Src homology 2 (SH2) domain found in the growth factor receptor bound, subclass 10 (Grb10) proteins; The Grb family binds to the epidermal growth factor receptor (EGFR, erbB1) via their SH2 domains. Grb10 is part of the Grb7 family of proteins which also includes Grb7, and Grb14. They are composed of an N-terminal Proline-rich domain, a Ras Associating-like (RA) domain, a Pleckstrin Homology (PH) domain, a phosphotyrosine interaction region (PIR, BPS) and a C-terminal SH2 domain. The SH2 domains of Grb7, Grb10 and Grb14 preferentially bind to a different RTK. Grb10 has been shown to interact with many different proteins, including the insulin and IGF1 receptors, platelet-derived growth factor (PDGF) receptor-beta, Ret, Kit, Raf1 and MEK1, and Nedd4. 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 1185542323 487 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 566
Cdd:cd10415     1 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 80

                          90       100
                  ....*....|....*....|....*...
gi 1185542323 567 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 594
Cdd:cd10415    81 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 10; GRB10, also termed insulin receptor-binding protein Grb-IR, is a multi-domain cytoplasmic adaptor protein that binds to the insulin-like growth factor 1 receptor (IGF-1R) and inhibits insulin signaling. Grb10 and its related family members Grb7 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb14 binds to both GTPase-defective mutant Rab5 as well as CNGA1, whereas Grb10 binds only to GTP-bound form of active Rab5.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 166 AKQDVKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVESTMASESKFLF 245
Cdd:cd16141     1 EKHIVKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVQSTMGSESKFLF 80

                          90
                  ....*....|..
gi 1185542323 246 RKNYAKYEFFKN 257
Cdd:cd16141    81 RKNYAKYEFFKN 92

Src homology 2 (SH2) domain found in the growth factor receptor bound, subclass 10 (Grb10) proteins; The Grb family binds to the epidermal growth factor receptor (EGFR, erbB1) via their SH2 domains. Grb10 is part of the Grb7 family of proteins which also includes Grb7, and Grb14. They are composed of an N-terminal Proline-rich domain, a Ras Associating-like (RA) domain, a Pleckstrin Homology (PH) domain, a phosphotyrosine interaction region (PIR, BPS) and a C-terminal SH2 domain. The SH2 domains of Grb7, Grb10 and Grb14 preferentially bind to a different RTK. Grb10 has been shown to interact with many different proteins, including the insulin and IGF1 receptors, platelet-derived growth factor (PDGF) receptor-beta, Ret, Kit, Raf1 and MEK1, and Nedd4. 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 1185542323 487 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 566
Cdd:cd10415     1 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 80

                          90       100
                  ....*....|....*....|....*...
gi 1185542323 567 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 594
Cdd:cd10415    81 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 10; GRB10, also termed insulin receptor-binding protein Grb-IR, is a multi-domain cytoplasmic adaptor protein that binds to the insulin-like growth factor 1 receptor (IGF-1R) and inhibits insulin signaling. Grb10 and its related family members Grb7 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb14 binds to both GTPase-defective mutant Rab5 as well as CNGA1, whereas Grb10 binds only to GTP-bound form of active Rab5.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 166 AKQDVKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVESTMASESKFLF 245
Cdd:cd16141     1 EKHIVKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVQSTMGSESKFLF 80

                          90
                  ....*....|..
gi 1185542323 246 RKNYAKYEFFKN 257
Cdd:cd16141    81 RKNYAKYEFFKN 92

BPS (Between PH and SH2); The BPS (Between PH and SH2) domain, comprised of 2 beta strands and a C-terminal helix, is an approximately 45 residue region found in the adaptor proteins Grb7/10/14 that mediates inhibition of the tyrosine kinase domain of the insulin receptor by binding of the N-terminal portion of the BPS domain to the substrate peptide groove of the kinase, acting as a pseudosubstrate inhibitor.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1185542323 425 RSVSENSLVAMDFSGQTGRVIENPAEAQSAALEEGHAWRKRSTR 468
Cdd:pfam08947   1 RSVSESSLVAMDFSGAGGRVIENPEEALSEAEEEGAAWRKKTLR 44

Ras association (RalGDS/AF-6) domain; RasGTP effectors (in cases of AF6, canoe and RalGDS); putative RasGTP effectors in other cases. Kalhammer et al. have shown that not all RA domains bind RasGTP. Predicted structure similar to that determined, and that of the RasGTP-binding domain of Raf kinase. Predicted RA domains in PLC210 and nore1 found to bind RasGTP. Included outliers (Grb7, Grb14, adenylyl cyclases etc.)

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323  166 AKQDVKVFSED---GTSKVVEILADMTARDLCQLLVYKSHCVDD-NSWTLVEHHPHlGLERCLEDHELVVQVES---TMA 238
Cdd:smart00314   1 DTFVLRVYVDDlpgGTYKTLRVSSRTTARDVIQQLLEKFHLTDDpEEYVLVEVLPD-GKERVLPDDENPLQLQKlwpRRG 79

                           90
                   ....*....|.
gi 1185542323  239 SESKFLFRKNY 249
Cdd:smart00314  80 PNLRFVLRKRD 90

Pleckstrin homology domain; Domain commonly found in eukaryotic signalling proteins. The domain family possesses multiple functions including the abilities to bind inositol phosphates, and various proteins. PH domains have been found to possess inserted domains (such as in PLC gamma, syntrophins) and to be inserted within other domains. Mutations in Brutons tyrosine kinase (Btk) within its PH domain cause X-linked agammaglobulinaemia (XLA) in patients. Point mutations cluster into the positively charged end of the molecule around the predicted binding site for phosphatidylinositol lipids.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323  291 PEIQGFLHVKE-LGKKSWKKLYVCLRRSGLYCSTKGTSKEPRHLQLLADLEDSNIfslIAGRKQYNAPTDHGLCIkpnkv 369
Cdd:smart00233   1 VIKEGWLYKKSgGGKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTV---REAPDPDSSKKPHCFEI----- 72

                           90       100       110
                   ....*....|....*....|....*....|
gi 1185542323  370 RNETKELRLLCAEDEQTRTCWMTAFRLLKY 399
Cdd:smart00233  73 KTSDRKTLLLQAESEEEREKWVEALRKAIA 102

Src homology 2 (SH2) domain found in the growth factor receptor bound, subclass 10 (Grb10) proteins; The Grb family binds to the epidermal growth factor receptor (EGFR, erbB1) via their SH2 domains. Grb10 is part of the Grb7 family of proteins which also includes Grb7, and Grb14. They are composed of an N-terminal Proline-rich domain, a Ras Associating-like (RA) domain, a Pleckstrin Homology (PH) domain, a phosphotyrosine interaction region (PIR, BPS) and a C-terminal SH2 domain. The SH2 domains of Grb7, Grb10 and Grb14 preferentially bind to a different RTK. Grb10 has been shown to interact with many different proteins, including the insulin and IGF1 receptors, platelet-derived growth factor (PDGF) receptor-beta, Ret, Kit, Raf1 and MEK1, and Nedd4. 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 1185542323 487 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 566
Cdd:cd10415     1 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 80

                          90       100
                  ....*....|....*....|....*...
gi 1185542323 567 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 594
Cdd:cd10415    81 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 108

Amyloid beta (A4) Precursor protein-Binding, family B, member 1 Interacting Protein pleckstrin homology (PH) domain; APBB1IP consists of a Ras-associated (RA) domain, a PH domain, a family-specific BPS region, and a C-terminal SH2 domain. Grb7, Grb10 and Grb14 are paralogs that are also present in this hierarchy. These adapter proteins bind a variety of receptor tyrosine kinases, including the insulin and insulin-like growth factor-1 (IGF1) receptors. Grb10 and Grb14 are important tissue-specific negative regulators of insulin and IGF1 signaling based and may contribute to type 2 (non-insulin-dependent) diabetes in humans. RA-PH function as a single structural unit and is dimerized via a helical extension of the PH domain. The PH domain here are proposed to bind phosphoinositides non-cannonically ahd are unlikely to bind an activated GTPase. The tandem RA-PH domains are present in a second adapter-protein family, MRL proteins, Caenorhabditis elegans protein MIG-1012, the mammalian proteins RIAM and lamellipodin and the Drosophila melanogaster protein Pico12, all of which are Ena/VASP-binding proteins involved in actin-cytoskeleton rearrangement. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 286 NSSSCPEIQGFLHVKELGKKSWKKLYVCLRRSGLYCSTKGTSKEPRHLQLLADLEDSNIFSLIAGRKQYNAPTDHGLCIK 365
Cdd:cd01259     1 NSVSCPEIEGFLYLKEDGKKSWKKRYFVLRASGLYYSPKGKSKESRDLQCLAQFDDYNVYTGLNGKKKYKAPTDFGFCLK 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1185542323 366 PNKVR-NETKELRLLCAEDEQTRTCWMTAFRLLKYGMLLYQNYR 408
Cdd:cd01259    81 PNKQQeKGSKDIKYLCAEDEQSRTCWLTAIRLAKYGKQLYENYR 124

Src homology 2 (SH2) domain found in the growth factor receptor bound, subclass 14 (Grb14) proteins; The Grb family binds to the epidermal growth factor receptor (EGFR, erbB1) via their SH2 domains. Grb14 is part of the Grb7 family of proteins which also includes Grb7, and Grb14. They are composed of an N-terminal Proline-rich domain, a Ras Associating-like (RA) domain, a Pleckstrin Homology (PH) domain, a phosphotyrosine interaction region (PIR, BPS) and a C-terminal SH2 domain. The SH2 domains of Grb7, Grb10 and Grb14 preferentially bind to a different RTK. Grb14 binds to Fibroblast Growth Factor Receptor (FGFR) and weakly to the erbB2 receptor. 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 1185542323 487 IHRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDGNTKFSD 566
Cdd:cd10414     1 IHRSQPWFHHKISRDEAQRLIIQQGLVDGVFLVRDSQSNPRTFVLSMSHGQKIKHFQIIPVEDDGELFHTLDDGHTRFTD 80

                          90       100
                  ....*....|....*....|....*...
gi 1185542323 567 LIQLVDFYQLNKGVLPCKLKHHCIRVAL 594
Cdd:cd10414    81 LIQLVEFYQLNKGVLPCKLKHYCARIAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 7/10/14; The RA domain is highly conserved among the members of the Grb proteins family which includes Grb7, Grb10 and Grb14. Grb7/10/14 are multi-domain cytoplasmic adaptor proteins that are recruited to activated receptor tyrosine kinases. RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 167 KQDVKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVESTMAS--ESKFL 244
Cdd:cd16124     1 KQVVKVYSEDGTSRSVEVAADATARDVCQLLVQKAHALDDESWTLVEHHPHLGLERGLEDHELVVEVQSAWPVggESKFV 80

                  ....*
gi 1185542323 245 FRKNY 249
Cdd:cd16124    81 FRKNY 85

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 7; GRB7, also termed B47, or epidermal growth factor receptor GRB-7, or GRB7 adapter protein, is a signal-transducing cytoplasmic adaptor protein that is co-opted by numerous tyrosine kinases involved in various cellular signaling and functions. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb7 could interact with activated N-Ras in transfected cells.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 170 VKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVEST--MASESKFLFRK 247
Cdd:cd16140     5 VKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATwpAGGDSRFVFRK 84

                  ....
gi 1185542323 248 NYAK 251
Cdd:cd16140    85 NFAK 88

Src homology 2 domains; Src homology 2 domains bind phosphotyrosine-containing polypeptides via 2 surface pockets. Specificity is provided via interaction with residues that are distinct from the phosphotyrosine. Only a single occurrence of a SH2 domain has been found in S. cerevisiae.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323  491 QHWFHGRISREESHRIIKQQGlvDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGqtfFSLdDGNTKFSDLIQL 570
Cdd:smart00252   1 QPWYHGFISREEAEKLLKNEG--DGDFLVRDSESSPGDYVLSVRVKGKVKHYRIRRNEDGK---FYL-EGGRKFPSLVEL 74

                           90
                   ....*....|
gi 1185542323  571 VDFYQLNKGV 580
Cdd:smart00252  75 VEHYQKNSLG 84

SH2 domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 493 WFHGRISREESHRIIKQQGlVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILpCEDDGQTFFSlddGNTKFSDLIQLVD 572
Cdd:pfam00017   1 WYHGKISRQEAERLLLNGK-PDGTFLVRESESTPGGYTLSVRDDGKVKHYKIQ-STDNGGYYIS---GGVKFSSLAELVE 75

                  ..
gi 1185542323 573 FY 574
Cdd:pfam00017  76 HY 77

Ras association (RalGDS/AF-6) domain; RasGTP effectors (in cases of AF6, canoe and RalGDS); putative RasGTP effectors in other cases. Kalhammer et al. have shown that not all RA domains bind RasGTP. Predicted structure similar to that determined, and that of the RasGTP-binding domain of Raf kinase. Predicted RA domains in PLC210 and nore1 found to bind RasGTP. Included outliers (Grb7, Grb14, adenylyl cyclases etc.)

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323  166 AKQDVKVFSED---GTSKVVEILADMTARDLCQLLVYKSHCVDD-NSWTLVEHHPHlGLERCLEDHELVVQVES---TMA 238
Cdd:smart00314   1 DTFVLRVYVDDlpgGTYKTLRVSSRTTARDVIQQLLEKFHLTDDpEEYVLVEVLPD-GKERVLPDDENPLQLQKlwpRRG 79

                           90
                   ....*....|.
gi 1185542323  239 SESKFLFRKNY 249
Cdd:smart00314  80 PNLRFVLRKRD 90

Ras-associating (RA) domain of Mig10/RIAM/Lpd (MRL) family; MRL proteins share a common structural architecture, including a central structural unit consisting of a Ras-associating (RA) domain and a pleckstrin homology (PH) domain, an upstream coiled-coil region, and a number of polyproline motifs. RA domain-containing proteins function by interacting with Ras proteins directly or indirectly and are involved in several different functions ranging from tumor suppression to being oncoproteins. Ras proteins are small GTPases that are involved in cellular signal transduction. RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. RA and PH form a tandem domain pair (RA-PH), and serve tightly coordinated functions in both Ras GTPase signaling via the RA domain and membrane translocalization via the PH domain. MRL proteins have distinct functions in cell migration and adhesion, signaling, and in cell growth.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1185542323 170 VKVFSEDGTSKVVEILADMTARDLCQLLVYKSHCVDDNSWTLVEHHPHLGLERCLEDHELVVQVES--TMASESKFLF 245
Cdd:cd01787     4 VKVHMEDGSSKTLLVDERMTVRQVLKQLIEKNHCDPSVDWCLVEQYPDLYMERVFEDHEKLVENLLnwTRDSTNKLLF 81

Src homology 2 (SH2) domain found in Carboxyl-Terminal Src Kinase (Csk); Both the C-terminal Src kinase (CSK) and CSK-homologous kinase (CHK) are members of the CSK-family of protein tyrosine kinases. These proteins suppress activity of Src-family kinases (SFK) by selectively phosphorylating the conserved C-terminal tail regulatory tyrosine by a similar mechanism. CHK is also capable of inhibiting SFKs by a non-catalytic mechanism that involves binding of CHK to SFKs to form stable protein complexes. The unphosphorylated form of SFKs is inhibited by CSK and CHK by a two-step mechanism. The first step involves the formation of a complex of SFKs with CSK/CHK with the SFKs in the complex are inactive. The second step, involves the phosphorylation of the C-terminal tail tyrosine of SFKs, which then dissociates and adopt an inactive conformation. The structural basis of how the phosphorylated SFKs dissociate from CSK/CHK to adopt the inactive conformation is not known. The inactive conformation of SFKs is stabilized by two intramolecular inhibitory interactions: (a) the pYT:SH2 interaction in which the phosphorylated C-terminal tail tyrosine (YT) binds to the SH2 domain, and (b) the linker:SH3 interaction of which the SH2-kinase domain linker binds to the SH3 domain. SFKs are activated by multiple mechanisms including binding of the ligands to the SH2 and SH3 domains to displace the two inhibitory intramolecular interactions, autophosphorylation, and dephosphorylation of YT. By selective phosphorylation and the non-catalytic inhibitory mechanism CSK and CHK are able to inhibit the active forms of SFKs. CSK and CHK are regulated by phosphorylation and inter-domain interactions. They both contain SH3, SH2, and kinase domains separated by the SH3-SH2 connector and SH2 kinase linker, intervening segments separating the three domains. They lack a conserved tyrosine phosphorylation site in the kinase domain and the C-terminal tail regulatory tyrosine phosphorylation site. The CSK SH2 domain is crucial for stabilizing the kinase domain in the active conformation. A disulfide bond here regulates CSK kinase activity. The subcellular localization and activity of CSK are regulated by its 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 1185542323 493 WFHGRISREESHRIIKQQGlvDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILpcEDDGQtfFSLDDGNTkFSDLIQLVD 572
Cdd:cd09937     5 WFHGKISREEAERLLQPPE--DGLFLVRESTNYPGDYTLCVSFEGKVEHYRVI--YRNGK--LTIDEEEY-FENLIQLVE 77

                          90
                  ....*....|....
gi 1185542323 573 FYQLNKGVLPCKLK 586
Cdd:cd09937    78 HYTKDADGLCTRLV 91

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 1185542323 493 WFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQIlpcEDDGQTFFSLDDGNtKFSDLIQLVD 572
Cdd:cd09938     3 FFYGSITREEAEEYLKLAGMSDGLFLLRQSLRSLGGYVLSVCHGRKFHHYTI---ERQLNGTYAIAGGK-AHCGPAELCE 78

                          90
                  ....*....|....*....
gi 1185542323 573 FYQLNKGVLPCKLKHHCIR 591
Cdd:cd09938    79 YHSTDLDGLVCLLRKPCNR 97

Pleckstrin homology domain; Domain commonly found in eukaryotic signalling proteins. The domain family possesses multiple functions including the abilities to bind inositol phosphates, and various proteins. PH domains have been found to possess inserted domains (such as in PLC gamma, syntrophins) and to be inserted within other domains. Mutations in Brutons tyrosine kinase (Btk) within its PH domain cause X-linked agammaglobulinaemia (XLA) in patients. Point mutations cluster into the positively charged end of the molecule around the predicted binding site for phosphatidylinositol lipids.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323  291 PEIQGFLHVKE-LGKKSWKKLYVCLRRSGLYCSTKGTSKEPRHLQLLADLEDSNIfslIAGRKQYNAPTDHGLCIkpnkv 369
Cdd:smart00233   1 VIKEGWLYKKSgGGKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTV---REAPDPDSSKKPHCFEI----- 72

                           90       100       110
                   ....*....|....*....|....*....|
gi 1185542323  370 RNETKELRLLCAEDEQTRTCWMTAFRLLKY 399
Cdd:smart00233  73 KTSDRKTLLLQAESEEEREKWVEALRKAIA 102

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 1185542323 490 TQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTL----------CHHQKIKNFqilpceDDGQTFFSldd 559
Cdd:cd09933     2 AEEWFFGKIKRKDAEKLLLAPGNPRGTFLIRESETTPGAYSLSVrdgddargdtVKHYRIRKL------DNGGYYIT--- 72

                          90       100
                  ....*....|....*....|....*.
gi 1185542323 560 GNTKFSDLIQLVDFYQLNKGVLPCKL 585
Cdd:cd09933    73 TRATFPTLQELVQHYSKDADGLCCRL 98

C-terminal Src homology 2 (C-SH2) domain found in SH2 domain Phosphatases (SHP) proteins; The SH2 domain phosphatases (SHP-1, SHP-2/Syp, Drosophila corkscrew (csw), and Caenorhabditis elegans Protein Tyrosine Phosphatase (Ptp-2)) are cytoplasmic signaling enzymes. They are both targeted and regulated by interactions of their SH2 domains with phosphotyrosine docking sites. These proteins contain two SH2 domains (N-SH2, C-SH2) followed by a tyrosine phosphatase (PTP) domain, and a C-terminal extension. Shp1 and Shp2 have two tyrosyl phosphorylation sites in their C-tails, which are phosphorylated differentially by receptor and nonreceptor PTKs. Csw retains the proximal tyrosine and Ptp-2 lacks both sites. Shp-binding proteins include receptors, scaffolding adapters, and inhibitory receptors. Some of these bind both Shp1 and Shp2 while others bind only one. Most proteins that bind a Shp SH2 domain contain one or more immuno-receptor tyrosine-based inhibitory motifs (ITIMs): [SIVL]xpYxx[IVL]. Shp1 N-SH2 domain blocks the catalytic domain and keeps the enzyme in the inactive conformation, and is thus believed to regulate the phosphatase activity of SHP-1. Its C-SH2 domain is thought to be involved in searching for phosphotyrosine activators. The SHP2 N-SH2 domain is a conformational switch; it either binds and inhibits the phosphatase, or it binds phosphoproteins and activates the enzyme. The C-SH2 domain contributes binding energy and specificity, but it does not have a direct role in activation. Csw SH2 domain function is essential, but either SH2 domain can fulfill this requirement. The role of the csw SH2 domains during Sevenless receptor tyrosine kinase (SEV) signaling is to bind Daughter of Sevenless rather than activated SEV. Ptp-2 acts in oocytes downstream of sheath/oocyte gap junctions to promote major sperm protein (MSP)-induced MAP Kinase (MPK-1) phosphorylation. Ptp-2 functions in the oocyte cytoplasm, not at the cell surface to inhibit multiple RasGAPs, resulting in sustained Ras activation. It is thought that MSP triggers PTP-2/Ras activation and ROS production to stimulate MPK-1 activity essential for oocyte maturation and that secreted MSP domains and Cu/Zn superoxide dismutases function antagonistically to control ROS and MAPK 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 1185542323 493 WFHGRISREESHRIIKQQGlVDGLFLLRDSQSNPKAFVLT-LCHHQKIKNFQILpCEDDGQTFfsldDGNTKFSDLIQLV 571
Cdd:cd09931     2 WFHGHLSGKEAEKLLLEKG-KPGSFLVRESQSKPGDFVLSvRTDDDKVTHIMIR-CQGGKYDV----GGGEEFDSLTDLV 75

                  ....*.
gi 1185542323 572 DFYQLN 577
Cdd:cd09931    76 EHYKKN 81

PH domain; PH stands for pleckstrin homology.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 291 PEIQGFLHVKELG-KKSWKKLYVCLRRSGLYC---STKGTSKEPRHLQLLADLEDSNIfsliagRKQYNAPTDHGLCIKP 366
Cdd:pfam00169   1 VVKEGWLLKKGGGkKKSWKKRYFVLFDGSLLYykdDKSGKSKEPKGSISLSGCEVVEV------VASDSPKRKFCFELRT 74

                          90       100       110
                  ....*....|....*....|....*....|...
gi 1185542323 367 NKVRNetKELRLLCAEDEQTRTCWMTAFRLLKY 399
Cdd:pfam00169  75 GERTG--KRTYLLQAESEEERKDWIKAIQSAIR 105

Src homology 2 (SH2) domain found in the Nck family; 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 1185542323 491 QHWFHGRISREESHRIIKQQGlVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQIlpceDDGQTFFSLddGNTKFSDLIQL 570
Cdd:cd09943     1 QPWYYGRITRHQAETLLNEHG-HEGDFLIRDSESNPGDYSVSLKAPGRNKHFKV----QVVDNVYCI--GQRKFHTMDEL 73

                  ....*
gi 1185542323 571 VDFYQ 575
Cdd:cd09943    74 VEHYK 78

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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 488 HRTQHWFHGRIS--REESHRIIKQ-QGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPCEDDGQTFFSLDDgNTKF 564
Cdd:cd10341     1 HFTEPWFHGKLGdgRDEAEKLLLEyCEGGDGTFLVRESETFVGDYTLSFWRNGKVQHCRIRSRQENGEKKYYLTD-NLVF 79

                          90
                  ....*....|....
gi 1185542323 565 SDLIQLVDFYQLNK 578
Cdd:cd10341    80 DSLYELIDYYRQNP 93

C-terminal Src homology 2 (SH2) domain found in 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 C-terminus SH2 domains of Syk. 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 1185542323 493 WFHGRISREESHRIIKQQGLVDGLFLLRDSQSNpKAFVLTLCHHQKIKNFQIlpcEDDGQTFFSLDDGNtKFSDLIQLVD 572
Cdd:cd10401     5 WFHGKISREESEQILLIGSKTNGKFLIRERDNN-GSYALCLLHDGKVLHYRI---DKDKTGKLSIPDGK-KFDTLWQLVE 79

                  ..
gi 1185542323 573 FY 574
Cdd:cd10401    80 HY 81

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 1185542323 493 WFHGRISREESHRIIKQqgLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQIlpCEDDGQTFFSLDDgnTKFSDLIQLVD 572
Cdd:cd09935     5 WYHGPISRNAAEYLLSS--GINGSFLVRESESSPGQYSISLRYDGRVYHYRI--SEDSDGKVYVTQE--HRFNTLAELVH 78

                          90
                  ....*....|....*
gi 1185542323 573 FYQLNKGVLPCKLKH 587
Cdd:cd09935    79 HHSKNADGLITTLRY 93

Src homology 2 domain found in cancer-related signaling adaptor protein CRK; SH2 domain in the CRK proteins. CRKI (SH2-SH3) and CRKII (SH2-SH3-SH3) are splicing isoforms of the oncoprotein CRK. CRKs regulate transcription and cytoskeletal reorganization for cell growth and motility by linking tyrosine kinases to small G proteins. The SH2 domain of CRK associates with tyrosine-phosphorylated receptors or components of focal adhesions, such as p130Cas and paxillin. CRK transmits signals to small G proteins through effectors that bind its SH3 domain, such as C3G, the guanine-nucleotide exchange factor (GEF) for Rap1 and R-Ras, and DOCK180, the GEF for Rac6. The binding of p130Cas to the CRK-C3G complex activates Rap1, leading to regulation of cell adhesion, and activates R-Ras, leading to JNK-mediated activation of cell proliferation, whereas the binding of CRK DOCK180 induces Rac1-mediated activation of cellular migration. The activity of the different splicing isoforms varies greatly with CRKI displaying substantial transforming activity, CRKII less so, and phosphorylated CRKII with no biological activity whatsoever. CRKII has a linker region with a phosphorylated Tyr and an additional C-terminal SH3 domain. The phosphorylated Tyr creates a binding site for its SH2 domain which disrupts the association between CRK and its SH2 target 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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 493 WFHGRISREESHRIIkqQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQI--LPCEDDGQTFFSLddGNTKFSDLIQL 570
Cdd:cd09926     9 WYFGPMSRQEAQELL--QGQRHGVFLVRDSSTIPGDYVLSVSENSRVSHYIInsLGQPAPNQSRYRI--GDQEFDDLPAL 84

                  ....*.
gi 1185542323 571 VDFYQL 576
Cdd:cd09926    85 LEFYKL 90

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 1185542323 493 WFHGRISREESHRIIKQQGlVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQIlpCEDDgqTFFSLddGNTKFSDLIQLVD 572
Cdd:cd10408     3 WYYGKVTRHQAEMALNERG-NEGDFLIRDSESSPNDFSVSLKAQGKNKHFKV--QLKE--CVYCI--GQRKFSSMEELVE 75

                  ...
gi 1185542323 573 FYQ 575
Cdd:cd10408    76 HYK 78

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 1185542323 494 FHGRISREESHRIIKqqGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILpceDDGQTFFsLDDGNTKFSDLIQLV 571
Cdd:cd10352     9 YHGLISREEAEQLLS--GASDGSYLIRESSRDDGYYTLSLRFNGKVKNYKLY---YDGKNHY-HYVGEKRFDTIHDLV 80

Src homology 2 (SH2) domain found in SLAM-associated protein (SAP) 1a; The X-linked lymphoproliferative syndrome (XLP) gene encodes SAP (also called SH2D1A/DSHP) a protein that consists of a 5 residue N-terminus, a single SH2 domain, and a short 25 residue C-terminal tail. XLP is characterized by an extreme sensitivity to Epstein-Barr virus. Both T and natural killer (NK) cell dysfunctions have been seen in XLP patients. SAP binds the cytoplasmic tail of Signaling lymphocytic activation molecule (SLAM), 2B4, Ly-9, and CD84. SAP is believed to function as a signaling inhibitor, by blocking or regulating binding of other signaling proteins. SAP and the SAP-like protein EAT-2 recognize the sequence motif TIpYXX[VI], which is found in the cytoplasmic domains of a restricted number of T, B, and NK cell surface receptors and are proposed to be natural inhibitors or regulators of the physiological role of a small family of receptors on the surface of these cells. 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 1185542323 494 FHGRISREESHRIIKQQGLvDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQI 544
Cdd:cd10400     6 YHGKISRETGEKLLLAAGL-DGSYLLRDSESVPGVYCLCVLYKGYVYTYRV 55

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1185542323 493 WFHGRISREESHRIIKQQGL-VDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQiLPCEDDGQ 552
Cdd:cd10346    10 WFHGTLSRSDAAQLVLHSGAdGHGVFLVRQSETRRGEFVLTFNFQGRAKHLR-LTLNEKGQ 69

Ras-associating (RA) domain found in Arf-GAP with Rho-GAP domain, ANK repeat and PH domain-containing proteins ARAP1, ARAP2, ARAP3, and similar proteins; ARAPs are phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3))-dependent Arf Rap-activated guanosine triphosphatase (GTPase)-activating proteins (GAPs). They contain multiple functional domains, including ArfGAP and RhoGAP domains, as well as a sterile alpha motif (Sam) domain, five PH domains, and a RA domain. The RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub); Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1185542323 170 VKVFSEDGTSKVVEILADMTARDLCQLLVYKSH-CVDDNSWTLVEHHPHLGLERCLEDHELVVQV----ESTMASESKFL 244
Cdd:cd17113     8 VYIEEKEGTSVNIKVTPTMTAEEVVEQALNKKNlGGPEGNWALFEVIEDGGLERPLHESEKVLDVvlrwSQWPRKSNYLC 87

                  ....*
gi 1185542323 245 FRKNY 249
Cdd:cd17113    88 VKKNP 92

Src homology 2 (SH2) domain found in tyrosine kinase sarcoma (Src); Src is a member of the Src non-receptor type tyrosine kinase family of proteins. Src is thought to play a role in the regulation of embryonic development and cell growth. Members here include v-Src and c-Src. v-Src lacks the C-terminal inhibitory phosphorylation site and is therefore constitutively active as opposed to normal cellular src (c-Src) which is only activated under certain circumstances where it is required (e.g. growth factor signaling). v-Src is an oncogene whereas c-Src is a proto-oncogene. c-Src consists of three domains, an N-terminal SH3 domain, a central SH2 domain and a tyrosine kinase domain. The SH2 and SH3 domains work together in the auto-inhibition of the kinase domain. The phosphorylation of an inhibitory tyrosine near the c-terminus of the protein produces a binding site for the SH2 domain which then facilitates binding of the SH3 domain to a polyproline site within the linker between the SH2 domain and the kinase domain. Binding of the SH3 domain inactivates the enzyme. This allows for multiple mechanisms for c-Src activation: dephosphorylation of the C-terminal tyrosine by a protein tyrosine phosphatase, binding of the SH2 domain by a competitive phospho-tyrosine residue, or competitive binding of a polyproline binding site to the SH3 domain. Unlike most other Src members Src lacks cysteine residues in the SH4 domain that undergo palmitylation. Serine and threonine phosphorylation sites have also been identified in the unique domains of Src and are believed to modulate protein-protein interactions or regulate catalytic activity. Alternatively spliced forms of Src, which contain 6- or 11-amino acid insertions in the SH3 domain, are expressed in CNS neurons. c-Src 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.

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gi 1185542323 489 RTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQ-----KIKNFQILPCEDDGQTFFSlddgNTK 563
Cdd:cd10365     1 QAEEWYFGKITRRESERLLLNAENPRGTFLVRESETTKGAYCLSVSDFDnakglNVKHYKIRKLDSGGFYITS----RTQ 76

                          90
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gi 1185542323 564 FSDLIQLVDFYQ 575
Cdd:cd10365    77 FNSLQQLVAYYS 88