Lymphocyte signaling adaptor protein; This domain family is found in eukaryotes, and is typically between 144 and 156 amino acids in length. The family is found in association with pfam07647, pfam07653. There is a conserved LGKK sequence motif. SLY contains a Src homology 3 domain and a sterile alpha motif, suggesting that it functions as a signaling adaptor protein in lymphocytes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     21 SLQRSSSFKDFAKSKPSSPVVSEKEFNLDDniPEDDSGVPTPEDAGKSGKKLGK---KWRAvISRTMNRKMGKMMVKALS 97
Cdd:pfam12485   1 SLQRSSSFGDFDKSRPSSPVVKPEEFNLEE--PEDEAGEPGPEEAGKPSTSGGKlgkKMRA-ISRTMRRKMGKKYVKALS 77

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     98 EEMADTLEEGSASPTSPDYSLDSPGPEKMALAFSEQEEHELPVLSRQASTGSELCSPSPGSGS-----FGEEPPapqYTG 172
Cdd:pfam12485  78 EEMGEDEEEGSDSPPSPDDPEDGPHTEKVSLKASDSEESLYSPLSGQSSSSSGVTSPSDGTSNrdslrLEEEPP---YTG 154

                  ..
gi 9506363    173 PF 174
Cdd:pfam12485 155 PF 156

Src homology 3 domain of Sam And SH3 Domain Containing Protein 3; SASH3, also called SLY/SLY1 (SH3-domain containing protein expressed in lymphocytes), is expressed exclusively in lymhocytes and is essential in the full activation of adaptive immunity. It is involved in the signaling of T cell receptors. It was the first described member of the SLY family of proteins, which are adaptor proteins containing a central conserved region with a bipartite nuclear localization signal (NLS) as well as SAM (sterile alpha motif) and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 9506363  176 GRARVHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDV 231
Cdd:cd11968   1 GRARVHTDFIPSPYDGDSLKLQKGDIIQIIEKPPVGTWTGLLNNKVGTFKFIYVDV 56

Lymphocyte signaling adaptor protein; This domain family is found in eukaryotes, and is typically between 144 and 156 amino acids in length. The family is found in association with pfam07647, pfam07653. There is a conserved LGKK sequence motif. SLY contains a Src homology 3 domain and a sterile alpha motif, suggesting that it functions as a signaling adaptor protein in lymphocytes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     21 SLQRSSSFKDFAKSKPSSPVVSEKEFNLDDniPEDDSGVPTPEDAGKSGKKLGK---KWRAvISRTMNRKMGKMMVKALS 97
Cdd:pfam12485   1 SLQRSSSFGDFDKSRPSSPVVKPEEFNLEE--PEDEAGEPGPEEAGKPSTSGGKlgkKMRA-ISRTMRRKMGKKYVKALS 77

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     98 EEMADTLEEGSASPTSPDYSLDSPGPEKMALAFSEQEEHELPVLSRQASTGSELCSPSPGSGS-----FGEEPPapqYTG 172
Cdd:pfam12485  78 EEMGEDEEEGSDSPPSPDDPEDGPHTEKVSLKASDSEESLYSPLSGQSSSSSGVTSPSDGTSNrdslrLEEEPP---YTG 154

                  ..
gi 9506363    173 PF 174
Cdd:pfam12485 155 PF 156

Src homology 3 domain of Sam And SH3 Domain Containing Protein 3; SASH3, also called SLY/SLY1 (SH3-domain containing protein expressed in lymphocytes), is expressed exclusively in lymhocytes and is essential in the full activation of adaptive immunity. It is involved in the signaling of T cell receptors. It was the first described member of the SLY family of proteins, which are adaptor proteins containing a central conserved region with a bipartite nuclear localization signal (NLS) as well as SAM (sterile alpha motif) and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 9506363  176 GRARVHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDV 231
Cdd:cd11968   1 GRARVHTDFIPSPYDGDSLKLQKGDIIQIIEKPPVGTWTGLLNNKVGTFKFIYVDV 56

SAM domain (Sterile alpha motif);

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 9506363    252 PKPKTLHELLERIGLEEHTSTLLLNGYQTLEDFKELRETHLNELNIMDPQHRAKLLTAAELLL 314
Cdd:pfam07647   4 WSLESVADWLRSIGLEQYTDNFRDQGITGAELLLRLTLEDLKRLGITSVGHRRKILKKIQELK 66

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 9506363    177 RARVHTDFTPSPYDHdsLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:pfam07653   1 YGRVIFDYVGTDKNG--LTLKKGDVVKVLGKDNDGWWEGETGGRVGLVPSTAV 51

Lymphocyte signaling adaptor protein; This domain family is found in eukaryotes, and is typically between 144 and 156 amino acids in length. The family is found in association with pfam07647, pfam07653. There is a conserved LGKK sequence motif. SLY contains a Src homology 3 domain and a sterile alpha motif, suggesting that it functions as a signaling adaptor protein in lymphocytes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     21 SLQRSSSFKDFAKSKPSSPVVSEKEFNLDDniPEDDSGVPTPEDAGKSGKKLGK---KWRAvISRTMNRKMGKMMVKALS 97
Cdd:pfam12485   1 SLQRSSSFGDFDKSRPSSPVVKPEEFNLEE--PEDEAGEPGPEEAGKPSTSGGKlgkKMRA-ISRTMRRKMGKKYVKALS 77

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363     98 EEMADTLEEGSASPTSPDYSLDSPGPEKMALAFSEQEEHELPVLSRQASTGSELCSPSPGSGS-----FGEEPPapqYTG 172
Cdd:pfam12485  78 EEMGEDEEEGSDSPPSPDDPEDGPHTEKVSLKASDSEESLYSPLSGQSSSSSGVTSPSDGTSNrdslrLEEEPP---YTG 154

                  ..
gi 9506363    173 PF 174
Cdd:pfam12485 155 PF 156

Src homology 3 domain of Sam And SH3 Domain Containing Protein 3; SASH3, also called SLY/SLY1 (SH3-domain containing protein expressed in lymphocytes), is expressed exclusively in lymhocytes and is essential in the full activation of adaptive immunity. It is involved in the signaling of T cell receptors. It was the first described member of the SLY family of proteins, which are adaptor proteins containing a central conserved region with a bipartite nuclear localization signal (NLS) as well as SAM (sterile alpha motif) and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 9506363  176 GRARVHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDV 231
Cdd:cd11968   1 GRARVHTDFIPSPYDGDSLKLQKGDIIQIIEKPPVGTWTGLLNNKVGTFKFIYVDV 56

Src homology 3 domain of SAM And SH3 Domain Containing Protein 1; SASH1 is a potential tumor suppressor in breast and colon cancer. Its decreased expression is associated with aggressive tumor growth, metastasis, and poor prognosis. It is widely expressed in normal tissues (except lymphocytes and dendritic cells) and is localized in the nucleus and the cytoplasm. SASH1 interacts with the oncoprotein cortactin and is important in cell migration and adhesion. It is a member of the SLY family of proteins, which are adaptor proteins containing a central conserved region with a bipartite nuclear localization signal (NLS) as well as SAM (sterile alpha motif) and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 9506363  176 GRARVHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDVL 232
Cdd:cd11967   1 GRARVHTDFTPSPYDTDSLKLKKGDIIDIISKPPMGTWMGLLNNKVGTFKFIYVDVL 57

SAM domain of SAMSN1 subfamily; SAM (sterile alpha motif) domain of SAMSN1 (also known as HACS1 or NASH1) proteins is a predicted protein-protein interaction domain. Members of this group are putative signaling/adaptor proteins. They appear to mediate signal transduction in lymphoid tissues. Murine HACS1 protein likely plays a role in B cell activation and differentiation. Potential binding partners of HACS1 are SLAM, DEC205 and PIR-B receptors and also some unidentified tyrosine-phosphorylated proteins. Proteins of this group were found preferentially expressed in normal hematopietic tissues and in some malignancies including lymphoma, myeloid leukemia and myeloma.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 9506363  250 KRPKPKTLHELLERIGLEEHTSTLLLNGYQTLEDFKELRETHLNELNIMDPQHRAKLLTAAELLLD 315
Cdd:cd09561   1 RRPKPKTLQELLERIHLQEYTSTLLLNGYETLEDLKDLKESHLIELNITDPEDRARLLSAAENLLD 66

C-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The C-terminal SH3 domain of CRK has not been shown to bind any target protein; it acts as a negative regulator of CRK function by stabilizing a structure that inhibits the access by target proteins to the N-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components, and mediating the formation of multiprotein complex assemblies.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 9506363  177 RARVHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDV 231
Cdd:cd11759   3 YARVIQKRVPNAYDKTALALEVGDLVKVTKINVSGQWEGELNGKVGHFPFTHVEL 57

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

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 9506363  183 DFTPSPYDHdsLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVDV 231
Cdd:cd11823   7 SYTANREDE--LSLQPGDIIEVHEKQDDGWWLGELNGKKGIFPATYVEE 53

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

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*.
gi 9506363     175 CGRARVHTDFTPSpyDHDSLKLQKGDVIQIIEKPPVGTWLG-LLNGKVGSFKFIYV 229
Cdd:smart00326   2 GPQVRALYDYTAQ--DPDELSFKKGDIITVLEKSDDGWWKGrLGRGKEGLFPSNYV 55

SAM domain (Sterile alpha motif); It has been suggested that SAM is an evolutionarily conserved protein binding domain that is involved in the regulation of numerous developmental processes in diverse eukaryotes. The SAM domain can potentially function as a protein interaction module through its ability to homo- and heterooligomerise with other SAM domains.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 9506363    254 PKTLHELLERIGLEEHTSTLLlNGYQTLEDFKELRETHLNELNIMDPQHRAKLLTAAELL 313
Cdd:pfam00536   5 VEDVGEWLESIGLGQYIDSFR-AGYIDGDALLQLTEDDLLKLGVTLLGHRKKILYAIQRL 63

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

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 9506363  177 RARVHTDFTPSPYDHdsLKLQKGDVIQIIEKPPVGTWLG-LLNGKVGSFKFIY 228
Cdd:cd00174   1 YARALYDYEAQDDDE--LSFKKGDIITVLEKDDDGWWEGeLNGGREGLFPANY 51

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 9506363    177 RARVHTDFTPSPYDHdsLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:pfam07653   1 YGRVIFDYVGTDKNG--LTLKKGDVVKVLGKDNDGWWEGETGGRVGLVPSTAV 51

SAM domain of Ship2 lipid phosphatase proteins; SAM (sterile alpha motif) domain of Ship2 subfamily is a protein-protein interaction domain. Ship2 proteins are lipid phosphatases (Phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 2) containing an N-terminal SH2 domain, a central phosphatase domain and a C-terminal SAM domain. Ship2 is involved in a number of PI3K signaling pathways. For example, it plays a role in regulation of the actin cytoskeleton remodeling, in insulin signaling pathways, and in EphA2 receptor endocytosis. SAM domain of Ship2 can interact with SAM domain of other proteins in these pathways, thus participating in signal transduction. In particular, SAM of Ship2 is known to form heterodimers with SAM domain of Eph-A2 receptor tyrosine kinase during receptor endocytosis as well as with SAM domain of PI3K effector protein Arap3 in the actin cytoskeleton signaling network. Since Ship2 plays a role in negatively regulating insulin signaling, it has been suggested that inhibition of its expression or function may contribute in treating type 2 diabetes and obesity-induced insulin resistance.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 9506363  254 PKTLHELLERIGLEEHTSTLLLNGYQTLEDFKELRETHLNELNIMDPQHRAKLL 307
Cdd:cd09491   5 PKTVSEWLMNLGLQQYEEGLMHNGWDSLEFLSDITEEDLEEAGVTNPAHKRRLL 58

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

                        10        20        30
                ....*....|....*....|....*....|....*....
gi 9506363  192 DSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVD 230
Cdd:cd11766  14 DELSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYVT 52

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

                        10        20        30
                ....*....|....*....|....*....|....*...
gi 9506363  192 DSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:cd11877  14 DELSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYV 51

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

                        10        20        30        40
                ....*....|....*....|....*....|....*....|...
gi 9506363  184 FTPSPYDHDSLKLQKGDVIQIIEKPP--VGTWLGLLNGKVGSF 224
Cdd:cd12142   6 FDYNPVAPDELALKKGDVIEVISKETedEGWWEGELNGRRGFF 48

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

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 9506363  179 RVHTDFTPSpyDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFK 225
Cdd:cd11883   3 VALYDFTPK--SKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKVK 47

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

                        10        20        30
                ....*....|....*....|....*....|...
gi 9506363  192 DSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSF 224
Cdd:cd11873  14 DELTLKVGDIITNVKKMEEGWWEGTLNGKRGMF 46

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

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 9506363  178 ARVHTDFtpSPYDHDSLKLQKGDVIQIIEKP-PVGTWLGLLNGKVGSFKFIYVD 230
Cdd:cd11976   2 AKARYDF--CARDRSELSLKEGDIIKILNKKgQQGWWRGEIYGRVGWFPANYVE 53

SAM domain of SASH1 proteins, repeat 2; SAM (sterile alpha motif) repeat 2 of SASH1 proteins is a protein-protein interaction domain. Members of this subfamily are putative adaptor proteins. They appear to mediate signal transduction. SASH1 can bind 14-3-3 proteins in response to IGF1/phosphatidylinositol 3-kinase signaling. SASH1 was found upregulated in different tissues including thymus, placenta, lungs and downregulated in some breast tumors, liver metastases and colon cancers if compare to corresponding normal tissues. SASH1 is a potential candidate for a tumor suppressor gene in breast cancers. At the same time, downregulation of SASH1 in colon cancer is associated with metastasis and a poor prognosis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 9506363  256 TLHELLERIGLEEHTSTLLLNGYQTLEDFKELRETHLNELNIMDPQHRAKLLTAAELL 313
Cdd:cd09492   9 SVSDWLVSIGLPMYSPPLLEAGFSTLSRVSSLSETCLREAGITEERHIRKLLSAARLV 66

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

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 9506363  177 RARVHTDFTPSpyDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:cd11805   1 RVQALYDFNPQ--EPGELEFRRGDIITVLDSSDPDWWKGELRGRVGIFPANYV 51

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

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                ....*....|....*....|....*....|....*....|....*....|
gi 9506363  180 VHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:cd12061   2 VRAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYV 51

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

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gi 9506363  192 DSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYVD 230
Cdd:cd11826  14 DELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYVE 52

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

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                ....*....|....*....|....*....|....*....|....*....|
gi 9506363  180 VHTDFTPSPYDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:cd11951   2 VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGRISGRVGFFPRNYV 51

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

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gi 9506363  190 DHDSLKLQKGDVIQIIEKPPV-GTWLGLLNGKVGSFKFIYVD 230
Cdd:cd11830  12 DMRELSLKEGDVVKIYNKKGQqGWWRGEINGRIGWFPSTYVE 53

Src Homology 3 domain of Src Kinase-Associated Phosphoprotein 1; SKAP1, also called SKAP55 (Src kinase-associated protein of 55kDa), is an immune cell-specific adaptor protein that plays an important role in T-cell adhesion, migration, and integrin clustering. It is expressed exclusively in T-lymphocytes, mast cells, and macrophages. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), Fyn, Riam, RapL, and RasGRP. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 9506363  192 DSLKLQKGDVIQIIEKP--PVGTWLGLLNGKVG 222
Cdd:cd12044  14 DELSFQRGDLIYILSKEynMYGWWVGELNGIVG 46

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

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                ....*....|....*....|....*....|....*....|....*..
gi 9506363  183 DFTPSpyDHDSLKLQKGDVIQIIEKPPVGTWLGLLNGKVGSFKFIYV 229
Cdd:cd11949   7 DFDPQ--EDGELGFRRGDFIEVMDNSDPNWWKGACHGQTGMFPRNYV 51