The Bin/Amphiphysin/Rvs (BAR) domain of Amphiphysin I and II; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Amphiphysins function primarily in endocytosis and other membrane remodeling events. They 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. 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. 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. The N-BAR domain of amphiphysin forms a curved dimer with a positively-charged concave face that can drive membrane bending and curvature. Human autoantibodies to amphiphysin-1 hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Mutations in amphiphysin-2 (BIN1) are associated with autosomal recessive centronuclear myopathy.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  31 QKLGKADETKDEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVYEPEWPGRDEANKIAENNDLL 110
Cdd:cd07611    1 QKLGKADETKDEQFEEYVQNFKRQETEGTRLQRELRAYLAAIKGMQEASKKLTESLHEVYEPDWYGRDDVKTIGEKCDLL 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 111 WMDYHQKLVDQALLTMDTYLGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKKKDEAKIAKAEEELIKAQKVFEEMNV 190
Cdd:cd07611   81 WEDFHQKLVDGALLTLDTYLGQFPDIKNRIAKRSRKLVDYDSARHHLEALQTSKRKDEGRIAKAEEEFQKAQKVFEEFNV 160

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|.
gi 134053947 191 DLQEELPSLWNSRVGFYVNTFQSIAGLEENFHKEMSKLNQNLNDVLVSLEK 241
Cdd:cd07611  161 DLQEELPSLWSRRVGFYVNTFKNVSSLEAKFHKEISVLCHKLYEVMTKLGE 211

The Bin/Amphiphysin/Rvs (BAR) domain of Amphiphysin I and II; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Amphiphysins function primarily in endocytosis and other membrane remodeling events. They 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. 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. 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. The N-BAR domain of amphiphysin forms a curved dimer with a positively-charged concave face that can drive membrane bending and curvature. Human autoantibodies to amphiphysin-1 hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Mutations in amphiphysin-2 (BIN1) are associated with autosomal recessive centronuclear myopathy.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  31 QKLGKADETKDEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVYEPEWPGRDEANKIAENNDLL 110
Cdd:cd07611    1 QKLGKADETKDEQFEEYVQNFKRQETEGTRLQRELRAYLAAIKGMQEASKKLTESLHEVYEPDWYGRDDVKTIGEKCDLL 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 111 WMDYHQKLVDQALLTMDTYLGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKKKDEAKIAKAEEELIKAQKVFEEMNV 190
Cdd:cd07611   81 WEDFHQKLVDGALLTLDTYLGQFPDIKNRIAKRSRKLVDYDSARHHLEALQTSKRKDEGRIAKAEEEFQKAQKVFEEFNV 160

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|.
gi 134053947 191 DLQEELPSLWNSRVGFYVNTFQSIAGLEENFHKEMSKLNQNLNDVLVSLEK 241
Cdd:cd07611  161 DLQEELPSLWSRRVGFYVNTFKNVSSLEAKFHKEISVLCHKLYEVMTKLGE 211

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 134053947 405 FMFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDWNQHKELEKCRGVFPENFTERV 476
Cdd:cd12139    1 FLFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDWNQHKKLEKCRGVFPENFTERV 72

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.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 134053947   407 FKVQAQHDYTATDTDELQLKAGDVVLVIpfqnpEEQDEGWLMGVKESdwnqhkeleKCRGVFPENFTE 474
Cdd:smart00326   3 PQVRALYDYTAQDPDELSFKKGDIITVL-----EKSDDGWWKGRLGR---------GKEGLFPSNYVE 56

The Bin/Amphiphysin/Rvs (BAR) domain of Amphiphysin I and II; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Amphiphysins function primarily in endocytosis and other membrane remodeling events. They 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. 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. 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. The N-BAR domain of amphiphysin forms a curved dimer with a positively-charged concave face that can drive membrane bending and curvature. Human autoantibodies to amphiphysin-1 hinder GABAergic signaling and contribute to the pathogenesis of paraneoplastic stiff-person syndrome. Mutations in amphiphysin-2 (BIN1) are associated with autosomal recessive centronuclear myopathy.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  31 QKLGKADETKDEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVYEPEWPGRDEANKIAENNDLL 110
Cdd:cd07611    1 QKLGKADETKDEQFEEYVQNFKRQETEGTRLQRELRAYLAAIKGMQEASKKLTESLHEVYEPDWYGRDDVKTIGEKCDLL 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 111 WMDYHQKLVDQALLTMDTYLGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKKKDEAKIAKAEEELIKAQKVFEEMNV 190
Cdd:cd07611   81 WEDFHQKLVDGALLTLDTYLGQFPDIKNRIAKRSRKLVDYDSARHHLEALQTSKRKDEGRIAKAEEEFQKAQKVFEEFNV 160

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|.
gi 134053947 191 DLQEELPSLWNSRVGFYVNTFQSIAGLEENFHKEMSKLNQNLNDVLVSLEK 241
Cdd:cd07611  161 DLQEELPSLWSRRVGFYVNTFKNVSSLEAKFHKEISVLCHKLYEVMTKLGE 211

The Bin/Amphiphysin/Rvs (BAR) domain of Bridging integrator 2; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Bridging integrator 2 (Bin2) is a BAR domain containing protein that is mainly expressed in hematopoietic cells. It is upregulated during granulocyte differentiation and is thought to function primarily in this lineage. The BAR domain of Bin2 is closely related to the BAR domains of amphiphysins, which function primarily in endocytosis and other membrane remodeling events. 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. Unlike amphiphysins, Bin2 does not appear to contain a C-terminal SH3 domain. Amphiphysin I proteins, enriched in the brain and nervous system, function in synaptic vesicle endocytosis. Some amphiphysin II isoforms, also called Bridging integrator 1 (Bin1), function in intracellular vessicle trafficking. Bin2 can form a stable complex with Bin1 in cells but cannot replace the function of Bin1, and thus, appears to harbor a nonredundant function. The N-BAR domain of amphiphysin forms a curved dimer with a positively-charged concave face that can drive membrane bending and curvature.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  31 QKLGKADETKDEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVYEPEWPGRDEANKIAENNDLL 110
Cdd:cd07612    1 QKLGKTVETKDEQFEQCAMNLNMQQSDGNRLYKDLKAYLNAVKVMHESSKRLSQTLQDIYEPDWDGHEDLGAIVEGEDLL 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 111 WMDYHQKLVDQALLTMDTYLGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKKKDEAKIAKAEEELIKAQKVFEEMNV 190
Cdd:cd07612   81 WNDYEAKLHDQALRTMESYMAQFPDVKERVAKRGRKLVDYDSARHHLEALQNAKKKDDAKIAKAEEEFNRAQVVFEDINR 160

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|.
gi 134053947 191 DLQEELPSLWNSRVGFYVNTFQSIAGLEENFHKEMSKLNQNLNDVLVSLEK 241
Cdd:cd07612  161 ELREELPILYDSRIGCYVTVFQNISNLRDTFYKEMSKLNHDLYNVMKKLED 211

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 134053947 405 FMFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDWNQHKELEKCRGVFPENFTERV 476
Cdd:cd12139    1 FLFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDWNQHKKLEKCRGVFPENFTERV 72

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 134053947 405 FMFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDwnqhkeleKCRGVFPENFTERV 476
Cdd:cd11790    1 VLYKVRATHDYTAEDTDELTFEKGDVILVIPFDDPEEQDEGWLMGVKEST--------GCRGVFPENFTERI 64

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 134053947 405 FMFKVQAQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGVKESDWNQHKELEKCRGVFPENFTERV 476
Cdd:cd12140    1 FLYKVETLHDFEAANSDELELKRGDIVLVVPSETAADQDAGWLTGVKESDWLQYRDASAYKGLFPENFTRRL 72

The Bin/Amphiphysin/Rvs (BAR) domain of Saccharomyces cerevisiae Reduced viability upon starvation protein 167 and similar proteins; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. This subfamily is composed of fungal proteins with similarity to Saccharomyces cerevisiae Reduced viability upon starvation protein 167 (Rvs167p) and Schizosaccharomyces pombe Hob1 (homolog of Bin1). S. cerevisiae Rvs167p plays a role in regulation of the actin cytoskeleton, endocytosis, and sporulation. It forms a heterodimer with another BAR domain protein Rvs161p. Rvs161p and Rvs167p share common functions but are not interchangeable. Their BAR domains cannot be replaced with each other and the overexpression of one cannot suppress the mutant phenotypes of the other. Rvs167p also interacts with the GTPase activating protein (GAP) Gyp5p, which is involved in ER to Golgi vesicle trafficking. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  41 DEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVYEPEwPGRDEANKIAENNDLLW------MDY 114
Cdd:cd07599    1 DEQFEELEKDFKSLEKSLKKLIEQSKAFRDSWRSILTHQIAFAKEFAELYDPI-VGPKESVGSHPAPESTLarlsryVKA 79

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 115 HQKLVDQALLTMDTY-----------LGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKK----KDEAKIAKAEEELI 179
Cdd:cd07599   80 LEELKKELLEELEFFeervilpakelKKYIKKIRKTIKKRDHKKLDYDKLQNKLNKLLQKKKelslKDEKQLAKLERKLE 159

                        170       180
                 ....*....|....*....|
gi 134053947 180 KAQKVFEEMNVDLQEELPSL 199
Cdd:cd07599  160 EAKEEYEALNELLKSELPKL 179

The Bin/Amphiphysin/Rvs (BAR) domain of Bridging integrator 3; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Bridging integrator 3 (Bin3) is widely expressed in many tissues except in the brain. It plays roles in regulating filamentous actin localization and in cell division. In humans, the Bin3 gene is located in chromosome 8p21.3, a region that is implicated in cancer suppression. Homozygous inactivation of the Bin3 gene in mice led to the development of cataracts and an increased likelihood of lymphomas during aging, suggesting a role for Bin3 in lens development and cancer suppression. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  32 KLGKADETKDEQFEQCVQNFNKQLTEGTRLQKDLRTYLASVKAMHEASKKLSECLQEVyePEWPGRDEANKIAENNDLLW 111
Cdd:cd07590    1 KKPILSKTVDRELEREVQKLQQLESTTKKLYKDMKKYIEAVLALSKAEQRLSQDLASG--PLCEDNDELRNLVEALDSVT 78

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 112 MDYH---QKLVDQALLT----MDTYLGQFPDIKSRIAKRGRKLVDYDSARHHYESLQTAKKK--DEAKIAKAEEELIKAQ 182
Cdd:cd07590   79 TQLDktvQELVNLIQKTfiepLKRLRSVFPSVNAAIKRREQSLQEYERLQAKVEKLAEKEKTgpNLAKLEQAEKALAAAR 158

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|..
gi 134053947 183 KVFEEMNVDLQEELPSLWNSRVGFYVNTFQSIAGLEENFHKEMSKLNQNLND 234
Cdd:cd07590  159 ADFEKQNIKLLEELPKFYNGRTDYFQPCFEALIKSQVLYYSQSTKIFTQLAP 210

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 409 VQAQHDYTATDTDELQLKAGDVVLVipfqNPEEQD---EGWLMGVkesDWnqhkeLEKCRGVFPENFTER 475
Cdd:cd11791    2 LRVLYPYTPQEEDELELVPGDYIYV----SPEELDsssDGWVEGT---SW-----LTGCSGLLPENYTEK 59

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 134053947 409 VQAQHDYTATDTDELQLKAGDVVLVIPFQNpEEQDEGWLMGVKESdwnqhkelEKCRGVFPENFTER 475
Cdd:cd11937    3 LRALFQYKPQNIDELMLSPGDYIFVDPTQQ-SEASEGWVIGISHR--------TGCRGFLPENYTER 60

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 134053947 409 VQAQHDYTATDTDELQLKAGDVVLVIpfqnpEEQDEGWLMGVKESDwnqhkeleKCRGVFPENFTE 474
Cdd:cd11793    2 VQCVHAYTAQQPDELTLEEGDVVNVL-----RKMPDGWYEGERLRD--------GERGWFPSSYTE 54

Variant SH3 domain;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 134053947  411 AQHDYTATDTDELQLKAGDVVLVIPfqnpeEQDEGWLMGvkesdwnqhkELEKCRGVFPENFTE 474
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIE-----ESEDGWWEG----------INTGRTGLVPANYVE 49

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVlvipfQNPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENF 472
Cdd:cd11873    1 EVIVEFDYDAEEPDELTLKVGDII-----TNVKKMEEGWWEG----------TLNGKRGMFPDNF 50

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVvlvipFQNPEEQDEGWLMGVKE 452
Cdd:cd11789    1 RYRAMYDYAAADDDEVSFQEGDV-----IINVEIIDDGWMEGTVQ 40

The Bin/Amphiphysin/Rvs (BAR) domain of Dynamin Binding Protein; BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. DyNamin Binding Protein (DNMBP), also called Tuba, is a Cdc42-specific Guanine nucleotide Exchange Factor (GEF) that binds dynamin and various actin regulatory proteins. It serves as a link between dynamin function, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. DNMBP contains BAR and SH3 domains as well as a Dbl Homology domain (DH domain), which harbors GEF activity. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions. The BAR domain of DNMBP may be involved in binding to membranes. The gene encoding DNMBP is a candidate gene for late onset Alzheimer's disease.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947  38 ETKDEQFEQCVQNFNkQLTEGTR-LQKDLRTYLASVKAMHEASKKLSECLQEVYEPEWPGRDEAN-----KIAENNDLLW 111
Cdd:cd07589    1 QTKDKEFDELEKKFG-SLEKQVQlVVRNVELYLQHVQESVLVKVLALEVVLDLYPSNHPRLESKWerfrrVVRGISSKAL 79

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 112 MDYHQKLVDQALLTMDTYLGQFPDIKSRIAKRGRKLVDYDSarhhYESlqtakKKDEAKiaKAEEELIKAQKVFEEMNVD 191
Cdd:cd07589   80 PEFKSRVRKLVIEPLSSLLKLFSGPQKLIQKRYDKLLDYER----YKE-----KKERGG--KVDEELEEAANQYEALNAQ 148

                 ....*...
gi 134053947 192 LQEELPSL 199
Cdd:cd07589  149 LKEELPKF 156

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 415 YTATDTDELQLKAGDVVLVIpfqNPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENFTE 474
Cdd:cd12057    8 YEAQNEDELTIKEGDIVTLI---SKDCIDAGWWEG----------ELNGRRGVFPDNFVK 54

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLvipfqNPEEQDEGWLMGVKESDWNQhkelekcrGVFPENFTERV 476
Cdd:cd11934    4 RYRAVYDYNAADEDEVSFQDGDTIV-----NVQQIDDGWMYGTVERTGDT--------GMLPANYVEAI 59

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIpfqnPEEQDEGWLMGVKESDwnqhkelekCRGVFPENFTE 474
Cdd:cd11999    3 RVRAVYDYTGQEPDELSFKAGEELLKV----EDEDEQGWCKGVTDGG---------AVGLYPANYVE 56

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 134053947 407 FKVQAQHDYTATDTDELQLKAGDVVLVIpfqnpEEQDEGWLMGVKESDWNQHKElekcrGVFPENFTER 475
Cdd:cd11887    2 FKVKALYPYESDHEDDLNFDVGQLITVT-----EEEDADWYFGEYVDSNGNTKE-----GIFPKNFVEV 60

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 134053947 411 AQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENFTER 475
Cdd:cd12058    4 ALYDYEASGEDELSLRRGDVVEVLSQDAAVSGDDGWWAG----------KIRHRLGIFPANYVTR 58

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 134053947 411 AQHDYTATDTDELQLKAGDVVLVIPFQNPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENF 472
Cdd:cd11876    4 ALFDYDARGEDELTLRRGQPVEVLSKDAAVSGDEGWWTG----------KIGDKVGIFPSNY 55

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIpfqnpEEQDEGWLMGvkesdwnqhkELEKCRGVFPENFTER 475
Cdd:cd11805    1 RVQALYDFNPQEPGELEFRRGDIITVL-----DSSDPDWWKG----------ELRGRVGIFPANYVQP 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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIpfqnPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENF 472
Cdd:cd11778    1 YVEALYDYEAQGDDEISIRVGDRIAVI----RGDDGSGWTYG----------EINGVKGLFPTSY 51

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 134053947 410 QAQHDYTATDTDELQLKAGDVVLVIpfqNPEEQDEGWLMGvkesdwnqhkELEKCRGVFPENF 472
Cdd:cd12056    5 KALFHYEGTNEDELDFKEGEIILII---SKDTGEPGWWKG----------ELNGKEGVFPDNF 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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 134053947 410 QAQHDYTATDTDELQLKAGDVVlvipfQNPEEQDEGWLMG-VKESDWNqhkelekcrGVFPENFTERVQ 477
Cdd:cd11935    4 RAMYDYSAQDEDEVSFRDGDYI-----VNVQPIDEGWMYGtVQRTGRT---------GMLPANYIEFVN 58

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIpfqnpEEQDEGWLMGVkesdwnqhkeLEKCRGVFPENFTE 474
Cdd:cd11877    1 LVRAKFNFEGTNEDELSFDKGDIITVT-----QVVEGGWWEGT----------LNGKTGWFPSNYVK 52

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 134053947 413 HDYTATDTDELQLKAGDVVLVIpfQNPEEQDEGWLMGvkesdwnqhKELEKCR-GVFPENF 472
Cdd:cd11886    6 HDFNARSEDELTLKPGDKIELI--EDDEEFGDGWYLG---------RNLRTGEtGLFPVVF 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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIpfqnPEEQDEGWLMGVkesdwNQHKElekcRGVFPENFTE 474
Cdd:cd11763    1 KVRALYDFDSQPSGELSLRAGEVLTIT----RQDVGDGWLEGR-----NSRGE----VGLFPSSYVE 54

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.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVIPfqnpeEQDEGWLMGVkesdwnqhkeLEKCRGVFPENFTE 474
Cdd:cd12055    1 RCQVAFSYLPQNEDELELKVGDIIEVVG-----EVEEGWWEGV----------LNGKTGMFPSNFIK 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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 134053947 408 KVQAQHDYTATDTDELQLKAGDVVLVipfqnPEEQD--EGWLMGvkesdwnqhkELEKCRGVFPENFTER 475
Cdd:cd11836    1 KYRALYAFEARNPDEISFQPGDIIQV-----DESQVaePGWLAG----------ELKGKTGWFPANYVEK 55

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.