Serine rich protein interaction domain; This is a serine rich domain that is found in the docking protein p130(cas) (Crk-associated substrate). This domain folds into a four helix bundle which is associated with protein-protein interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 435 MDVDFAKETAVSLQHKVASSAAGLLLFVSRTWRFKDSLETNIHRIRRAADHVEESVREFLDFAQGVGGTACNLTDSYLQA 514
Cdd:pfam08824   1 LDLDSALETLSRLQQEVESSVSKLMSFVSSNWRSRENLEAHLNEIRRAVDRVRQSLREFLEFARGAVGNAAQLTDSNLQT 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677 515 RIRDQLQTISSSYQTLLDAKGSLDRCNWSLEVLVTDKVQNSLDDLERFVATARIVPEDVKRFTSIVIANGKLLFKQN 591
Cdd:pfam08824  81 KLRKQLQRLEDSYQILLQTSQALDSCGWSLDVLATDKPQNSPDDLDRFVMVARTVPDDVKQLASIIQGNGSLLFKRA 157

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member 4; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677  14 LLARALYDNHADCSDELAFSRGDILTIVEQNVPESEGWWRCLLHGRQGLAPANRLQV 70
Cdd:cd12000     1 LLARALYDNKADCSDELAFRRGDILTVLEQNVPGSEGWWKCLLHGRQGLAPANRLQL 57

Serine rich protein interaction domain; This is a serine rich domain that is found in the docking protein p130(cas) (Crk-associated substrate). This domain folds into a four helix bundle which is associated with protein-protein interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 435 MDVDFAKETAVSLQHKVASSAAGLLLFVSRTWRFKDSLETNIHRIRRAADHVEESVREFLDFAQGVGGTACNLTDSYLQA 514
Cdd:pfam08824   1 LDLDSALETLSRLQQEVESSVSKLMSFVSSNWRSRENLEAHLNEIRRAVDRVRQSLREFLEFARGAVGNAAQLTDSNLQT 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677 515 RIRDQLQTISSSYQTLLDAKGSLDRCNWSLEVLVTDKVQNSLDDLERFVATARIVPEDVKRFTSIVIANGKLLFKQN 591
Cdd:pfam08824  81 KLRKQLQRLEDSYQILLQTSQALDSCGWSLDVLATDKPQNSPDDLDRFVMVARTVPDDVKQLASIIQGNGSLLFKRA 157

C-terminal FAT-like Four helix bundle domain, also called DUF3513, of CAS (Crk-Associated Substrate) scaffolding protein family member 4; a protein interaction module; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain, which binds to the C-terminal domain of NSPs (novel SH2-containing proteins) to form multidomain signaling modules that mediate cell migration and invasion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 684 TERKIHLSKHSRLYFGALFKAISVFASSLSNGQPPEVFITQSKLVITVGQKLVDTLCSETQEKDERNEILCGSSHLCGLL 763
Cdd:cd11568     2 PARKCPLSEHCRLYFGALQKAISVFHSSLSSNQPPEVFISHSKLIIMVGQKLVDTLCQEAKEREARNEILAGSSQLCALL 81

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1828054677 764 KDLALATKSAVIQYPSPSALSLLQSEVERLEHHSRKFRDTLE 805
Cdd:cd11568    82 KNLALATKNAALQYPSPAALRELQDIADELAKHTQQFRAMLE 123

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member 4; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677  14 LLARALYDNHADCSDELAFSRGDILTIVEQNVPESEGWWRCLLHGRQGLAPANRLQV 70
Cdd:cd12000     1 LLARALYDNKADCSDELAFRRGDILTVLEQNVPGSEGWWKCLLHGRQGLAPANRLQL 57

Variant SH3 domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1828054677  18 ALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPANRLQ 69
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEE---SEDGWWEGINTGRTGLVPANYVE 49

Serine rich protein interaction domain; This is a serine rich domain that is found in the docking protein p130(cas) (Crk-associated substrate). This domain folds into a four helix bundle which is associated with protein-protein interactions.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 435 MDVDFAKETAVSLQHKVASSAAGLLLFVSRTWRFKDSLETNIHRIRRAADHVEESVREFLDFAQGVGGTACNLTDSYLQA 514
Cdd:pfam08824   1 LDLDSALETLSRLQQEVESSVSKLMSFVSSNWRSRENLEAHLNEIRRAVDRVRQSLREFLEFARGAVGNAAQLTDSNLQT 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677 515 RIRDQLQTISSSYQTLLDAKGSLDRCNWSLEVLVTDKVQNSLDDLERFVATARIVPEDVKRFTSIVIANGKLLFKQN 591
Cdd:pfam08824  81 KLRKQLQRLEDSYQILLQTSQALDSCGWSLDVLATDKPQNSPDDLDRFVMVARTVPDDVKQLASIIQGNGSLLFKRA 157

C-terminal FAT-like Four helix bundle domain, also called DUF3513, of CAS (Crk-Associated Substrate) scaffolding protein family member 4; a protein interaction module; CASS4, also called HEPL (HEF1-EFS-p130Cas-like), localizes to focal adhesions and plays a role in regulating FAK activity, focal adhesion integrity, and cell spreading. It is most abundant in blood cells and lung tissue, and is also found in high levels in leukemia and ovarian cell lines. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain, which binds to the C-terminal domain of NSPs (novel SH2-containing proteins) to form multidomain signaling modules that mediate cell migration and invasion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 684 TERKIHLSKHSRLYFGALFKAISVFASSLSNGQPPEVFITQSKLVITVGQKLVDTLCSETQEKDERNEILCGSSHLCGLL 763
Cdd:cd11568     2 PARKCPLSEHCRLYFGALQKAISVFHSSLSSNQPPEVFISHSKLIIMVGQKLVDTLCQEAKEREARNEILAGSSQLCALL 81

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1828054677 764 KDLALATKSAVIQYPSPSALSLLQSEVERLEHHSRKFRDTLE 805
Cdd:cd11568    82 KNLALATKNAALQYPSPAALRELQDIADELAKHTQQFRAMLE 123

Crk-Associated Substrate C-terminal domain; This is a C-terminal domain found in CAS family members. The CAS (Crk-Associated Substrate) protein family is a group of scaffolding proteins that play important modulatory roles in both normal and pathological cell growth regulation. They contain an N-terminal Src homology 3 (SH3) domain pfam00018 and a substrate domain (SD). The SD contains a large number of YxxP motifs, which when phosphorylated by Src-family kinases provide canonical binding sites for proteins containing SH2 domains such as Crk, Crk-L, CRKII presumed domain is functionally uncharacterized.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 608 PQRETESYQESSPFDRQPTTEHSFELARKNRVNVCWQspnlqekgkptmegKSNRNPDFHGMSPPPLTSPSPSGQNTERK 687
Cdd:pfam12026  17 QGKEEFERQQKELLEKLPAEEQFENLIKQSKSQLEQQ--------------QQEVTQPVEDPSNWTPPQSQLSPNDRQLL 82

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 688 IHLSKHSRLYFGALFKAISVFASSLSNGQPPEVFITQSKLVITVGQKLV---DTLCSETQEKDERNEILCGSSHLCGLLK 764
Cdd:pfam12026  83 LFYSEQCETHFGALLNAIDAFFSSLSNNQPPKIFVAHSKFVILSAHKLVfigDTLCRQASAADVRNRVLHCSNALCELLK 162

                         170       180       190       200
                  ....*....|....*....|....*....|....*....|
gi 1828054677 765 DLALATKSAVIQYPSPSALSLLQSEVERLEHHSRKFRDTL 804
Cdd:pfam12026 163 TLVLATKKAALQYPSPAAVQEMVDRVTELSHHAQQFKTVL 202

Serine rich Four helix bundle domain of CAS (Crk-Associated Substrate) scaffolding protein, Neural precursor cell Expressed, Developmentally Down-regulated 9; a protein interaction module; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. CAS proteins associate with the 14-3-3 family; this interaction is regulated by integrin-mediated cell adhesion. The serine rich four helix bundle domain of BCAR1, another CAS protein, has been shown to bind 14-3-3 in a phosphorylation-dependent manner. This domain is structurally similar to other helical bundles found in cell adhesion components such as alpha-catenin, vinculin, and FAK, and may bind other proteins in addition to the 14-3-3 family.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 433 LWMDVDFAKETAVSLQHKVASSAAGLLLFVSRTWRFKDSLETNIHRIRRAADHVEESVREFLDFAQGVGGTACNLTDSYL 512
Cdd:cd11550     2 LALDPDTAIERLYRLQQAVESSVSNLMALVSPDWRTYSFMERHINEIRTAVDRVELSLGEYLQFGKGAAANATALSENGL 81

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1828054677 513 QARIRDQLQTISSSYQTLLDAKGSLDRCNWSLEVLVTDKVQNSLDDLERFVATARIVPEDVKRFTSIVIANGKLLFKQ 590
Cdd:cd11550    82 HNKMRRELQRLEDSHQILLQTYQDLNSCNWSLNILAANGHHNKCDDLDRFVMVAKTVPDDAKQLTTTIGSNAELLFRR 159

Serine rich Four helix bundle domain of CAS (Crk-Associated Substrate) scaffolding protein, Breast Cancer Anti-estrogen Resistance 1; a protein interaction module; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. CAS proteins associate with the 14-3-3 family; this interaction is regulated by integrin-mediated cell adhesion. The serine rich four helix bundle domain of BCAR1 has been shown to bind 14-3-3 in a phosphorylation-dependent manner. This domain is structurally similar to other helical bundles found in cell adhesion components such as alpha-catenin, vinculin, and FAK, and may bind other proteins in addition to the 14-3-3 family.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 435 MDVDFAKETAVSLQHKVASSAAGLLLFVSRTWRFKDSLETNIHRIRRAADHVEESVREFLDFAQGVGGTACNLTDSYLQA 514
Cdd:cd11552     1 LDLEAAMETLARLQQGVSSSVSHLMSFIGGNWRSPEHMEANVQDIHAAVEGVHGAVRELLEFARGAVSNAAQASDRTLHA 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1828054677 515 RIRDQLQTISSSYQTLLDAKGSLDRCNWSLEVLVTDkvQNSLDDLERFVATARIVPEDVKRFTSIVIANGKLLFKQ 590
Cdd:cd11552    81 KLSRQLQKMEEVYQTLVRHSQALDACRWSPAALAAP--GPTLDDLDRLVMYSRGVPDDAKQLASFLHGNASLLFRR 154

Src homology 3 domain of CAS (Crk-Associated Substrate) scaffolding protein family member, Neural precursor cell Expressed, Developmentally Down-regulated 9; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure that includes an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain. The SH3 domain of CAS proteins binds to diverse partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1828054677  15 LARALYDNHADCSDELAFSRGDILTIVEQNVPESEGWWRCLLHGRQGLAPANRLQVL 71
Cdd:cd12002     1 MARALYDNVPECAEELAFRKGDILTVIEQNTGGLEGWWLCSLHGRQGIAPGNRLKLL 57

C-terminal FAT-like Four helix bundle domain, also called DUF3513, of CAS (Crk-Associated Substrate) scaffolding protein, Breast Cancer Anti-estrogen Resistance 1; a protein interaction module; BCAR1, also called p130cas or CASS1, is the founding member of the CAS family of scaffolding proteins and was originally identified through its ability to associate with Crk. The name BCAR1 was designated because the human gene was identified in a screen for genes that promote resistance to tamoxifen. It is widely expressed and its deletion is lethal in mice. It plays a role in regulating cell motility, survival, proliferation, transformation, cancer progression, and bacterial pathogenesis. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain, which binds to the C-terminal domain of NSPs (novel SH2-containing proteins) to form multidomain signaling modules that mediate cell migration and invasion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 701 LFKAISVFASSLSNGQPPEVFITQSKLVITVGQKLV---DTLCSETQEKDERNEILCGSSHLCGLLKDLALATKSAVIQY 777
Cdd:cd11569    24 LTNAIDAFFTSISSNQPPKIFVAHSKFVILSAHKLVfigDTLSRQAKAADVRSKVTHYSNLLCEKLKEIVLSTKTAALQY 103

                          90       100
                  ....*....|....*....|....*..
gi 1828054677 778 PSPSALSLLQSEVERLEHHSRKFRDTL 804
Cdd:cd11569   104 PSPAAAKDMVERVKELGGSTQQFRMVL 130

C-terminal FAT-like Four helix bundle domain, also called DUF3513, of CAS (Crk-Associated Substrate) scaffolding protein, Neural precursor cell Expressed, Developmentally Down-regulated 9; a protein interaction module; NEDD9 is also called human enhancer of filamentation 1 (HEF1) or CAS-L (Crk-associated substrate in lymphocyte). It was first described as a gene predominantly expressed in early embryonic brain, and was also isolated from a screen of human proteins that regulate filamentous budding in yeast, and as a tyrosine phosphorylated protein in lymphocytes. It promotes metastasis in different solid tumors. NEDD9 localizes in focal adhesions and associates with FAK and Abl kinase. It also interacts with SMAD3 and the proteasomal machinery which allows its rapid turnover; these interactions are not shared by other CAS proteins. CAS proteins function as molecular scaffolds to regulate protein complexes that are involved in many cellular processes. They share a common domain structure containing protein interaction modules that enable their scaffolding function, including an N-terminal SH3 domain, an unstructured substrate domain that contains many YxxP motifs, a serine-rich four-helix bundle, and a FAT-like C-terminal domain, which binds to the C-terminal domain of NSPs (novel SH2-containing proteins) to form multidomain signaling modules that mediate cell migration and invasion.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1828054677 697 YFGALFKAISVFASSLSNGQPPEVFITQSKLVITVGQKLV---DTLCSETQEKDERNEILCGSSHLCGLLKDLALATKSA 773
Cdd:cd11570    15 HFISLLNAIDAFFSCVSSGQPPRIFVAHSKFVILSAHKLVfigDTLTRQVTVQDIRNRVMNSSNQLCELLKTIVMATKMA 94

                          90       100       110
                  ....*....|....*....|....*....|.
gi 1828054677 774 VIQYPSPSALSLLQSEVERLEHHSRKFRDTL 804
Cdd:cd11570    95 ALHYPSTAALQEMVDRVTDLSHLAQLFKLSL 125

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 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLH-GRQGLAPAN 66
Cdd:cd00174     2 ARALYDYEAQDDDELSFKKGDIITVLEK---DDDGWWEGELNgGREGLFPAN 50

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPANRLQV 70
Cdd:cd11959     2 AVALYDYQAADDDEISFDPDDIITNIEM---IDEGWWRGVCRGKYGLFPANYVEL 53

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPANRLQ 69
Cdd:cd11827     2 CKALYAYDAQDTDELSFNEGDIIEILKE---DPSGWWTGRLRGKEGLFPGNYVE 52

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLH-GRQGLAPA 65
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEK---SEDGWWKGRNKgGKEGLIPS 47

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWR-CLLHGRQGLAPAN 66
Cdd:cd11960     2 ARALYDYQAADDTEISFDPGDIITDIEQ---IDEGWWRgTGPDGTYGLFPAN 50

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLL-HGRQGLAPAN 66
Cdd:cd11819     2 AKALYDYQAAEDNEISFVEGDIITQIEQ---IDEGWWLGVNaKGQKGLFPAN 50

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.

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPANRLQV 70
Cdd:cd11823     3 KALYSYTANREDELSLQPGDIIEVHEK---QDDGWWLGELNGKKGIFPATYVEE 53

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

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVeqNVPESEGWWRCLLHGRQGLAPAN 66
Cdd:cd11804     2 AVAKHDFKATAEDELSFKKGSILKVL--NMEDDPNWYKAELDGKEGLIPKN 50

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

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnVPESEGWWRCLLHGRQGLAPANRLQV 70
Cdd:cd11842     2 AVALYDFAGEQPGDLAFQKGDIITILKK-SDSQNDWWTGRIGGREGIFPANYVEL 55

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

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQNVPESeGWWRCLLHGRQGLAPAN 66
Cdd:cd11875     2 ARVLFDYEAENEDELTLREGDIVTILSKDCEDK-GWWKGELNGKRGVFPDN 51

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

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gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQNVPEsegWWRCLLHGRQGLAPANRLQV 70
Cdd:cd11840     3 IALFPYTAQNEDELSFQKGDIINVLSKDDPD---WWRGELNGQTGLFPSNYVEP 53

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

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPANRLQ 69
Cdd:cd11824     2 YSVLYDYTAQEDDELSISKGDVVAVIEK---GEDGWWTVERNGQKGLVPGTYLE 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.

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1828054677  15 LARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPAN 66
Cdd:cd11877     1 LVRAKFNFEGTNEDELSFDKGDIITVTQV---VEGGWWEGTLNGKTGWFPSN 49

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

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQNVPEsegWWRCLLHGRQGLAPAN 66
Cdd:cd11950     2 VRALYDFEALEDDELGFNSGDVIEVLDSSNPS---WWKGRLHGKLGLFPAN 49

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

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQNVPEsegWWRCLLHGRQGLAPAN 66
Cdd:cd11817     2 AVALYDFTGETEEDLSFQRGDRILVTEHLDAE---WSRGRLNGREGIFPRA 49

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

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gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQNVPEsegWWRCLLHGRQGLAPAN 66
Cdd:cd11820     4 RALYDFEAAEDNELTFKAGEIITVLDDSDPN---WWKGSNHRGEGLFPAN 50

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

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gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQNvpESEGWWRCLLHGRQGLAPAN 66
Cdd:cd11882     2 ARALYACKAEDESELSFEPGQIITNVQPS--DEPGWLEGTLNGRTGLIPEN 50

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

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gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQNVPEsegWWRCLLHG---RQGLAPAN 66
Cdd:cd11821     2 VRALYDCQADNDDELTFSEGEIIVVTGEEDDE---WWEGHIEGdpsRRGVFPVS 52

Src homology 3 domain of Apoptosis Stimulating of p53 proteins (ASPP); The ASPP family of proteins bind to important regulators of apoptosis (p53, Bcl-2, and RelA) and cell growth (APCL, PP1). They share similarity at their C-termini, where they harbor a proline-rich region, four ankyrin (ANK) repeats, and an SH3 domain. Vertebrates contain three members of the family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2 activate the apoptotic function of the p53 family of tumor suppressors (p53, p63, and p73), while iASPP is an oncoprotein that specifically inhibits p53-induced apoptosis. The expression of ASPP proteins is altered in tumors; ASPP1 and ASPP2 are downregulated whereas iASPP is upregulated is some cancer types. ASPP proteins also bind and regulate protein phosphatase 1 (PP1), and this binding is competitive with p53 binding. The SH3 domain and the ANK repeats of ASPP contribute to the p53 binding site; they bind to the DNA binding domain of p53. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1828054677  18 ALYDNHADCSDELAFSRGDILTIVEQNVPESEGWWRCLLHGRQGLAPANRL 68
Cdd:cd11807     5 ALFDYEAENGDELSFREGDELTVLRKGDDDETEWWWARLNDKEGYVPRNLL 55

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

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gi 1828054677  18 ALYDNHADCSDELAFSRGDILTIVEQnvpESEGWW-RCLLHGRQGLAPAN 66
Cdd:cd11812     4 ALYDYTANRSDELTIHRGDIIRVLYK---DNDNWWfGSLVNGQQGYFPAN 50

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

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gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQNvpESEGWWRCLL-HGRQGLAPANRLQ 69
Cdd:cd11998     4 RALYDYDGQEQDELSFKAGDELTKLEDE--DEQGWCKGRLdSGQVGLYPANYVE 55

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

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gi 1828054677  16 ARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPAN 66
Cdd:cd11873     2 VIVEFDYDAEEPDELTLKVGDIITNVKK---MEEGWWEGTLNGKRGMFPDN 49

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 1828054677  15 LARALYDNHADCSDELAFSRGDILTIVEQnvpESEGWWRCLLHGRQGLAPAN 66
Cdd:cd12061     1 VVRAKFNFQQTNEDELSFSKGDVIHVTRV---EEGGWWEGTHNGRTGWFPSN 49

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1828054677  17 RALYDNHADCSDELAFSRGDILTIVEQNVPEsegWW--RCLLHGRQGLAPAN 66
Cdd:cd11845     3 VALYDYEARTDDDLSFKKGDRLQILDDSDGD---WWlaRHLSTGKEGYIPSN 51

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