin and related domains; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), are localized in many different tissues and may function in intracellular vesicle trafficking. In skeletal muscle, Bin1 plays a role in the organization and maintenance of the T-tubule network. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212724 [Multi-domain] Cd Length: 64 Bit Score: 45.01 E-value: 2.42e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI-----HKEVDKNWLEG--EHHGRLGIFPANYVEVL 327
Cdd:cd11790     5 VRATHDYTAEDTDELTFEKGDVILVipfddPEEQDEGWLMGvkESTGCRGVFPENFTERI 64

Second Src Homology 3 domain of FCH and double SH3 domains protein 1; FCHSD1 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212828 Cd Length: 58 Bit Score: 44.96 E-value: 2.43e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI----HKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11895     2 ARALYSYTGQSPEELSFPEGALIRLlpraQDGVDDGFWRGEFGGRVGVFPSLLVEEL 58

Src Homology 3 domain of Bbc1 and similar domains; This subfamily is composed of Saccharomyces cerevisiae Bbc1p, also called Mti1p (Myosin tail region-interacting protein), and similar proteins. Bbc1p interacts with and regulates type I myosins in yeast, Myo3p and Myo5p, which are involved in actin cytoskeletal reorganization. It also binds and inhibits Las17, a WASp family protein that functions as an activator of the Arp2/3 complex. Bbc1p contains an N-terminal SH3 domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212820 [Multi-domain] Cd Length: 60 Bit Score: 45.03 E-value: 2.51e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 505 PYR--AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGV---SRRTQKFGTFPGNYVAP 559
Cdd:cd11887     1 PFKvkALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEyvdSNGNTKEGIFPKNFVEV 60

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 44.89 E-value: 2.54e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVM-QQC-DDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd12057     3 KVLFPYEAQNEDELTIKEGDIVTLIsKDCiDAGWWEG--ELNGRRGVFPDNFV 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 44.61 E-value: 2.62e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG---RLGIFPANY 323
Cdd:cd11821     6 YDCQADNDDELTFSEGEIIVVTGEEDDEWWEGHIEGdpsRRGVFPVSF 53

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 3 (PACSIN3); PACSIN 3 or Syndapin III (Synaptic dynamin-associated protein III) is expressed ubiquitously and regulates glucose uptake in adipocytes through its role in GLUT1 trafficking. It also modulates the subcellular localization and stimulus-specific function of the cation channel TRPV4. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212930 [Multi-domain] Cd Length: 56 Bit Score: 44.57 E-value: 2.71e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRITgTGRQGIFPASYVQ 401
Cdd:cd11997     6 ALYDYTGQEADELSFKAGEELLKIGEEDEQgWCKGRLL-SGRIGLYPANYVE 56

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 44.66 E-value: 2.76e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFvGVSRRTQKfGTFPGNYV 557
Cdd:cd11837     2 ATALYPWRAKKENHLSFAKGDIITVLEQQEMWWF-GELEGGEE-GWFPKSYV 51

First C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212895 [Multi-domain] Cd Length: 54 Bit Score: 44.40 E-value: 2.81e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGrITGTGRQGIFPASYVQI 402
Cdd:cd11962     2 AVVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMG-TNSKGESGLFPSNYVEL 54

Src Homology 3 domain of Bbc1 and similar domains; This subfamily is composed of Saccharomyces cerevisiae Bbc1p, also called Mti1p (Myosin tail region-interacting protein), and similar proteins. Bbc1p interacts with and regulates type I myosins in yeast, Myo3p and Myo5p, which are involved in actin cytoskeletal reorganization. It also binds and inhibits Las17, a WASp family protein that functions as an activator of the Arp2/3 complex. Bbc1p contains an N-terminal SH3 domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212820 [Multi-domain] Cd Length: 60 Bit Score: 44.64 E-value: 2.82e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRIT---GTGRQGIFPASYVQ 401
Cdd:cd11887     3 KVKALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYVdsnGNTKEGIFPKNFVE 59

Src homology 3 domain of Slit-Robo GTPase Activating Proteins 1, 2, and 3; srGAP1, also called Rho GTPase-Activating Protein 13 (ARHGAP13), is a Cdc42- and RhoA-specific GAP and is expressed later in the development of central nervous system tissues. srGAP2 is expressed in zones of neuronal differentiation. It plays a role in the regeneration of neurons and axons. srGAP3, also called MEGAP (MEntal disorder associated GTPase-Activating Protein), is a Rho GAP with activity towards Rac1 and Cdc42. It impacts cell migration by regulating actin and microtubule cytoskeletal dynamics. The association between srGAP3 haploinsufficiency and mental retardation is under debate. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212888 [Multi-domain] Cd Length: 53 Bit Score: 44.55 E-value: 2.84e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11955     1 EAIAKFDYVGRSARELSFKKGASLLLYHRASDDWWEGRHNGI--DGLVPHQYIVV 53

Src Homology 3 domain of Amphiphysin and related domains; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), are localized in many different tissues and may function in intracellular vesicle trafficking. In skeletal muscle, Bin1 plays a role in the organization and maintenance of the T-tubule network. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212724 [Multi-domain] Cd Length: 64 Bit Score: 45.01 E-value: 2.86e-06

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                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVM-----QQCDDGWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd11790     6 RATHDYTAEDTDELTFEKGDVILVIpfddpEEQDEGWLMGVKESTGCRGVFPENFTERI 64

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212830 [Multi-domain] Cd Length: 55 Bit Score: 44.60 E-value: 3.15e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCD-DGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11897     1 RARALYDFRSENPGEISLREHEVLSLCSEQDiEGWLEGVNSRGDR-GLFPASYV 53

Src homology 3 domain of Abl Interactor 1; Abi1, also called e3B1, is a central regulator of actin cytoskeletal reorganization through interactions with many protein complexes. It is part of WAVE, a nucleation-promoting factor complex, that links Rac 1 activation to actin polymerization causing lamellipodia protrusion at the plasma membrane. Abi1 interact with formins to promote protrusions at the leading edge of motile cells. It also is a target of alpha4 integrin, regulating membrane protrusions at sites of integrin engagement. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain. The SH3 domain of Abi binds to a PxxP motif in Abl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212904 [Multi-domain] Cd Length: 59 Bit Score: 44.63 E-value: 3.19e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQ 401
Cdd:cd11971     3 VAIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEG--VCNGVTGLFPGNYVE 52

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212712 [Multi-domain] Cd Length: 51 Bit Score: 44.41 E-value: 3.28e-06

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                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKN-WLEGEHHGRLGIFPANY 323
Cdd:cd11778     6 YDYEAQGDDEISIRVGDRIAVIRGDDGSgWTYGEINGVKGLFPTSY 51

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 44.43 E-value: 3.30e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYVAP 559
Cdd:cd11950     3 RALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKG--RLHGKLGLFPANYVAP 53

C-terminal Src Homology 3 domain of Nebulette and LIM-nebulette (or Lasp2); Nebulette is a cardiac-specific protein that localizes to the Z-disc. It interacts with tropomyosin and is important in stabilizing actin thin filaments in cardiac muscles. Polymorphisms in the nebulette gene are associated with dilated cardiomyopathy, with some mutations resulting in severe heart failure. Nebulette is a 107kD protein that contains an N-terminal acidic region, multiple nebulin repeats, and a C-terminal SH3 domain. LIM-nebulette, also called Lasp2 (LIM and SH3 domain protein 2), is an alternatively spliced variant of nebulette. Although it shares a gene with nebulette, Lasp2 is not transcribed from a muscle-specific promoter, giving rise to its multiple tissue expression pattern with highest amounts in the brain. It can crosslink actin filaments and it affects cell spreading. Lasp2 is a 34kD protein containing an N-terminal LIM domain, three nebulin repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212868 [Multi-domain] Cd Length: 58 Bit Score: 44.61 E-value: 3.43e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11935     5 AMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVQRTGRTGMLPANYIE 55

Src homology 3 domain of Cortactin; Cortactin was originally identified as a substrate of Src kinase. It is an actin regulatory protein that binds to the Arp2/3 complex and stabilizes branched actin filaments. It is involved in cellular processes that affect cell motility, adhesion, migration, endocytosis, and invasion. It is expressed ubiquitously except in hematopoietic cells, where the homolog hematopoietic lineage cell-specific 1 (HS1) is expressed instead. Cortactin contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region interacts with the Arp2/3 complex and F-actin, and is crucial in regulating branched actin assembly. Cortactin also serves as a scaffold and provides a bridge to the actin cytoskeleton for membrane trafficking and signaling proteins that bind to its SH3 domain. Binding partners for the SH3 domain of cortactin include dynamin2, N-WASp, MIM, FGD1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212892 [Multi-domain] Cd Length: 53 Bit Score: 44.33 E-value: 3.44e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVA 558
Cdd:cd11959     4 ALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGVCR--GKYGLFPANYVE 52

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 44.31 E-value: 3.46e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSrRTQKFGTFPGNYV 557
Cdd:cd11960     3 RALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGTG-PDGTYGLFPANYV 52

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 44.22 E-value: 3.59e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11902     3 AFVKFAYVAEREDELSLVKGSRVTVMEKCSDGWWRGSYNGQIGWFPSNYV 52

Src homology 3 domain of eumetazoan Actin-binding protein 1; Abp1, also called drebrin-like protein, is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a helical domain, and a C-terminal SH3 domain. Mammalian Abp1, unlike yeast Abp1, does not contain an acidic domain that interacts with the Arp2/3 complex. It regulates actin dynamics indirectly by interacting with dynamin and WASP family proteins. Abp1 deficiency causes abnormal organ structure and function of the spleen, heart, and lung of mice. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212893 [Multi-domain] Cd Length: 54 Bit Score: 44.31 E-value: 3.67e-06

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11960     2 ARALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGT-GPDGTYGLFPANYVEL 54

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. Its N-terminal SH3 domain binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212879 [Multi-domain] Cd Length: 56 Bit Score: 44.25 E-value: 3.69e-06

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERI-CLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11946     2 EAIAKYDFKATADDELSFKRGDILkVLNEECDQNWYKAEL--NGKDGFIPKNYIEM 55

Second Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212856 [Multi-domain] Cd Length: 57 Bit Score: 44.52 E-value: 3.70e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11923     5 AKYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGKIPGTNRQGIFPVSYV 54

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Embryonal Fyn-associated Substrate; EFS is also called HEFS, CASS3 (Cas scaffolding protein family member 3) or SIN (Src-interacting protein). It was identified based on interactions with the Src kinases, Fyn and Yes. It plays a role in thymocyte development and acts as a negative regulator of T cell proliferation. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212936 Cd Length: 62 Bit Score: 44.50 E-value: 3.80e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKN---WLEGEHHGRLGIFPANYVEVLPA 329
Cdd:cd12003     3 AKALYDNAAESPEELSFRRGDVLMVLKREHGSlpgWWLCSLHGQQGIAPANRLRLLPT 60

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 44.19 E-value: 3.89e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1958679458 275 ARLKFDFQAQSPK-ELTLQKGDIVYIHKEVDK-----NWLEGE-HHGRLGIFPANYVEV 326
Cdd:cd11771     2 CRALYDFTPENPEmELSLKKGDIVAVLSKTDPlgrdsEWWKGRtRDGRIGWFPSNYVEV 60

Src homology 3 domain of Ubiquitin-associated and SH3 domain-containing proteins, also called TULA (T cell Ubiquitin LigAnd) family of proteins; UBASH3 or TULA proteins are also referred to as Suppressor of T cell receptor Signaling (STS) proteins. They contain an N-terminal UBA domain, a central SH3 domain, and a C-terminal histidine phosphatase domain. They bind c-Cbl through the SH3 domain and to ubiquitin via UBA. In some vertebrates, there are two TULA family proteins, called UBASH3A (also called TULA or STS-2) and UBASH3B (also called TULA-2 or STS-1), which show partly overlapping as well as distinct functions. UBASH3B is widely expressed while UBASH3A is only found in lymphoid cells. UBASH3A facilitates apoptosis induced in T cells through its interaction with the apoptosis-inducing factor AIF. UBASH3B is an active phosphatase while UBASH3A is not. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212725 [Multi-domain] Cd Length: 59 Bit Score: 44.21 E-value: 3.92e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIH-KEVDKN---WLEGEHH--GRLGIFPANYVE 325
Cdd:cd11791     3 RVLYPYTPQEEDELELVPGDYIYVSpEELDSSsdgWVEGTSWltGCSGLLPENYTE 58

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 44.06 E-value: 3.99e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRitGTGRQGIFPASYVQ 401
Cdd:cd11870     3 VALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGH--SDGRVGIFPKCFVV 52

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 394975 [Multi-domain] Cd Length: 47 Bit Score: 43.73 E-value: 4.41e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTqKFGTFP 553
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRNKGG-KEGLIP 46

Src Homology 3 domain of Saccharomyces cerevisiae Nap1-binding protein 2 and similar fungal proteins; This subfamily includes Saccharomyces cerevisiae Nbp2 (Nucleosome assembly protein 1 (Nap1)-binding protein 2), Schizosaccharomyces pombe Skb5, and similar proteins. Nbp2 interacts with Nap1, which is essential for maintaining proper nucleosome structures in transcription and replication. It is also the binding partner of the yeast type II protein phosphatase Ptc1p and serves as a scaffolding protein that brings seven kinases in close contact to Ptc1p. Nbp2 plays a role many cell processes including organelle inheritance, mating hormone response, cell wall stress, mitotic cell growth at elevated temperatures, and high osmolarity. Skb5 interacts with the p21-activated kinase (PAK) homolog Shk1, which is critical for fission yeast cell viability. Skb5 activates Shk1 and plays a role in regulating cell morphology and growth under hypertonic conditions. Nbp2 and Skb5 contain an SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212799 Cd Length: 55 Bit Score: 44.04 E-value: 4.44e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11865     4 ALYDFEPEHDNELGFAEGQILFILYKHGQGWLIAEDESGGKTGLVPEEFV 53

Fourth N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP bind the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212731 Cd Length: 50 Bit Score: 43.95 E-value: 4.44e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFP 320
Cdd:cd11797     6 YRFQALEPNELDFEVGDRIRIIATLEDGWLEGELKGRRGIFP 47

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 43.82 E-value: 4.63e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11996     7 YDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVTGLFPSNYVKM 54

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing (Stac) proteins; Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. This model represents the first C-terminal SH3 domain of Stac1 and Stac3, and the single C-terminal SH3 domain of Stac2. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212767 [Multi-domain] Cd Length: 53 Bit Score: 43.64 E-value: 5.14e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11833     6 YKFKPQENEDLEMRPGDKITLLDDSNEDWWKGKIEDRVGFFPANFV 51

Second Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212865 Cd Length: 57 Bit Score: 44.06 E-value: 5.29e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKE----LTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11932     4 ALYNFDLKEKNREEskdcLKFQKDDIITVISRVDENWAEGKLGDQVGIFPILFV 57

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 43.74 E-value: 5.56e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1958679458 362 ELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:pfam07653  15 GLTLKKGDVVKVLGKDNDGWWEGET--GGRVGLVPSTAVEE 53

Src homology 3 domain of Alpha Spectrin; Spectrin is a major structural component of the red blood cell membrane skeleton and is important in erythropoiesis and membrane biogenesis. It is a flexible, rope-like molecule composed of two subunits, alpha and beta, which consist of many spectrin-type repeats. Alpha and beta spectrin associate to form heterodimers and tetramers; spectrin tetramer formation is critical for red cell shape and deformability. Defects in alpha spectrin have been associated with inherited hemolytic anemias including hereditary spherocytosis (HSp), hereditary elliptocytosis (HE), and hereditary pyropoikilocytosis (HPP). Alpha spectrin contains a middle SH3 domain and a C-terminal EF-hand binding motif in addition to multiple spectrin repeats. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212742 [Multi-domain] Cd Length: 53 Bit Score: 43.63 E-value: 5.68e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11808     6 YDYQEKSPREVSMKKGDILTLLNSSNKDWWKVEVNDRQGFVPAAYVK 52

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 43.65 E-value: 5.78e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11812     6 YDYTANRSDELTIHRGDIIRVlYKDNDNWWFGSLVNGQQGYFPANYV 52

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212777 [Multi-domain] Cd Length: 53 Bit Score: 43.56 E-value: 5.89e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDD-GWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11843     1 PVRALYDYEGQESDELSFKAGDILTKLEEEDEqGWCKG--RLDGRVGLYPANYV 52

Third Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212717 [Multi-domain] Cd Length: 55 Bit Score: 43.54 E-value: 5.99e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11783     3 VALYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTSLRTGQSGVFPGNYVQ 54

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 43.82 E-value: 6.10e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 347 GDAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11996     1 CQVIAMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGV--TGLFPSNYVKM 54

Src Homology 3 domain of the p85 regulatory subunit of Class IA Phosphatidylinositol 3-kinases; Class I PI3Ks convert PtdIns(4,5)P2 to the critical second messenger PtdIns(3,4,5)P3. They are heterodimers and exist in multiple isoforms consisting of one catalytic subunit (out of four isoforms) and one of several regulatory subunits. Class IA PI3Ks associate with the p85 regulatory subunit family, which contains SH3, RhoGAP, and SH2 domains. The p85 subunits recruit the PI3K p110 catalytic subunit to the membrane, where p110 phosphorylates inositol lipids. Vertebrates harbor two p85 isoforms, called alpha and beta. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212710 Cd Length: 72 Bit Score: 44.04 E-value: 6.65e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 506 YRAMYQYRPQNEDELELREGD-------------RVDVMQQCDD--GWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11776     3 YRALYDYEKERDEDIILKTGDvlvvenpellalgVPDGKETVPKpeGWLEGKNERTGERGDFPGTYV 69

Src homology 3 domain of Src Protein Tyrosine Kinase; Src (or c-Src) is a cytoplasmic (or non-receptor) PTK and is the vertebrate homolog of the oncogenic protein (v-Src) from Rous sarcoma virus. Together with other Src subfamily proteins, it is involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. Src also play a role in regulating cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Elevated levels of Src kinase activity have been reported in a variety of human cancers. Several inhibitors of Src have been developed as anti-cancer drugs. Src is also implicated in acute inflammatory responses and osteoclast function. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212941 [Multi-domain] Cd Length: 56 Bit Score: 43.56 E-value: 6.99e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd12008     2 FVALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQTGYIPSNYVAP 55

Src Homology 3 domain of Rho GTPase-activating protein 9 and similar proteins; This subfamily is composed of Rho GTPase-activating proteins including mammalian ARHGAP9, and vertebrate ARHGAPs 12 and 27. RhoGAPs (or ARHGAPs) bind to Rho proteins and enhance the hydrolysis rates of bound GTP. ARHGAP9 functions as a GAP for Rac and Cdc42, but not for RhoA. It negatively regulates cell migration and adhesion. It also acts as a docking protein for the MAP kinases Erk2 and p38alpha, and may facilitate cross-talk between the Rho GTPase and MAPK pathways to control actin remodeling. ARHGAP27, also called CAMGAP1, shows GAP activity towards Rac1 and Cdc42. It binds the adaptor protein CIN85 and may play a role in clathrin-mediated endocytosis. ARHGAP12 has been shown to display GAP activity towards Rac1. It plays a role in regulating HFG-driven cell growth and invasiveness. ARHGAPs in this subfamily contain SH3, WW, Pleckstin homology (PH), and RhoGAP domains. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212821 [Multi-domain] Cd Length: 54 Bit Score: 43.51 E-value: 7.11e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 353 YTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASY 399
Cdd:cd11888     8 FEYTGKDGRKVSIKEGERFLLLKKSNDDWWQVRRPGDSKPFYVPAQY 54

Src Homology 3 domain of Sorting Nexin 33; SNX33 interacts with Wiskott-Aldrich syndrome protein (WASP) and plays a role in the maintenance of cell shape and cell cycle progression. It modulates the shedding and endocytosis of cellular prion protein (PrP(c)) and amyloid precursor protein (APP). SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX33 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212829 [Multi-domain] Cd Length: 55 Bit Score: 43.41 E-value: 7.13e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKN-WLEGEH-HGRLGIFPANYVEV 326
Cdd:cd11896     2 ARALYSFQSENKEEINIQENEELVIFSENSLDgWLQGQNsRGETGLFPASYVEI 55

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1) and PACSIN 2; PACSIN 1 or Syndapin I (Synaptic dynamin-associated protein I) is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. PACSIN 2 or Syndapin II is expressed ubiquitously and is involved in the regulation of tubulin polymerization. It associates with Golgi membranes and forms a complex with dynamin II which is crucial in promoting vesicle formation from the trans-Golgi network. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212931 [Multi-domain] Cd Length: 56 Bit Score: 43.40 E-value: 7.29e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGD-IVYIHKEVDKNWLEGE-HHGRLGIFPANYVE 325
Cdd:cd11998     4 RALYDYDGQEQDELSFKAGDeLTKLEDEDEQGWCKGRlDSGQVGLYPANYVE 55

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212783 [Multi-domain] Cd Length: 53 Bit Score: 43.46 E-value: 7.70e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLE-GEHHGRLGIFPANYVE 325
Cdd:cd11849     6 YDFKSAEPNTLSFSEGETFLLLERSNAHWWLvTNHSGETGYVPANYVK 53

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212783 [Multi-domain] Cd Length: 53 Bit Score: 43.07 E-value: 7.86e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGrITGTGRQGIFPASYVQ 401
Cdd:cd11849     4 ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLV-TNHSGETGYVPANYVK 53

Fifth Src homology 3 domain (or SH3E) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212774 [Multi-domain] Cd Length: 53 Bit Score: 43.17 E-value: 7.93e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11840     3 IALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGEL--NGQTGLFPSNYVE 52

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212716 [Multi-domain] Cd Length: 53 Bit Score: 43.11 E-value: 7.98e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11782     3 RAKYNFNADTGVELSFRKGDVITLTRRVDENWYEG--RIGGRQGIFPVSYV 51

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212697 [Multi-domain] Cd Length: 55 Bit Score: 43.47 E-value: 8.03e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRK-VNEHWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11763     4 ALYDFDSQPSGELSLRAGEVLTITRQdVGDGWLEGR-NSRGEVGLFPSSYVEI 55

Src Homology 3 domain of eumetazoan Peroxisomal biogenesis factor 13; PEX13 is a peroxin and is required for protein import into the peroxisomal matrix and membrane. It is an integral membrane protein that is essential for the localization of PEX14 and the import of proteins containing the peroxisome matrix targeting signals, PTS1 and PTS2. Mutations of the PEX13 gene in humans lead to a wide range of peroxisome biogenesis disorders (PBDs), the most severe of which is known as Zellweger syndrome (ZS), a severe multisystem disorder characterized by hypotonia, psychomotor retardation, and neuronal migration defects. PEX13 contains two transmembrane regions and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212798 Cd Length: 58 Bit Score: 43.39 E-value: 8.14e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIH-KEVDKN---WLEGEHHG-RLGIFPANYVEV 326
Cdd:cd11864     2 ARAEYDFVAESEDELSFRAGDKLRLApKELQPRvrgWLLATVDGqKIGLVPANYVKI 58

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 43.04 E-value: 8.53e-06

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGI-----FPANY 323
Cdd:cd11883     6 YDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKvkrgwFPSNY 55

Third Src homology 3 domain (or SH3C) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. The SH3C of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212772 [Multi-domain] Cd Length: 52 Bit Score: 43.17 E-value: 9.70e-06

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1958679458 281 FQAQSPKELTLQKGDIVYIHKEvDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11838     8 YESNEPGDLTFNAGDVILVTKK-DGEWWTGTIGDRTGIFPSNYV 50

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 42.90 E-value: 9.78e-06

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQ 401
Cdd:cd11961     2 AKALYDYDAAEDNELSFFENDKIINIEFVDDDWWLG--ECHGSRGLFPSNYVE 52

Src Homology 3 domain of Abelson helper integration site-1 (AHI-1); AHI-1, also called Jouberin, is expressed in high levels in the brain, gonad tissues, and skeletal muscle. It is an adaptor protein that interacts with the small GTPase Rab8a and regulates it distribution and function, affecting cilium formation and vesicle transport. Mutations in the AHI-1 gene can cause Joubert syndrome, a disorder characterized by brainstem malformations, cerebellar aplasia/hypoplasia, and retinal dystrophy. AHI-1 variation is also associated with susceptibility to schizophrenia and type 2 diabetes mellitus progression. AHI-1 contains WD40 and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212746 [Multi-domain] Cd Length: 52 Bit Score: 42.88 E-value: 1.10e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11812     4 ALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFGSLVNGQQ-GYFPANYV 52

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212707 [Multi-domain] Cd Length: 57 Bit Score: 42.80 E-value: 1.15e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWF-----VGVSRRTQKFGTFPGNY 556
Cdd:cd11773     2 YKALYDYEPQTEDELTIQEDDILYLLEKSDDDWWkvklkVNSSDDDEPVGLVPATY 57

C-terminal Src Homology 3 domain of the p67phox subunit of NADPH oxidase and similar proteins; This subfamily is composed of p67phox, NADPH oxidase activator 1 (Noxa1), and similar proteins. p67phox, also called Neutrophil cytosol factor 2 (NCF-2), and Noxa1 are homologs and are the cytosolic subunits of the phagocytic (Nox2) and nonphagocytic (Nox1) NADPH oxidase complexes, respectively. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox and Noxa1 play regulatory roles. p67phox contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. Noxa1 has a similar domain architecture except it is lacking the N-terminal SH3 domain. The TPR domain of both binds activated GTP-bound Rac, while the C-terminal SH3 domain of p67phox and Noxa1 binds the polyproline motif found at the C-terminus of p47phox and Noxo1, respectively. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212803 [Multi-domain] Cd Length: 53 Bit Score: 42.90 E-value: 1.21e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVAP 559
Cdd:cd11870     4 ALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHSD--GRVGIFPKCFVVP 53

Src homology 3 domain of Myosins Ie, If, and similar proteins; Myosins Ie (MyoIe) and If (MyoIf) are nonmuscle, unconventional, long tailed, class I myosins containing an N-terminal motor domain and a myosin tail with TH1, TH2, and SH3 domains. MyoIe interacts with the endocytic proteins, dynamin and synaptojanin-1, through its SH3 domain; it may play a role in clathrin-dependent endocytosis. In the kidney, MyoIe is critical for podocyte function and normal glomerular filtration. Mutations in MyoIe is associated with focal segmental glomerulosclerosis, a disease characterized by massive proteinuria and progression to end-stage kidney disease. MyoIf is predominantly expressed in the immune system; it plays a role in immune cell motility and innate immunity. Mutations in MyoIf may be associated with the loss of hearing. The MyoIf gene has also been found to be fused to the MLL (Mixed lineage leukemia) gene in infant acute myeloid leukemias (AML). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212761 [Multi-domain] Cd Length: 53 Bit Score: 42.79 E-value: 1.23e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKG-DLDvELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11827     4 ALYAYDAqDTD-ELSFNEGDIIEILKEDPSGWWTGRL--RGKEGLFPGNYVE 52

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 3 (PACSIN3); PACSIN 3 or Syndapin III (Synaptic dynamin-associated protein III) is expressed ubiquitously and regulates glucose uptake in adipocytes through its role in GLUT1 trafficking. It also modulates the subcellular localization and stimulus-specific function of the cation channel TRPV4. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212930 [Multi-domain] Cd Length: 56 Bit Score: 42.64 E-value: 1.32e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGD-IVYIHKEVDKNWLEGE-HHGRLGIFPANYVE 325
Cdd:cd11997     5 RALYDYTGQEADELSFKAGEeLLKIGEEDEQGWCKGRlLSGRIGLYPANYVE 56

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212939 [Multi-domain] Cd Length: 56 Bit Score: 42.73 E-value: 1.38e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd12006     4 VALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGETGYIPSNYV 54

N-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212692 [Multi-domain] Cd Length: 55 Bit Score: 42.73 E-value: 1.43e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRiTGTGRQGIFPASYVQ 401
Cdd:cd11758     5 ALFDFPGNDDEDLPFKKGEILTVIRKPEEQWWNAR-NSEGKTGMIPVPYVE 54

First Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212715 [Multi-domain] Cd Length: 53 Bit Score: 42.33 E-value: 1.51e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVsrRTQKFGTFPGNYV 557
Cdd:cd11781     3 RALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGE--HNGRVGIFPASYV 51

Src homology 3 domain of an unknown subfamily of proteins with similarity to Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212932 [Multi-domain] Cd Length: 56 Bit Score: 42.62 E-value: 1.57e-05

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 276 RLKFDFQAQSPKELTLQKGD-IVYIHKEVDKNWLEG-EHHGRLGIFPANYVE 325
Cdd:cd11999     5 RAVYDYTGQEPDELSFKAGEeLLKVEDEDEQGWCKGvTDGGAVGLYPANYVE 56

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 42.50 E-value: 1.69e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd12047     3 VAQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEGHC--DGRIGIFPKCFAV 52

Src Homology 3 domain of Insulin Receptor tyrosine kinase Substrate p53, Brain-specific Angiogenesis Inhibitor 1-Associated Protein 2 (BAIAP2)-Like proteins, and similar proteins; Proteins in this family include IRSp53, BAIAP2L1, BAIAP2L2, and similar proteins. They all contain an Inverse-Bin/Amphiphysin/Rvs (I-BAR) or IMD domain in addition to the SH3 domain. IRSp53, also known as BAIAP2, is a scaffolding protein that takes part in many signaling pathways including Cdc42-induced filopodia formation, Rac-mediated lamellipodia extension, and spine morphogenesis. IRSp53 exists as multiple splicing variants that differ mainly at the C-termini. BAIAP2L1, also called IRTKS (Insulin Receptor Tyrosine Kinase Substrate), serves as a substrate for the insulin receptor and binds the small GTPase Rac. It plays a role in regulating the actin cytoskeleton and colocalizes with F-actin, cortactin, VASP, and vinculin. IRSp53 and IRTKS also mediate the recruitment of effector proteins Tir and EspFu, which regulate host cell actin reorganization, to bacterial attachment sites. BAIAP2L2 co-localizes with clathrin plaques but its function has not been determined. The SH3 domains of IRSp53 and IRTKS have been shown to bind the proline-rich C-terminus of EspFu. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212713 [Multi-domain] Cd Length: 57 Bit Score: 42.31 E-value: 1.75e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVM-QQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11779     4 KALYPHAAGGETQLSFEEGDVITLLgPEPRDGWHYGENERSGRRGWFPIAYTEP 57

First Src Homology 3 domain of Sorbin and SH3 domain containing 2 (Sorbs2), also called Arg-binding protein 2 (ArgBP2); Sorbs2 or ArgBP2 is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It regulates actin-dependent processes including cell adhesion, morphology, and migration. It is expressed in many tissues and is abundant in the heart. Like vinexin, it is found in focal adhesion where it interacts with vinculin and afadin. It also localizes in epithelial cell stress fibers and in cardiac muscle cell Z-discs. Sorbs2 has been implicated to play roles in the signaling of c-Arg, Akt, and Pyk2. Other interaction partners of Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2, synaptojanin, PTP-PEST, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212853 [Multi-domain] Cd Length: 55 Bit Score: 42.30 E-value: 1.75e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11920     2 PARAVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEG--EHHGRVGIFPISYV 52

Fourth Src homology 3 domain (or SH3D) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212926 Cd Length: 65 Bit Score: 42.80 E-value: 1.91e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 270 KKRKAARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGR-----LGIFPANYVEVL 327
Cdd:cd11993     1 KKPEIAQVIASYTATGPEQLTLAPGQLILIRKKNPGGWWEGELQARgkkrqIGWFPANYVKLL 63

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212779 [Multi-domain] Cd Length: 52 Bit Score: 41.80 E-value: 2.29e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNY 556
Cdd:cd11845     2 YVALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHLSTGKEGYIPSNY 52

N-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212692 [Multi-domain] Cd Length: 55 Bit Score: 41.96 E-value: 2.35e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH-HGRLGIFPANYVE 325
Cdd:cd11758     4 RALFDFPGNDDEDLPFKKGEILTVIRKPEEQWWNARNsEGKTGMIPVPYVE 54

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 41.80 E-value: 2.40e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCdDGWFVGVSRRT-QKFGTFPGNYV 557
Cdd:cd11872     4 AIYNFQGDGEHQLSLQVGDTVQILEEC-EGWYRGFSLRNkSLKGIFPKSYV 53

Src homology 3 domain of Slit-Robo GTPase Activating Protein 4; srGAP4, also called ARHGAP4, is highly expressed in hematopoietic cells and may play a role in lymphocyte differentiation. It is able to stimulate the GTPase activity of Rac1, Cdc42, and RhoA. In the nervous system, srGAP4 has been detected in differentiating neurites and may be involved in axon and dendritic growth. srGAPs are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212889 [Multi-domain] Cd Length: 55 Bit Score: 41.75 E-value: 2.55e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11956     3 EAVACFDYTGRTAQELSFKRGDVLLLHSKASSDWWRGEHNGM--RGLIPHKYISV 55

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212707 [Multi-domain] Cd Length: 57 Bit Score: 42.03 E-value: 2.56e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLE-------GEHHGRLGIFPANY 323
Cdd:cd11773     6 YDYEPQTEDELTIQEDDILYLLEKSDDDWWKvklkvnsSDDDEPVGLVPATY 57

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212779 [Multi-domain] Cd Length: 52 Bit Score: 41.80 E-value: 2.78e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASY 399
Cdd:cd11845     3 VALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHLSTGKEGYIPSNY 52

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase and similar proteins; This subfamily is composed of Rho GTPase activating proteins (GAPs) with similarity to GRAF. Members contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. Although vertebrates harbor four Rho GAPs in the GRAF subfamily including GRAF, GRAF2, GRAF3, and Oligophrenin-1 (OPHN1), only three are included in this model. OPHN1 contains the BAR, PH and GAP domains, but not the C-terminal SH3 domain. GRAF and GRAF2 show GAP activity towards RhoA and Cdc42. GRAF influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase. GRAF2 regulates caspase-activated p21-activated protein kinase-2. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212815 [Multi-domain] Cd Length: 54 Bit Score: 41.51 E-value: 2.93e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11882     2 ARALYACKAEDESELSFEPGQIITNVQPSDEPgWLEGTL--NGRTGLIPENYVEF 54

Src Homology 3 domain of beta-Pak Interactive eXchange factor; Beta-PIX, also called Rho guanine nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212994 [Multi-domain] Cd Length: 54 Bit Score: 41.59 E-value: 2.96e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQ 401
Cdd:cd12061     4 AKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEG--THNGRTGWFPSNYVR 52

Src Homology 3 domain of the p85alpha regulatory subunit of Class IA Phosphatidylinositol 3-kinases; Class I PI3Ks convert PtdIns(4,5)P2 to the critical second messenger PtdIns(3,4,5)P3. They are heterodimers and exist in multiple isoforms consisting of one catalytic subunit (out of four isoforms) and one of several regulatory subunits. Class IA PI3Ks associate with the p85 regulatory subunit family, which contains SH3, RhoGAP, and SH2 domains. The p85 subunits recruit the PI3K p110 catalytic subunit to the membrane, where p110 phosphorylates inositol lipids. Vertebrates harbor two p85 isoforms, called alpha and beta. In addition to regulating the p110 subunit, p85alpha interacts with activated FGFR3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212843 Cd Length: 75 Bit Score: 42.19 E-value: 3.00e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQ------CDD---------GWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11910     4 YRALYDYKKEREEDIDLHLGDILTVNKGsllalgFSEgqearpeeiGWLNGYNETTGERGDFPGTYV 70

First N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212728 Cd Length: 51 Bit Score: 41.73 E-value: 3.08e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11794     2 VRAIFDFCPSVSEELPLFAGDVIEVLKVVDEFWLLGTKEGVTGQFPSSFV 51

Src Homology 3 domain of Bbc1 and similar domains; This subfamily is composed of Saccharomyces cerevisiae Bbc1p, also called Mti1p (Myosin tail region-interacting protein), and similar proteins. Bbc1p interacts with and regulates type I myosins in yeast, Myo3p and Myo5p, which are involved in actin cytoskeletal reorganization. It also binds and inhibits Las17, a WASp family protein that functions as an activator of the Arp2/3 complex. Bbc1p contains an N-terminal SH3 domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212820 [Multi-domain] Cd Length: 60 Bit Score: 41.94 E-value: 3.13e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH---HGRL--GIFPANYVEV 326
Cdd:cd11887     7 LYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYvdsNGNTkeGIFPKNFVEV 60

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 41.75 E-value: 3.13e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSrrTQKFGTFPGNYVAP 559
Cdd:cd11949     3 QALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGAC--HGQTGMFPRNYVTP 53

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212712 [Multi-domain] Cd Length: 51 Bit Score: 41.33 E-value: 3.24e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCD-DGWFVGvSRRTQKfGTFPGNY 556
Cdd:cd11778     4 ALYDYEAQGDDEISIRVGDRIAVIRGDDgSGWTYG-EINGVK-GLFPTSY 51

Src homology 3 domain of JNK-interacting proteins 1 and 2, and similar domains; JNK-interacting proteins (JIPs) function as scaffolding proteins for c-Jun N-terminal kinase (JNK) signaling pathways. They bind to components of Mitogen-activated protein kinase (MAPK) pathways such as JNK, MKK, and several MAP3Ks such as MLK and DLK. There are four JIPs (JIP1-4); all contain a JNK binding domain. JIP1 and JIP2 also contain SH3 and Phosphotyrosine-binding (PTB) domains. Both are highly expressed in the brain and pancreatic beta-cells. JIP1 functions as an adaptor linking motor to cargo during axonal transport and also is involved in regulating insulin secretion. JIP2 form complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. The SH3 domain of JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212735 Cd Length: 55 Bit Score: 41.53 E-value: 3.31e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11801     2 HRALHKFIPRHEDEIELDIGDPVYVEQEADDLWCEGTNLRTGQRGIFPAAYVV 54

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212873 Cd Length: 55 Bit Score: 41.70 E-value: 3.46e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 281 FQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPANYVE 325
Cdd:cd11940     8 YKAQENDELTLEKADIIMVRQQSSDGWLEGVRlsDGERGWFPQSHVE 54

Second or C-terminal Src homology 3 domain of the p47phox subunit of NADPH oxidase, also called Neutrophil Cytosolic Factor 1; p47phox, or NCF1, is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox), which plays a key role in the ability of phagocytes to defend against bacterial infections. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p47phox is required for activation of NADH oxidase and plays a role in translocation. It contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), a polybasic/autoinhibitory region, and a C-terminal proline-rich region (PRR). This model characterizes the second SH3 domain (or C-SH3) of p47phox. In its inactive state, the tandem SH3 domains interact intramolecularly with the autoinhibitory region; upon activation, the tandem SH3 domains are exposed through a conformational change, resulting in their binding to the PRR of p22phox and the activation of NADPH oxidase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212955 [Multi-domain] Cd Length: 53 Bit Score: 41.36 E-value: 3.49e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFvgVSRRTQKFGTFPGNYV 557
Cdd:cd12022     1 LYITIKAYTAVEEDELTLLEGEAIEVIHKLLDGWW--VVRKGEVTGYFPSMYL 51

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1) and PACSIN 2; PACSIN 1 or Syndapin I (Synaptic dynamin-associated protein I) is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. PACSIN 2 or Syndapin II is expressed ubiquitously and is involved in the regulation of tubulin polymerization. It associates with Golgi membranes and forms a complex with dynamin II which is crucial in promoting vesicle formation from the trans-Golgi network. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212931 [Multi-domain] Cd Length: 56 Bit Score: 41.47 E-value: 3.55e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDD-GWFVGVSRRTQkFGTFPGNYVAP 559
Cdd:cd11998     4 RALYDYDGQEQDELSFKAGDELTKLEDEDEqGWCKGRLDSGQ-VGLYPANYVEP 56

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 41.51 E-value: 3.71e-05

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                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEvDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11991     6 YTYESNEQGDLTFQQGDVILVTKK-DGDWWTGTVGDKTGVFPSNYV 50

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 41.21 E-value: 3.83e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11828     6 WDHVTMDPEELGFKAGDVIEVLDMSDKDWWWGSIRDEEGWFPASFVRL 53

Src homology 3 domain of Proline-Serine-Threonine Phosphatase-Interacting Protein 1; PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1), is mainly expressed in hematopoietic cells. It is a binding partner of the cell surface receptor CD2 and PTP-PEST, a tyrosine phosphatase which functions in cell motility and Rac1 regulation. It also plays a role in the activation of the Wiskott-Aldrich syndrome protein (WASP), which couples actin rearrangement and T cell activation. Mutations in the gene encoding PSTPIP1 cause the autoinflammatory disorder known as PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) syndrome. PSTPIP1 contains an N-terminal F-BAR domain, PEST motifs, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212758 [Multi-domain] Cd Length: 53 Bit Score: 41.20 E-value: 3.86e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11824     2 YSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTVERNGQKGLVPGTYLE 52

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212852 [Multi-domain] Cd Length: 55 Bit Score: 41.49 E-value: 4.01e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11919     2 PARAKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEG--EHHGRVGIFPRSYI 52

First Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212695 [Multi-domain] Cd Length: 57 Bit Score: 41.19 E-value: 4.20e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCD-DGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11761     6 VLYSYEAQRPDELTITEGEELEVIEDGDgDGWVKARNKSGEV-GYVPENYL 55

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 41.12 E-value: 4.52e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTqkfGTFPGNYVAP 559
Cdd:cd11991     2 YVAMYTYESNEQGDLTFQQGDVILVTKKDGDWWTGTVGDKT---GVFPSNYVRP 52

Third N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212730 Cd Length: 51 Bit Score: 41.19 E-value: 4.57e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSR-RTqkfGTFPGNYV 557
Cdd:cd11796     3 RVLQDLSAQLDEELDLREGDVVTITGILDKGWFRGELNgRR---GIFPEGFV 51

Src homology 3 domain of Srms Protein Tyrosine Kinase; Src-related kinase lacking C-terminal regulatory tyrosine and N-terminal myristoylation sites (Srms) is a cytoplasmic (or non-receptor) PTK with limited homology to Src kinases. Src kinases in general contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr; they are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Srms lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212780 Cd Length: 55 Bit Score: 41.30 E-value: 4.66e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11846     3 TALYDFTARSTHELSVEQGDKLCVIEEEGDYIFARKLTGNPESGLVPASYV 53

Src homology 3 domain of Hematopoietic lineage cell-specific protein 1; HS1, also called HCLS1 (hematopoietic cell-specific Lyn substrate 1), is a cortactin homolog expressed specifically in hematopoietic cells. It is an actin regulatory protein that binds the Arp2/3 complex and stabilizes branched actin filaments. It is required for cell spreading and signaling in lymphocytes. It regulates cytoskeletal remodeling that controls lymphocyte trafficking, and it also affects tissue invasion and infiltration of leukemic B cells. Like cortactin, HS1 contains an N-terminal acidic domain, several copies of a repeat domain found in cortactin and HS1, a proline-rich region, and a C-terminal SH3 domain. The N-terminal region binds the Arp2/3 complex and F-actin, while the C-terminal region acts as an adaptor or scaffold that can connect varied proteins that bind the SH3 domain within the actin network. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213006 [Multi-domain] Cd Length: 55 Bit Score: 41.36 E-value: 4.66e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd12073     5 ALYDYQGEGDDEISFDPQETITDIEMVDEGWWKGTCH--GHRGLFPANYV 52

Src homology 3 domain of an unknown subfamily of proteins with similarity to Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212932 [Multi-domain] Cd Length: 56 Bit Score: 41.08 E-value: 5.04e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDD-GWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11999     5 RAVYDYTGQEPDELSFKAGEELLKVEDEDEqGWCKGVTDGGAV-GLYPANYV 55

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 41.09 E-value: 5.14e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11995     5 GMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKG--ELNGQVGLFPSNYV 52

Fifth Src homology 3 domain (or SH3E) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN2 is expected to bind protein partners, similar to ITSN1 which has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212929 [Multi-domain] Cd Length: 54 Bit Score: 41.12 E-value: 5.19e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11996     5 AMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVT--GLFPSNYV 52

Third Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212858 Cd Length: 57 Bit Score: 41.14 E-value: 5.42e-05

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11925     4 LALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSLRTGVSGVFPGNYV 54

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 41.14 E-value: 5.59e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVsrRTQKFGTFPGNYV 557
Cdd:cd12060     5 KARFNFKQTNEDELSVCKGDIIYVTRVEEGGWWEGT--LNGKTGWFPSNYV 53

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212734 [Multi-domain] Cd Length: 57 Bit Score: 40.82 E-value: 5.66e-05

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCD-----DGWFvgVSRRTQKfGTFPGNYVAP 559
Cdd:cd11800     1 YYYALYTFEARSPGELSVTEGQVVTVLEKHDlkgnpEWWL--VEDRGKQ-GYVPSNYLAK 57

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 40.53 E-value: 6.82e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQI 402
Cdd:cd11820     5 ALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKG--SNHRGEGLFPANFVTA 54

Second Src Homology 3 domain of Nck adaptor proteins; Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212700 [Multi-domain] Cd Length: 53 Bit Score: 40.33 E-value: 7.49e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11766     2 AVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGEC--NGQVGWFPSNYVT 52

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase 3; GRAF3 is also called Rho GTPase activating protein 42 (ARHGAP42) or ARHGAP10-like. Though its function has not been characterized, it may be a GAP with activity towards RhoA and Cdc42, based on its similarity to GRAF and GRAF2. It contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212999 Cd Length: 55 Bit Score: 40.43 E-value: 7.68e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVY-IHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd12066     2 AKAMYSCKAEHSHELSFPQGAIFSnVYPSVEPGWLKATYEGKTGLVPENYVVFL 55

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 40.39 E-value: 7.78e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItGTGRQGIFPASYVQ 401
Cdd:cd11825     4 ALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDY-GGKKQKWFPANYVE 53

Second C-terminal Src homology 3 domain of Fungal Actin-binding protein 1; Abp1 is an adaptor protein that functions in receptor-mediated endocytosis and vesicle trafficking. It contains an N-terminal actin-binding module, the actin-depolymerizing factor (ADF) homology domain, a central proline-rich region, and a C-terminal SH3 domain (many yeast Abp1 proteins contain two C-terminal SH3 domains). Yeast Abp1 also contains two acidic domains that bind directly to the Arp2/3 complex, which is required to initiate actin polymerization. The SH3 domain of yeast Abp1 binds and localizes the kinases, Ark1p and Prk1p, which facilitate actin patch disassembly following vesicle internalization. It also mediates the localization to the actin patch of the synaptojanin-like protein, Sjl2p, which plays a key role in endocytosis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212894 [Multi-domain] Cd Length: 53 Bit Score: 40.59 E-value: 7.85e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11961     3 KALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGECH--GSRGLFPSNYV 51

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 40.38 E-value: 8.38e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 353 YTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITG-TGRQGIFPASYVQI 402
Cdd:cd11965     6 YDCQADNDDELTFVEGEVIIVTGEEDQEWWIGHIEGqPERKGVFPVSFVHI 56

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 40.46 E-value: 8.49e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRK----VNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11762     4 ALYDYEAQSDEELSFPEGAIIRILRKddngVDDGWWEGEF--NGRVGVFPSLVVEE 57

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1) and PACSIN 2; PACSIN 1 or Syndapin I (Synaptic dynamin-associated protein I) is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. PACSIN 2 or Syndapin II is expressed ubiquitously and is involved in the regulation of tubulin polymerization. It associates with Golgi membranes and forms a complex with dynamin II which is crucial in promoting vesicle formation from the trans-Golgi network. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212931 [Multi-domain] Cd Length: 56 Bit Score: 40.32 E-value: 8.51e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRITGtGRQGIFPASYVQ 401
Cdd:cd11998     5 ALYDYDGQEQDELSFKAGDELTKLEDEDEQgWCKGRLDS-GQVGLYPANYVE 55

Src homology 3 domain of Blk Protein Tyrosine Kinase; Blk is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. It is expressed specifically in B-cells and is involved in pre-BCR (B-cell receptor) signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212942 [Multi-domain] Cd Length: 54 Bit Score: 40.57 E-value: 8.55e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKvNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd12009     3 IAQYDFVPSNERDLQLKKGEKLQVLKS-DGEWWLAKSLTTGKEGYIPSNYV 52

First Src homology 3 domain of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212947 Cd Length: 62 Bit Score: 40.80 E-value: 8.56e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 275 ARLKFDFQAQSPK-----ELTLQKGDIVYIHKEVDKN-WLEGEH-HGRLGIFPANYVE 325
Cdd:cd12014     4 ARYSYNPLRDSPNenpeaELPLNAGDYVYVYGDMDEDgFYEGELlDGRRGLVPSNFVE 61

Second Src Homology 3 domain of Bud emergence protein 1 and similar domains; Members of this subfamily bear similarity to Saccharomyces cerevisiae Bem1p, containing two Src Homology 3 (SH3) domains at the N-terminus, a central PX domain, and a C-terminal PB1 domain. Bem1p is a scaffolding protein that is critical for proper Cdc42p activation during bud formation in yeast. During budding and mating, Bem1p migrates to the plasma membrane where it can serve as an adaptor for Cdc42p and some other proteins. Bem1p also functions as an effector of the G1 cyclin Cln3p and the cyclin-dependent kinase Cdc28p in promoting vacuolar fusion. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212812 [Multi-domain] Cd Length: 56 Bit Score: 40.39 E-value: 8.59e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITG-TGRQGIFPASYVQI 402
Cdd:cd11879     2 GIVLYDFKAERPDELDAKAGDAIIICAHSNYEWFVAKPIGrLGGPGLIPVSFVEI 56

Src homology 3 domain of Lyn Protein Tyrosine Kinase; Lyn is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lyn is expressed in B lymphocytes and myeloid cells. It exhibits both positive and negative regulatory roles in B cell receptor (BCR) signaling. Lyn, as well as Fyn and Blk, promotes B cell activation by phosphorylating ITAMs (immunoreceptor tyr activation motifs) in CD19 and in Ig components of BCR. It negatively regulates signaling by its unique ability to phosphorylate ITIMs (immunoreceptor tyr inhibition motifs) in cell surface receptors like CD22 and CD5. Lyn also plays an important role in G-CSF receptor signaling by phosphorylating a variety of adaptor molecules. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212937 [Multi-domain] Cd Length: 56 Bit Score: 40.36 E-value: 8.67e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEhWYEGRITGTGRQGIFPASYV 400
Cdd:cd12004     3 VALYPYDGIHEDDLSFKKGEKLKVIEEHGE-WWKARSLTTKKEGFIPSNYV 52

Src Homology 3 domain of Tec-like Protein Tyrosine Kinases; The Tec (Tyrosine kinase expressed in hepatocellular carcinoma) subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) tyr kinases containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Most Tec subfamily members (except Rlk) also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. The function of Tec kinases in lymphoid cells have been studied extensively. They play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212702 [Multi-domain] Cd Length: 54 Bit Score: 40.33 E-value: 9.12e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRiTGTGRQGIFPASYVQ 401
Cdd:cd11768     3 VALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRAR-DKNGNEGYIPSNYVT 53

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212718 Cd Length: 55 Bit Score: 40.15 E-value: 9.36e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11784     3 VALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLSLVTGRVGIFPSNYV 53

C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 2 (Stac2); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac2 contains a single SH3 domain at the C-terminus unlike Stac1 and Stac3, which contain two C-terminal SH3 domains. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212918 Cd Length: 53 Bit Score: 40.32 E-value: 9.64e-05

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11985     6 YKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGKSGDRVGFFPANFVQ 52

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 3 (Stac3); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212919 [Multi-domain] Cd Length: 53 Bit Score: 40.28 E-value: 9.80e-05

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11986     3 VALYRFKALEKDDLDFHPGERITVIDDSNEEWWRGKI--GEKTGYFPMNFI 51

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212704 [Multi-domain] Cd Length: 54 Bit Score: 39.99 E-value: 1.02e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH-HGRLGIFPANYVEV 326
Cdd:cd11770     7 DFQAEQEGDLSFKKGEVLRIISKRADGWWLAENsKGNRGLVPKTYLKV 54

Second Src Homology 3 domain of FCH and double SH3 domains protein 2; FCHSD2 has a domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. It has only been characterized in silico and its function is unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212827 Cd Length: 56 Bit Score: 40.31 E-value: 1.03e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYI---HKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11894     3 KALYDYEGQTDDELSFPEGAIIRIlnkENQDDDGFWEGEFNGRIGVFPSVLVE 55

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212714 [Multi-domain] Cd Length: 55 Bit Score: 39.98 E-value: 1.05e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11780     4 ALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSERTGLFGTFPGNYVA 54

Src Homology 3 domain of alpha-Pak Interactive eXchange factor; Alpha-PIX, also called Rho guanine nucleotide exchange factor 6 (ARHGEF6) or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac 1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. PIX proteins contain an N-terminal SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains, and a C-terminal leucine-zipper domain for dimerization. The SH3 domain of PIX binds to an atypical PxxxPR motif in p21-activated kinases (PAKs) with high affinity. The binding of PAKs to PIX facilitate the localization of PAKs to focal complexes and also localizes PAKs to PIX targets Cdc43 and Rac, leading to the activation of PAKs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212993 Cd Length: 58 Bit Score: 40.37 E-value: 1.10e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYVQ 401
Cdd:cd12060     6 ARFNFKQTNEDELSVCKGDIIYVTRVEEGGWWEG--TLNGKTGWFPSNYVR 54

Variant SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

Pssm-ID: 429575 [Multi-domain] Cd Length: 54 Bit Score: 39.89 E-value: 1.15e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYVAPV 560
Cdd:pfam07653   1 YGRVIFDYVGTDKNGLTLKKGDVVKVLGKDNDGWWEG--ETGGRVGLVPSTAVEEI 54

N-terminal Src homology 3 domain of Growth factor receptor-bound protein 2 (GRB2) and related proteins; This family includes the adaptor protein GRB2 and related proteins including Drosophila melanogaster Downstream of receptor kinase (DRK), Caenorhabditis elegans Sex muscle abnormal protein 5 (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and similar proteins. Family members contain an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. GRB2/Sem-5/DRK is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. GRAP2 plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. GRAP acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. The N-terminal SH3 domain of GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212738 [Multi-domain] Cd Length: 52 Bit Score: 40.03 E-value: 1.21e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGEriclIRKV-----NEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11804     1 EAVAKHDFKATAEDELSFKKGS----ILKVlnmedDPNWYKAEL--DGKEGLIPKNYI 52

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212777 [Multi-domain] Cd Length: 53 Bit Score: 39.71 E-value: 1.24e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRITGtgRQGIFPASYVQ 401
Cdd:cd11843     4 ALYDYEGQESDELSFKAGDILTKLEEEDEQgWCKGRLDG--RVGLYPANYVE 53

Src homology 3 domain of Phospholipase C (PLC) gamma 2; PLCgamma2 is primarily expressed in haematopoietic cells, specifically in B cells. It is activated by tyrosine phosphorylation by B cell receptor (BCR) kinases and is recruited to the plasma membrane where its substrate is located. It is required in pre-BCR signaling and in the maturation of B cells. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212902 Cd Length: 55 Bit Score: 39.82 E-value: 1.26e-04

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLG-IFPANYVE 325
Cdd:cd11969     6 YDYRAKRSDELSFCKGALIHNVSKETGGWWKGDYGGKVQhYFPSNYVE 53

C-terminal Src homology 3 domain of GRB2-related adaptor protein; GRAP is a GRB-2 like adaptor protein that is highly expressed in lymphoid tissues. It acts as a negative regulator of T cell receptor (TCR)-induced lymphocyte proliferation by downregulating the signaling to the Ras/ERK pathway. It has been identified as a regulator of TGFbeta signaling in diabetic kidney tubules and may have a role in the pathogenesis of the disease. GRAP contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domains (SH3c) of the related proteins, GRB2 and GRAP2, have been shown to bind to classical PxxP motif ligands, as well as to non-classical motifs. GRB2 SH3c binds Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, while the SH3c of GRAP2 binds to the phosphatase-like protein HD-PTP via a RxxxxK motif. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212884 Cd Length: 53 Bit Score: 39.78 E-value: 1.31e-04

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYVAP 559
Cdd:cd11951     3 QAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRG--RISGRVGFFPRNYVHP 53

Src Homology 3 domain of Mixed Lineage Kinases; MLKs are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212809 [Multi-domain] Cd Length: 58 Bit Score: 39.80 E-value: 1.34e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRK-----VNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11876     3 TALFDYDARGEDELTLRRGQPVEVLSKdaavsGDEGWWTGKI--GDKVGIFPSNYVA 57

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding proteins; CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes including migration, chemotaxis, apoptosis, differentiation, and progenitor cell function. They mediate the signaling of integrins at focal adhesions where they localize, and thus, regulate cell invasion and survival. Over-expression of these proteins is implicated in poor prognosis, increased metastasis, and resistance to chemotherapeutics in many cancers such as breast, lung, melanoma, and glioblastoma. CAS proteins have also been linked to the pathogenesis of inflammatory disorders, Alzheimer's, Parkinson's, and developmental defects. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. Vertebrates contain four CAS proteins: BCAR1 (or p130Cas), NEDD9 (or HEF1), EFS (or SIN), and CASS4 (or HEPL). The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212778 Cd Length: 56 Bit Score: 39.64 E-value: 1.43e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIhkeVDKN------WLEGEHHGRLGIFPANYVEV 326
Cdd:cd11844     2 ARALYDNVAESPDELAFRRGDILTV---LEQNtaglegWWLCSLRGRQGIAPGNRLKL 56

Src Homology 3 domain of Saccharomyces cerevisiae Nap1-binding protein 2 and similar fungal proteins; This subfamily includes Saccharomyces cerevisiae Nbp2 (Nucleosome assembly protein 1 (Nap1)-binding protein 2), Schizosaccharomyces pombe Skb5, and similar proteins. Nbp2 interacts with Nap1, which is essential for maintaining proper nucleosome structures in transcription and replication. It is also the binding partner of the yeast type II protein phosphatase Ptc1p and serves as a scaffolding protein that brings seven kinases in close contact to Ptc1p. Nbp2 plays a role many cell processes including organelle inheritance, mating hormone response, cell wall stress, mitotic cell growth at elevated temperatures, and high osmolarity. Skb5 interacts with the p21-activated kinase (PAK) homolog Shk1, which is critical for fission yeast cell viability. Skb5 activates Shk1 and plays a role in regulating cell morphology and growth under hypertonic conditions. Nbp2 and Skb5 contain an SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212799 Cd Length: 55 Bit Score: 39.81 E-value: 1.54e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQI 402
Cdd:cd11865     1 RAVALYDFEPEHDNELGFAEGQILFILYKHGQGWLIAEDESGGKTGLVPEEFVSY 55

Src homology 3 domain of Src Protein Tyrosine Kinase; Src (or c-Src) is a cytoplasmic (or non-receptor) PTK and is the vertebrate homolog of the oncogenic protein (v-Src) from Rous sarcoma virus. Together with other Src subfamily proteins, it is involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. Src also play a role in regulating cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Elevated levels of Src kinase activity have been reported in a variety of human cancers. Several inhibitors of Src have been developed as anti-cancer drugs. Src is also implicated in acute inflammatory responses and osteoclast function. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212941 [Multi-domain] Cd Length: 56 Bit Score: 39.71 E-value: 1.56e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd12008     3 VALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQTGYIPSNYV 53

Src homology 3 domain of Lyn Protein Tyrosine Kinase; Lyn is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lyn is expressed in B lymphocytes and myeloid cells. It exhibits both positive and negative regulatory roles in B cell receptor (BCR) signaling. Lyn, as well as Fyn and Blk, promotes B cell activation by phosphorylating ITAMs (immunoreceptor tyr activation motifs) in CD19 and in Ig components of BCR. It negatively regulates signaling by its unique ability to phosphorylate ITIMs (immunoreceptor tyr inhibition motifs) in cell surface receptors like CD22 and CD5. Lyn also plays an important role in G-CSF receptor signaling by phosphorylating a variety of adaptor molecules. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212937 [Multi-domain] Cd Length: 56 Bit Score: 39.59 E-value: 1.63e-04

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDgWFVGVSRRTQKFGTFPGNYVAPV 560
Cdd:cd12004     4 ALYPYDGIHEDDLSFKKGEKLKVIEEHGE-WWKARSLTTKKEGFIPSNYVAKV 55

Src homology 3 domain of Type I fungal Myosins; Type I myosins (myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Saccharomyces cerevisiae has two myosins-I, Myo3 and Myo5, which are involved in endocytosis and the polarization of the actin cytoskeleton. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212792 [Multi-domain] Cd Length: 55 Bit Score: 39.68 E-value: 1.65e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI-HKEVDKNWL------EGEhhgrlGIFPANYVE 325
Cdd:cd11858     2 YKALYDFAGSVANELSLKKDDIVYIvQKEDNGWWLakkldeSKE-----GWVPAAYLE 54

C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 2 (Stac2); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac2 contains a single SH3 domain at the C-terminus unlike Stac1 and Stac3, which contain two C-terminal SH3 domains. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212918 Cd Length: 53 Bit Score: 39.55 E-value: 1.66e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11985     3 VALYKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGKS--GDRVGFFPANFVQ 52

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 39.57 E-value: 1.66e-04

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGV---SRRTQKFGTFPGNY 556
Cdd:cd11883     3 VALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGViisSSGKVKRGWFPSNY 55

Src homology 3 domain of Phospholipase C (PLC) gamma 1; PLCgamma1 is widely expressed and is essential in growth and development. It is activated by the TrkA receptor tyrosine kinase and functions as a key regulator of cell differentiation. It is also the predominant PLCgamma in T cells and is required for T cell and NK cell function. PLCs catalyze the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212903 Cd Length: 60 Bit Score: 39.97 E-value: 1.67e-04

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gi 1958679458 274 AARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGI-FPANYVE 325
Cdd:cd11970     5 AVKALFDYKAQREDELTFTKNAIIQNVEKQEGGWWRGDYGGKKQLwFPSNYVE 57

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212706 [Multi-domain] Cd Length: 53 Bit Score: 39.59 E-value: 1.67e-04

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11772     4 ALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATC--GGKTGLIPSNYV 51

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212873 Cd Length: 55 Bit Score: 39.39 E-value: 1.70e-04

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 512 YRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11940     8 YKAQENDELTLEKADIIMVRQQSSDGWLEGVRLSDGERGWFPQSHVEE 55

First Src homology 3 domain of Tyrosine kinase substrate (Tks) proteins; Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Vertebrates contain two Tks proteins, Tks4 (Tyr kinase substrate with four SH3 domains) and Tks5 (Tyr kinase substrate with five SH3 domains), which display partially overlapping but non-redundant functions. Both associate with the ADAMs family of transmembrane metalloproteases, which function as sheddases and mediators of cell and matrix interactions. Tks5 interacts with N-WASP and Nck, while Tks4 is essential for the localization of MT1-MMP (membrane-type 1 matrix metalloproteinase) to invadopodia. Tks proteins contain an N-terminal Phox homology (PX) domain and four or five SH3 domains. This model characterizes the first SH3 domain of Tks proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212948 Cd Length: 53 Bit Score: 39.33 E-value: 1.75e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDG-WFVGVSrrtQKFGTFPGNYVAP 559
Cdd:cd12015     2 YVVVADYKKQQPNEISLRAGDVVDVIEKNENGwWFVSLE---DEQGWVPATYLEP 53

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212849 [Multi-domain] Cd Length: 59 Bit Score: 39.59 E-value: 1.81e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHH--GRLGIFPANYVEVL 327
Cdd:cd11916     8 YSYAPQNDDELELRDGDIVDVMEKCDDGWFVGTSRrtKQFGTFPGNYVKLL 58

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212754 [Multi-domain] Cd Length: 54 Bit Score: 39.37 E-value: 1.88e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11820     4 RALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGE--GLFPANFV 52

Src homology 3 domains of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212785 Cd Length: 62 Bit Score: 39.61 E-value: 1.95e-04

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                  ....*....|....*....|....*....|....*....|
gi 1958679458 288 ELTLQKGDIVYIHKEVDKN-WLEGEHHG-RLGIFPANYVE 325
Cdd:cd11851    22 ELSFHAGDVVRVYGPMDEDgFYYGELEGgRKGLVPSNFVQ 61

Src homology 3 domain of Type I fungal Myosins; Type I myosins (myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Saccharomyces cerevisiae has two myosins-I, Myo3 and Myo5, which are involved in endocytosis and the polarization of the actin cytoskeleton. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212792 [Multi-domain] Cd Length: 55 Bit Score: 39.29 E-value: 2.03e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVAP 559
Cdd:cd11858     2 YKALYDFAGSVANELSLKKDDIVYIVQKEDNGWWLAKKLDESKEGWVPAAYLEE 55

N-terminal (or first) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. The N-terminal SH3 domain increases the affinity of p67phox for the oxidase complex. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212804 Cd Length: 54 Bit Score: 39.50 E-value: 2.07e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11871     3 RVLYEFVPETKEELQVLPGNIVFVLKKGTDNWATVVFNGKKGLVPCNFLE 52

Third Src homology 3 domain (or SH3C) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212924 Cd Length: 52 Bit Score: 39.20 E-value: 2.10e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWyegriTGT--GRQGIFPASYVQ 401
Cdd:cd11991     3 VAMYTYESNEQGDLTFQQGDVILVTKKDGDWW-----TGTvgDKTGVFPSNYVR 51

Third Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212717 [Multi-domain] Cd Length: 55 Bit Score: 39.30 E-value: 2.12e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPANYVEV 326
Cdd:cd11783     5 LYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTSlrTGQSGVFPGNYVQP 55

First Src Homology 3 domain (SH3A) of CD2-associated protein and similar proteins; This subfamily is composed of the first SH3 domain (SH3A) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3A of both proteins bind to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic domain of the cell adhesion protein CD2. CIN85 SH3A binds to internal proline-rich motifs within the proline-rich region; this intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. CIN85 SH3A has also been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212806 [Multi-domain] Cd Length: 53 Bit Score: 39.17 E-value: 2.17e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 510 YQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11873     6 FDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTLN--GKRGMFPDNFV 51

Fifth Src homology 3 domain (or SH3E) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fifth SH3 domain (or SH3E) of ITSN1 has been shown to bind many protein partners including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212928 [Multi-domain] Cd Length: 54 Bit Score: 39.17 E-value: 2.18e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11995     4 IGMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGEL--NGQVGLFPSNYVKL 54

First Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the first SH3 domain, located at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212862 Cd Length: 54 Bit Score: 39.15 E-value: 2.18e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11929     4 KALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGEINGVS--GIFPASSV 52

Src Homology 3 domain of Tec (Tyrosine kinase expressed in hepatocellular carcinoma); Tec is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. It is more widely-expressed than other Tec subfamily kinases. Tec is found in endothelial cells, both B- and T-cells, and a variety of myeloid cells including mast cells, erythroid cells, platelets, macrophages and neutrophils. Tec is a key component of T-cell receptor (TCR) signaling, and is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212838 [Multi-domain] Cd Length: 56 Bit Score: 39.41 E-value: 2.20e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG-EHHGRLGIFPANYV 324
Cdd:cd11905     7 YDFQPTEPHDLRLETGEEYVILEKNDVHWWKArDKYGKEGYIPSNYV 53

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 39.18 E-value: 2.23e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 351 AQYTFKGDLD-VELSFRKGERICLIRKVNE-----HWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11771     4 ALYDFTPENPeMELSLKKGDIVAVLSKTDPlgrdsEWWKGR-TRDGRIGWFPSNYVEV 60

Src homology 3 domain of JNK-interacting proteins 1 and 2, and similar domains; JNK-interacting proteins (JIPs) function as scaffolding proteins for c-Jun N-terminal kinase (JNK) signaling pathways. They bind to components of Mitogen-activated protein kinase (MAPK) pathways such as JNK, MKK, and several MAP3Ks such as MLK and DLK. There are four JIPs (JIP1-4); all contain a JNK binding domain. JIP1 and JIP2 also contain SH3 and Phosphotyrosine-binding (PTB) domains. Both are highly expressed in the brain and pancreatic beta-cells. JIP1 functions as an adaptor linking motor to cargo during axonal transport and also is involved in regulating insulin secretion. JIP2 form complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. The SH3 domain of JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212735 Cd Length: 55 Bit Score: 39.22 E-value: 2.25e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPANYV 324
Cdd:cd11801     2 HRALHKFIPRHEDEIELDIGDPVYVEQEADDLWCEGTNlrTGQRGIFPAAYV 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 1; ASAP1 is also called DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6. However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212898 [Multi-domain] Cd Length: 57 Bit Score: 39.22 E-value: 2.31e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG---RLGIFPANYVEVL 327
Cdd:cd11965     6 YDCQADNDDELTFVEGEVIIVTGEEDQEWWIGHIEGqpeRKGVFPVSFVHIL 57

Third Src Homology 3 domain of SH3 domain containing ring finger 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212859 [Multi-domain] Cd Length: 55 Bit Score: 39.18 E-value: 2.37e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11926     3 VAIYPYTPRKEDELELRKGEMFLVFERCQDGWFKGTSMHTSKIGVFPGNYV 53

Src Homology 3 domain of Bruton's tyrosine kinase; BTK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain with proline-rich and zinc-binding regions. Btk is expressed in B-cells, and a variety of myeloid cells including mast cells, platelets, neutrophils, and dendrictic cells. It interacts with a variety of partners, from cytosolic proteins to nuclear transcription factors, suggesting a diversity of functions. Stimulation of a diverse array of cell surface receptors, including antigen engagement of the B-cell receptor (BCR), leads to PH-mediated membrane translocation of Btk and subsequent phosphorylation by Src kinase and activation. Btk plays an important role in the life cycle of B-cells including their development, differentiation, proliferation, survival, and apoptosis. Mutations in Btk cause the primary immunodeficiency disease, X-linked agammaglobulinaemia (XLA) in humans. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212839 [Multi-domain] Cd Length: 55 Bit Score: 39.04 E-value: 2.37e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKfGTFPGNYV 557
Cdd:cd11906     5 ALYDYTPMNAQDLQLRKGEEYVILEESNLPWWRARDKNGRE-GYIPSNYV 53

C-terminal (Fourth) Src Homology 3 domain of SH3 domain containing ring finger 1 (SH3RF1), SH3RF3, and similar domains; SH3RF1 (or POSH) and SH3RF3 (or POSH2) are scaffold proteins that function as E3 ubiquitin-protein ligases. They contain an N-terminal RING finger domain and four SH3 domains. This model represents the fourth SH3 domain, located at the C-terminus of SH3RF1 and SH3RF3, and similar domains. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212719 Cd Length: 55 Bit Score: 38.99 E-value: 2.48e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1958679458 360 DVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11785    13 EAELELKEGDIVFVHKKREDGWFKGTLQRTGKTGLFPGSFVE 54

First Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212720 [Multi-domain] Cd Length: 53 Bit Score: 38.88 E-value: 2.62e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11786     3 KALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNGKQ--GFFPASYV 51

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213017 [Multi-domain] Cd Length: 57 Bit Score: 39.02 E-value: 2.68e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVD----KNWLEGEHHGRLGIFPANYV 324
Cdd:cd12141     6 YTFKARSPNELSVSANQRVRILEFSDltgnKEWWLAEANGQKGYVPSNYI 55

Second Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212696 [Multi-domain] Cd Length: 57 Bit Score: 38.92 E-value: 2.68e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVM----QQCDDGWFVGvsRRTQKFGTFPG 554
Cdd:cd11762     3 RALYDYEAQSDEELSFPEGAIIRILrkddNGVDDGWWEG--EFNGRVGVFPS 52

Second Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212834 [Multi-domain] Cd Length: 55 Bit Score: 38.86 E-value: 2.78e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYV 400
Cdd:cd11901     4 AYVKFNYTAEREDELSLVKGTKVIVMEKCSDGWWRG--SYNGQVGWFPSNYV 53

Second Src Homology 3 domain of SH3 domain containing ring finger proteins; This model represents the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or POSHER), SH3RF3 (POSH2), and similar domains. Members of this family are scaffold proteins that function as E3 ubiquitin-protein ligases. They all contain an N-terminal RING finger domain and multiple SH3 domains; SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has three. SH3RF1 plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF3 interacts with p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It may play a role in regulating JNK mediated apoptosis in certain conditions. SH3RF2 acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212721 [Multi-domain] Cd Length: 53 Bit Score: 38.85 E-value: 2.86e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDE---LELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNY 556
Cdd:cd11787     3 KALYDFEMKDEDEkdcLTFKKGDVITVIRRVDENWAEG--RLGDKIGIFPISF 53

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212830 [Multi-domain] Cd Length: 55 Bit Score: 38.82 E-value: 2.87e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVN-EHWYEGrITGTGRQGIFPASYVQI 402
Cdd:cd11897     2 ARALYDFRSENPGEISLREHEVLSLCSEQDiEGWLEG-VNSRGDRGLFPASYVEV 55

Src Homology 3 domain of Class A Dedicator of Cytokinesis proteins 1 and 5; Dock1, also called Dock180, and Dock5 are class A DOCKs and are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. Dock1 interacts with the scaffold protein Elmo and the resulting complex functions upstream of Rac in many biological events including phagocytosis of apoptotic cells, cell migration and invasion. Dock5 functions upstream of Rac1 to regulate osteoclast function. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock1 binds to DHR-2 in an autoinhibitory manner; binding of Elmo to the SH3 domain of Dock1 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212984 [Multi-domain] Cd Length: 56 Bit Score: 39.03 E-value: 2.89e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCdDGWFVGVS-RRTQKFGTFPGNYV 557
Cdd:cd12051     4 AIYNYDARGPDELSLQIGDTVHILETY-EGWYRGYTlRKKSKKGIFPASYI 53

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 39.04 E-value: 2.98e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQ--CDDGWFVGvsRRTQKFGTFPGNYVA 558
Cdd:cd12056     5 KALFHYEGTNEDELDFKEGEIILIISKdtGEPGWWKG--ELNGKEGVFPDNFVS 56

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 38.53 E-value: 3.28e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYV 400
Cdd:cd11806     3 VAIADFVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGC--CGYIPASHL 51

Src Homology 3 domain of fungal BOI-like proteins; This subfamily includes the Saccharomyces cerevisiae proteins BOI1 and BOI2, and similar proteins. They contain an N-terminal SH3 domain, a Sterile alpha motif (SAM), and a Pleckstrin homology (PH) domain at the C-terminus. BOI1 and BOI2 interact with the SH3 domain of Bem1p, a protein involved in bud formation. They promote polarized cell growth and participates in the NoCut signaling pathway, which is involved in the control of cytokinesis. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212819 Cd Length: 55 Bit Score: 38.85 E-value: 3.29e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1958679458 362 ELSFRKGERICLI---RKVNEHWYEGRITGTGRQGIFPASY 399
Cdd:cd11886    15 ELTLKPGDKIELIeddEEFGDGWYLGRNLRTGETGLFPVVF 55

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase 2; GRAF2, also called Rho GTPase activating protein 10 (ARHGAP10) or PS-GAP, is a GAP with activity towards Cdc42 and RhoA. It regulates caspase-activated p21-activated protein kinase-2 (PAK-2p34). GRAF2 interacts with PAK-2p34, leading to its stabilization and decrease of cell death. It is highly expressed in skeletal muscle, and is involved in alpha-catenin recruitment at cell-cell junctions. GRAF2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212998 [Multi-domain] Cd Length: 54 Bit Score: 38.81 E-value: 3.29e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVY-IHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd12065     2 AKAVYPCEAEHSSELSFEVGAIFEdVTLSREPGWLEGTLNGKRGLIPENYVEI 54

Src homology 3 domain of Apoptosis Stimulating of p53 proteins (ASPP); The ASPP family of proteins bind to important regulators of apoptosis (p53, Bcl-2, and RelA) and cell growth (APCL, PP1). They share similarity at their C-termini, where they harbor a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain. Vertebrates contain three members of the family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2 activate the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73), while iASPP is an oncoprotein that specifically inhibits p53-induced apoptosis. The expression of ASPP proteins is altered in tumors; ASPP1 and ASPP2 are downregulated whereas iASPP is upregulated is some cancer types. ASPP proteins also bind and regulate protein phosphatase 1 (PP1), and this binding is competitive with p53 binding. The SH3 domain and the ANK repeats of ASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212741 [Multi-domain] Cd Length: 57 Bit Score: 38.90 E-value: 3.41e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDG----WFvgvSRRTQKFGTFPGNYVA 558
Cdd:cd11807     5 ALFDYEAENGDELSFREGDELTVLRKGDDDetewWW---ARLNDKEGYVPRNLLG 56

Src homology 3 domain of yeast cell fusion protein Fus1p; Fus1p is required at the cell surface for cell fusion during the mating response in yeast. It requires Bch1p and Bud7p, which are Chs5p-Arf1p binding proteins, for localization to the plasma membrane. It acts as a scaffold protein to assemble a cell surface complex which is involved in septum degradation and inhibition of the NOG pathway to promote cell fusion. The SH3 domain of Fus1p interacts with Bin1p, a formin that controls the assembly of actin cables in response to Cdc42 signaling. It has been shown to bind the motif, R(S/T)(S/T)SL, instead of PxxP motifs. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212788 [Multi-domain] Cd Length: 56 Bit Score: 38.84 E-value: 3.53e-04

                          10        20        30
                  ....*....|....*....|....*....|...
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGW 538
Cdd:cd11854     2 MTVISTFEPSLDDELLIKVGETVRVLAEYDDGW 34

Src Homology 3 domain of Bridging integrator 1 (Bin1), also called Amphiphysin-2; Bin1 isoforms are localized in many different tissues and may function in intracellular vesicle trafficking. It plays a role in the organization and maintenance of the T-tubule network in skeletal muscle. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Bin1 contains an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR) and a C-terminal SH3 domain. The SH3 domain of Bin1 forms transient complexes with actin, myosin filaments, and CDK5, to facilitate sarcomere organization and myofiber maturation. It also binds dynamin and prevents its self-assembly. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213015 Cd Length: 72 Bit Score: 39.13 E-value: 3.57e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQ-----QCDDGWFVGVSR----RTQKF----GTFPGNY 556
Cdd:cd12139     6 QAQHDYTATDTDELQLKAGDVVLVIPfqnpeEQDEGWLMGVKEsdwnQHKKLekcrGVFPENF 68

Src Homology 3 domain of Cytokinesis protein 3 and similar proteins; Cytokinesis protein 3 (Cyk3 or Cyk3p) is a component of the actomyosin ring independent cytokinesis pathway in yeast. It interacts with Inn1 and facilitates its recruitment to the bud neck, thereby promoting cytokinesis. Cyk3p contains an N-terminal SH3 domain and a C-terminal transglutaminase-like domain. The Cyk3p SH3 domain binds to the C-terminal proline-rich region of Inn1. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212822 Cd Length: 53 Bit Score: 38.63 E-value: 3.64e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11889     4 AVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLRRNGAEGIFPSNFV 53

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Neural precursor cell Expressed, Developmentally Down-regulated 9; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212935 Cd Length: 57 Bit Score: 38.81 E-value: 3.80e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIhKEVDKNWLEG----EHHGRLGIFPANYVEVL 327
Cdd:cd12002     2 ARALYDNVPECAEELAFRKGDILTV-IEQNTGGLEGwwlcSLHGRQGIAPGNRLKLL 57

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212734 [Multi-domain] Cd Length: 57 Bit Score: 38.51 E-value: 4.21e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKN-----WLEgEHHGRLGIFPANY 323
Cdd:cd11800     6 YTFEARSPGELSVTEGQVVTVLEKHDLKgnpewWLV-EDRGKQGYVPSNY 54

Src homology 3 domain of the Rho guanine nucleotide exchange factor, ephexin-1 (also called NGEF or ARHGEF27); Ephexin-1, also called NGEF (neuronal GEF) or ARHGEF27, activates RhoA, Tac1, and Cdc42 by exchanging bound GDP for free GTP. It is expressed mainly in the brain in a region associated with movement control. It regulates the stability of postsynaptic acetylcholine receptor (AChR) clusters and thus, plays a critical role in the maturation and neurotransmission of neuromuscular junctions. Ephexin-1 directly interacts with the ephrin receptor EphA4 and their coexpression enhances the ability of ephexin-1 to activate RhoA. It is required for normal axon growth and EphA-induced growth cone collapse. Ephexin-1 contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212872 [Multi-domain] Cd Length: 55 Bit Score: 38.39 E-value: 4.23e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 281 FQAQSPKELTLQKGDIVYIHKEVDKNWLEGE--HHGRLGIFPANYVE 325
Cdd:cd11939     8 YVSQEPDELSLELADVLNILDKTDDGWIFGErlHDQERGWFPSSVVE 54

Src homology 3 domain of the CAS (Crk-Associated Substrate) scaffolding protein family member, Breast Cancer Anti-estrogen Resistance 1; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212934 Cd Length: 68 Bit Score: 38.87 E-value: 4.26e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIhKEVDKNWLEG----EHHGRLGIFPANYVEVLPADEIPKP 335
Cdd:cd12001     5 AKALYDNVAESPDELSFRKGDIMTV-LERDTQGLDGwwlcSLHGRQGIVPGNRLKILVGMYDKKQ 68

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 38.27 E-value: 4.55e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYI-HKEV-DKNWLEGEHHGRLGIFPANYV 324
Cdd:cd12056     5 KALFHYEGTNEDELDFKEGEIILIiSKDTgEPGWWKGELNGKEGVFPDNFV 55

Fourth Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212751 [Multi-domain] Cd Length: 50 Bit Score: 38.23 E-value: 4.61e-04

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNY 556
Cdd:cd11817     4 ALYDFTGETEEDLSFQRGDRILVTEHLDAEWSRG--RLNGREGIFPRAF 50

Src homology 3 domain of an unknown subfamily of proteins with similarity to Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; PACSINs, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212932 [Multi-domain] Cd Length: 56 Bit Score: 38.38 E-value: 4.70e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGrITGTGRQGIFPASYVQ 401
Cdd:cd11999     6 AVYDYTGQEPDELSFKAGEELLKVEDEDEQgWCKG-VTDGGAVGLYPANYVE 56

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1 and similar proteins; This subfamily is composed of SKAP1, SKAP2, and similar proteins. SKAP1 and SKAP2 are immune cell-specific adaptor proteins that play roles in T- and B-cell adhesion, respectively, and are thus important in the migration of T- and B-cells to sites of inflammation and for movement during T-cell conjugation with antigen-presenting cells. Both SKAP1 and SKAP2 bind to ADAP (adhesion and degranulation-promoting adaptor protein), among many other binding partners. They contain a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212800 Cd Length: 53 Bit Score: 38.18 E-value: 4.73e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVDK-NWLEGEHHGRLGIFPANYV 324
Cdd:cd11866     6 WDCSGNEPDELSFKRGDLIYIiSKEYDSfGWWVGELNGKVGLVPKDYL 53

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212807 [Multi-domain] Cd Length: 53 Bit Score: 38.08 E-value: 5.01e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11874     4 VLFSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKL--NGKVGVFPSNFVKE 53

C-terminal (or second) Src homology 3 domain of VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and scaffold proteins and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212764 [Multi-domain] Cd Length: 54 Bit Score: 38.38 E-value: 5.15e-04

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11830     2 AKARYDFCARDMRELSLKEGDVVKIYNKKGQQgWWRGEI--NGRIGWFPSTYVE 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 2; ASAP2 is also called DDEF2 (Development and Differentiation Enhancing Factor 2), AMAP2, centaurin beta-3, or PAG3. It mediates the functions of Arf GTPases vial dual mechanisms: it exhibits GTPase activating protein (GAP) activity towards class I (Arf1) and II (Arf5) Arfs; and it binds class III Arfs (GTP-Arf6) stably without GAP activity. It binds paxillin and is implicated in Fcgamma receptor-mediated phagocytosis in macrophages and in cell migration. ASAP2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212899 Cd Length: 56 Bit Score: 38.40 E-value: 5.18e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 283 AQSPKELTLQKGDIVYIHKEVDKNWLEGEHHG---RLGIFPANYV 324
Cdd:cd11966    10 ADNPDELTFSEGEIIIVDGEEDKEWWIGHIDGeptRRGAFPVSFV 54

C-terminal Src Homology 3 domain of NADPH oxidase activator 1; Noxa1 is a homolog of p67phox and is a cytosolic subunit of the nonphagocytic NADPH oxidase complex Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Noxa1 is co-expressed with Nox1 in colon, stomach, uterus, prostate, and vascular smooth muscle cells, consistent with its regulatory role. It does not interact with p40phox, unlike p67phox, making Nox1 activity independent of p40phox, unlike Nox2. Noxa1 contains TPR, PB1, and C-terminal SH3 domains, but lacks the central SH3 domain that is present in p67phox. The TPR domain binds activated GTP-bound Rac. The C-terminal SH3 domain binds the polyproline motif found at the C-terminus of Noxo1, a homolog of p47phox. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212980 Cd Length: 53 Bit Score: 38.26 E-value: 5.24e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRtqKFGTFPGNYVAP 559
Cdd:cd12047     3 VAQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEGHCDG--RIGIFPKCFAVR 53

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 2; SKAP2, also called SKAP55-Related (SKAP55R) or SKAP55 homolog (SKAP-HOM or SKAP55-HOM), is an immune cell-specific adaptor protein that plays an important role in adhesion and migration of B-cells and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), YopH, SHPS1, and HPK1. SKAP2 has also been identified as a substrate for lymphoid-specific tyrosine phosphatase (Lyp), which has been implicated in a wide variety of autoimmune diseases. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. Like SKAP1, SKAP2 is expected to bind primarily to a proline-rich region of ADAP through its SH3 domain; its degradation may be regulated by ADAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212978 Cd Length: 53 Bit Score: 37.96 E-value: 5.52e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVDK-NWLEGEHHGRLGIFPANYV 324
Cdd:cd12045     6 WDCTGDQPDELSFKRGDTIYIlSKEYNRfGWWVGEMKGTIGLVPKAYI 53

Src Homology 3 domain of Apoptosis Stimulating of p53 protein 1; ASPP1, like ASPP2, activates the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73). In addition, it functions in the cytoplasm to regulate the nuclear localization of the transcriptional cofactors YAP and TAZ by inihibiting their phosphorylation; YAP and TAZ are important regulators of cell expansion, differentiation, migration, and invasion. ASPP1 is downregulated in breast tumors expressing wild-type p53. It contains a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain at its C-terminal half. The SH3 domain and the ANK repeats of ASPP1 contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212887 [Multi-domain] Cd Length: 57 Bit Score: 38.08 E-value: 5.66e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDG----WFvgvSRRTQKFGTFPGN 555
Cdd:cd11954     5 ALWDYEAQNADELSFQEGDAITILRRKDDSetewWW---ARLNDKEGYVPKN 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing proteins; ASAPs are Arf GTPase activating proteins (GAPs) and they function in regulating cell growth, migration, and invasion. They contain an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. Vertebrates contain at least three members, ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2 show GTPase activating protein (GAP) activity towards Arf1 and Arf5. They do not show GAP activity towards Arf6, but are able to mediate Arf6 signaling by binding stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212755 [Multi-domain] Cd Length: 53 Bit Score: 38.06 E-value: 5.72e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVG-VSRRTQKFGTFPGNY 556
Cdd:cd11821     3 RALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGhIEGDPSRRGVFPVSF 53

First Src Homology 3 domain (SH3A) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CIN85; SH3A binds to internal proline-rich motifs within the proline-rich region. This intramolecular interaction serves as a regulatory mechanism to keep CIN85 in a closed conformation, preventing the recruitment of other proteins. SH3A has also been shown to bind ubiquitin and to an atypical PXXXPR motif at the C-terminus of Cbl and the cytoplasmic end of the cell adhesion protein CD2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212985 [Multi-domain] Cd Length: 53 Bit Score: 37.95 E-value: 5.82e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 510 YQYRPQNEDELELREGDRVDVMQQCDDGWFVGV--SRRtqkfGTFPGNYV 557
Cdd:cd12052     6 FDYKAQHEDELTITVGDIITKIKKDDGGWWEGEikGRR----GLFPDNFV 51

Src Homology 3 domain of Class A Dedicator of Cytokinesis proteins 1 and 5; Dock1, also called Dock180, and Dock5 are class A DOCKs and are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. Dock1 interacts with the scaffold protein Elmo and the resulting complex functions upstream of Rac in many biological events including phagocytosis of apoptotic cells, cell migration and invasion. Dock5 functions upstream of Rac1 to regulate osteoclast function. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock1 binds to DHR-2 in an autoinhibitory manner; binding of Elmo to the SH3 domain of Dock1 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212984 [Multi-domain] Cd Length: 56 Bit Score: 37.88 E-value: 6.10e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1958679458 346 YGDAVAQYTFKGDldVELSFRKGERIcLIRKVNEHWYEG-RITGTGRQGIFPASYVQI 402
Cdd:cd12051     1 YGVAIYNYDARGP--DELSLQIGDTV-HILETYEGWYRGyTLRKKSKKGIFPASYIHL 55

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 37.93 E-value: 6.15e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 504 TPYRAMYQYRPQNEDELELREGD--RVDVMQQCDDGWFVGVSRrtQKFGTFPGNYV 557
Cdd:cd11988     2 VNYRALYPFEARNHDEMSFNAGDiiQVDEKTVGEPGWLYGSFQ--GNFGWFPCNYV 55

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212907 Cd Length: 54 Bit Score: 38.12 E-value: 6.21e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1958679458 360 DVELSFRKGERICLIRKVNEHWYEGRitGTGRQGIFPASYVQI 402
Cdd:cd11974    14 DQELAFKAGDVIRVLEASNKDWWWGR--NEDREAWFPASFVRL 54

Third (or C-terminal) Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212851 [Multi-domain] Cd Length: 58 Bit Score: 38.01 E-value: 6.24e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG--EHHGRLGIFPANYV 324
Cdd:cd11918     8 YQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 55

Src Homology 3 domain of Amphiphysin and related domains; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), are localized in many different tissues and may function in intracellular vesicle trafficking. In skeletal muscle, Bin1 plays a role in the organization and maintenance of the T-tubule network. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212724 [Multi-domain] Cd Length: 64 Bit Score: 38.08 E-value: 6.29e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVN-----EHWYEGRITGTGRQGIFPASY 399
Cdd:cd11790     7 ATHDYTAEDTDELTFEKGDVILVIPFDDpeeqdEGWLMGVKESTGCRGVFPENF 60

Third Src homology 3 domain (or SH3C) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (SH3C) of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212925 Cd Length: 52 Bit Score: 37.68 E-value: 6.77e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTqkfGTFPGNYVAP 559
Cdd:cd11992     2 YIALYPYSSSEPGDLTFNEGEEILVTQKDGEWWTGSIEDRT---GIFPSNYVRP 52

Second Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212863 Cd Length: 55 Bit Score: 38.05 E-value: 6.82e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKE----LTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11930     6 YDFEVKDKEAdkdcLPFAKDDILTVIRRVDENWAEGMLGDKIGIFPISYV 55

Src homology 3 domain of Protein arginine N-methyltransferase 2; PRMT2, also called HRMT1L1, belongs to the arginine methyltransferase protein family. It functions as a coactivator to both estrogen receptor alpha (ER-alpha) and androgen receptor (AR), presumably through arginine methylation. The ER-alpha transcription factor is involved in cell proliferation, differentiation, morphogenesis, and apoptosis, and is also implicated in the development and progression of breast cancer. PRMT2 and its variants are upregulated in breast cancer cells and may be involved in modulating the ER-alpha signaling pathway during formation of breast cancer. PRMT2 also plays a role in regulating the function of E2F transcription factors, which are critical cell cycle regulators, by binding to the retinoblastoma gene product (RB). It contains an N-terminal SH3 domain and an AdoMet binding domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212740 [Multi-domain] Cd Length: 53 Bit Score: 37.76 E-value: 6.87e-04

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11806     7 DFVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGCCGYIPASHL 51

Src homology 3 domain of Protein kinase C and Casein kinase Substrate in Neurons 3 (PACSIN3); PACSIN 3 or Syndapin III (Synaptic dynamin-associated protein III) is expressed ubiquitously and regulates glucose uptake in adipocytes through its role in GLUT1 trafficking. It also modulates the subcellular localization and stimulus-specific function of the cation channel TRPV4. PACSINs act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212930 [Multi-domain] Cd Length: 56 Bit Score: 38.02 E-value: 7.08e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDD-GWFVGvSRRTQKFGTFPGNYV 557
Cdd:cd11997     5 RALYDYTGQEADELSFKAGEELLKIGEEDEqGWCKG-RLLSGRIGLYPANYV 55

Src Homology 3 domain of Small G protein Signaling Modulator 3; SGSM3 is also called Merlin-associated protein (MAP), RUN and SH3 domain-containing protein (RUSC3), RUN and TBC1 domain-containing protein 3 (RUTBC3), Rab GTPase-activating protein 5 (RabGAP5), or Rab GAP-like protein (RabGAPLP). It is expressed ubiquitously and functions as a regulator of small G protein RAP- and RAB-mediated neuronal signaling. It is involved in modulating NGF-mediated neurite outgrowth and differentiation. It also interacts with the tumor suppressor merlin and may play a role in the merlin-associated suppression of cell growth. SGSM3 contains TBC, SH3, and RUN domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212747 Cd Length: 53 Bit Score: 37.86 E-value: 7.39e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd11813     2 AKALLDFERHDDDELGFRKNDIITIISQKDEHCWVGELNGLRGWFPAKFVEL 53

Src homology 3 domain of Signal Transducing Adaptor Molecule 2; STAM2, also called EAST (Epidermal growth factor receptor-associated protein with SH3 and TAM domain) or Hbp (Hrs binding protein), is part of the endosomal sorting complex required for transport (ESCRT-0). It plays a role in sorting mono-ubiquinated endosomal cargo for trafficking to the lysosome for degradation. It is also involved in the regulation of exocytosis. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212896 [Multi-domain] Cd Length: 57 Bit Score: 37.69 E-value: 7.76e-04

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRtqKFGTFPGNYVA 558
Cdd:cd11963     5 RALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHR--GVGLFPSNFVT 54

Third Src homology 3 domain of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212946 Cd Length: 61 Bit Score: 37.74 E-value: 7.80e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 272 RKAARLKFDFQAQSPK-----ELTLQKGDIVYIHKEVDKN-WLEGEHHGRLGIFPANYVE 325
Cdd:cd12013     1 RMVALFDYDPRESSPNvdaevELSFRAGDIITVFGEMDEDgFYYGELNGQRGLVPSNFLE 60

Second Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212855 [Multi-domain] Cd Length: 58 Bit Score: 37.66 E-value: 7.80e-04

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11922     5 AKFNFNGDTQVEMSFRKGERITLLRQVDENWYEGRIPGTSRQGIFPITYV 54

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212897 [Multi-domain] Cd Length: 55 Bit Score: 37.62 E-value: 7.83e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSrrTQKFGTFPGNYV 557
Cdd:cd11964     4 RAIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGET--PQGTGLFPSNFV 52

Second Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2, which show partly overlapping functions but also bind distinct targets. The second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212835 [Multi-domain] Cd Length: 55 Bit Score: 37.68 E-value: 7.84e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGriTGTGRQGIFPASYV 400
Cdd:cd11902     3 AFVKFAYVAEREDELSLVKGSRVTVMEKCSDGWWRG--SYNGQIGWFPSNYV 52

First Src homology 3 domain (or SH3A) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN2 is expected to bind many protein partners, similar to ITSN1 which has been shown to bind Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212921 [Multi-domain] Cd Length: 57 Bit Score: 37.93 E-value: 7.86e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVyihkEVDKN------WLEGEHHGRLGIFPANYVE 325
Cdd:cd11988     5 RALYPFEARNHDEMSFNAGDII----QVDEKtvgepgWLYGSFQGNFGWFPCNYVE 56

Src homology 3 domain of ephexin-1-like SH3 domain containing Rho guanine nucleotide exchange factors; Members of this family contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and C-terminal SH3 domains. They include the Rho guanine nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19, ARHGEF26, ARHGEF27 (also called ephexin-1), and similar proteins, and are also called ephexins because they interact directly with ephrin A receptors. GEFs interact with Rho GTPases via their DH domains to catalyze nucleotide exchange by stabilizing the nucleotide-free GTPase intermediate. They play important roles in neuronal development. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212727 [Multi-domain] Cd Length: 55 Bit Score: 37.70 E-value: 8.27e-04

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                  ....*....|....*....|....*....|....*....|
gi 1958679458 362 ELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd11793    15 ELTLEEGDVVNVLRKMPDGWYEGERLRDGERGWFPSSYTE 54

Second Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212865 Cd Length: 57 Bit Score: 37.51 E-value: 8.36e-04

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                  ....*....|....*....|....*....|....*...
gi 1958679458 363 LSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11932    22 LKFQKDDIITVISRVDENWAEGKL--GDQVGIFPILFV 57

C-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also has roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRAP2 binds to different motifs found in substrate peptides including the typical PxxP motif in hematopoietic progenitor kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and the RxxxxK motif in phosphatase-like protein HD-PTP. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212883 [Multi-domain] Cd Length: 53 Bit Score: 37.50 E-value: 8.53e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11950     2 VRALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRL--HGKLGLFPANYV 51

Src Homology 3 domain of Small G protein Signaling Modulator 3; SGSM3 is also called Merlin-associated protein (MAP), RUN and SH3 domain-containing protein (RUSC3), RUN and TBC1 domain-containing protein 3 (RUTBC3), Rab GTPase-activating protein 5 (RabGAP5), or Rab GAP-like protein (RabGAPLP). It is expressed ubiquitously and functions as a regulator of small G protein RAP- and RAB-mediated neuronal signaling. It is involved in modulating NGF-mediated neurite outgrowth and differentiation. It also interacts with the tumor suppressor merlin and may play a role in the merlin-associated suppression of cell growth. SGSM3 contains TBC, SH3, and RUN domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212747 Cd Length: 53 Bit Score: 37.48 E-value: 8.82e-04

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11813     2 AKALLDFERHDDDELGFRKNDIITIISQKDEHCWVGELNGL--RGWFPAKFVEL 53

Src homology 3 domain of Ysc84p and similar fungal proteins; This family is composed of the Saccharomyces cerevisiae proteins, Ysc84p (also called LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar fungal proteins. They contain an N-terminal SYLF domain (also called DUF500) and a C-terminal SH3 domain. Ysc84p localizes to actin patches and plays an important in actin polymerization during endocytosis. The N-terminal domain of both Ysc84p and Lsb3p can bind and bundle actin filaments. A study of the yeast SH3 domain interactome predicts that the SH3 domains of Lsb3p and Lsb4p may function as molecular hubs for the assembly of endocytic complexes. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212776 [Multi-domain] Cd Length: 55 Bit Score: 37.40 E-value: 8.84e-04

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCD--DGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11842     3 VALYDFAGEQPGDLAFQKGDIITILKKSDsqNDWWTG--RIGGREGIFPANYV 53

Src Homology 3 domain of Sorting Nexin 33; SNX33 interacts with Wiskott-Aldrich syndrome protein (WASP) and plays a role in the maintenance of cell shape and cell cycle progression. It modulates the shedding and endocytosis of cellular prion protein (PrP(c)) and amyloid precursor protein (APP). SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX33 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212829 [Multi-domain] Cd Length: 55 Bit Score: 37.63 E-value: 9.18e-04

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVN-EHWYEGRiTGTGRQGIFPASYVQI 402
Cdd:cd11896     2 ARALYSFQSENKEEINIQENEELVIFSENSlDGWLQGQ-NSRGETGLFPASYVEI 55

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212779 [Multi-domain] Cd Length: 52 Bit Score: 37.18 E-value: 9.33e-04

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPANY 323
Cdd:cd11845     6 YDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHlsTGKEGYIPSNY 52

Src homology 3 domain of Lck Protein Tyrosine Kinase; Lck is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Lck is expressed in T-cells and natural killer cells. It plays a critical role in T-cell maturation, activation, and T-cell receptor (TCR) signaling. Lck phosphorylates ITAM (immunoreceptor tyr activation motif) sequences on several subunits of TCRs, leading to the activation of different second messenger cascades. Phosphorylated ITAMs serve as binding sites for other signaling factor such as Syk and ZAP-70, leading to their activation and propagation of downstream events. In addition, Lck regulates drug-induced apoptosis by interfering with the mitochondrial death pathway. The apototic role of Lck is independent of its primary function in T-cell signaling. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212938 [Multi-domain] Cd Length: 54 Bit Score: 37.50 E-value: 9.38e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMqQCDDGWFVGVSRRTQKFGTFPGNYVA 558
Cdd:cd12005     4 ALYSYEPSHDGDLGFEKGEKLRIL-EQSGEWWKAQSLTTGQEGFIPFNFVA 53

First C-terminal Src homology 3 domain of SH3 and cysteine-rich domain-containing protein 3 (Stac3); Stac proteins are putative adaptor proteins that contain a cysteine-rich C1 domain and one or two SH3 domains at the C-terminus. There are three mammalian members (Stac1, Stac2, and Stac3) of this family. Stac1 and Stac3 contain two SH3 domains while Stac2 contains a single SH3 domain at the C-terminus. Stac1 and Stac2 have been found to be expressed differently in mature dorsal root ganglia (DRG) neurons. Stac1 is mainly expressed in peptidergic neurons while Stac2 is found in a subset of nonpeptidergic and all trkB+ neurons. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212919 [Multi-domain] Cd Length: 53 Bit Score: 37.58 E-value: 9.52e-04

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11986     2 FVALYRFKALEKDDLDFHPGERITVIDDSNEEWWRG--KIGEKTGYFPMNFI 51

C-terminal Src homology 3 domain of Growth factor receptor-bound protein 2; GRB2 is a critical signaling molecule that regulates the Ras pathway by linking tyrosine kinases to the Ras guanine nucleotide releasing protein Sos (son of sevenless), which converts Ras to the active GTP-bound state. It is ubiquitously expressed in all tissues throughout development and is important in cell cycle progression, motility, morphogenesis, and angiogenesis. In lymphocytes, GRB2 is associated with antigen receptor signaling components. GRB2 contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The C-terminal SH3 domain of GRB2 binds to Gab2 (Grb2-associated binder 2) through epitopes containing RxxK motifs, as well as to the proline-rich C-terminus of FGRF2. SH3 domains are protein interaction domains that typically bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212882 [Multi-domain] Cd Length: 53 Bit Score: 37.51 E-value: 9.90e-04

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11949     4 ALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGAC--HGQTGMFPRNYVT 52

Src homology 3 domain of Endophilin-B1; Endophilin-B1, also called Bax-interacting factor 1 (Bif-1) or SH3GLB1 (SH3-domain GRB2-like endophilin B1), is localized mainly to the Golgi apparatus. It is involved in the regulation of many biological events including autophagy, tumorigenesis, nerve growth factor (NGF) trafficking, neurite outgrowth, mitochondrial outer membrane dynamics, and cell death. Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. Endophilin-B1 forms homo- and heterodimers (with endophilin-B2) through its BAR domain. It interacts with amphiphysin 1 and dynamin 1 through its SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212878 Cd Length: 61 Bit Score: 37.70 E-value: 1.02e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIVYIHKEV--DKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd11945     4 RKARVLYDYDAANSTELSLLADEVITVYSVPgmDSDWLMGERGNQKGKVPITYLELL 60

Src Homology 3 domain of SH3 domain and tetratricopeptide repeat-containing (SH3TC) proteins and similar domains; This subfamily is composed of vertebrate SH3TC proteins and hypothetical fungal proteins containing BAR and SH3 domains. Mammals contain two SH3TC proteins, SH3TC1 and SH3TC2. The function of SH3TC1 is unknown. SH3TC2 is localized in Schwann cells in the peripheral nervous system, where it interacts with Rab11 and plays a role in peripheral nerve myelination. Mutations in SH3TC2 are associated with Charcot-Marie-Tooth disease type 4C, a severe hereditary peripheral neuropathy with symptoms that include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212818 Cd Length: 55 Bit Score: 37.30 E-value: 1.02e-03

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gi 1958679458 278 KFDFQAQSPKELTLQKGDIVYIHKEVDK--NWLEGEH--HGRLGIFPANYV 324
Cdd:cd11885     5 KMDFEGVEPGELSFRQGDSIEIIGDLIPglQWFVGRSksSGRVGFVPTNHF 55

Src Homology 3 domain of Epidermal growth factor receptor kinase substrate 8 and similar proteins; This group is composed of Eps8 and Eps8-like proteins including Eps8-like 1-3, among others. These proteins contain N-terminal Phosphotyrosine-binding (PTB), central SH3, and C-terminal effector domains. Eps8 binds either Abi1 (also called E3b1) or Rab5 GTPase activating protein RN-tre through its SH3 domain. With Abi1 and Sos1, it becomes part of a trimeric complex that is required to activate Rac. Together with RN-tre, it inhibits the internalization of EGFR. The SH3 domains of Eps8 and similar proteins recognize peptides containing a PxxDY motif, instead of the classical PxxP motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212698 [Multi-domain] Cd Length: 54 Bit Score: 37.24 E-value: 1.02e-03

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11764     2 VRVLYDFTARNSKELSVLKGEYLEVLDDSRQWWKVRNSRGQVGYVPHNILE 52

Src Homology 3 domain of Class A Dedicator of Cytokinesis protein 2; Dock2 is a hematopoietic cell-specific, class A DOCK and is an atypical guanine nucleotide exchange factor (GEF) that lacks the conventional Dbl homology (DH) domain. It plays an important role in lymphocyte migration and activation, T-cell differentiation, neutrophil chemotaxis, and type I interferon induction. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock2 binds to DHR-2 in an autoinhibitory manner; binding of the scaffold protein Elmo to the SH3 domain of Dock2 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212983 Cd Length: 56 Bit Score: 37.52 E-value: 1.09e-03

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gi 1958679458 350 VAQYTFKGDLDVELSFRKGErICLIRKVNEHWYEGR-ITGTGRQGIFPASYVQI 402
Cdd:cd12050     3 VAIYNFKGSGVPQLSLQIGD-VVHIQETCEDWYKGYlVRHKDLQGIFPKSFIHI 55

Third Src homology 3 domain (or SH3C) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (SH3C) of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212925 Cd Length: 52 Bit Score: 37.30 E-value: 1.13e-03

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gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEhWYEGRItgTGRQGIFPASYVQ 401
Cdd:cd11992     3 IALYPYSSSEPGDLTFNEGEEILVTQKDGE-WWTGSI--EDRTGIFPSNYVR 51

First Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the first C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212845 [Multi-domain] Cd Length: 55 Bit Score: 37.20 E-value: 1.20e-03

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQcDD--GWfVGVSRRTQKFGTFPGNYV 557
Cdd:cd11912     3 KVLYDYTASGDDEVSISEGEEVTVLEP-DDgsGW-TKVRNGSGEEGLVPTSYI 53

Third Src homology 3 domain (or SH3C) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The third SH3 domain (or SH3C) of ITSN1 has been shown to bind many proteins including dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK, among others. The SH3C of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212772 [Multi-domain] Cd Length: 52 Bit Score: 37.01 E-value: 1.23e-03

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTqkfGTFPGNYVAP 559
Cdd:cd11838     2 YIALYPYESNEPGDLTFNAGDVILVTKKDGEWWTGTIGDRT---GIFPSNYVRP 52

Src Homology 3 domain of Cdc42-Interacting Protein 4; This subfamily is composed of Cdc42-Interacting Protein 4 (CIP4), Formin Binding Protein 17 (FBP17), FormiN Binding Protein 1-Like (FNBP1L), and similar proteins. CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. CIP4 and FBP17 bind to the Fas ligand and may be implicated in the inflammatory response. CIP4 may also play a role in phagocytosis. It functions downstream of Cdc42 in PDGF-dependent actin reorganization and cell migration, and also regulates the activity of PDGFRbeta. It uses Src as a substrate in regulating the invasiveness of breast tumor cells. CIP4 may also play a role in the pathogenesis of Huntington's disease. Members of this subfamily typically contain an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, a central Cdc42-binding HR1 domain, and a C-terminal SH3 domain. The SH3 domain of CIP4 associates with Gapex-5, a Rab31 GEF. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212844 [Multi-domain] Cd Length: 55 Bit Score: 37.24 E-value: 1.24e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRK-VNEHWYEGRItGTGRQGIFPASYVQI 402
Cdd:cd11911     2 CTALYDFDGTSEGTLSMEEGEILLVLEEdGGDGWTRVRK-NNGDEGYVPTSYIEV 55

Src Homology 3 domain of Class A Dedicator of Cytokinesis protein 2; Dock2 is a hematopoietic cell-specific, class A DOCK and is an atypical guanine nucleotide exchange factor (GEF) that lacks the conventional Dbl homology (DH) domain. It plays an important role in lymphocyte migration and activation, T-cell differentiation, neutrophil chemotaxis, and type I interferon induction. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock2 binds to DHR-2 in an autoinhibitory manner; binding of the scaffold protein Elmo to the SH3 domain of Dock2 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212983 Cd Length: 56 Bit Score: 37.13 E-value: 1.28e-03

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDkNWLEG---EHHGRLGIFPANYVEV 326
Cdd:cd12050     6 YNFKGSGVPQLSLQIGDVVHIQETCE-DWYKGylvRHKDLQGIFPKSFIHI 55

Src Homology 3 domain of Class A and B Dedicator of Cytokinesis proteins; DOCK proteins are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. They are divided into four classes (A-D) based on sequence similarity and domain architecture: class A includes Dock1, 2 and 5; class B includes Dock3 and 4; class C includes Dock6, 7, and 8; and class D includes Dock9, 10 and 11. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. This subfamily includes only Class A and B DOCKs, which also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. Class A/B DOCKs are mostly specific GEFs for Rac, except Dock4 which activates the Ras family GTPase Rap1, probably indirectly through interaction with Rap regulatory proteins. The SH3 domain of class A/B DOCKs have been shown to bind Elmo, a scaffold protein that promotes GEF activity of DOCKs by releasing DHR-2 autoinhibition by the intramolecular SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212805 [Multi-domain] Cd Length: 56 Bit Score: 37.18 E-value: 1.36e-03

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDkNWLEG---EHHGRLGIFPANYVEV 326
Cdd:cd11872     7 NFQGDGEHQLSLQVGDTVQILEECE-GWYRGfslRNKSLKGIFPKSYVHI 55

Third Src Homology 3 domain (SH3C) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CIN85. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212990 [Multi-domain] Cd Length: 56 Bit Score: 37.19 E-value: 1.37e-03

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                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 360 DVELSFRKGERICLIRK--VNEHWYEGRITGtgRQGIFPASYVQI 402
Cdd:cd12057    13 EDELTIKEGDIVTLISKdcIDAGWWEGELNG--RRGVFPDNFVKL 55

Src homology 3 domain of Phospholipase C (PLC) gamma; PLC catalyzes the hydrolysis of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in response to various receptors. Ins(1,4,5)P3 initiates the calcium signaling cascade while DAG functions as an activator of PKC. PLCgamma catalyzes this reaction in tyrosine kinase-dependent signaling pathways. It is activated and recruited to its substrate at the membrane. Vertebrates contain two forms of PLCgamma, PLCgamma1, which is widely expressed, and PLCgamma2, which is primarily found in haematopoietic cells. PLCgamma contains a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, two catalytic regions of PLC domains that flank two tandem SH2 domains, followed by a SH3 domain and C2 domain. The SH3 domain of PLCgamma1 directly interacts with dynamin-1 and can serve as a guanine nucleotide exchange factor (GEF). It also interacts with Cbl, inhibiting its phosphorylation and activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212759 [Multi-domain] Cd Length: 54 Bit Score: 36.93 E-value: 1.46e-03

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGvSRRTQKFGTFPGNYV 557
Cdd:cd11825     3 KALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRG-DYGGKKQKWFPANYV 52

Second or C-terminal Src homology 3 domain of NADPH oxidase (Nox) Organizing protein 1; Nox Organizing protein 1 (NoxO1) is a critical regulator of enzyme kinetics of the nonphagocytic NADPH oxidase Nox1, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Nox1 is expressed in colon, stomach, uterus, prostate, and vascular smooth muscle cells. NoxO1 is involved in targeting activator subunits (such as NoxA1) to Nox1. It is co-localized with Nox1 in the membranes of resting cells and directs the subcellular localization of Nox1. NoxO1 contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), and a C-terminal proline-rich region (PRR). This model characterizes the second SH3 domain (or C-SH3) of NoxO1. The tandem SH3 domains of NoxO1 interact with the PRR of p22phox, which also complexes with Nox1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212957 Cd Length: 53 Bit Score: 36.93 E-value: 1.48e-03

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFvgVSRRTQKFGTFPGNYVAP 559
Cdd:cd12024     2 YYATRAYEAQKEDELSVPAGVVVEVLQKSDNGWW--LIRYNGRAGYVPSMYLQP 53

N-terminal (or first) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. The N-terminal SH3 domain increases the affinity of p67phox for the oxidase complex. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212804 Cd Length: 54 Bit Score: 36.80 E-value: 1.53e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 505 PYRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSrrTQKFGTFPGNYVAPV 560
Cdd:cd11871     1 PHRVLYEFVPETKEELQVLPGNIVFVLKKGTDNWATVVF--NGKKGLVPCNFLEPV 54

Third Src homology 3 domain (or SH3C) of Intersectin-2; Intersectin-2 (ITSN2) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN2 also functions as a specific GEF for Cdc42 activation in epithelial morphogenesis, and is required in mitotic spindle orientation. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The third SH3 domain (SH3C) of ITSN2 has been shown to bind the K15 protein of Kaposi's sarcoma-associated herpesvirus. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212925 Cd Length: 52 Bit Score: 36.91 E-value: 1.53e-03

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                  ....*....|....*....|....*....|....*....|....*.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEvDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11992     6 YPYSSSEPGDLTFNEGEEILVTQK-DGEWWTGSIEDRTGIFPSNYV 50

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 36.93 E-value: 1.59e-03

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                  ....*....|....*....|....*....|....*....|....*
gi 1958679458 362 ELSFRKGERIcLIRKVNEH-WYEGRITGTGRQ---GIFPASYVQI 402
Cdd:cd11839    15 QLSLAVGQLV-LVRKKSPSgWWEGELQARGKKrqiGWFPANYVKL 58

Third Src Homology 3 domain of SH3 domain containing ring finger 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212859 [Multi-domain] Cd Length: 55 Bit Score: 36.87 E-value: 1.60e-03

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                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE--HHGRLGIFPANYV 324
Cdd:cd11926     6 YPYTPRKEDELELRKGEMFLVFERCQDGWFKGTsmHTSKIGVFPGNYV 53

Second Src homology 3 domain (or SH3B) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The second SH3 domain (or SH3B) of ITSN1 has been shown to bind WNK and CdGAP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212771 [Multi-domain] Cd Length: 53 Bit Score: 36.57 E-value: 1.65e-03

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIhKEVDKNWLEGE-HHGRLGIFPANYV 324
Cdd:cd11837     6 YPWRAKKENHLSFAKGDIITV-LEQQEMWWFGElEGGEEGWFPKSYV 51

Src Homology 3 domain of GTPase Regulator Associated with Focal adhesion kinase; GRAF, also called Rho GTPase activating protein 26 (ARHGAP26), Oligophrenin-1-like (OPHN1L) or GRAF1, is a GAP with activity towards RhoA and Cdc42 and is only weakly active towards Rac1. It influences Rho-mediated cytoskeletal rearrangements and binds focal adhesion kinase (FAK), which is a critical component of integrin signaling. It is essential for the major clathrin-independent endocytic pathway mediated by pleiomorphic membranes. GRAF contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, a Rho GAP domain, and a C-terminal SH3 domain. The SH3 domain of GRAF binds PKNbeta, a target of the small GTPase Rho. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212997 Cd Length: 56 Bit Score: 37.02 E-value: 1.70e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 273 KAARLKFDFQAQSPKELTLQKGDIV-YIHKEVDKNWLEGEHHGRLGIFPANYVEVL 327
Cdd:cd12064     1 RKAKALYACKAEHDSELSFTAGTVFdNVHPSQEPGWLEGTLNGKTGLIPENYVEFL 56

Src Homology 3 domain of Class A Dedicator of Cytokinesis proteins 1 and 5; Dock1, also called Dock180, and Dock5 are class A DOCKs and are atypical guanine nucleotide exchange factors (GEFs) that lack the conventional Dbl homology (DH) domain. Dock1 interacts with the scaffold protein Elmo and the resulting complex functions upstream of Rac in many biological events including phagocytosis of apoptotic cells, cell migration and invasion. Dock5 functions upstream of Rac1 to regulate osteoclast function. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate while DHR-2 contains the catalytic activity for Rac and/or Cdc42. Class A DOCKs also contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus; they are specific GEFs for Rac. The SH3 domain of Dock1 binds to DHR-2 in an autoinhibitory manner; binding of Elmo to the SH3 domain of Dock1 exposes the DHR-2 domain and promotes GEF activity. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212984 [Multi-domain] Cd Length: 56 Bit Score: 36.72 E-value: 1.73e-03

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIhKEVDKNWLEG---EHHGRLGIFPANYV 324
Cdd:cd12051     6 YNYDARGPDELSLQIGDTVHI-LETYEGWYRGytlRKKSKKGIFPASYI 53

Third Src Homology 3 domain (SH3C) of CD2-associated protein and similar proteins; This subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212808 [Multi-domain] Cd Length: 55 Bit Score: 36.56 E-value: 1.75e-03

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 353 YTFKGDLDVELSFRKGERICLIRKVNEH--WYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11875     6 FDYEAENEDELTLREGDIVTILSKDCEDkgWWKGEL--NGKRGVFPDNFVEP 55

First Src homology 3 domain (or SH3A) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212920 [Multi-domain] Cd Length: 55 Bit Score: 36.90 E-value: 1.78e-03

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 506 YRAMYQYRPQNEDELELREGD--RVDVMQQCDDGWFVGVSRrtQKFGTFPGNY 556
Cdd:cd11987     2 YRALYPFEARSHDEITIQPGDivMVDESQTGEPGWLGGELK--GKTGWFPANY 52

Second Src Homology 3 domain of SH3 domain containing ring finger 3, an E3 ubiquitin-protein ligase; SH3RF3 is also called POSH2 (Plenty of SH3s 2) or SH3MD4 (SH3 multiple domains protein 4). It is a scaffold protein with E3 ubiquitin-protein ligase activity. It was identified in the screen for interacting partners of p21-activated kinase 2 (PAK2). It may play a role in regulating JNK mediated apoptosis in certain conditions. It also interacts with GTP-loaded Rac1. SH3RF3 is highly homologous to SH3RF1; it also contains an N-terminal RING finger domain and four SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF3. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212864 Cd Length: 55 Bit Score: 36.82 E-value: 1.86e-03

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKE----LTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11931     6 YDFEIKDKDQdkdcLTFTKDEILTVIRRVDENWAEGMLGDKIGIFPILYV 55

Src Homology 3 domain of Tec (Tyrosine kinase expressed in hepatocellular carcinoma); Tec is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. It is more widely-expressed than other Tec subfamily kinases. Tec is found in endothelial cells, both B- and T-cells, and a variety of myeloid cells including mast cells, erythroid cells, platelets, macrophages and neutrophils. Tec is a key component of T-cell receptor (TCR) signaling, and is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212838 [Multi-domain] Cd Length: 56 Bit Score: 36.72 E-value: 1.88e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRiTGTGRQGIFPASYV 400
Cdd:cd11905     3 VVAMYDFQPTEPHDLRLETGEEYVILEKNDVHWWKAR-DKYGKEGYIPSNYV 53

Src homology 3 domain of the Rho guanine nucleotide exchange factor, ephexin-1 (also called NGEF or ARHGEF27); Ephexin-1, also called NGEF (neuronal GEF) or ARHGEF27, activates RhoA, Tac1, and Cdc42 by exchanging bound GDP for free GTP. It is expressed mainly in the brain in a region associated with movement control. It regulates the stability of postsynaptic acetylcholine receptor (AChR) clusters and thus, plays a critical role in the maturation and neurotransmission of neuromuscular junctions. Ephexin-1 directly interacts with the ephrin receptor EphA4 and their coexpression enhances the ability of ephexin-1 to activate RhoA. It is required for normal axon growth and EphA-induced growth cone collapse. Ephexin-1 contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212872 [Multi-domain] Cd Length: 55 Bit Score: 36.46 E-value: 2.00e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 509 MYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11939     5 VHPYVSQEPDELSLELADVLNILDKTDDGWIFGERLHDQERGWFPSSVV 53

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member 4; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212933 Cd Length: 57 Bit Score: 36.78 E-value: 2.01e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYI---HKEVDKNWLEGEHHGRLGIFPANYVEV 326
Cdd:cd12000     3 ARALYDNKADCSDELAFRRGDILTVleqNVPGSEGWWKCLLHGRQGLAPANRLQL 57

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212712 [Multi-domain] Cd Length: 51 Bit Score: 36.32 E-value: 2.02e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVN-EHWYEGRITGTgrQGIFPASY 399
Cdd:cd11778     4 ALYDYEAQGDDEISIRVGDRIAVIRGDDgSGWTYGEINGV--KGLFPTSY 51

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212979 [Multi-domain] Cd Length: 53 Bit Score: 36.32 E-value: 2.02e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 508 AMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVAP 559
Cdd:cd12046     4 ALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCK--GKIGIFPSAFVED 53

First Src Homology 3 domain of Bud emergence protein 1 and similar domains; Members of this subfamily bear similarity to Saccharomyces cerevisiae Bem1p, containing two Src Homology 3 (SH3) domains at the N-terminus, a central PX domain, and a C-terminal PB1 domain. Bem1p is a scaffolding protein that is critical for proper Cdc42p activation during bud formation in yeast. During budding and mating, Bem1p migrates to the plasma membrane where it can serve as an adaptor for Cdc42p and some other proteins. Bem1p also functions as an effector of the G1 cyclin Cln3p and the cyclin-dependent kinase Cdc28p in promoting vacuolar fusion. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212811 [Multi-domain] Cd Length: 54 Bit Score: 36.50 E-value: 2.13e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 276 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKN-WLEGEH--HGRLGIFPANY 323
Cdd:cd11878     3 RALYDYRAQTPGELSFSKGDFFHVIGEEDQGeWYEATNpvTGKRGLVPKSY 53

Src Homology 3 domain of SH3 domain-containing protein 21 (SH3D21) and similar proteins; N-terminal SH3 domain of the uncharacterized protein SH3 domain-containing protein 21, and similar uncharacterized domains, it belongs to the CD2AP-like_3 subfamily of proteins. The CD2AP-like_3 subfamily is composed of the third SH3 domain (SH3C) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3C of both proteins have been shown to bind to ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213018 [Multi-domain] Cd Length: 55 Bit Score: 36.29 E-value: 2.30e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1958679458 362 ELSFRKGERICLIRKVNEH--WYEGRItgTGRQGIFPASYV 400
Cdd:cd12142    15 ELALKKGDVIEVISKETEDegWWEGEL--NGRRGFFPDNFV 53

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212940 [Multi-domain] Cd Length: 58 Bit Score: 36.55 E-value: 2.33e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE--HHGRLGIFPANYveVLPAD 330
Cdd:cd12007     7 YDYEARTTEDLSFKKGERFQIINNTEGDWWEARsiATGKNGYIPSNY--VAPAD 58

First Src Homology 3 domain of FCH and double SH3 domains proteins; This group is composed of FCH and double SH3 domains protein 1 (FCHSD1) and FCHSD2. These proteins have a common domain structure consisting of an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), two SH3, and C-terminal proline-rich domains. They have only been characterized in silico and their functions remain unknown. This group also includes the insect protein, nervous wreck, which acts as a regulator of synaptic growth signaling. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212695 [Multi-domain] Cd Length: 57 Bit Score: 36.57 E-value: 2.37e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVD-KNWLEGEH-HGRLGIFPANYVE 325
Cdd:cd11761     8 YSYEAQRPDELTITEGEELEVIEDGDgDGWVKARNkSGEVGYVPENYLQ 56

Src Homology 3 domain of Bruton's tyrosine kinase; BTK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation, and the Tec homology (TH) domain with proline-rich and zinc-binding regions. Btk is expressed in B-cells, and a variety of myeloid cells including mast cells, platelets, neutrophils, and dendrictic cells. It interacts with a variety of partners, from cytosolic proteins to nuclear transcription factors, suggesting a diversity of functions. Stimulation of a diverse array of cell surface receptors, including antigen engagement of the B-cell receptor (BCR), leads to PH-mediated membrane translocation of Btk and subsequent phosphorylation by Src kinase and activation. Btk plays an important role in the life cycle of B-cells including their development, differentiation, proliferation, survival, and apoptosis. Mutations in Btk cause the primary immunodeficiency disease, X-linked agammaglobulinaemia (XLA) in humans. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212839 [Multi-domain] Cd Length: 55 Bit Score: 36.34 E-value: 2.38e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG-EHHGRLGIFPANYV 324
Cdd:cd11906     7 YDYTPMNAQDLQLRKGEEYVILEESNLPWWRArDKNGREGYIPSNYV 53

Third Src Homology 3 domain (SH3C) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the third SH3 domain (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212989 [Multi-domain] Cd Length: 57 Bit Score: 36.34 E-value: 2.38e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 345 EYGDAVAQYTfkGDLDVELSFRKGERICLIRKV--NEHWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd12056     2 EYCKALFHYE--GTNEDELDFKEGEIILIISKDtgEPGWWKGEL--NGKEGVFPDNFVSQ 57

First Src Homology 3 domain (SH3A) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present in c-Cbl and the cytoplasmic domain of cell adhesion protein CD2. Its interaction with CD2 anchors CD2 at sites of cell contact. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212986 Cd Length: 56 Bit Score: 36.36 E-value: 2.43e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEH-WYEGRItgTGRQGIFPASYVQ 401
Cdd:cd12053     1 EYIVEYDYDAVHEDELTIRVGEIIRNVKKLEEEgWLEGEL--NGRRGMFPDNFVK 53

Src homology 3 domain of Apoptosis Stimulating of p53 proteins (ASPP); The ASPP family of proteins bind to important regulators of apoptosis (p53, Bcl-2, and RelA) and cell growth (APCL, PP1). They share similarity at their C-termini, where they harbor a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain. Vertebrates contain three members of the family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2 activate the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73), while iASPP is an oncoprotein that specifically inhibits p53-induced apoptosis. The expression of ASPP proteins is altered in tumors; ASPP1 and ASPP2 are downregulated whereas iASPP is upregulated is some cancer types. ASPP proteins also bind and regulate protein phosphatase 1 (PP1), and this binding is competitive with p53 binding. The SH3 domain and the ANK repeats of ASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212741 [Multi-domain] Cd Length: 57 Bit Score: 36.20 E-value: 2.52e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVD--KNWLEGEHHGRLGIFPANY 323
Cdd:cd11807     7 FDYEAENGDELSFREGDELTVlRKGDDdeTEWWWARLNDKEGYVPRNL 54

First N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212728 Cd Length: 51 Bit Score: 35.95 E-value: 2.58e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11794     3 RAIFDFCPSVSEELPLFAGDVIEVLKVVDEFWLLGTKEGVT--GQFPSSFV 51

Fourth N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP bind the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212731 Cd Length: 50 Bit Score: 36.25 E-value: 2.60e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRItgTGRQGIFP 396
Cdd:cd11797     2 GVALYRFQALEPNELDFEVGDRIRIIATLEDGWLEGEL--KGRRGIFP 47

Src Homology 3 domain of Saccharomyces cerevisiae Nap1-binding protein 2 and similar fungal proteins; This subfamily includes Saccharomyces cerevisiae Nbp2 (Nucleosome assembly protein 1 (Nap1)-binding protein 2), Schizosaccharomyces pombe Skb5, and similar proteins. Nbp2 interacts with Nap1, which is essential for maintaining proper nucleosome structures in transcription and replication. It is also the binding partner of the yeast type II protein phosphatase Ptc1p and serves as a scaffolding protein that brings seven kinases in close contact to Ptc1p. Nbp2 plays a role many cell processes including organelle inheritance, mating hormone response, cell wall stress, mitotic cell growth at elevated temperatures, and high osmolarity. Skb5 interacts with the p21-activated kinase (PAK) homolog Shk1, which is critical for fission yeast cell viability. Skb5 activates Shk1 and plays a role in regulating cell morphology and growth under hypertonic conditions. Nbp2 and Skb5 contain an SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212799 Cd Length: 55 Bit Score: 36.34 E-value: 2.73e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWL--EGEHHGRLGIFPANYVEV 326
Cdd:cd11865     6 YDFEPEHDNELGFAEGQILFILYKHGQGWLiaEDESGGKTGLVPEEFVSY 55

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 36.08 E-value: 2.73e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERI-CLIRKVNEHWYEGRITGtgRQGIFPASYVQ 401
Cdd:cd11976     2 AKARYDFCARDRSELSLKEGDIIkILNKKGQQGWWRGEIYG--RVGWFPANYVE 53

Src homology 3 domain of Endophilin-B; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain two endophilin-B isoforms. Endophilin-B proteins are cytoplasmic proteins expressed mainly in the heart, placenta, and skeletal muscle. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212736 [Multi-domain] Cd Length: 52 Bit Score: 36.11 E-value: 2.80e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 275 ARLKFDFQAQSPKELTLQKGDIVYIH--KEVDKNWLEGEHHGRLGIFPANY 323
Cdd:cd11802     2 ARVLYDYDAEDSTELSLLADEVITVYelPGMDEDYMMGERGSQRGKVPVAY 52

104 kDa microneme/rhoptry antigen; Provisional

Pssm-ID: 185628 [Multi-domain] Cd Length: 943 Bit Score: 40.44 E-value: 2.87e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958679458 132 ELETGHKPKKSLVDDPVE--KPAQPIEVLLERELAKLSAELDKDLRAIETRLPSPKNSQAPRRPlEQPGPEQQPSarlsS 209
Cdd:PTZ00449  528 EGEEGEHEDSKESDEPKEggKPGETKEGEVGKKPGPAKEHKPSKIPTLSKKPEFPKDPKHPKDP-EEPKKPKRPR----S 602

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 210 AWRPNSPHAPYFGSSR--PLSPHRMADgggspflgrrdfvyPSSAREPSASERGSSPARKEEKK 271
Cdd:PTZ00449  603 AQRPTRPKSPKLPELLdiPKSPKRPES--------------PKSPKRPPPPQRPSSPERPEGPK 652

Src Homology 3 domain of fungal peroxisomal membrane protein Pex13p; Pex13p, located in the peroxisomal membrane, contains two transmembrane regions and a C-terminal SH3 domain. It binds to the peroxisomal targeting type I (PTS1) receptor Pex5p and the docking factor Pex14p through its SH3 domain. It is essential for both PTS1 and PTS2 protein import pathways into the peroxisomal matrix. Pex13p binds Pex14p, which contains a PxxP motif, in a classical fashion to the proline-rich ligand binding site of its SH3 domain. It binds the WxxxF/Y motif of Pex5p in a novel site that does not compete with Pex14p binding. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212705 [Multi-domain] Cd Length: 60 Bit Score: 36.10 E-value: 2.94e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1958679458 507 RAMYQYRPQN-EDELELREGDRVDVMQQCD-----DGWFVGvsrRTQ--KFGTFPGNYV 557
Cdd:cd11771     3 RALYDFTPENpEMELSLKKGDIVAVLSKTDplgrdSEWWKG---RTRdgRIGWFPSNYV 58

Sorbin homologous domain;

Pssm-ID: 460492 Cd Length: 45 Bit Score: 35.70 E-value: 2.94e-03

                          10        20
                  ....*....|....*....|..
gi 1958679458  11 ALGESVDSPRDWYRRMFQQIHR 32
Cdd:pfam02208  17 ALRNTVERSKDWYKTMFKQIHK 38

Src homology 3 domains of Rab3-interacting molecules (RIMs) binding proteins; RIMs binding proteins (RBPs, RIM-BPs) associate with calcium channels present in photoreceptors, neurons, and hair cells; they interact simultaneously with specific calcium channel subunits, and active zone proteins, RIM1 and RIM2. RIMs are part of the matrix at the presynaptic active zone and are associated with synaptic vesicles through their interaction with the small GTPase Rab3. RIM-BPs play a role in regulating synaptic transmission by serving as adaptors and linking calcium channels with the synaptic vesicle release machinery. RIM-BPs contain three SH3 domains and two to three fibronectin III repeats. Invertebrates contain one, while vertebrates contain at least two RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called peripheral-type benzodiazapine receptor associated protein 1 (PRAX-1). Mammals contain a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly expressed in the brain where they display overlapping but distinct expression patterns, while RIM-BP3 is almost exclusively expressed in the testis and is essential in spermiogenesis. The SH3 domains of RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and L-type (alpha1D) and N-type (alpha1B) calcium channel subunits. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212785 Cd Length: 62 Bit Score: 36.14 E-value: 3.00e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 506 YRAMYQYRP-------QNEDELELREGDRVDVMQQCD-DGWFVGVSRRTQKfGTFPGNYVAP 559
Cdd:cd11851     2 MVALYDYNPetmspndDPEEELSFHAGDVVRVYGPMDeDGFYYGELEGGRK-GLVPSNFVQE 62

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212871 Cd Length: 55 Bit Score: 35.97 E-value: 3.00e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1958679458 512 YRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFP 553
Cdd:cd11938     8 YTAKQPDELSLQQADVVLVLQTESDGWYYGERLRDGERGWFP 49

Src Homology 3 domain of Myosin XV; This subfamily is composed of proteins with similarity to Myosin XVa. Myosin XVa is an unconventional myosin that is critical for the normal growth of mechanosensory stereocilia of inner ear hair cells. Mutations in the myosin XVa gene are associated with nonsyndromic hearing loss. Myosin XVa contains a unique N-terminal extension followed by a motor domain, light chain-binding IQ motifs, and a tail consisting of a pair of MyTH4-FERM tandems separated by a SH3 domain, and a PDZ domain. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212817 [Multi-domain] Cd Length: 56 Bit Score: 36.15 E-value: 3.10e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1958679458 363 LSFRKGERICLIRK---VNEHWYEGRITGtgRQGIFPASYVQ 401
Cdd:cd11884    16 LSFHKGDVIKLLPKegpLDPGWLFGTLDG--RSGAFPKEYVQ 55

Src Homology 3 domain of SH3 domain and tetratricopeptide repeat-containing (SH3TC) proteins and similar domains; This subfamily is composed of vertebrate SH3TC proteins and hypothetical fungal proteins containing BAR and SH3 domains. Mammals contain two SH3TC proteins, SH3TC1 and SH3TC2. The function of SH3TC1 is unknown. SH3TC2 is localized in Schwann cells in the peripheral nervous system, where it interacts with Rab11 and plays a role in peripheral nerve myelination. Mutations in SH3TC2 are associated with Charcot-Marie-Tooth disease type 4C, a severe hereditary peripheral neuropathy with symptoms that include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212818 Cd Length: 55 Bit Score: 36.14 E-value: 3.14e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 349 AVAQYTFKGDLDVELSFRKGERICLIRKVNE--HWYEGRITGTGRQGIFPASYV 400
Cdd:cd11885     2 CTAKMDFEGVEPGELSFRQGDSIEIIGDLIPglQWFVGRSKSSGRVGFVPTNHF 55

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212871 Cd Length: 55 Bit Score: 35.97 E-value: 3.22e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1958679458 281 FQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH--HGRLGIFPA 321
Cdd:cd11938     8 YTAKQPDELSLQQADVVLVLQTESDGWYYGERlrDGERGWFPS 50

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1; SKAP1, also called SKAP55 (Src kinase-associated protein of 55kDa), is an immune cell-specific adaptor protein that plays an important role in T-cell adhesion, migration, and integrin clustering. It is expressed exclusively in T-lymphocytes, mast cells, and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), Fyn, Riam, RapL, and RasGRP. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212977 Cd Length: 53 Bit Score: 35.99 E-value: 3.45e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI-HKEVDK-NWLEGEHHGRLGIFPANYV 324
Cdd:cd12044     6 WDCFGDNPDELSFQRGDLIYIlSKEYNMyGWWVGELNGIVGIVPKDYL 53

Src homology 3 domain of ArfGAP with SH3 domain, ankyrin repeat and PH domain containing protein 2; ASAP2 is also called DDEF2 (Development and Differentiation Enhancing Factor 2), AMAP2, centaurin beta-3, or PAG3. It mediates the functions of Arf GTPases vial dual mechanisms: it exhibits GTPase activating protein (GAP) activity towards class I (Arf1) and II (Arf5) Arfs; and it binds class III Arfs (GTP-Arf6) stably without GAP activity. It binds paxillin and is implicated in Fcgamma receptor-mediated phagocytosis in macrophages and in cell migration. ASAP2 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212899 Cd Length: 56 Bit Score: 36.09 E-value: 3.57e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGT-GRQGIFPASYVQ 401
Cdd:cd11966     4 ALYNCVADNPDELTFSEGEIIIVDGEEDKEWWIGHIDGEpTRRGAFPVSFVH 55

N-terminal Src homology 3 domain of GRB2-related adaptor protein 2; GRAP2 is also called GADS (GRB2-related adapter downstream of Shc), GrpL, GRB2L, Mona, or GRID (Grb2-related protein with insert domain). It is expressed specifically in the hematopoietic system. It plays an important role in T cell receptor (TCR) signaling by promoting the formation of the SLP-76:LAT complex, which couples the TCR to the Ras pathway. It also have roles in antigen-receptor and tyrosine kinase mediated signaling. GRAP2 is unique from other GRB2-like adaptor proteins in that it can be regulated by caspase cleavage. It contains an N-terminal SH3 domain, a central SH2 domain, and a C-terminal SH3 domain. The N-terminal SH3 domain of the related protein GRB2 binds to Sos and Sos-derived proline-rich peptides. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212880 [Multi-domain] Cd Length: 52 Bit Score: 35.93 E-value: 3.59e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 348 DAVAQYTFKGDLDVELSFRKGERICLIRKVNEhWYEGRItgTGRQGIFPASYVQI 402
Cdd:cd11947     1 EARGKFDFTASGEDELSFKKGDVLKILSSDDI-WFKAEL--NGEEGYVPKNFVDI 52

C-terminal (or second) Src homology 3 domain of VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The C-terminal SH3 domain of Vav1 interacts with a wide variety of proteins including cytoskeletal regulators (zyxin), RNA-binding proteins (Sam68), transcriptional regulators, viral proteins, and dynamin 2. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212909 [Multi-domain] Cd Length: 54 Bit Score: 35.69 E-value: 3.64e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVM-QQCDDGWFVGvsRRTQKFGTFPGNYV 557
Cdd:cd11976     3 KARYDFCARDRSELSLKEGDIIKILnKKGQQGWWRG--EIYGRVGWFPANYV 52

Src Homology 3 domain of SH3 domain and tetratricopeptide repeat-containing (SH3TC) proteins and similar domains; This subfamily is composed of vertebrate SH3TC proteins and hypothetical fungal proteins containing BAR and SH3 domains. Mammals contain two SH3TC proteins, SH3TC1 and SH3TC2. The function of SH3TC1 is unknown. SH3TC2 is localized in Schwann cells in the peripheral nervous system, where it interacts with Rab11 and plays a role in peripheral nerve myelination. Mutations in SH3TC2 are associated with Charcot-Marie-Tooth disease type 4C, a severe hereditary peripheral neuropathy with symptoms that include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212818 Cd Length: 55 Bit Score: 35.75 E-value: 3.68e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDVMQQCDDG--WFVGVSRRTQKFGTFPGNYV 557
Cdd:cd11885     3 TAKMDFEGVEPGELSFRQGDSIEIIGDLIPGlqWFVGRSKSSGRVGFVPTNHF 55

Src Homology 3 domain of eumetazoan Peroxisomal biogenesis factor 13; PEX13 is a peroxin and is required for protein import into the peroxisomal matrix and membrane. It is an integral membrane protein that is essential for the localization of PEX14 and the import of proteins containing the peroxisome matrix targeting signals, PTS1 and PTS2. Mutations of the PEX13 gene in humans lead to a wide range of peroxisome biogenesis disorders (PBDs), the most severe of which is known as Zellweger syndrome (ZS), a severe multisystem disorder characterized by hypotonia, psychomotor retardation, and neuronal migration defects. PEX13 contains two transmembrane regions and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212798 Cd Length: 58 Bit Score: 35.68 E-value: 3.73e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1958679458 507 RAMYQYRPQNEDELELREGDRVDV----MQQCDDGWFVGvSRRTQKFGTFPGNYV 557
Cdd:cd11864     3 RAEYDFVAESEDELSFRAGDKLRLapkeLQPRVRGWLLA-TVDGQKIGLVPANYV 56

Src Homology 3 domain of TXK, also called Resting lymphocyte kinase (Rlk); TXK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal cysteine-rich region. Rlk is expressed in T-cells and mast cell lines, and is a key component of T-cell receptor (TCR) signaling. It is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212840 [Multi-domain] Cd Length: 55 Bit Score: 35.70 E-value: 3.85e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG-EHHGRLGIFPANYV 324
Cdd:cd11907     7 YDFLPREPSNLALKRAEEYLILEQYDPHWWKArDRYGNEGLIPSNYV 53

First or N-terminal Src homology 3 domain of the p47phox subunit of NADPH oxidase, also called Neutrophil Cytosolic Factor 1; p47phox, or NCF1, is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox), which plays a key role in the ability of phagocytes to defend against bacterial infections. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p47phox is required for activation of NADH oxidase and plays a role in translocation. It contains an N-terminal Phox homology (PX) domain, tandem SH3 domains (N-SH3 and C-SH3), a polybasic/autoinhibitory region, and a C-terminal proline-rich region (PRR). This model characterizes the first SH3 domain (or N-SH3) of p47phox. In its inactive state, the tandem SH3 domains interact intramolecularly with the autoinhibitory region; upon activation, the tandem SH3 domains are exposed through a conformational change, resulting in their binding to the PRR of p22phox and the activation of NADPH oxidase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212954 [Multi-domain] Cd Length: 53 Bit Score: 35.70 E-value: 4.20e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRrtQKFGTFPGNYVAP 559
Cdd:cd12021     2 YRAIADYEKSSKSEMALKTGDVVEVVEKSENGWWFCQLK--AKRGWVPASYLEP 53

First Src Homology 3 domain of Bud emergence protein 1 and similar domains; Members of this subfamily bear similarity to Saccharomyces cerevisiae Bem1p, containing two Src Homology 3 (SH3) domains at the N-terminus, a central PX domain, and a C-terminal PB1 domain. Bem1p is a scaffolding protein that is critical for proper Cdc42p activation during bud formation in yeast. During budding and mating, Bem1p migrates to the plasma membrane where it can serve as an adaptor for Cdc42p and some other proteins. Bem1p also functions as an effector of the G1 cyclin Cln3p and the cyclin-dependent kinase Cdc28p in promoting vacuolar fusion. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212811 [Multi-domain] Cd Length: 54 Bit Score: 35.73 E-value: 4.24e-03

                          10        20        30
                  ....*....|....*....|....*....|....*....
gi 1958679458 362 ELSFRKGERICLIRKVN-EHWYEGRITGTGRQGIFPASY 399
Cdd:cd11878    15 ELSFSKGDFFHVIGEEDqGEWYEATNPVTGKRGLVPKSY 53

Src homology 3 domain of Alpha Spectrin; Spectrin is a major structural component of the red blood cell membrane skeleton and is important in erythropoiesis and membrane biogenesis. It is a flexible, rope-like molecule composed of two subunits, alpha and beta, which consist of many spectrin-type repeats. Alpha and beta spectrin associate to form heterodimers and tetramers; spectrin tetramer formation is critical for red cell shape and deformability. Defects in alpha spectrin have been associated with inherited hemolytic anemias including hereditary spherocytosis (HSp), hereditary elliptocytosis (HE), and hereditary pyropoikilocytosis (HPP). Alpha spectrin contains a middle SH3 domain and a C-terminal EF-hand binding motif in addition to multiple spectrin repeats. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212742 [Multi-domain] Cd Length: 53 Bit Score: 35.54 E-value: 4.31e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1958679458 362 ELSFRKGERICLIRKVNEHWYegRITGTGRQGIFPASYVQ 401
Cdd:cd11808    15 EVSMKKGDILTLLNSSNKDWW--KVEVNDRQGFVPAAYVK 52

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212763 [Multi-domain] Cd Length: 52 Bit Score: 35.18 E-value: 4.97e-03

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1958679458 289 LTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYV 324
Cdd:cd11829    17 LSFEAGELIRVLQAPDGGWWEGEKDGLRGWFPASYV 52

C-terminal (or second) Src homology 3 domain of VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. The SH3 domain of VAV is involved in the localization of proteins to specific sites within the cell, by interacting with proline-rich sequences within target proteins. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212910 [Multi-domain] Cd Length: 58 Bit Score: 35.76 E-value: 5.00e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 347 GDAVAQYTFKGDLDVELSFRKGERICLIRKV--NEHWYEGRitGTGRQGIFPASYVQ 401
Cdd:cd11977     1 GTAVARYNFAARDMRELSLREGDVVRIYSRIggDQGWWKGE--TNGRIGWFPSTYVE 55

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212762 [Multi-domain] Cd Length: 53 Bit Score: 35.43 E-value: 5.11e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1958679458 362 ELSFRKGERICLIRKVNEHWYEGRITGtgRQGIFPASYVQI 402
Cdd:cd11828    15 ELGFKAGDVIEVLDMSDKDWWWGSIRD--EEGWFPASFVRL 53

First Src Homology 3 domain (SH3A) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the first SH3 domain (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present in c-Cbl and the cytoplasmic domain of cell adhesion protein CD2. Its interaction with CD2 anchors CD2 at sites of cell contact. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212986 Cd Length: 56 Bit Score: 35.59 E-value: 5.25e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1958679458 506 YRAMYQYRPQNEDELELREGDRV-DVMQQCDDGWFVGvsRRTQKFGTFPGNYVAPV 560
Cdd:cd12053     2 YIVEYDYDAVHEDELTIRVGEIIrNVKKLEEEGWLEG--ELNGRRGMFPDNFVKEI 55

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor; ASEF, also called ARHGEF4, exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli). GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF can activate Rac1 or Cdc42. Truncated ASEF, which is found in colorectal cancers, is constitutively active and has been shown to promote angiogenesis and cancer cell migration. ASEF contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212906 [Multi-domain] Cd Length: 73 Bit Score: 35.76 E-value: 5.55e-03

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                  ....*....|....*....|....*....|....*....|...
gi 1958679458 360 DVELSFRKGERICLIRKVNEHWYEGRITGTgrQGIFPASYVQI 402
Cdd:cd11973    31 DQELGFKAGDVIEVMDATNKEWWWGRVLDS--EGWFPASFVRL 71

Second N-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin and key regulatory proteins of the actin cytoskeleton. It plays an important role in regulating cell junction configuration. The four N-terminal SH3 domains of DNMBP binds the GTPase dynamin, which plays an important role in the fission of endocytic vesicles. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212729 Cd Length: 54 Bit Score: 35.12 E-value: 5.80e-03

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                  ....*....|....*....|....*....|....*....|....*..
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGE-HHGRLGIFPANYVE 325
Cdd:cd11795     7 AFTSQEPGHLNLQRGDLVELTGTTDSGWLQGRsCWGSSGFFPSSCVQ 53

Fourth Src homology 3 domain (or SH3D) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212773 [Multi-domain] Cd Length: 58 Bit Score: 35.39 E-value: 5.84e-03

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 512 YRPQNEDELELREGDRVDVMQQCDDGWFVG---VSRRTQKFGTFPGNYV 557
Cdd:cd11839     8 FTATAENQLSLAVGQLVLVRKKSPSGWWEGelqARGKKRQIGWFPANYV 56

Third Src Homology 3 domain of Nck adaptor proteins; This group contains the third SH3 domain of Nck, the first SH3 domain of Caenorhabditis elegans Ced-2 (Cell death abnormality protein 2), and similar domains. Nck adaptor proteins regulate actin cytoskeleton dynamics by linking proline-rich effector molecules to protein tyrosine kinases and phosphorylated signaling intermediates. They contain three SH3 domains and a C-terminal SH2 domain. They function downstream of the PDGFbeta receptor and are involved in Rho GTPase signaling and actin dynamics. Vertebrates contain two Nck adaptor proteins: Nck1 (also called Nckalpha) and Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4), which show partly overlapping functions but also bind distinct targets. Their SH3 domains are involved in recruiting downstream effector molecules, such as the N-WASP/Arp2/3 complex, which when activated induces actin polymerization that results in the production of pedestals, or protrusions of the plasma membrane. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. Ced-2 is a cell corpse engulfment protein that interacts with Ced-5 in a pathway that regulates the activation of Ced-10, a Rac small GTPase.

Pssm-ID: 212701 [Multi-domain] Cd Length: 56 Bit Score: 35.36 E-value: 5.89e-03

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958679458 279 FDFQAQSPKELTLQKGDIVYI--HKEVDKNWLEGEH-HGRLGIFPANYVEV 326
Cdd:cd11767     6 YPFTGENDEELSFEKGERLEIieKPEDDPDWWKARNaLGTTGLVPRNYVEV 56

Second Src homology 3 domain of ADAM-binding protein Eve-1; Eve-1, also called SH3 domain-containing protein 19 (SH3D19) or EEN-binding protein (EBP), exists in multiple alternatively spliced isoforms. The longest isoform contains five SH3 domain in the C-terminal region and seven proline-rich motifs in the N-terminal region. It is abundantly expressed in skeletal muscle and heart, and may be involved in regulating the activity of ADAMs (A disintegrin and metalloproteases). Eve-1 interacts with EEN, an endophilin involved in endocytosis and may be the target of the MLL-EEN fusion protein that is implicated in leukemogenesis. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212749 [Multi-domain] Cd Length: 52 Bit Score: 35.23 E-value: 5.96e-03

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 509 MYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQkfGTFPGNYV 557
Cdd:cd11815     5 LHDFPAEHSDDLSLNSGEIVYLLEKIDTEWYRGKCKNTT--GIFPANHV 51

Src Homology 3 domain of Rho GTPase-activating protein 27; Rho GTPase-activating proteins (RhoGAPs or ARHGAPs) bind to Rho proteins and enhance the hydrolysis rates of bound GTP. ARHGAP27, also called CAMGAP1, shows GAP activity towards Rac1 and Cdc42. It binds the adaptor protein CIN85 and may play a role in clathrin-mediated endocytosis. It contains SH3, WW, Pleckstin homology (PH), and RhoGAP domains. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 213002 Cd Length: 57 Bit Score: 35.18 E-value: 6.23e-03

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                  ....*....|....*....|....*....|....*....
gi 1958679458 363 LSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYVQ 401
Cdd:cd12069    18 VSIKPNERYILLRRTNEHWWHVRRDKGTRPFYIPAKYVK 56

Second Src Homology 3 domain of SH3 domain containing ring finger protein 1, an E3 ubiquitin-protein ligase; SH3RF1 is also called POSH (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein 2). It is a scaffold protein that acts as an E3 ubiquitin-protein ligase. It plays a role in calcium homeostasis through the control of the ubiquitin domain protein Herp. It may also have a role in regulating death receptor mediated and JNK mediated apoptosis. SH3RF1 also enhances the ubiquitination of ROMK1 potassium channel resulting in its increased endocytosis. It contains an N-terminal RING finger domain and four SH3 domains. This model represents the second SH3 domain, located C-terminal of the first SH3 domain at the N-terminal half, of SH3RF1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212863 Cd Length: 55 Bit Score: 34.97 E-value: 6.99e-03

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                  ....*....|....*....|....*....|....*...
gi 1958679458 363 LSFRKGERICLIRKVNEHWYEGRItgTGRQGIFPASYV 400
Cdd:cd11930    20 LPFAKDDILTVIRRVDENWAEGML--GDKIGIFPISYV 55

Src Homology 3 domain of Mixed Lineage Kinases 1, 2, and 3; MLKs 1, 2, and 3 are Serine/Threonine Kinases (STKs), catalyzing the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. Little is known about the specific function of MLK1, also called MAP3K9. It is capable of activating the c-Jun N-terminal kinase pathway. Mice lacking both MLK1 and MLK2 are viable, fertile, and have normal life spans. MLK2, also called MAP3K10, is abundant in brain, skeletal muscle, and testis. It functions upstream of the MAPK, c-Jun N-terminal kinase. It binds hippocalcin, a calcium-sensor protein that protects neurons against calcium-induced cell death. Both MLK2 and hippocalcin may be associated with the pathogenesis of Parkinson's disease. MLK3, also called MAP3K11, is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. It also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and thus, impacts inflammation and immunity. MLKs contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212992 [Multi-domain] Cd Length: 58 Bit Score: 35.13 E-value: 7.73e-03

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958679458 349 AVAQYTFKGDldVELSFRKGERICLIRKV-----NEHWYEGRITGtgRQGIFPASYV 400
Cdd:cd12059     4 AVFDYEASAE--DELTLRRGDRVEVLSKDsavsgDEGWWTGKIND--RVGIFPSNYV 56

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212790 [Multi-domain] Cd Length: 53 Bit Score: 34.92 E-value: 7.98e-03

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gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRLGIFPANYVE 325
Cdd:cd11856     7 DYEAQGDDEISLQEGEVVEVLEKNDSGWWYVRKGDKEGWVPASYLE 52

Src Homology 3 domain of Amphiphysin I; Amphiphysins function primarily in endocytosis and other membrane remodeling events. They exist in several isoforms and mammals possess two amphiphysin proteins from distinct genes. Amphiphysin I proteins, enriched in the brain and nervous system, contain domains that bind clathrin, Adaptor Protein complex 2 (AP2), dynamin, and synaptojanin. They function in synaptic vesicle endocytosis. Human autoantibodies to amphiphysin I hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Amphiphysins contain an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR), a variable central domain, and a C-terminal SH3 domain. The SH3 domain of amphiphysins bind proline-rich motifs present in binding partners such as dynamin, synaptojanin, and nsP3. It also belongs to a subset of SH3 domains that bind ubiquitin in a site that overlaps with the peptide binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 213016 Cd Length: 72 Bit Score: 35.26 E-value: 8.32e-03

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gi 1958679458 280 DFQAQSPKELTLQKGDIVYI-----HKEVDKNWLEG-------EHHG---RLGIFPANYVEVL 327
Cdd:cd12140    10 DFEAANSDELELKRGDIVLVvpsetAADQDAGWLTGvkesdwlQYRDasaYKGLFPENFTRRL 72

Third (or C-terminal) Src Homology 3 domain of Vinexin, also called Sorbin and SH3 domain containing 3 (Sorbs3); Vinexin is also called Sorbs3, SH3P3, and SH3-containing adapter molecule 1 (SCAM-1). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. Vinexin was first identified as a vinculin binding protein; it is co-localized with vinculin at cell-ECM and cell-cell adhesion sites. There are several splice variants of vinexin: alpha, which contains the SoHo and three SH3 domains and displays tissue-specific expression; and beta, which contains only the three SH3 domains and is widely expressed. Vinexin alpha stimulates the accumulation of F-actin at focal contact sites. Vinexin also promotes keratinocyte migration and wound healing. The SH3 domains of vinexin have been reported to bind a number of ligands including vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212851 [Multi-domain] Cd Length: 58 Bit Score: 34.93 E-value: 8.33e-03

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1958679458 351 AQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQGIFPASYV 400
Cdd:cd11918     6 AVYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 55

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212816 Cd Length: 55 Bit Score: 34.56 E-value: 8.88e-03

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1958679458 350 VAQYTFKGDLDVELSFRKGERICLIRKVNEHWYEGRITGTGRQ---GIFPASY 399
Cdd:cd11883     3 VALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKvkrGWFPSNY 55

Src Homology 3 domain of Tec-like Protein Tyrosine Kinases; The Tec (Tyrosine kinase expressed in hepatocellular carcinoma) subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) tyr kinases containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Most Tec subfamily members (except Rlk) also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. The function of Tec kinases in lymphoid cells have been studied extensively. They play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

Pssm-ID: 212702 [Multi-domain] Cd Length: 54 Bit Score: 34.56 E-value: 8.89e-03

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gi 1958679458 279 FDFQAQSPKELTLQKGDIVYIHKEVDKNWLEG-EHHGRLGIFPANYVE 325
Cdd:cd11768     6 YDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRArDKNGNEGYIPSNYVT 53

Src Homology 3 domain of fungal BOI-like proteins; This subfamily includes the Saccharomyces cerevisiae proteins BOI1 and BOI2, and similar proteins. They contain an N-terminal SH3 domain, a Sterile alpha motif (SAM), and a Pleckstrin homology (PH) domain at the C-terminus. BOI1 and BOI2 interact with the SH3 domain of Bem1p, a protein involved in bud formation. They promote polarized cell growth and participates in the NoCut signaling pathway, which is involved in the control of cytokinesis. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

Pssm-ID: 212819 Cd Length: 55 Bit Score: 34.62 E-value: 9.37e-03

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                  ....*....|....*....|....*....|....*....|....*....
gi 1958679458 280 DFQAQSPKELTLQKGDIVYIHK---EVDKNWLEGEH--HGRLGIFPANY 323
Cdd:cd11886     7 DFNARSEDELTLKPGDKIELIEddeEFGDGWYLGRNlrTGETGLFPVVF 55