calponin homology (CH) domain found in 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. This model corresponds to the CH domain, an actin-binding domain which is present as a single copy in VAV1 protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   2 ELWRQCTHWLIQCRVLPPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLST 81
Cdd:cd21262     1 ELWRQCAHWLIQCRVLPPNHRVTWDSAQVCDLAQALRDGVLLCQLLNNLLPHAVNLREINLRPQMSQFLCLKNIRTFLST 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 1777309805  82 CCEKFGLKRSELFEAFDLFDVQDFGKVIYTLSALSWTPIA 121
Cdd:cd21262    81 CCEKFGLRKSELFEAFDLFDVRDFGKVIDTLSILSWTPIA 120

Vav pleckstrin homology (PH) domain; Vav acts as a guanosine nucleotide exchange factor (GEF) for Rho/Rac proteins. They control processes including T cell activation, phagocytosis, and migration of cells. The Vav subgroup of Dbl GEFs consists of three family members (Vav1, Vav2, and Vav3) in mammals. Vav1 is preferentially expressed in the hematopoietic system, while Vav2 and Vav3 are described by broader expression patterns. Mammalian Vav proteins consist of a calponin homology (CH) domain, an acidic region, a catalytic Dbl homology (DH) domain, a PH domain, a zinc finger cysteine rich domain (C1/CRD), and an SH2 domain, flanked by two SH3 domains. In invertebrates such as Drosophila and C. elegans, Vav is missing the N-terminal SH3 domain. The DH domain is involved in RhoGTPase recognition and selectivity and stimulates the reorganization of the switch regions for GDP/GTP exchange. The PH domain is implicated in directing membrane localization, allosteric regulation of guanine nucleotide exchange activity, and as a phospholipid- dependent regulator of GEF activity. Vavs bind RhoGTPases including Rac1, RhoA, RhoG, and Cdc42, while other members of the GEF family are specific for a single RhoGTPase. This promiscuity is thought to be a result of its CRD. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.polarized. PH domains also have diverse functions. They are often involved in targeting proteins to the plasma membrane, but only a few (less than 10%) display strong specificity in binding inositol phosphates. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinases, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, cytoskeletal associated molecules, and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 385 NFQLSIENLDQSLAHYGRPKIDGELKITSVERRSKMDRYAFLLDKALLICKR-RGDSYDLKDFVNLHSFQIRDDSSG--D 461
Cdd:cd01223     1 SIQDLIENLNESLADYGRLQIDGELKIKSHEDQKKKDRYAFLFDKVLLICKSlRGDQYEYKEIINLSEYRIEDDPSRrtL 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1777309805 462 RDNKKWSHMFLLIEDQGAQGYELFFKTRELKKKWMEQFEMAISNIYP 508
Cdd:cd01223    81 KRDKRWSYQFLLVHKQGKTAYTLYAKTEELKKKWMEAIEMALSNIEP 127

First 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 first SH3 domain of Vav1 has been shown to bind the adaptor protein Grb2. 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        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1777309805 596 KMEVFQEYYGLPPPPGAIGPFLRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKPY 658
Cdd:cd11979     1 KMEVFQEYYGIPPPPGAFGPFLRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKPY 63

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

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1777309805 786 TAKARYDFCARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRV 829
Cdd:cd11976     1 TAKARYDFCARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRV 44

calponin homology (CH) domain found in 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. This model corresponds to the CH domain, an actin-binding domain which is present as a single copy in VAV1 protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   2 ELWRQCTHWLIQCRVLPPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLST 81
Cdd:cd21262     1 ELWRQCAHWLIQCRVLPPNHRVTWDSAQVCDLAQALRDGVLLCQLLNNLLPHAVNLREINLRPQMSQFLCLKNIRTFLST 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 1777309805  82 CCEKFGLKRSELFEAFDLFDVQDFGKVIYTLSALSWTPIA 121
Cdd:cd21262    81 CCEKFGLRKSELFEAFDLFDVRDFGKVIDTLSILSWTPIA 120

Vav pleckstrin homology (PH) domain; Vav acts as a guanosine nucleotide exchange factor (GEF) for Rho/Rac proteins. They control processes including T cell activation, phagocytosis, and migration of cells. The Vav subgroup of Dbl GEFs consists of three family members (Vav1, Vav2, and Vav3) in mammals. Vav1 is preferentially expressed in the hematopoietic system, while Vav2 and Vav3 are described by broader expression patterns. Mammalian Vav proteins consist of a calponin homology (CH) domain, an acidic region, a catalytic Dbl homology (DH) domain, a PH domain, a zinc finger cysteine rich domain (C1/CRD), and an SH2 domain, flanked by two SH3 domains. In invertebrates such as Drosophila and C. elegans, Vav is missing the N-terminal SH3 domain. The DH domain is involved in RhoGTPase recognition and selectivity and stimulates the reorganization of the switch regions for GDP/GTP exchange. The PH domain is implicated in directing membrane localization, allosteric regulation of guanine nucleotide exchange activity, and as a phospholipid- dependent regulator of GEF activity. Vavs bind RhoGTPases including Rac1, RhoA, RhoG, and Cdc42, while other members of the GEF family are specific for a single RhoGTPase. This promiscuity is thought to be a result of its CRD. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.polarized. PH domains also have diverse functions. They are often involved in targeting proteins to the plasma membrane, but only a few (less than 10%) display strong specificity in binding inositol phosphates. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinases, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, cytoskeletal associated molecules, and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 385 NFQLSIENLDQSLAHYGRPKIDGELKITSVERRSKMDRYAFLLDKALLICKR-RGDSYDLKDFVNLHSFQIRDDSSG--D 461
Cdd:cd01223     1 SIQDLIENLNESLADYGRLQIDGELKIKSHEDQKKKDRYAFLFDKVLLICKSlRGDQYEYKEIINLSEYRIEDDPSRrtL 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1777309805 462 RDNKKWSHMFLLIEDQGAQGYELFFKTRELKKKWMEQFEMAISNIYP 508
Cdd:cd01223    81 KRDKRWSYQFLLVHKQGKTAYTLYAKTEELKKKWMEAIEMALSNIEP 127

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains. Improved coverage.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805  198 CLREIQQTEEKYTDTLGSIQQHFMKPLQR---FLKPQDIEIIFINIEDLLRVHTHFLKEMKEALGT--PGAANLYQVFIK 272
Cdd:smart00325   1 VLKELLQTERNYVRDLKLLVEVFLKPLKKelkLLSPNELETLFGNIEEIYEFHRDFLDELEERIEEwdDSVERIGDVFLK 80

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805  273 YKERFLVYGRYCSQVESASKHLDRvAAAREDVQMKLEECSQRANNGRFTLRDLLMVPMQRVLKYHLLLQELVKHTQEAM- 351
Cdd:smart00325  81 LEEFFKIYSEYCSNHPDALELLKK-LKKNPRFQKFLKEIESSPQCRRLTLESLLLKPVQRLTKYPLLLKELLKHTPEDHe 159

                          170       180
                   ....*....|....*....|.
gi 1777309805  352 EKENLRLALDAMRDLAQCVNE 372
Cdd:smart00325 160 DREDLKKALKAIKELANQVNE 180

RhoGEF domain; Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases Also called Dbl-homologous (DH) domain. It appears that pfam00169 domains invariably occur C-terminal to RhoGEF/DH domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 198 CLREIQQTEEKYTDTLGSIQQHFMKPLQRFLK--PQDIEIIFINIEDLLRVHTHFLKEMKEALGtPGAANLYQVFIKYKE 275
Cdd:pfam00621   1 VIKELLQTERSYVRDLEILVEVFLPPNSKPLSesEEEIKTIFSNIEEIYELHRQLLLEELLKEW-ISIQRIGDIFLKFAP 79

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 276 RFLVYGRYCSQVESASKHLDRVAAAREDVQMKLEECSQRANNGRFTLRDLLMVPMQRVLKYHLLLQELVKHTQEA-MEKE 354
Cdd:pfam00621  80 GFKVYSTYCSNYPKALKLLKKLLKKNPKFRAFLEELEANPECRGLDLNSFLIKPVQRIPRYPLLLKELLKHTPPDhPDYE 159

                         170
                  ....*....|....*..
gi 1777309805 355 NLRLALDAMRDLAQCVN 371
Cdd:pfam00621 160 DLKKALEAIKEVAKQIN 176

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
                  ....*....|....*....|....*....|....*....|....
gi 1777309805 786 TAKARYDFCARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRV 829
Cdd:cd11976     1 TAKARYDFCARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRV 44

SH2 domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1777309805 671 WYAGPMERAGAESILANR-SDGTFLVRQRVKDAAEFAISIKYNVEVKHIKIM-TAEGLYRITEKKAFRGLTELVEFY 745
Cdd:pfam00017   1 WYHGKISRQEAERLLLNGkPDGTFLVRESESTPGGYTLSVRDDGKVKHYKIQsTDNGGYYISGGVKFSSLAELVEHY 77

Phorbol esters/diacylglycerol binding domain (C1 domain); This domain is also known as the Protein kinase C conserved region 1 (C1) domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1777309805 516 HDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPP-CGRH 567
Cdd:pfam00130   1 HHFVHRNFKQPTFCDHCGEFLWGLGKQGLKCSWCKLNVHKRCHEKVPPeCGCD 53

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805  403 PKIDGEL-KITSVERRSKMDRYAFLLDKALLICKRRGD--SYDLKDFVNLHSFQIRDdsSGDRDNKKWSHMFLLIEDQGA 479
Cdd:smart00233   1 VIKEGWLyKKSGGGKKSWKKRYFVLFNSTLLYYKSKKDkkSYKPKGSIDLSGCTVRE--APDPDSSKKPHCFEIKTSDRK 78

                           90       100
                   ....*....|....*....|....*
gi 1777309805  480 QgYELFFKTRELKKKWMEQFEMAIS 504
Cdd:smart00233  79 T-LLLQAESEEEREKWVEALRKAIA 102

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
                   ....*....|....*....|....*....|....*....|.
gi 1777309805  785 GTAKARYDFCARDRSELSLKEGDIIKILNKKGqQGWWRGEI 825
Cdd:smart00326   3 PQVRALYDYTAQDPDELSFKKGDIITVLEKSD-DGWWKGRL 42

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
                   ....*....|....*....|....*....|....*....|
gi 1777309805  617 LRLNPGDIVELTKaEAEQNWWEGRNtSTNEIGWFPCNRVK 656
Cdd:smart00326  19 LSFKKGDIITVLE-KSDDGWWKGRL-GRGKEGLFPSNYVE 56

Calponin homology domain; Actin binding domains present in duplicate at the N-termini of spectrin-like proteins (including dystrophin, alpha-actinin). These domains cross-link actin filaments into bundles and networks. A calponin homology domain is predicted in yeasst Cdc24p.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   32 ELAQALRDGVLLCQLLNNLLPHAINLREVNlrPQMSQFLCLKNIRTFLStCCEKFGLKRsELFEAFDLFDVQ-DFGKVIY 110
Cdd:smart00033  21 NFSSDLKDGVALCALLNSLSPGLVDKKKVA--ASLSRFKKIENINLALS-FAEKLGGKV-VLFEPEDLVEGPkLILGVIW 96

                   ....*
gi 1777309805  111 TLSAL 115
Cdd:smart00033  97 TLISL 101

calponin homology (CH) domain found in 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. This model corresponds to the CH domain, an actin-binding domain which is present as a single copy in VAV1 protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   2 ELWRQCTHWLIQCRVLPPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLST 81
Cdd:cd21262     1 ELWRQCAHWLIQCRVLPPNHRVTWDSAQVCDLAQALRDGVLLCQLLNNLLPHAVNLREINLRPQMSQFLCLKNIRTFLST 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 1777309805  82 CCEKFGLKRSELFEAFDLFDVQDFGKVIYTLSALSWTPIA 121
Cdd:cd21262    81 CCEKFGLRKSELFEAFDLFDVRDFGKVIDTLSILSWTPIA 120

Vav pleckstrin homology (PH) domain; Vav acts as a guanosine nucleotide exchange factor (GEF) for Rho/Rac proteins. They control processes including T cell activation, phagocytosis, and migration of cells. The Vav subgroup of Dbl GEFs consists of three family members (Vav1, Vav2, and Vav3) in mammals. Vav1 is preferentially expressed in the hematopoietic system, while Vav2 and Vav3 are described by broader expression patterns. Mammalian Vav proteins consist of a calponin homology (CH) domain, an acidic region, a catalytic Dbl homology (DH) domain, a PH domain, a zinc finger cysteine rich domain (C1/CRD), and an SH2 domain, flanked by two SH3 domains. In invertebrates such as Drosophila and C. elegans, Vav is missing the N-terminal SH3 domain. The DH domain is involved in RhoGTPase recognition and selectivity and stimulates the reorganization of the switch regions for GDP/GTP exchange. The PH domain is implicated in directing membrane localization, allosteric regulation of guanine nucleotide exchange activity, and as a phospholipid- dependent regulator of GEF activity. Vavs bind RhoGTPases including Rac1, RhoA, RhoG, and Cdc42, while other members of the GEF family are specific for a single RhoGTPase. This promiscuity is thought to be a result of its CRD. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.polarized. PH domains also have diverse functions. They are often involved in targeting proteins to the plasma membrane, but only a few (less than 10%) display strong specificity in binding inositol phosphates. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinases, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, cytoskeletal associated molecules, and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 385 NFQLSIENLDQSLAHYGRPKIDGELKITSVERRSKMDRYAFLLDKALLICKR-RGDSYDLKDFVNLHSFQIRDDSSG--D 461
Cdd:cd01223     1 SIQDLIENLNESLADYGRLQIDGELKIKSHEDQKKKDRYAFLFDKVLLICKSlRGDQYEYKEIINLSEYRIEDDPSRrtL 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*..
gi 1777309805 462 RDNKKWSHMFLLIEDQGAQGYELFFKTRELKKKWMEQFEMAISNIYP 508
Cdd:cd01223    81 KRDKRWSYQFLLVHKQGKTAYTLYAKTEELKKKWMEAIEMALSNIEP 127

calponin homology (CH) domain found in VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and as scaffold proteins, and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. This model corresponds to the CH domain, an actin-binding domain which is present as a single copy in VAV proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   2 ELWRQCTHWLIQCRVLPPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLST 81
Cdd:cd21201     1 ELWRQCADWLIRCGVLPPDHRATQPNATVFDLAQALRDGVLLCQLLNRLSPGSVDDREINLRPQMSQFLCLKNIRTFLQA 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1777309805  82 CCEKFGLKRSELFEAFDLFDVQDFGKVIYTLSALSWT 118
Cdd:cd21201    81 CRTVFGLRSADLFEPEDLYDVTNFGKVIRTLSKLSHT 117

Src homology 2 (SH2) domain found in the Vav family; Vav proteins are involved in several processes that require cytoskeletal reorganization, such as the formation of the immunological synapse (IS), phagocytosis, platelet aggregation, spreading, and transformation. Vavs function as guanine nucleotide exchange factors (GEFs) for the Rho/Rac family of GTPases. Vav family members have several conserved motifs/domains including: a leucine-rich region, a leucine-zipper, a calponin homology (CH) domain, an acidic domain, a Dbl-homology (DH) domain, a pleckstrin homology (PH) domain, a cysteine-rich domain, 2 SH3 domains, a proline-rich region, and a SH2 domain. Vavs are the only known Rho GEFs that have both the DH/PH motifs and SH2/SH3 domains in the same protein. The leucine-rich helix-loop-helix (HLH) domain is thought to be involved in protein heterodimerization with other HLH proteins and it may function as a negative regulator by forming inactive heterodimers. The CH domain is usually involved in the association with filamentous actin, but in Vav it controls NFAT stimulation, Ca2+ mobilization, and its transforming activity. Acidic domains are involved in protein-protein interactions and contain regulatory tyrosines. The DH domain is a GDP-GTP exchange factor on Rho/Rac GTPases. The PH domain in involved in interactions with GTP-binding proteins, lipids and/or phosphorylated serine/threonine residues. The SH3 domain is involved in localization of proteins to specific sites within the cell interacting with protein with proline-rich sequences. The SH2 domain mediates a high affinity interaction with tyrosine phosphorylated proteins. There are three Vav mammalian family members: Vav1 which is expressed in the hematopoietic system, Vav2 and Vav3 are more ubiquitously expressed. The members here include insect and amphibian Vavs. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 665 DLSVHLWYAGPMERAGAESILANRSDGTFLVRQRVKDAAEFAISIKYNVEVKHIKIMT-AEGLYRITEKKAFRGLTELVE 743
Cdd:cd09940     1 DLSEFLWFVGEMERDTAENRLENRPDGTYLVRVRPQGETQYALSIKYNGDVKHMKIEQrSDGLYYLSESRHFKSLVELVN 80

                          90       100
                  ....*....|....*....|..
gi 1777309805 744 FYQQNSLKDCFKSLDTTLQFPF 765
Cdd:cd09940    81 YYERNSLGENFAGLDTTLKWPY 102

First 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 first SH3 domain of Vav1 has been shown to bind the adaptor protein Grb2. 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        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1777309805 596 KMEVFQEYYGLPPPPGAIGPFLRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKPY 658
Cdd:cd11979     1 KMEVFQEYYGIPPPPGAFGPFLRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKPY 63

calponin homology (CH) domain found in VAV2 protein and similar proteins; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. 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 model corresponds to CH domain, an actin-binding domain which is present as a single copy in VAV2 protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805   2 ELWRQCTHWLIQCRVLPPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLST 81
Cdd:cd21263     1 EEWRQCGRWLIDCKVLPPNHRVVWPSAVVFDLAQALRDGVLLCQLLHNLSPGSIDLKDINFRPQMSQFLCLKNIRTFLKV 80

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1777309805  82 CCEKFGLKRSELFEAFDLFDVQDFGKVIYTLSALSWTPI 120
Cdd:cd21263    81 CHDKFGLRNSELFDPFDLFDVRDFGKVISALSRLSHHSI 119

protein kinase C conserved region 1 (C1 domain) found in VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and 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. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1777309805 510 NATANGHDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPPCGR 566
Cdd:cd20867     1 NATANGHDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPPCGR 57

Src homology 2 (SH2) domain found in the Vav2 proteins; Proto-oncogene vav is a member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding proteins. All vavs are activated by tyrosine phosphorylation leading to their activation. There are three Vav mammalian family members: Vav1 which is expressed in the hematopoietic system, and Vav2 and Vav3 are more ubiquitously expressed. Vav2 is a GEF for RhoA, RhoB and RhoG and may activate Rac1 and Cdc42. Vav2 has been shown to interact with CD19 and Grb2. Alternatively spliced transcript variants encoding different isoforms have been found for Vav2. Vav proteins are involved in several processes that require cytoskeletal reorganization, such as the formation of the immunological synapse (IS), phagocytosis, platelet aggregation, spreading, and transformation. Vavs function as guanine nucleotide exchange factors (GEFs) for the Rho/Rac family of GTPases. Vav family members have several conserved motifs/domains including: a leucine-rich region, a leucine-zipper, a calponin homology (CH) domain, an acidic domain, a Dbl-homology (DH) domain, a pleckstrin homology (PH) domain, a cysteine-rich domain, 2 SH3 domains, a proline-rich region, and a SH2 domain. Vavs are the only known Rho GEFs that have both the DH/PH motifs and SH2/SH3 domains in the same protein. The leucine-rich helix-loop-helix (HLH) domain is thought to be involved in protein heterodimerization with other HLH proteins and it may function as a negative regulator by forming inactive heterodimers. The CH domain is usually involved in the association with filamentous actin, but in Vav it controls NFAT stimulation, Ca2+ mobilization, and its transforming activity. Acidic domains are involved in protein-protein interactions and contain regulatory tyrosines. The DH domain is a GDP-GTP exchange factor on Rho/Rac GTPases. The PH domain in involved in interactions with GTP-binding proteins, lipids and/or phosphorylated serine/threonine residues. The SH3 domain is involved in localization of proteins to specific sites within the cell interacting with protein with proline-rich sequences. The SH2 domain mediates a high affinity interaction with tyrosine phosphorylated proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 665 DLSVHLWYAGPMERAGAESILANRSDGTFLVRQRVKDAAEFAISIKYNVEVKHIKIMTAEGLYRITEKKAFRGLTELVEF 744
Cdd:cd10406     1 DYTAYPWFAGNMERQQTDNLLKSHASGTYLIRERPAEAERFAISIKFNDEVKHIKVVEKDNWIHITEAKKFESLLELVEY 80

                          90       100
                  ....*....|....*....|..
gi 1777309805 745 YQQNSLKDCFKSLDTTLQFPFK 766
Cdd:cd10406    81 YQCHSLKESFKQLDTTLKYPYK 102

protein kinase C conserved region 1 (C1 domain) found in VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. 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. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1777309805 511 ATANGHDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPPC 564
Cdd:cd20868     1 ATANHHNFQMYTFDKTTNCKACKMLLRGTFYQGYYCSKCGAGAHKECLEVIPPC 54

protein kinase C conserved region 1 (C1 domain) found in VAV proteins; VAV proteins function both as cytoplasmic guanine nucleotide exchange factors (GEFs) for Rho GTPases and as scaffold proteins, and they play important roles in cell signaling by coupling cell surface receptors to various effector functions. They play key roles in processes that require cytoskeletal reorganization including immune synapse formation, phagocytosis, cell spreading, and platelet aggregation, among others. Vertebrates have three VAV proteins (VAV1, VAV2, and VAV3). VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1777309805 514 NGHDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPPCG 565
Cdd:cd20810     1 TGHSFELTTFKEPTTCSVCKKLLKGLFFQGYKCSVCGAAVHKECIAKVKRCG 52

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805  669 HLWYAGPMERAGAESILANRSDGTFLVRQRVKDAAEFAISIKYNVEVKHIKIM-TAEGLYRITEKKAFRGLTELVEFYQQ 747
Cdd:smart00252   1 QPWYHGFISREEAEKLLKNEGDGDFLVRDSESSPGDYVLSVRVKGKVKHYRIRrNEDGKFYLEGGRKFPSLVELVEHYQK 80

                   ...
gi 1777309805  748 NSL 750
Cdd:smart00252  81 NSL 83

First 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.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1777309805 596 KMEVFQEYYGLPPPPGAIGPFLRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKP 657
Cdd:cd11981     1 KMQVIRNYSGVPKPQLHGGPPLNAQIGDTIEVLYADPHSLFWQGRNLTTGELGFFPSDAVKP 62

CAMSAP CH domain; This domain is the N-terminal CH domain from the CAMSAP proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805  18 PPSHRVTWDGAQVCELAQALRDGVLLCQLLNNLLPHAINLREVNLRPQMSQFLCLKNIRTFLSTCCEKFGLKRSELfEAF 97
Cdd:pfam11971   1 PLSQRSLPLSPPVEDLLRDLSDGCALAALIHFYCPQLIDLEDICLKESMSLADSLYNIQLLQEFCQRHLGNRCCHL-TLE 79

                  ....*
gi 1777309805  98 DLFDV 102
Cdd:pfam11971  80 DLLYA 84

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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 669 HLWYAGPMERAGAESILANRSDGTFLVRQRVKDAAEFAISIKYNVEVKHIKIMT-AEGLYRITEKKAFRGLTELVEFYQQ 747
Cdd:cd09935     3 HSWYHGPISRNAAEYLLSSGINGSFLVRESESSPGQYSISLRYDGRVYHYRISEdSDGKVYVTQEHRFNTLAELVHHHSK 82

                          90
                  ....*....|....*..
gi 1777309805 748 NSlkdcfKSLDTTLQFP 764
Cdd:cd09935    83 NA-----DGLITTLRYP 94

C-terminal Src homology 2 (cSH2) domain found in p85; Phosphoinositide 3-kinases (PI3Ks) are essential for cell growth, migration, and survival. p110, the catalytic subunit, is composed of an adaptor-binding domain, a Ras-binding domain, a C2 domain, a helical domain, and a kinase domain. The regulatory unit is called p85 and is composed of an SH3 domain, a RhoGap domain, a N-terminal SH2 (nSH2) domain, a inter SH2 (iSH2) domain, and C-terminal (cSH2) domain. There are 2 inhibitory interactions between p110alpha and p85 of P13K: 1) p85 nSH2 domain with the C2, helical, and kinase domains of p110alpha and 2) p85 iSH2 domain with C2 domain of p110alpha. There are 3 inhibitory interactions between p110beta and p85 of P13K: 1) p85 nSH2 domain with the C2, helical, and kinase domains of p110beta, 2) p85 iSH2 domain with C2 domain of p110alpha, and 3) p85 cSH2 domain with the kinase domain of p110alpha. It is interesting to note that p110beta is oncogenic as a wild type protein while p110alpha lacks this ability. One explanation is the idea that the regulation of p110beta by p85 is unique because of the addition of inhibitory contacts from the cSH2 domain and the loss of contacts in the iSH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 670 LWYAGPMERAGAESILANRSDGTFLVRQRVKdAAEFAISIKYNVEVKHIKIMTAEGLYRITEK-KAFRGLTELVEFYQQN 748
Cdd:cd09930     7 TWLVGDINRTQAEELLRGKPDGTFLIRESST-QGCYACSVVCNGEVKHCVIYKTETGYGFAEPyNLYESLKELVLHYAHN 85

                          90
                  ....*....|....*.
gi 1777309805 749 SLKDCFKSLDTTLQFP 764
Cdd:cd09930    86 SLEQHNDSLTVTLAYP 101

C-terminal (or second) Src homology 3 domain of VAV2 protein; VAV2 is widely expressed and functions as a guanine nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG and also activates Rac1 and Cdc42. It is implicated in many cellular and physiological functions including blood pressure control, eye development, neurite outgrowth and branching, EGFR endocytosis and degradation, and cell cluster morphology, among others. It has been reported to associate with Nek3. 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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1777309805 785 GTAKARYDFCARDRSELSLKEGDIIKILNK-KGQQGWWRGEIYGRV 829
Cdd:cd11977     1 GTAVARYNFAARDMRELSLREGDVVRIYSRiGGDQGWWKGETNGRI 46

Phorbol esters/diacylglycerol binding domain (C1 domain); This domain is also known as the Protein kinase C conserved region 1 (C1) domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1777309805 516 HDFQMFSFEETTSCKACQMLLRGTFYQGYRCHRCRAPAHKECLGRVPP-CGRH 567
Cdd:pfam00130   1 HHFVHRNFKQPTFCDHCGEFLWGLGKQGLKCSWCKLNVHKRCHEKVPPeCGCD 53

PH domain; PH stands for pleckstrin homology.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 403 PKIDGEL-KITSVERRSKMDRYAFLLDKALLICK--RRGDSYDLKDFVNLHSFQIRDDSSGDRDNKKWSHMFLLIEDQGA 479
Cdd:pfam00169   1 VVKEGWLlKKGGGKKKSWKKRYFVLFDGSLLYYKddKSGKSKEPKGSISLSGCEVVEVVASDSPKRKFCFELRTGERTGK 80

                          90       100
                  ....*....|....*....|....*
gi 1777309805 480 QGYELFFKTRELKKKWMEQFEMAIS 504
Cdd:pfam00169  81 RTYLLQAESEEERKDWIKAIQSAIR 105

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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1777309805 671 WYAGPMERAGAESILANR-SDGTFLVRQRVKDAAEFAISIKYN-VEVKHIKIMTAEGLYRITEKKAFRGLTELVEFYQQN 748
Cdd:cd09931     2 WFHGHLSGKEAEKLLLEKgKPGSFLVRESQSKPGDFVLSVRTDdDKVTHIMIRCQGGKYDVGGGEEFDSLTDLVEHYKKN 81

                  ....
gi 1777309805 749 SLKD 752
Cdd:cd09931    82 PMVE 85