Epidermal growth factor receptor kinase substrate (EPS8)-like Phosphotyrosine-binding (PTB) domain; EPS8 is a regulator of Rac signaling. It consists of a PTB and an SH3 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868  64 QYRVEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWTQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAHTC 143
Cdd:cd01210     4 QYRVEHLATFTLGREEGVQTVEDALRKLKELDAKGRIWSQEMLLQVNDGWVLLLDIETKEELESFPLSSIQECTAVLSTC 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1779948868 144 SYDSILALVCKEPTQNKPDLHLFQCDEVKANLISEDIESAISDSKGGK 191
Cdd:cd01210    84 SYNSILLLVVQEPDQPKPEMHLFQCDEVGAELLVEDLQKALSGKRSGR 131

Src Homology 3 domain of Epidermal growth factor receptor kinase substrate 8 and similar proteins; This group is composed of Eps8 and Eps8-like proteins including Eps8-like 1-3, among others. These proteins contain N-terminal Phosphotyrosine-binding (PTB), central SH3, and C-terminal effector domains. Eps8 binds either Abi1 (also called E3b1) or Rab5 GTPase activating protein RN-tre through its SH3 domain. With Abi1 and Sos1, it becomes part of a trimeric complex that is required to activate Rac. Together with RN-tre, it inhibits the internalization of EGFR. The SH3 domains of Eps8 and similar proteins recognize peptides containing a PxxDY motif, instead of the classical PxxP motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity. 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 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGDSGFVPNNILDIM 588
Cdd:cd11764     1 YVRVLYDFTARNSKELSVLKGEYLEVLDDSRQWWKVRNSRGQVGYVPHNILEPY 54

Epidermal growth factor receptor kinase substrate (EPS8)-like Phosphotyrosine-binding (PTB) domain; EPS8 is a regulator of Rac signaling. It consists of a PTB and an SH3 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868  64 QYRVEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWTQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAHTC 143
Cdd:cd01210     4 QYRVEHLATFTLGREEGVQTVEDALRKLKELDAKGRIWSQEMLLQVNDGWVLLLDIETKEELESFPLSSIQECTAVLSTC 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1779948868 144 SYDSILALVCKEPTQNKPDLHLFQCDEVKANLISEDIESAISDSKGGK 191
Cdd:cd01210    84 SYNSILLLVVQEPDQPKPEMHLFQCDEVGAELLVEDLQKALSGKRSGR 131

SAM domain of EPS8-like subfamily; SAM (sterile alpha motif) domain of EPS8-like subfamily is a putative protein-protein interaction domain. This subfamily includes epidermal growth factor receptor kinase substrate 8 proteins (EPS8) and epidermal growth factor receptor kinase substrate 8-like (EPSL8) 1, 2, 3 proteins with the SAM domain located in the C-terminal effector region. This region is responsible for intracellular protein localization and is involved in small GTPases (such as Rac and Rab5) activation/inhibition. Proteins belonging to this group participate in coordination and integration of multiple signaling pathways; in particular, they play a role in the control of actin dynamics and in receptor endocytosis. They can form complexes with other proteins; for example, in the actin signaling network they interact with SOS1 and E3b1 (Abl1) proteins as well as with CRIB (via SH3 domains) during the actin filament formation, and in the receptor endocytosis their partner is RN-tre protein.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1779948868 720 NITYDSSPEEVKTWLQSKGFNPVTVSSLGVLNGAQLFSLNKDELRSVCP-EGARVFSQITVQKAAL 784
Cdd:cd09540     1 PLTYDSSPEEVKAWLQAKGFSKITVRSLGVLTGAQLFSLNKEELKTVCPeEGARVYSQLTVQKSAL 66

Phosphotyrosine-binding domain, phosphotyrosine-interaction (PI) domain; PTB/PI domain structure similar to those of pleckstrin homology (PH) and IRS-1-like PTB domains.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868   64 QYRVEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWTQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAHtc 143
Cdd:smart00462   5 SFRVKYLGSVEVPEARGLQVVQEAIRKLRAAQGSEKKEPQKVILSISSRGVKLIDEDTKAVLHEHPLRRISFCAVGPD-- 82

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....
gi 1779948868  144 sYDSILALVCKEPTQNKPDLHLFQCDEVkANLISEDIESAISDSKGGKQKRRPE 197
Cdd:smart00462  83 -DLDVFGYIARDPGSSRFACHVFRCEKA-AEDIALAIGQAFQLAYELKLKARSE 134

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 1779948868  532 PKKYAKSKYDFVARNSSELSVMKDDVLEILDDR-KQWWKVRNASGDSGFVPNNIL 585
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKSdDGWWKGRLGRGKEGLFPSNYV 55

Epidermal growth factor receptor kinase substrate (EPS8)-like Phosphotyrosine-binding (PTB) domain; EPS8 is a regulator of Rac signaling. It consists of a PTB and an SH3 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868  64 QYRVEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWTQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAHTC 143
Cdd:cd01210     4 QYRVEHLATFTLGREEGVQTVEDALRKLKELDAKGRIWSQEMLLQVNDGWVLLLDIETKEELESFPLSSIQECTAVLSTC 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1779948868 144 SYDSILALVCKEPTQNKPDLHLFQCDEVKANLISEDIESAISDSKGGK 191
Cdd:cd01210    84 SYNSILLLVVQEPDQPKPEMHLFQCDEVGAELLVEDLQKALSGKRSGR 131

SAM domain of EPS8-like subfamily; SAM (sterile alpha motif) domain of EPS8-like subfamily is a putative protein-protein interaction domain. This subfamily includes epidermal growth factor receptor kinase substrate 8 proteins (EPS8) and epidermal growth factor receptor kinase substrate 8-like (EPSL8) 1, 2, 3 proteins with the SAM domain located in the C-terminal effector region. This region is responsible for intracellular protein localization and is involved in small GTPases (such as Rac and Rab5) activation/inhibition. Proteins belonging to this group participate in coordination and integration of multiple signaling pathways; in particular, they play a role in the control of actin dynamics and in receptor endocytosis. They can form complexes with other proteins; for example, in the actin signaling network they interact with SOS1 and E3b1 (Abl1) proteins as well as with CRIB (via SH3 domains) during the actin filament formation, and in the receptor endocytosis their partner is RN-tre protein.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1779948868 720 NITYDSSPEEVKTWLQSKGFNPVTVSSLGVLNGAQLFSLNKDELRSVCP-EGARVFSQITVQKAAL 784
Cdd:cd09540     1 PLTYDSSPEEVKAWLQAKGFSKITVRSLGVLTGAQLFSLNKEELKTVCPeEGARVYSQLTVQKSAL 66

Phosphotyrosine-binding domain, phosphotyrosine-interaction (PI) domain; PTB/PI domain structure similar to those of pleckstrin homology (PH) and IRS-1-like PTB domains.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868   64 QYRVEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWTQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAHtc 143
Cdd:smart00462   5 SFRVKYLGSVEVPEARGLQVVQEAIRKLRAAQGSEKKEPQKVILSISSRGVKLIDEDTKAVLHEHPLRRISFCAVGPD-- 82

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....
gi 1779948868  144 sYDSILALVCKEPTQNKPDLHLFQCDEVkANLISEDIESAISDSKGGKQKRRPE 197
Cdd:smart00462  83 -DLDVFGYIARDPGSSRFACHVFRCEKA-AEDIALAIGQAFQLAYELKLKARSE 134

First 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 first SH3 domain of Nck proteins preferentially binds the PxxDY sequence, which is present in the CD3e cytoplasmic tail. This binding inhibits phosphorylation by Src kinases, resulting in the downregulation of TCR surface expression. 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        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGDSGFVPNN 583
Cdd:cd11765     1 YVVAKYDYTAQGDQELSIKKNEKLTLLDDSKHWWKVQNSSNQTGYVPSN 49

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 1779948868  532 PKKYAKSKYDFVARNSSELSVMKDDVLEILDDR-KQWWKVRNASGDSGFVPNNIL 585
Cdd:smart00326   1 EGPQVRALYDYTAQDPDELSFKKGDIITVLEKSdDGWWKGRLGRGKEGLFPSNYV 55

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
                  ....*....|....*....|....*....|....*....|....*.
gi 1779948868 537 KSKYDFVARNSSELSVMKDDVLEILDDRK-QWWKVRNASGDSGFVP 581
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEdGWWKGRNKGGKEGLIP 46

First Src Homology 3 domain of Nck1 adaptor protein; Nck1 (also called Nckalpha) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds and activates RasGAP, resulting in the downregulation of Ras. It is also involved in the signaling of endothilin-mediated inhibition of cell migration. 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, which show partly overlapping functions but also bind distinct targets. The first SH3 domain of Nck1 binds the PxxDY sequence in the CD3e cytoplasmic tail; this binding inhibits phosphorylation by Src kinases, resulting in the downregulation of TCR surface expression. 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        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1779948868 538 SKYDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGDSGFVPNNILD 586
Cdd:cd11900     7 AKFDYVAQQDQELDIKKNERLWLLDDSKSWWRVRNAMNKTGFVPSNYVE 55

First Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. 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, which show partly overlapping functions but also bind distinct targets. The first SH3 domain of Nck2 binds the PxxDY sequence in the CD3e cytoplasmic tail; this binding inhibits phosphorylation by Src kinases, resulting in the downregulation of TCR surface expression. 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        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1779948868 538 SKYDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGDSGFVPNNILD 586
Cdd:cd11899     8 AKWDYTAQQDQELDIKKNERLWLLDDSKTWWRVRNAANRTGYVPSNYVE 56

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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1779948868 540 YDFVARNSSELSVMKDDVLEILDD-RKQWWKVRN-ASGDSGFVPNN 583
Cdd:cd11845     6 YDYEARTDDDLSFKKGDRLQILDDsDGDWWLARHlSTGKEGYIPSN 51

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. 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 1779948868 539 KYDFVARNSSELSVMKDDVLEILDDRK--QWWKVRNASGDSGFVPNN 583
Cdd:cd11769     7 KYNFNGASEEDLPFKKGDILTIVAVTKdpNWYKAKNKDGREGMIPAN 53

Src homology 3 domain of High osmolarity signaling protein Sho1p; Sho1p (or Sho1), also called SSU81 (Suppressor of SUA8-1 mutation), is a yeast membrane protein that regulates adaptation to high salt conditions by activating the HOG (high-osmolarity glycerol) pathway. High salt concentrations lead to the localization to the membrane of the MAPKK Pbs2, which is then activated by the MAPKK Ste11 and in turn, activates the MAPK Hog1. Pbs2 is localized to the membrane though the interaction of its PxxP motif with the SH3 domain of Sho1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGDSGFVPNNIL 585
Cdd:cd11855     8 YDASPDDPNELSFEKGEILEVSDTSGKWWQARKSNGETGICPSNYL 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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1779948868 540 YDFVARNSSELSVMKDDVLEILD-DRKQWWKV-RNasGDSGFVPNNIL 585
Cdd:cd11824     6 YDYTAQEDDELSISKGDVVAVIEkGEDGWWTVeRN--GQKGLVPGTYL 51

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 1779948868 536 AKSKYDFVARNSSELSVMKDDVLEILDDRKQ--WWKvRNASGDSGFVPNNILD 586
Cdd:cd11976     2 AKARYDFCARDRSELSLKEGDIIKILNKKGQqgWWR-GEIYGRVGWFPANYVE 53

N-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 N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). 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 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILD-DRKQWWKVRNASGDSGFVP 581
Cdd:cd11758     2 YVRALFDFPGNDDEDLPFKKGEILTVIRkPEEQWWNARNSEGKTGMIP 49

First Src homology 3 domain of the RhoGEF kinase, Kalirin; Kalirin, also called Duo, Duet, or TRAD, is a large neuronal dual Rho guanine nucleotide exchange factor (RhoGEF) that activates Rac1, RhoA, and RhoG using two RhoGEF domains. Kalirin exists in many isoforms generated by alternative splicing and the use of multiple promoters; the major isoforms are kalirin-7, -9, and -12, which differ at their C-terminal ends. Kalirin-12, the longest isoform, contains an N-terminal Sec14p domain, spectrin-like repeats, two RhoGEF domains, two SH3 domains, as well as Ig, FNIII, and kinase domains at the C-terminal end. Kalirin-7 contains only a single RhoGEF domain and does not contain an SH3 domain. Kalirin, through its many isoforms, interacts with many different proteins and is able to localize to different locations within the cell. It influences neurite initiation, axon growth, dendritic morphogenesis, vesicle trafficking, neuronal maintenance, and neurodegeneration. 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 1779948868 541 DFVARNSSELSVMKDDVLEILD---DRKQWWKVR-----NASGDSGFVPNNILDI 587
Cdd:cd11852     8 DFEATSSQELTVSKGQTVEVLErpsSRPDWCLVRtleqdNSPPQEGLVPSSILCI 62

Phosphotyrosine interaction domain (PTB/PID);

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868  67 VEHLTTFVLDRKDAMITVDDGIRKLKLLDAKGKVWT-------QDMILQVDDRAVSLIDLESKNELENFPLNTIQHCqav 139
Cdd:pfam00640   9 VEVPEERAPDKNTRMQQAREAIRRVKAAKINKIRGLsgetgpgTKVDLFISTDGLKLLNPDTQELIHDHPLVSISFC--- 85

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1779948868 140 AHTCSYDS-ILALVCKEPTQNKPDLHLFQCDEvKANLISEDIESAIS 185
Cdd:pfam00640  86 ADGDPDLMrYFAYIARDKATNKFACHVFESED-GAQDIAQSIGQAFA 131

Low Density Lipoprotein Receptor Adaptor Protein 1 (LDLRAP1) in mammals and similar proteins Phosphotyrosine-binding (PTB) PH-like fold; The null mutations in the LDL receptor adaptor protein 1 (LDLRAP1) gene, which serves as an adaptor for LDLR endocytosis in the liver, causes autosomal recessive hypercholesterolemia (ARH). LDLRAP1 contains a single PTB domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd contains mammals, insects, and sponges.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1779948868  64 QYRVEHL-TTFVLDRKDAMITVDDGIRKLKLLDAKGKVWtQDMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAht 142
Cdd:cd13159     4 TFYLKYLgSTLVEKPKGEGATAEAVKTIIAMAKASGKKL-QKVTLTVSPKGIKVTDSATNETILEVSIYRISYCTADA-- 80

                          90       100
                  ....*....|....*....|....*.
gi 1779948868 143 cSYDSILALVCKEPTQNKPDLHLFQC 168
Cdd:cd13159    81 -NHDKVFAFIATNQDNEKLECHAFLC 105

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 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILD-DRKQWWKVRnASGDSGFVPNN 583
Cdd:cd11951     1 FVQAQYDFSAEDPSQLSFRRGDIIEVLDcPDPNWWRGR-ISGRVGFFPRN 49

Third Src Homology 3 domain of Nck2 adaptor protein; Nck2 (also called Nckbeta or Growth factor receptor-bound protein 4, Grb4) plays a crucial role in connecting signaling pathways of tyrosine kinase receptors and important effectors in actin dynamics and cytoskeletal remodeling. It binds neuronal signaling proteins such as ephrinB and Disabled-1 (Dab-1) exclusively. 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, which show partly overlapping functions but also bind distinct targets. The third SH3 domain of Nck appears to prefer ligands with a PxAPxR 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.

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1779948868 537 KSKYDFVARNSSELSVMKDDVLEIL---DDRKQWWKVRNASGDSGFVPNNILDIM 588
Cdd:cd11903     4 QTLYPFSSVTEEELNFEKGETMEVIekpENDPEWWKCKNSRGQVGLVPKNYVVVL 58

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. Also included in this subfamily is the second C-terminal SH3 domain of Rho guanine nucleotide exchange factor 37 (ARHGEF37), whose function is still unknown. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILD--DRK---QWWKVRNaSGDSGFVPNNILD 586
Cdd:cd11800     6 YTFEARSPGELSVTEGQVVTVLEkhDLKgnpEWWLVED-RGKQGYVPSNYLA 56

Src homology 3 domain of Brk (Breast tumor kinase) Protein Tyrosine Kinase (PTK), also called PTK6; Brk is a cytoplasmic (or non-receptor) PTK with limited homology to Src kinases. It has been found to be overexpressed in a majority of breast tumors. It plays roles in normal cell differentiation, proliferation, survival, migration, and cell cycle progression. Brk substrates include RNA-binding proteins (SLM-1/2, Sam68), transcription factors (STAT3/5), and signaling molecules (Akt, paxillin, IRS-4). Src kinases in general 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 site. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILDDRKQWWKVRNASGD-----SGFVPNNIL 585
Cdd:cd11847     6 WDFKARGDEELSFQAGDQFRIAERSGDWWTALKLDRAggvvaQGFVPNNYL 56

Src homology 3 domain of Alpha Spectrin; Spectrin is a major structural component of the red blood cell membrane skeleton and is important in erythropoiesis and membrane biogenesis. It is a flexible, rope-like molecule composed of two subunits, alpha and beta, which consist of many spectrin-type repeats. Alpha and beta spectrin associate to form heterodimers and tetramers; spectrin tetramer formation is critical for red cell shape and deformability. Defects in alpha spectrin have been associated with inherited hemolytic anemias including hereditary spherocytosis (HSp), hereditary elliptocytosis (HE), and hereditary pyropoikilocytosis (HPP). Alpha spectrin contains a middle SH3 domain and a C-terminal EF-hand binding motif in addition to multiple spectrin repeats. 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 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILD-DRKQWWKVRNaSGDSGFVPNNIL 585
Cdd:cd11808     1 CVVALYDYQEKSPREVSMKKGDILTLLNsSNKDWWKVEV-NDRQGFVPAAYV 51

Src Homology 3 domain of TXK, also called Resting lymphocyte kinase (Rlk); TXK is a cytoplasmic (or nonreceptor) tyr kinase containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. It also contains an N-terminal cysteine-rich region. Rlk is expressed in T-cells and mast cell lines, and is a key component of T-cell receptor (TCR) signaling. It is important in TCR-stimulated proliferation, IL-2 production and phospholipase C-gamma1 activation. 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 1779948868 537 KSKYDFVARNSSELSVMKDDVLEILDD-RKQWWKVRNASGDSGFVPNN 583
Cdd:cd11907     4 KALYDFLPREPSNLALKRAEEYLILEQyDPHWWKARDRYGNEGLIPSN 51

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases 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). 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 1779948868 540 YDFVARNSSELSVMKDDVLEILDDRK-QWWKVRN-ASGDSGFVPNNIL 585
Cdd:cd12006     7 YDYEARTEDDLSFHKGEKFQILNSSEgDWWEARSlTTGETGYIPSNYV 54

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. 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 1779948868 536 AKSKYDFVARNSSELSVMKDDVLEILD-DRKQWWKVR---NASGDS---GFVPNN 583
Cdd:cd11773     2 YKALYDYEPQTEDELTIQEDDILYLLEkSDDDWWKVKlkvNSSDDDepvGLVPAT 56

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.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1779948868 536 AKSKYDFVARNSSELSVMKDDV---LEILDDrkQWWKVRNASGDSGFVPNN 583
Cdd:cd11819     2 AKALYDYQAAEDNEISFVEGDIitqIEQIDE--GWWLGVNAKGQKGLFPAN 50

Src Homology 3 domain of Formin Binding Protein 1-Like; FormiN Binding Protein 1-Like (FNBP1L), also known as Toca-1 (Transducer of Cdc42-dependent actin assembly), forms a complex with neural Wiskott-Aldrich syndrome protein (N-WASP). The FNBP1L/N-WASP complex induces the formation of filopodia and endocytic vesicles. FNBP1L is required for Cdc42-induced actin assembly and is essential for autophagy of intracellular pathogens. It contains an N-terminal F-BAR domain, a central Cdc42-binding HR1 domain, and a C-terminal SH3 domain. The SH3 domain of the related protein, CIP4, associates with Gapex-5, a Rab31 GEF. 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 1779948868 535 YAKSKYDFVARNSSELSVMKDDVLEILDDRKQ--WWKVRNASGDSGFVPNNILDI 587
Cdd:cd12072     2 HCKALYPFDGSNEGTLAMKEGEVLYIIEEDKGdgWTRARKQNGEEGYVPTSYIEI 56

Src homology 3 domain of SH3 protein interacting with Nck, 90 kDa (SPIN90); SPIN90 is also called NCK interacting protein with SH3 domain (NCKIPSD), Dia-interacting protein (DIP), 54 kDa vimentin-interacting protein (VIP54), or WASP-interacting SH3-domain protein (WISH). It is an F-actin binding protein that regulates actin polymerization and endocytosis. It associates with the Arp2/3 complex near actin filaments and determines filament localization at the leading edge of lamellipodia. SPIN90 is expressed in the early stages of neuronal differentiation and plays a role in regulating growth cone dynamics and neurite outgrowth. It also interacts with IRSp53 and regulates cell motility by playing a role in the formation of membrane protrusions. SPIN90 contains an N-terminal SH3 domain, a proline-rich domain, and a C-terminal VCA (verprolin-homology and cofilin-like acidic) 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 1779948868 537 KSKYDFVARNSSELSVMKDDVLEILDDRKQ-WWKVRNASGDSGFVPNNIL 585
Cdd:cd11849     3 RALYDFKSAEPNTLSFSEGETFLLLERSNAhWWLVTNHSGETGYVPANYV 52

Src Homology 3 domain of metazoan osteoclast stimulating factor 1; OSTF1, also named OSF or SH3P2, is a signaling protein containing SH3 and ankyrin-repeat domains. It acts through a Src-related pathway to enhance the formation of osteoclasts and bone resorption. It also acts as a negative regulator of cell motility. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILD-DRKQWWKVRnASGDSGFVPNN 583
Cdd:cd11772     6 YDYEAQHPDELSFEEGDLLYISDkSDPNWWKAT-CGGKTGLIPSN 49

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 1779948868 540 YDFVARNSSELSVMKDDVLEIL----DDRKQWWKVRNaSGDSGFVPNNIL 585
Cdd:cd11807     7 FDYEAENGDELSFREGDELTVLrkgdDDETEWWWARL-NDKEGYVPRNLL 55

Second C-terminal Src homology 3 domain of Dynamin Binding Protein, also called Tuba, and similar domains; DNMBP or Tuba is a cdc42-specific guanine nucleotide exchange factor (GEF) that contains four N-terminal SH3 domains, a central RhoGEF [or Dbl homology (DH)] domain followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two C-terminal SH3 domains. It provides a functional link between dynamin, Rho GTPase signaling, and actin dynamics. It plays an important role in regulating cell junction configuration. The C-terminal SH3 domains of DNMBP bind to N-WASP and Ena/VASP proteins, which are key regulatory proteins of the actin cytoskeleton. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILDDR-----KQWWkVRNASGDSGFVPNNIL 585
Cdd:cd12141     6 YTFKARSPNELSVSANQRVRILEFSdltgnKEWW-LAEANGQKGYVPSNYI 55

Src homology 3 domain of Signal Transducing Adaptor Molecule 1; STAM1 is part of the endosomal sorting complex required for transport (ESCRT-0) and is involved in sorting ubiquitinated cargo proteins from the endosome. It may also be involved in the regulation of IL2 and GM-CSF mediated signaling, and has been implicated in neural cell survival. 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. 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 1779948868 540 YDFVARNSSELSVMKDDVLEILDDRK-QWWKVRNASGdSGFVPNNIL 585
Cdd:cd11964     7 YDFEAAEDNELTFKAGDIITILDDSDpNWWKGETPQG-TGLFPSNFV 52

Tyrosine-specific kinase/HM-motif TK (TM/HMTK) Phosphotyrosine-binding (PTB) PH-like fold; TK kinases catalyzes the transfer of the terminal phosphate of ATP to a specific tyrosine residue on its target protein. TK kinases play significant roles in development and cell division. Tyrosine-protein kinases can be divided into two subfamilies: receptor tyrosine kinases, which have an intracellular tyrosine kinase domain, a transmembrane domain and an extracellular ligand-binding domain; and non-receptor (cytoplasmic) tyrosine kinases, which are soluble, cytoplasmic kinases. In HMTK the conserved His-Arg-Asp sequence within the catalytic loop is replaced by a His-Met sequence. TM/HMTK have are 2-3 N-terminal PTB domains. PTB domains in TKs are thought to function analogously to the membrane targeting (PH, myristoylation) and pTyr binding (SH2) domains of Src subgroup kinases. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

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gi 1779948868  83 TVDDGIRKLKLLDAKGKVwtqdMILQVDDRAVSLIDLESKNELENFPLNTIQHCQAVAhtcSYDSILALVCKEPTQNKPD 162
Cdd:cd13161    22 VVMAAVKRLKDLKLKPKP----VVLVVSSEGIRVVERLTGEVLTNVPIKDISFVTVDP---KDKKLFAFISHDPRLGRIT 94

                          90
                  ....*....|....*...
gi 1779948868 163 LHLFQCDEvKANLISEDI 180
Cdd:cd13161    95 CHVFRCKR-GAQEICDTI 111

N-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 N-terminal SH3 domain of the related protein 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 1779948868 540 YDFVARNSSELSVMKDDVLEIL--DDRKQWWKVRnASGDSGFVPNNILDI 587
Cdd:cd11948     6 YSFQATESDELPFQKGDILKILnmEDDQNWYKAE-LQGREGYIPKNYIKV 54

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 1779948868 537 KSKYDFVARNSSELSVMKDDVLEILDDRK-QWWKVRNASGdSGFVPNN 583
Cdd:cd11820     4 RALYDFEAAEDNELTFKAGEIITVLDDSDpNWWKGSNHRG-EGLFPAN 50

C-terminal (or second) Src homology 3 domain of VAV3 protein; VAV3 is ubiquitously expressed and functions as a phosphorylation-dependent guanine nucleotide exchange factor (GEF) for RhoA, RhoG, and Rac1. It has been implicated to function in the hematopoietic, bone, cerebellar, and cardiovascular systems. VAV3 is essential in axon guidance in neurons that control blood pressure and respiration. It is overexpressed in prostate cancer cells and it plays a role in regulating androgen receptor transcriptional activity. 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 1779948868 536 AKSKYDFVARNSSELSVMKDDVLEILDDR--KQWWKvRNASGDSGFVPNNILD 586
Cdd:cd11978     3 AIARYDFCARDMRELSLLKGDVVKIYTKMstNGWWR-GEVNGRVGWFPSTYVE 54