Src homology 2 domain found in SH2 domain-containing adapter proteins B, D, E, and F (SHB, SHD, SHE, SHF); SHB, SHD, SHE, and SHF are SH2 domain-containing proteins that play various roles throughout the cell. SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. SHE is expressed in heart, lung, brain, and skeletal muscle, while expression of SHD is restricted to the brain. SHF is mainly expressed in skeletal muscle, brain, liver, prostate, testis, ovary, small intestine, and colon. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. SHF contains four putative tyrosine phosphorylation sites and an SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHFC 857
Cdd:cd09945    1 QGWYHGAITRIEAESLLRPCKEGSYLVRNSESTKQDYSLSLKSAKGFMHMRIQRNETGQYILGQFSRPFETIPEMIRHYC 80

                         90
                 ....*....|....*...
gi 442616108 858 LNRLPVRGAEHMCLIEPV 875
Cdd:cd09945   81 LNKLPVRGAEHMCLLEPV 98

Src homology 2 domain found in SH2 domain-containing adapter proteins B, D, E, and F (SHB, SHD, SHE, SHF); SHB, SHD, SHE, and SHF are SH2 domain-containing proteins that play various roles throughout the cell. SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. SHE is expressed in heart, lung, brain, and skeletal muscle, while expression of SHD is restricted to the brain. SHF is mainly expressed in skeletal muscle, brain, liver, prostate, testis, ovary, small intestine, and colon. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. SHF contains four putative tyrosine phosphorylation sites and an SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHFC 857
Cdd:cd09945    1 QGWYHGAITRIEAESLLRPCKEGSYLVRNSESTKQDYSLSLKSAKGFMHMRIQRNETGQYILGQFSRPFETIPEMIRHYC 80

                         90
                 ....*....|....*...
gi 442616108 858 LNRLPVRGAEHMCLIEPV 875
Cdd:cd09945   81 LNKLPVRGAEHMCLLEPV 98

SH2 domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 442616108  780 WYHGAITRIEAETTLRPL-SEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQfSRPFETVPEMIRHF 856
Cdd:pfam00017   1 WYHGKISRQEAERLLLNGkPDGTFLVRESESTPGGYTLSVRDDGKVKHYKIQSTDNGGYYISG-GVKFSSLAELVEHY 77

Src homology 2 domain found in SH2 domain-containing adapter proteins B, D, E, and F (SHB, SHD, SHE, SHF); SHB, SHD, SHE, and SHF are SH2 domain-containing proteins that play various roles throughout the cell. SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. SHE is expressed in heart, lung, brain, and skeletal muscle, while expression of SHD is restricted to the brain. SHF is mainly expressed in skeletal muscle, brain, liver, prostate, testis, ovary, small intestine, and colon. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. SHF contains four putative tyrosine phosphorylation sites and an SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHFC 857
Cdd:cd09945    1 QGWYHGAITRIEAESLLRPCKEGSYLVRNSESTKQDYSLSLKSAKGFMHMRIQRNETGQYILGQFSRPFETIPEMIRHYC 80

                         90
                 ....*....|....*...
gi 442616108 858 LNRLPVRGAEHMCLIEPV 875
Cdd:cd09945   81 LNKLPVRGAEHMCLLEPV 98

Src homology 2 domain found in SH2 domain-containing adapter protein B (SHB); SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETgQYILGQFSRPFETVPEMIRHFC 857
Cdd:cd10389    1 QIWYHGAISRGDAENLLRLCKECSYLVRNSQTSKHDYSLSLKSNQGFMHMKLAKTKE-KYVLGQNSPPFDSVPEVIHYYT 79

                         90
                 ....*....|....*...
gi 442616108 858 LNRLPVRGAEHMCLIEPV 875
Cdd:cd10389   80 TRKLPIKGAEHLSLLYPV 97

Src homology 2 domain found in SH2 domain-containing adapter protein E (SHE); SHE is expressed in heart, lung, brain, and skeletal muscle. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHFC 857
Cdd:cd10391    1 QPWYHGSISRAEAESRLQPCKEASYLVRNSESGNSKYSIALKTSQGCVHIIVAQTKDNKYTLNQTSAVFDSIPEVVHYYS 80

                         90
                 ....*....|....*...
gi 442616108 858 LNRLPVRGAEHMCLIEPV 875
Cdd:cd10391   81 NEKLPFKGAEHMTLLHPV 98

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 442616108 780 WYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLK-GAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHF 856
Cdd:cd00173    2 WFHGSISREEAERLLRGKPDGTFLVRESSSEPGDYVLSVRsGDGKVKHYLIERNEGGYYLLGGSGRTFPSLPELVEHY 79

Src homology 2 (SH2) domain found in Abelson murine lymphosarcoma virus (ABL) proteins; ABL-family proteins are highly conserved tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. Several types of posttranslational modifications control ABL catalytic activity, subcellular localization, and stability, with consequences for both cytoplasmic and nuclear ABL functions. Binding partners provide additional regulation of ABL catalytic activity, substrate specificity, and downstream signaling. By combining this cassette with actin-binding and -bundling domain, ABL proteins are capable of connecting phosphoregulation with actin-filament reorganization. Vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions. ABL1 includes nuclear localization signals and a DNA binding domain which is used to mediate DNA damage-repair functions, while ABL2 has additional binding capacity for actin and for microtubules to enhance its cytoskeletal remodeling functions. SH2 is involved in several autoinhibitory mechanism that constrain the enzymatic activity of the ABL-family kinases. In one mechanism SH2 and SH3 cradle the kinase domain while a cap sequence stabilizes the inactive conformation resulting in a locked inactive state. Another involves phosphatidylinositol 4,5-bisphosphate (PIP2) which binds the SH2 domain through residues normally required for phosphotyrosine binding in the linker segment between the SH2 and kinase domains. The SH2 domain contributes to ABL catalytic activity and target site specificity. It is thought that the ABL catalytic site and SH2 pocket have coevolved to recognize the same sequences. Recent work now supports a hierarchical processivity model in which the substrate target site most compatible with ABL kinase domain preferences is phosphorylated with greatest efficiency. If this site is compatible with the ABL SH2 domain specificity, it will then reposition and dock in the SH2 pocket. This mechanism also explains how ABL kinases phosphorylates poor targets on the same substrate if they are properly positioned and how relatively poor substrate proteins might be recruited to ABL through a complex with strong substrates that can also dock with the SH2 pocket. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 776 ERQGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRpFETVPEMIRH 855
Cdd:cd09935    1 EKHSWYHGPISRNAAEYLLSSGINGSFLVRESESSPGQYSISLRYDGRVYHYRISEDSDGKVYVTQEHR-FNTLAELVHH 79

                 ....
gi 442616108 856 FCLN 859
Cdd:cd09935   80 HSKN 83

Src homology 2 (SH2) domain found in Nck; Nck proteins are adaptors that modulate actin cytoskeleton dynamics by linking proline-rich effector molecules to tyrosine kinases or phosphorylated signaling intermediates. There are two members known in this family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth factor receptor-bound protein 4 (Grb4)). They are characterized by having 3 SH3 domains and a C-terminal SH2 domain. Nck1 and Nck2 have overlapping functions as determined by gene knockouts. Both bind receptor tyrosine kinases and other tyrosine-phosphorylated proteins through their SH2 domains. In addition they also bind distinct targets. Neuronal signaling proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1) all bind to Nck-2 exclusively. And in the case of PDGFR, Tyr(P)751 binds to Nck1 while Tyr(P)1009 binds to Nck2. Nck1 and Nck2 have a role in the infection process of enteropathogenic Escherichia coli (EPEC). Their SH3 domains are involved in recruiting and activating the N-WASP/Arp2/3 complex inducing actin polymerization resulting in the production of pedestals, dynamic bacteria-presenting protrusions of the plasma membrane. A similar thing occurs in the vaccinia virus where motile plasma membrane projections are formed beneath the virus. Recently it has been shown that the SH2 domains of both Nck1 and Nck2 bind the G-protein coupled receptor kinase-interacting protein 1 (GIT1) in a phosphorylation-dependent manner. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 778 QGWYHGAITRIEAETTLRPLS-EGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNEtGQYILGQfsRPFETVPEMIRHF 856
Cdd:cd10409    1 KEWYYGNVTRHQAECALNERGvEGDFLIRDSESSPSDFSVSLKAVGKNKHFKVQLVD-NVYCIGQ--RRFNSMDELVEHY 77

                         90
                 ....*....|..
gi 442616108 857 clNRLPVRGAEH 868
Cdd:cd10409   78 --KKAPIFTSEH 87

Src homology 2 (SH2) domain found in the Src family of non-receptor tyrosine kinases; The Src family kinases are nonreceptor tyrosine kinases that have been implicated in pathways regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. It is thought that transforming ability of Src is linked to its ability to activate key signaling molecules in these pathways, rather than through direct activity. As such blocking Src activation has been a target for drug companies. Src family members can be divided into 3 groups based on their expression pattern: 1) Src, Fyn, and Yes; 2) Blk, Fgr, Hck, Lck, and Lyn; and 3) Frk-related kinases Frk/Rak and Iyk/Bsk Of these, cellular c-Src is the best studied and most frequently implicated in oncogenesis. The c-Src contains five distinct regions: a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. Src exists in both active and inactive conformations. Negative regulation occurs through phosphorylation of Tyr, resulting in an intramolecular association between phosphorylated Tyr and the SH2 domain of SRC, which locks the protein in a closed conformation. Further stabilization of the inactive state occurs through interactions between the SH3 domain and a proline-rich stretch of residues within the kinase domain. Conversely, dephosphorylation of Tyr allows SRC to assume an open conformation. Full activity requires additional autophosphorylation of a Tyr residue within the catalytic domain. Loss of the negative-regulatory C-terminal segment has been shown to result in increased activity and transforming potential. Phosphorylation of the C-terminal Tyr residue by C-terminal Src kinase (Csk) and Csk homology kinase results in increased intramolecular interactions and consequent Src inactivation. Specific phosphatases, protein tyrosine phosphatase a (PTPa) and the SH-containing phosphatases SHP1/SHP2, have also been shown to take a part in Src activation. Src is also activated by direct binding of focal adhesion kinase (Fak) and Crk-associated substrate (Cas) to the SH2 domain. SRC activity can also be regulated by numerous receptor tyrosine kinases (RTKs), such as Her2, epidermal growth factor receptor (EGFR), fibroblast growth factor receptor, platelet-derived growth factor receptor (PDGFR), and vascular endothelial growth factor receptor (VEGFR). In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 776 ERQGWYHGAITRIEAETTL--RPLSEGSFLVRNCESTKQDYSLSLK---GAKGFM--HMRIQRNETGQYILGQfSRPFET 848
Cdd:cd09933    1 EAEEWFFGKIKRKDAEKLLlaPGNPRGTFLIRESETTPGAYSLSVRdgdDARGDTvkHYRIRKLDNGGYYITT-RATFPT 79

                 ....*...
gi 442616108 849 VPEMIRHF 856
Cdd:cd09933   80 LQELVQHY 87

Src homology 2 (SH2) domain found in Nck; Nck proteins are adaptors that modulate actin cytoskeleton dynamics by linking proline-rich effector molecules to tyrosine kinases or phosphorylated signaling intermediates. There are two members known in this family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth factor receptor-bound protein 4 (Grb4)). They are characterized by having 3 SH3 domains and a C-terminal SH2 domain. Nck1 and Nck2 have overlapping functions as determined by gene knockouts. Both bind receptor tyrosine kinases and other tyrosine-phosphorylated proteins through their SH2 domains. In addition they also bind distinct targets. Neuronal signaling proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1) all bind to Nck-2 exclusively. And in the case of PDGFR, Tyr(P)751 binds to Nck1 while Tyr(P)1009 binds to Nck2. Nck1 and Nck2 have a role in the infection process of enteropathogenic Escherichia coli (EPEC). Their SH3 domains are involved in recruiting and activating the N-WASP/Arp2/3 complex inducing actin polymerization resulting in the production of pedestals, dynamic bacteria-presenting protrusions of the plasma membrane. A similar thing occurs in the vaccinia virus where motile plasma membrane projections are formed beneath the virus. Recently it has been shown that the SH2 domains of both Nck1 and Nck2 bind the G-protein coupled receptor kinase-interacting protein 1 (GIT1) in a phosphorylation-dependent manner. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLRPLS-EGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETgQYILGQfsRPFETVPEMIRHFcl 858
Cdd:cd10408    3 WYYGKVTRHQAEMALNERGnEGDFLIRDSESSPNDFSVSLKAQGKNKHFKVQLKEC-VYCIGQ--RKFSSMEELVEHY-- 77

                         90       100
                 ....*....|....*....|
gi 442616108 859 NRLPVRGAEH---MCLIEPV 875
Cdd:cd10408   78 KKAPIFTSEQgekLYLIKAL 97

C-terminal Src homology 2 (C-SH2) domain in Phospholipase C gamma; Phospholipase C gamma is a signaling molecule that is recruited to the C-terminal tail of the receptor upon autophosphorylation of a highly conserved tyrosine. PLCgamma is composed of a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, 2 catalytic regions of PLC domains that flank 2 tandem SH2 domains (N-SH2, C-SH2), and ending with a SH3 domain and C2 domain. N-SH2 SH2 domain-mediated interactions represent a crucial step in transmembrane signaling by receptor tyrosine kinases. SH2 domains recognize phosphotyrosine (pY) in the context of particular sequence motifs in receptor phosphorylation sites. Both N-SH2 and C-SH2 have a very similar binding affinity to pY. But in growth factor stimulated cells these domains bind to different target proteins. N-SH2 binds to pY containing sites in the C-terminal tails of tyrosine kinases and other receptors. Recently it has been shown that this interaction is mediated by phosphorylation-independent interactions between a secondary binding site found exclusively on the N-SH2 domain and a region of the FGFR1 tyrosine kinase domain. This secondary site on the SH2 cooperates with the canonical pY site to regulate selectivity in mediating a specific cellular process. C-SH2 binds to an intramolecular site on PLCgamma itself which allows it to hydrolyze phosphatidylinositol-4,5-bisphosphate into diacylglycerol and inositol triphosphate. These then activate protein kinase C and release calcium. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 776 ERQGWYHGAITRIEAETTLRPLSE-GSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRnETGQYILGQFSrpFETVPEMIR 854
Cdd:cd09932    2 ESKEWFHANLTREQAEEMLMRVPRdGAFLVRPSETDPNSFAISFRAEGKIKHCRIKQ-EGRLFVIGTSQ--FESLVELVS 78

                         90       100
                 ....*....|....*....|....*.
gi 442616108 855 HFCLNRLpVRGaehMCLIEPVIAQLL 880
Cdd:cd09932   79 YYEKHPL-YRK---IKLRYPVNEELL 100

C-terminal Src homology 2 (SH2) domain found in Ras GTPase-activating protein 1 (GAP); RasGAP is part of the GAP1 family of GTPase-activating proteins. The protein is located in the cytoplasm and stimulates the GTPase activity of normal RAS p21, but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in RAS inactivation, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Alternative splicing results in two isoforms. The shorter isoform which lacks the N-terminal hydrophobic region, has the same activity, and is expressed in placental tissues. In general longer isoform contains 2 SH2 domains, a SH3 domain, a pleckstrin homology (PH) domain, and a calcium-dependent phospholipid-binding C2 domain. The C-terminus contains the catalytic domain of RasGap which catalyzes the activation of Ras by hydrolyzing GTP-bound active Ras into an inactive GDP-bound form of Ras. This model contains the C-terminal SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 442616108 780 WYHGAITRIEAETTL-RPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGqfSRPFETVPEMIRHF 856
Cdd:cd10354    2 WFHGKISREEAYNMLvKVGGPGSFLVRESDNTPGDYSLSFRVNEGIKHFKIIPTGNNQFMMG--GRYFSSLDDVIDRY 77

Src homology 2 (SH2) domain found in B-cell linker (BLNK) protein and SH2 domain-containing leukocyte protein of 76 kDa (SLP-76); BLNK (also known as SLP-65 or BASH) is an important adaptor protein expressed in B-lineage cells. BLNK consists of a N-terminal sterile alpha motif (SAM) domain and a C-terminal SH2 domain. BLNK is a cytoplasmic protein, but a part of it is bound to the plasma membrane through an N-terminal leucine zipper motif and transiently bound to a cytoplasmic domain of Iga through its C-terminal SH2 domain upon B cell antigen receptor (BCR)-stimulation. A non-ITAM phosphotyrosine in Iga is necessary for the binding with the BLNK SH2 domain and/or for normal BLNK function in signaling and B cell activation. Upon phosphorylation BLNK binds Btk and PLCgamma2 through their SH2 domains and mediates PLCgamma2 activation by Btk. BLNK also binds other signaling molecules such as Vav, Grb2, Syk, and HPK1. BLNK has been shown to be necessary for BCR-mediated Ca2+ mobilization, for the activation of mitogen-activated protein kinases such as ERK, JNK, and p38 in a chicken B cell line DT40, and for activation of transcription factors such as NF-AT and NF-kappaB in human or mouse B cells. BLNK is involved in B cell development, B cell survival, activation, proliferation, and T-independent immune responses. BLNK is structurally homologous to SLP-76. SLP-76 and (linker for activation of T cells) LAT are adaptor/linker proteins in T cell antigen receptor activation and T cell development. BLNK interacts with many downstream signaling proteins that interact directly with both SLP-76 and LAT. New data suggest functional complementation of SLP-76 and LAT in T cell antigen receptor function with BLNK in BCR function. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 774 PLERQGWYHGAITRIEAETTLRPLS-EGSFLVRNC--ESTKQDYSLSLKGAKGFMHMRIQRNE-TGQYILG---QFSRPF 846
Cdd:cd09929    7 DLLPKEWYAGNIDRKEAEEALRRSNkDGTFLVRDSsgKDSSQPYTLMVLYNDKVYNIQIRFLEnTRQYALGtglRGEETF 86

                         90       100       110
                 ....*....|....*....|....*....|....
gi 442616108 847 ETVPEMIRHFCLNRLPV-----RGAEHMCLIEPV 875
Cdd:cd09929   87 SSVAEIIEHHQKTPLLLidgkdNTKDSTCLLYAA 120

Src homology 2 (SH2) domain found in suppressor of cytokine signaling (SOCS) proteins; SH2 domain found in SOCS proteins. SOCS was first recognized as a group of cytokine-inducible SH2 (CIS) domain proteins comprising eight family members in human (CIS and SOCS1-SOCS7). In addition to the SH2 domain, SOCS proteins have a variable N-terminal domain and a conserved SOCS box in the C-terminal domain. SOCS proteins bind to a substrate via their SH2 domain. The prototypical members, CIS and SOCS1-SOCS3, have been shown to regulate growth hormone signaling in vitro and in a classic negative feedback response compete for binding at phosphotyrosine sites in JAK kinase and receptor pathways to displace effector proteins and target bound receptors for proteasomal degradation. Loss of SOCS activity results in excessive cytokine signaling associated with a variety of hematopoietic, autoimmune, and inflammatory diseases and certain cancers. Members (SOCS4-SOCS7) were identified by their conserved SOCS box, an adapter motif of 3 helices that associates substrate binding domains, such as the SOCS SH2 domain, ankryin, and WD40 with ubiquitin ligase components. These show limited cytokine induction. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 775 LERQGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNEtgqyilGQFSrpFETVPEMIR 854
Cdd:cd10387    7 LAKQGWYWGPITRWEAEGKLANVPDGSFLVRDSSDDRYLLSLSFRSHGKTLHTRIEHSN------GRFS--FYEQPDVEG 78

                 .
gi 442616108 855 H 855
Cdd:cd10387   79 H 79

Src homology 2 (SH2) domain found in Tec-like proteins; The Tec protein tyrosine kinase is the founding member of a family that includes Btk, Itk, Bmx, and Txk. The members have a PH domain, a zinc-binding motif, a SH3 domain, a SH2 domain, and a protein kinase catalytic domain. Btk is involved in B-cell receptor signaling with mutations in Btk responsible for X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency (xid) in mice. Itk is involved in T-cell receptor signaling. Tec is expressed in both T and B cells, and is thought to function in activated and effector T lymphocytes to induce the expression of genes regulated by NFAT transcription factors. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 775 LERQGWYHGAITRIEAETTLRPLS-EGSFLVRNcESTKQDYSLSL----KGAKGFMHMRIQRNETGQYILGQfSRPFETV 849
Cdd:cd09934    3 LEKYEWYVGDMSRQRAESLLKQEDkEGCFVVRN-SSTKGLYTVSLftkvPGSPHVKHYHIKQNARSEFYLAE-KHCFETI 80

                 ....*.
gi 442616108 850 PEMIRH 855
Cdd:cd09934   81 PELINY 86

Src homology 2 (SH2) domain found in cytokine-inducible SH2-containing protein (CIS); CIS family members are known to be cytokine-inducible negative regulators of cytokine signaling. The expression of the CIS gene can be induced by IL2, IL3, GM-CSF and EPO in hematopoietic cells. Proteasome-mediated degradation of this protein has been shown to be involved in the inactivation of the erythropoietin receptor. Suppressor of cytokine signalling (SOCS) was first recognized as a group of cytokine-inducible SH2 (CIS) domain proteins comprising eight family members in human (CIS and SOCS1-SOCS7). In addition to the SH2 domain, SOCS proteins have a variable N-terminal domain and a conserved SOCS box in the C-terminal domain. SOCS proteins bind to a substrate via their SH2 domain. The prototypical members, CIS and SOCS1-SOCS3, have been shown to regulate growth hormone signaling in vitro and in a classic negative feedback response compete for binding at phosphotyrosine sites in JAK kinase and receptor pathways to displace effector proteins and target bound receptors for proteasomal degradation. Loss of SOCS activity results in excessive cytokine signaling associated with a variety of hematopoietic, autoimmune, and inflammatory diseases and certain cancers. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 775 LERQGWYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIqrnetgQYILGQF-------SRP-- 845
Cdd:cd10718    1 LRESGWYWGSITASEAHQALQKAPEGTFLVRDSSHPSYMLTLSVKTTRGPTNVRI------EYSDGSFrldssslARPrl 74

                         90
                 ....*....|...
gi 442616108 846 --FETVPEMIRHF 856
Cdd:cd10718   75 lsFPDVVSLVQHY 87

Src homology 2 domain found in the SH2 domain containing protein 2A and 7 (SH2D2A and SH2D7); SH2D2A and SH7 both contain a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 442616108 780 WYHGAITRIEAETTLRPLSEGSFLVRNCEStKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHF 856
Cdd:cd10349    2 WFHGFITRREAERLLEPKPQGCYLVRFSES-AVTFVLSYRSRTCCRHFLLAQLRDGRHVVLGEDSAHARLQDLLLHY 77

Src homology 2 (SH2) domain found in Gardner-Rasheed feline sarcoma viral (v-fgr) oncogene homolog, Fgr; Fgr is a member of the Src non-receptor type tyrosine kinase family of proteins. The protein contains N-terminal sites for myristoylation and palmitoylation, a PTK domain, and SH2 and SH3 domains which are involved in mediating protein-protein interactions with phosphotyrosine-containing and proline-rich motifs, respectively. Fgr is expressed in B-cells and myeloid cells, localizes to plasma membrane ruffles, and functions as a negative regulator of cell migration and adhesion triggered by the beta-2 integrin signal transduction pathway. Multiple alternatively spliced variants, encoding the same protein, have been identified Fgr has been shown to interact with Wiskott-Aldrich syndrome protein. Fgr has a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLrpLSE----GSFLVRNCESTKQDYSLSLK---GAKG--FMHMRIQRNETGQYILGQFSRpFETVP 850
Cdd:cd10367    5 WYFGKIGRKDAERQL--LSPgnprGAFLIRESETTKGAYSLSIRdwdQNRGdhVKHYKIRKLDTGGYYITTRAQ-FDTVQ 81

                 ....*.
gi 442616108 851 EMIRHF 856
Cdd:cd10367   82 ELVQHY 87

N-terminal Src homology 2 (SH2) domain found in SH2 domains, ANK, and kinase domain (shark) proteins; These non-receptor protein-tyrosine kinases contain two SH2 domains, five ankyrin (ANK)-like repeats, and a potential tyrosine phosphorylation site in the carboxyl-terminal tail which resembles the phosphorylation site in members of the src family. Like, mammalian non-receptor protein-tyrosine kinases, ZAP-70 and syk proteins, they do not have SH3 domains. However, the presence of ANK makes these unique among protein-tyrosine kinases. Both tyrosine kinases and ANK repeats have been shown to transduce developmental signals, and SH2 domains are known to participate intimately in tyrosine kinase signaling. These tyrosine kinases are believed to be involved in epithelial cell polarity. The members of this family include the shark (SH2 domains, ANK, and kinase domain) gene in Drosophila and yellow fever mosquitos, as well as the hydra protein HTK16. Drosophila Shark is proposed to transduce intracellularly the Crumbs, a protein necessary for proper organization of ectodermal epithelia, intercellular signal. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 442616108 780 WYHGAITRIEAETTLRPLS--EGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHF 856
Cdd:cd10347    3 WYHGKISREVAEALLLREGgrDGLFLVRESTSAPGDYVLSLLAQGEVLHYQIRRHGEDAFFSDDGPLIFHGLDTLIEHY 81

Src homology 2 (SH2) domain found in alpha2-chimerin and beta2-chimerin proteins; Chimerins are a family of phorbol ester- and diacylglycerol-responsive GTPase-activating proteins. Alpha1-chimerin (formerly known as n-chimerin) and alpha2-chimerin are alternatively spliced products of a single gene, as are beta1- and beta2-chimerin. alpha1- and beta1-chimerin have a relatively short N-terminal region that does not encode any recognizable domains, whereas alpha2- and beta2-chimerin both include a functional SH2 domain that can bind to phosphotyrosine motifs within receptors. All of the isoforms contain a GAP domain with specificity in vitro for Rac1 and a diacylglycerol (DAG)-binding C1 domain which allows them to translocate to membranes in response to DAG signaling and anchors them in close proximity to activated Rac. Other C1 domain-containing diacylglycerol receptors including: PKC, Munc-13 proteins, phorbol ester binding scaffolding proteins involved in Ca2+-stimulated exocytosis, and RasGRPs, diacylglycerol-activated guanine-nucleotide exchange factors (GEFs) for Ras and Rap1. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 442616108 781 YHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRpFETVPEMIR 854
Cdd:cd10352    9 YHGLISREEAEQLLSGASDGSYLIRESSRDDGYYTLSLRFNGKVKNYKLYYDGKNHYHYVGEKR-FDTIHDLVA 81

Src homology 2 (SH2) domain found in SH2B adapter proteins (SH2B1, SH2B2, SH2B3); SH2B2 (APS), like other members of the SH2B adapter protein family, contains a pleckstrin homology domain, at least one dimerization domain, and a C-terminal SH2 domain which binds to phosphorylated tyrosines in a variety of tyrosine kinases. SH2B1 and SH2B2 function in signaling pathways found downstream of growth hormone receptor and receptor tyrosine kinases, including the insulin, insulin-like growth factor-I (IGF-I), platelet-derived growth factor (PDGF), nerve growth factor, hepatocyte growth factor, and fibroblast growth factor receptors. SH2B2beta, a new isoform of SH2B2, is an endogenous inhibitor of SH2B1 and/or SH2B2 (SH2B2alpha), negatively regulating insulin signaling and/or JAK2-mediated cellular responses. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLR---PLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSrpFETVPEMIRHF 856
Cdd:cd10411   10 WFHGTLSRVKAAQLVLaggPRSHGLFVIRQSETRPGEYVLTFNFQGKAKHLRLSLNGHGQCHVQHLW--FQSVFDMLRHF 87

                 ....*..
gi 442616108 857 CLNRLPV 863
Cdd:cd10411   88 HTHPIPL 94

Src homology 2 (SH2) domain found in SH2 domain-bearing protein kinases D and E (ShkD and ShkE); SH2-bearing genes cloned from Dictyostelium include two transcription factors, STATa and STATc, and a signaling factor, SHK1 (shkA). A database search of the Dictyostelium discoideum genome revealed two additional putative STAT sequences, dd-STATb and dd-STATd, and four additional putative SHK genes, dd-SHK2 (shkB), dd-SHK3 (shkC), dd-SHK4 (shkD), and dd-SHK5 (shkE). This model contains members of shkD and shkE. All of the SHK members are most closely related to the protein kinases found in plants. However these kinases in plants are not conjugated to any SH2 or SH2-like sequences. Alignment data indicates that the SHK SH2 domains carry some features of the STAT SH2 domains in Dictyostelium. When STATc's linker domain was used for a BLAST search, the sequence between the protein kinase domain and the SH2 domain (the linker) of SHK was recovered, suggesting a close relationship among these molecules within this region. SHK's linker domain is predicted to contain an alpha-helix which is indeed homologous to that of STAT. Based on the phylogenetic alignment, SH2 domains can be grouped into two categories, STAT-type and Src-type. SHK family members are in between, but are closer to the STAT-type which indicates a close relationship between SHK and STAT families in their SH2 domains and further supports the notion that SHKs linker-SH2 domain evolved from STAT or STATL (STAT-like Linker-SH2) domain found in plants. In SHK, STAT, and SPT6, the linker-SH2 domains all reside exclusively in the C-terminal regions. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 442616108 769 IDVTIPLERQGWYHGAITRIEAETTLRPLSEGSFLVR--NCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQF 842
Cdd:cd10357    1 IMNINILLAKSWFHGDISRDEAEKRLRGRPEGTFLIRlsSTDPKKTPFTISKKKKSKPVHKRISRIDVNNYTSFKI 76

C-terminal Src homology 2 (SH2) domain found in SH2 domains, ANK, and kinase domain (shark) proteins; These non-receptor protein-tyrosine kinases contain two SH2 domains, five ankyrin (ANK)-like repeats, and a potential tyrosine phosphorylation site in its carboxyl-terminal tail which resembles the phosphorylation site in members of the src family. Like, mammalian non-receptor protein-tyrosine kinases, ZAP-70 and syk proteins, they do not have SH3 domains. However, the presence of ANK makes these unique among protein-tyrosine kinases. Both tyrosine kinases and ANK repeats have been shown to transduce developmental signals, and SH2 domains are known to participate intimately in tyrosine kinase signaling. These tyrosine kinases are believed to be involved in epithelial cell polarity. The members of this family include the shark (SH2 domains, ANK, and kinase domain) gene in Drosophila and yellow fever mosquitos, as well as the hydra protein HTK16. Drosophila Shark is proposed to transduce intracellularly the Crumbs, a protein necessary for proper organization of ectodermal epithelia, intercellular signal. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLR--PLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYIL--GQFsrpFETVPEMIRH 855
Cdd:cd10348    2 WLHGALDRNEAVEILKqkADADGSFLVRYSRRRPGGYVLTLVYENHVYHFEIQNRDDKWFYIddGPY---FESLEHLIEH 78

                 .
gi 442616108 856 F 856
Cdd:cd10348   79 Y 79

Src homology 2 domain found in the SH2 domain containing protein 4B (SH2D4B); SH2D4B contains a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLRPLSEGSFLVRNCESTkQDYSLSLKGAKGFMHMRI 829
Cdd:cd10351    9 WFHGIISREEAEALLMNATEGSFLVRVSEKI-WGYTLSYRLQSGFKHFLV 57

N-terminal Src homology 2 (SH2) domain found in Zeta-chain-associated protein kinase 70 (ZAP-70) and Spleen tyrosine kinase (Syk) proteins; ZAP-70 and Syk comprise a family of hematopoietic cell specific protein tyrosine kinases (PTKs) that are required for antigen and antibody receptor function. ZAP-70 is expressed in T and natural killer (NK) cells and Syk is expressed in B cells, mast cells, polymorphonuclear leukocytes, platelets, macrophages, and immature T cells. They are required for the proper development of T and B cells, immune receptors, and activating NK cells. They consist of two N-terminal Src homology 2 (SH2) domains and a C-terminal kinase domain separated from the SH2 domains by a linker or hinge region. Phosphorylation of both tyrosine residues within the Immunoreceptor Tyrosine-based Activation Motifs (ITAM; consensus sequence Yxx[LI]x(7,8)Yxx[LI]) by the Src-family PTKs is required for efficient interaction of ZAP-70 and Syk with the receptor subunits and for receptor function. ZAP-70 forms two phosphotyrosine binding pockets, one of which is shared by both SH2 domains. In Syk the two SH2 domains do not form such a phosphotyrosine-binding site. The SH2 domains here are believed to function independently. In addition, the two SH2 domains of Syk display flexibility in their relative orientation, allowing Syk to accommodate a greater variety of spacing sequences between the ITAM phosphotyrosines and singly phosphorylated non-classical ITAM ligands. This model contains the N-terminus SH2 domains of both Syk and Zap70. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLRP--LSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQY-ILGqfSRPFETVPEMIRHF 856
Cdd:cd09938    3 FFYGSITREEAEEYLKLagMSDGLFLLRQSLRSLGGYVLSVCHGRKFHHYTIERQLNGTYaIAG--GKAHCGPAELCEYH 80

                         90
                 ....*....|....
gi 442616108 857 --------CLNRLP 862
Cdd:cd09938   81 stdldglvCLLRKP 94

Src homology 2 domain found in the SH2 domain containing protein 7 (SH2D7); SH2D7 contains a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 442616108 780 WYHGAITRIEAETTLRPLSEGSFLVRNCEStKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSRPFETVPEMIRHF 856
Cdd:cd10417    9 WFHGFITRKQTEQLLRDKALGSFLIRLSDR-ATGYILSYRGSDRCRHFVINQLRNRRYLISGDTSSHSTLAELVRHY 84

Src homology 2 (SH2) domain found in Fyn isoform b like proteins; Fyn is a member of the Src non-receptor type tyrosine kinase family of proteins. This cd contains the SH2 domain found in Fyn isoform b type proteins. Fyn is involved in the control of cell growth and is required in the following pathways: T and B cell receptor signaling, integrin-mediated signaling, growth factor and cytokine receptor signaling, platelet activation, ion channel function, cell adhesion, axon guidance, fertilization, entry into mitosis, and differentiation of natural killer cells, oligodendrocytes and keratinocytes. The protein associates with the p85 subunit of phosphatidylinositol 3-kinase and interacts with the Fyn-binding protein. Alternatively spliced transcript variants encoding distinct isoforms exist. Fyn is primarily localized to the cytoplasmic leaflet of the plasma membrane. Tyrosine phosphorylation of target proteins by Fyn serves to either regulate target protein activity, and/or to generate a binding site on the target protein that recruits other signaling molecules. FYN has been shown to interact with a number of proteins including: BCAR1, Cbl, Janus kinase, nephrin, Sky, tyrosine kinase, Wiskott-Aldrich syndrome protein, and Zap-70. Fyn has a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 780 WYHGAITRIEAETTLRPLS--EGSFLVRNCESTKQDYSLSLK---GAKG--FMHMRIQRNETGQYILGQFSRpFETVPEM 852
Cdd:cd10419    5 WYFGKLGRKDAERQLLSFGnpRGTFLIRESETTKGAYSLSIRdwdDMKGdhVKHYKIRKLDNGGYYITTRAQ-FETLQQL 83

                 ....
gi 442616108 853 IRHF 856
Cdd:cd10419   84 VQHY 87

Src homology 2 (SH2) domain found in suppressor of cytokine signaling (SOCS) proteins; SH2 domain found in SOCS proteins. SOCS was first recognized as a group of cytokine-inducible SH2 (CIS) domain proteins comprising eight family members in human (CIS and SOCS1-SOCS7). In addition to the SH2 domain, SOCS proteins have a variable N-terminal domain and a conserved SOCS box in the C-terminal domain. SOCS proteins bind to a substrate via their SH2 domain. The prototypical members, CIS and SOCS1-SOCS3, have been shown to regulate growth hormone signaling in vitro and in a classic negative feedback response compete for binding at phosphotyrosine sites in JAK kinase and receptor pathways to displace effector proteins and target bound receptors for proteasomal degradation. Loss of SOCS activity results in excessive cytokine signaling associated with a variety of hematopoietic, autoimmune, and inflammatory diseases and certain cancers. Members (SOCS4-SOCS7) were identified by their conserved SOCS box, an adapter motif of 3 helices that associates substrate binding domains, such as the SOCS SH2 domain, ankryin, and WD40 with ubiquitin ligase components. These show limited cytokine induction. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 775 LERQGWYHGAITRIEAETTLRPLSEGSFLVRncESTKQDY--SLSLKGAKGFMHMRIQRNEtGQYILGQFS------RPF 846
Cdd:cd10383    4 LSQTGWYWGSMTVNEAKEKLQDAPEGTFLVR--DSSHSDYllTISVKTSAGPTNLRIEYQD-GKFRLDSIIcvksklKQF 80

                         90
                 ....*....|..
gi 442616108 847 ETVPEMIRHFCL 858
Cdd:cd10383   81 DSVVHLIEYYVQ 92

Src homology 2 (SH2) domain found in SH2B adapter protein family; The SH2B adapter protein family has 3 members: SH2B1 (SH2-B, PSM), SH2B2 (APS), and SH2B3 (Lnk). SH2B family members contain a pleckstrin homology domain, at least one dimerization domain, and a C-terminal SH2 domain which binds to phosphorylated tyrosines in a variety of tyrosine kinases. SH2B1 and SH2B2 function in signaling pathways found downstream of growth hormone receptor and receptor tyrosine kinases, including the insulin, insulin-like growth factor-I (IGF-I), platelet-derived growth factor (PDGF), nerve growth factor, hepatocyte growth factor, and fibroblast growth factor receptors. SH2B2beta, a new isoform of SH2B2, is an endogenous inhibitor of SH2B1 and/or SH2B2 (SH2B2alpha), negatively regulating insulin signaling and/or JAK2-mediated cellular responses. SH2B3 negatively regulates lymphopoiesis and early hematopoiesis. The lnk-deficiency results in enhanced production of B cells, and expansion as well as enhanced function of hematopoietic stem cells (HSCs), demonstrating negative regulatory functions of Sh2b3/Lnk in cytokine signaling. Sh2b3/Lnk also functions in responses controlled by cell adhesion and in crosstalk between integrin- and cytokine-mediated signaling. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 772 TIPLERQGWYHGAITRIEA-ETTLR--PLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNETGQYILGQFSrpFET 848
Cdd:cd10346    2 TAELSEYPWFHGTLSRSDAaQLVLHsgADGHGVFLVRQSETRRGEFVLTFNFQGRAKHLRLTLNEKGQCRVQHLW--FPS 79

                         90
                 ....*....|....
gi 442616108 849 VPEMIRHFCLNRLP 862
Cdd:cd10346   80 IFDMLEHFRQNPIP 93

Src homology 2 (SH2) domain found in Lyn; Lyn is a member of the Src non-receptor type tyrosine kinase family of proteins and is expressed in the hematopoietic cells, in neural tissues, liver, and adipose tissue. There are two alternatively spliced forms of Lyn. Lyn plays an inhibitory role in myeloid lineage proliferation. Following engagement of the B cell receptors, Lyn undergoes rapid phosphorylation and activation, triggering a cascade of signaling events mediated by Lyn phosphorylation of tyrosine residues within the immunoreceptor tyrosine-based activation motifs (ITAM) of the receptor proteins, and subsequent recruitment and activation of other kinases including Syk, phospholipase C2 (PLC2) and phosphatidyl inositol-3 kinase. These kinases play critical roles in proliferation, Ca2+ mobilization and cell differentiation. Lyn plays an essential role in the transmission of inhibitory signals through phosphorylation of tyrosine residues within the immunoreceptor tyrosine-based inhibitory motifs (ITIM) in regulatory proteins such as CD22, PIR-B and FC RIIb1. Their ITIM phosphorylation subsequently leads to recruitment and activation of phosphatases such as SHIP-1 and SHP-1 which further down modulate signaling pathways, attenuate cell activation and can mediate tolerance. Lyn also plays a role in the insulin signaling pathway. Activated Lyn phosphorylates insulin receptor substrate 1 (IRS1) leading to an increase in translocation of Glut-4 to the cell membrane and increased glucose utilization. It is the primary Src family member involved in signaling downstream of the B cell receptor. Lyn plays an unusual, 2-fold role in B cell receptor signaling; it is essential for initiation of signaling but is also later involved in negative regulation of the signal. Lyn has a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616108 776 ERQGWYHGAITRIEAETTLRPL--SEGSFLVRNCESTKQDYSLSLK-----GAKGFMHMRIQRNETGQYILGQfSRPFET 848
Cdd:cd10364    1 ETEEWFFKDITRKDAERQLLAPgnSAGAFLIRESETLKGSYSLSVRdydpqHGDVIKHYKIRSLDNGGYYISP-RITFPC 79

                 ....*...
gi 442616108 849 VPEMIRHF 856
Cdd:cd10364   80 ISDMIKHY 87

N-terminal Src homology 2 (N-SH2) domain in Phospholipase C gamma; Phospholipase C gamma is a signaling molecule that is recruited to the C-terminal tail of the receptor upon autophosphorylation of a highly conserved tyrosine. PLCgamma is composed of a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, 2 catalytic regions of PLC domains that flank 2 tandem SH2 domains (N-SH2, C-SH2), and ending with a SH3 domain and C2 domain. N-SH2 SH2 domain-mediated interactions represent a crucial step in transmembrane signaling by receptor tyrosine kinases. SH2 domains recognize phosphotyrosine (pY) in the context of particular sequence motifs in receptor phosphorylation sites. Both N-SH2 and C-SH2 have a very similar binding affinity to pY. But in growth factor stimulated cells these domains bind to different target proteins. N-SH2 binds to pY containing sites in the C-terminal tails of tyrosine kinases and other receptors. Recently it has been shown that this interaction is mediated by phosphorylation-independent interactions between a secondary binding site found exclusively on the N-SH2 domain and a region of the FGFR1 tyrosine kinase domain. This secondary site on the SH2 cooperates with the canonical pY site to regulate selectivity in mediating a specific cellular process. C-SH2 binds to an intramolecular site on PLCgamma itself which allows it to hydrolyze phosphatidylinositol-4,5-bisphosphate into diacylglycerol and inositol triphosphate. These then activate protein kinase C and release calcium. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

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gi 442616108 780 WYHGAIT--RIEAETTLR---PLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQ-RNETGQ---YILGQFSrpFETVP 850
Cdd:cd10341    6 WFHGKLGdgRDEAEKLLLeycEGGDGTFLVRESETFVGDYTLSFWRNGKVQHCRIRsRQENGEkkyYLTDNLV--FDSLY 83

                         90
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gi 442616108 851 EMIRHFCLNRLpvRGAE 867
Cdd:cd10341   84 ELIDYYRQNPL--RCAE 98

Src homology 2 (SH2) domain found in the Vav1 proteins; Proto-oncogene vav is a member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding proteins. All vavs are activated by tyrosine phosphorylation leading to their activation. There are three Vav mammalian family members: Vav1 which is expressed in the hematopoietic system, and Vav2 and Vav3 are more ubiquitously expressed. Vav1 plays a role in T-cell and B-cell development and activation. It has been identified as the specific binding partner of Nef proteins from HIV-1, resulting in morphological changes, cytoskeletal rearrangements, and the JNK/SAPK signaling cascade, leading to increased levels of viral transcription and replication. Vav1 has been shown to interact with Ku70, PLCG1, Lymphocyte cytosolic protein 2, Janus kinase 2, SIAH2, S100B, Abl gene, ARHGDIB, SHB, PIK3R1, PRKCQ, Grb2, MAPK1, Syk, Linker of activated T cells, Cbl gene and EZH2. Vav proteins are involved in several processes that require cytoskeletal reorganization, such as the formation of the immunological synapse (IS), phagocytosis, platelet aggregation, spreading, and transformation. Vavs function as guanine nucleotide exchange factors (GEFs) for the Rho/Rac family of GTPases. Vav family members have several conserved motifs/domains including: a leucine-rich region, a leucine-zipper, a calponin homology (CH) domain, an acidic domain, a Dbl-homology (DH) domain, a pleckstrin homology (PH) domain, a cysteine-rich domain, 2 SH3 domains, a proline-rich region, and a SH2 domain. Vavs are the only known Rho GEFs that have both the DH/PH motifs and SH2/SH3 domains in the same protein. The leucine-rich helix-loop-helix (HLH) domain is thought to be involved in protein heterodimerization with other HLH proteins and it may function as a negative regulator by forming inactive heterodimers. The CH domain is usually involved in the association with filamentous actin, but in Vav it controls NFAT stimulation, Ca2+ mobilization, and its transforming activity. Acidic domains are involved in protein-protein interactions and contain regulatory tyrosines. The DH domain is a GDP-GTP exchange factor on Rho/Rac GTPases. The PH domain in involved in interactions with GTP-binding proteins, lipids and/or phosphorylated serine/threonine residues. The SH3 domain is involved in localization of proteins to specific sites within the cell interacting with protein with proline-rich sequences. The SH2 domain mediates a high affinity interaction with tyrosine phosphorylated proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

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gi 442616108 780 WYHGAITRIEAETTLRPLSEGSFLVRNCESTKQDYSLSLKGAKGFMHMRIQRNEtGQYILGQfSRPFETVPEMIRHFCLN 859
Cdd:cd10405    7 WYAGPMERAGAESILANRSDGTYLVRQRVKDAAEFAISIKYNVEVKHIKIMTAE-GLYRITE-KKAFRGLTELVEFYQQN 84