Ephexin Pleckstrin homology (PH) domain; Ephexin-1 (also called NGEF/ neuronal guanine nucleotide exchange factor) plays a role in the homeostatic modulation of presynaptic neurotransmitter release. Specific functions are still unknown for Ephexin-2 (also called RhoGEF19) and Ephexin-3 (also called Rho guanine nucleotide exchange factor 5/RhoGEF5, Transforming immortalized mammary oncogene/p60 TIM, and NGEF/neuronalGEF). Ephexin-4 (also called RhoGEF16) acts downstream of EphA2 to promote ligand-independent breast cancer cell migration and invasion toward epidermal growth factor through activation of RhoG. This in turn results in the activation of RhoG which recruits ELMO2 and Dock4 to form a complex with EphA2 at the tips of cortactin-rich protrusions in migrating breast cancer cells. Ephexin-5 is the specific GEF for RhoA activation and the regulation of vascular smooth muscle contractility. It interacts with EPHA4 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. The members of the Ephexin family contains a RhoGEF (DH) followed by a PH domain and an SH3 domain. The ephexin PH domain is believed to act with the DH domain in mediating protein-protein interactions. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392 643 KIKPFPLVSSSRWLVKRGELTAYVEDTV--LFSRRTSKQQVYFFLFNDVLIITKKKSEESYNVNDYSLRDQLLVESCDNE 720
Cdd:cd01221    1 KIKAFPLISSSRWLVKRGELTELVEDGGslTFRKKFSKTPVYLFLFNDLLLITKKKSEERYLVLDYAPRNLVQVEEVEDP 80

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 354459392 721 ELNSSPGknsstmlysrqssASHLFTLTVLSNHANEKVEMLLGAETQSERARWITALGHSS 781
Cdd:cd01221   81 LQLPQPL-------------GKNLFLLTLLENHEGKTVELLLSAESESDRERWLSALSPPK 128

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH 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        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 354459392 793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMECAKE 847
Cdd:cd11938    1 QVEIIKAYTAKQPDELSLQQADVVLVLQTESDGWYYGERLRDGERGWFPSSCAKE 55

Ephexin Pleckstrin homology (PH) domain; Ephexin-1 (also called NGEF/ neuronal guanine nucleotide exchange factor) plays a role in the homeostatic modulation of presynaptic neurotransmitter release. Specific functions are still unknown for Ephexin-2 (also called RhoGEF19) and Ephexin-3 (also called Rho guanine nucleotide exchange factor 5/RhoGEF5, Transforming immortalized mammary oncogene/p60 TIM, and NGEF/neuronalGEF). Ephexin-4 (also called RhoGEF16) acts downstream of EphA2 to promote ligand-independent breast cancer cell migration and invasion toward epidermal growth factor through activation of RhoG. This in turn results in the activation of RhoG which recruits ELMO2 and Dock4 to form a complex with EphA2 at the tips of cortactin-rich protrusions in migrating breast cancer cells. Ephexin-5 is the specific GEF for RhoA activation and the regulation of vascular smooth muscle contractility. It interacts with EPHA4 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. The members of the Ephexin family contains a RhoGEF (DH) followed by a PH domain and an SH3 domain. The ephexin PH domain is believed to act with the DH domain in mediating protein-protein interactions. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392 643 KIKPFPLVSSSRWLVKRGELTAYVEDTV--LFSRRTSKQQVYFFLFNDVLIITKKKSEESYNVNDYSLRDQLLVESCDNE 720
Cdd:cd01221    1 KIKAFPLISSSRWLVKRGELTELVEDGGslTFRKKFSKTPVYLFLFNDLLLITKKKSEERYLVLDYAPRNLVQVEEVEDP 80

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 354459392 721 ELNSSPGknsstmlysrqssASHLFTLTVLSNHANEKVEMLLGAETQSERARWITALGHSS 781
Cdd:cd01221   81 LQLPQPL-------------GKNLFLLTLLENHEGKTVELLLSAESESDRERWLSALSPPK 128

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 354459392   443 AIFEVISSEHSYLLSLEILIRMF-KNSKELSDTMTKTERHHLFSNITDVCEASKKFFIELEARHQN-NIFIDDISDIVEK 520
Cdd:smart00325   1 VLKELLQTERNYVRDLKLLVEVFlKPLKKELKLLSPNELETLFGNIEEIYEFHRDFLDELEERIEEwDDSVERIGDVFLK 80

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392   521 HtASTFDPYVKYCTNEVYQQRTLQKLlATNPSFKEVLSRIESHEDCRNLPMISFLILPMQRVTRLPLLMDTICQKTPKDS 600
Cdd:smart00325  81 L-EEFFKIYSEYCSNHPDALELLKKL-KKNPRFQKFLKEIESSPQCRRLTLESLLLKPVQRLTKYPLLLKELLKHTPEDH 158

                          170       180
                   ....*....|....*....|..
gi 354459392   601 PKYEVCKRALKEVSKLVRLCNE 622
Cdd:smart00325 159 EDREDLKKALKAIKELANQVNE 180

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH 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        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 354459392 793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMECAKE 847
Cdd:cd11938    1 QVEIIKAYTAKQPDELSLQQADVVLVLQTESDGWYYGERLRDGERGWFPSSCAKE 55

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 354459392   793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGeRLRDGERGWFP 841
Cdd:smart00326   4 QVRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKG-RLGRGKEGLFP 51

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 354459392   656 LVKRGELTAYVEdtvlfSRRTSKQQVYFFLFNDVLIITKKKSEESynvnDYSLRDQLLVESCDNEELNSSPGKNsstmly 735
Cdd:smart00233   1 VIKEGWLYKKSG-----GGKKSWKKRYFVLFNSTLLYYKSKKDKK----SYKPKGSIDLSGCTVREAPDPDSSK------ 65

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|..
gi 354459392   736 srqssASHLFTLTVlsnhaNEKVEMLLGAETQSERARWITAL 777
Cdd:smart00233  66 -----KPHCFEIKT-----SDRKTLLLQAESEEEREKWVEAL 97

large tegument protein UL36; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392   18 WRRRSIPQ---PHQVLGRSKPRPQSYQSPNGLLITDFPVEDGGTLLAAQIPAqVPTASDSRTVHRSPLLLGAQRRAVANG 94
Cdd:PHA03247 2683 PRRRAARPtvgSLTSLADPPPPPPTPEPAPHALVSATPLPPGPAAARQASPA-LPAAPAPPAVPAGPATPGGPARPARPP 2761

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392   95 GTASPEY------RAASPRLRRPKSPKLPKAVpgGSPKSPANGAVTLPAPPPPPVLRPPRTPNAPAPCTPeedlTGLTAS 168
Cdd:PHA03247 2762 TTAGPPApappaaPAAGPPRRLTRPAVASLSE--SRESLPSPWDPADPPAAVLAPAAALPPAASPAGPLP----PPTSAQ 2835

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 354459392  169 PVPSPTANGLAANNDSPGSGSQSGR--KAKDPERglfPGPQKSSSEQKLPLQRLP 221
Cdd:PHA03247 2836 PTAPPPPPGPPPPSLPLGGSVAPGGdvRRRPPSR---SPAAKPAAPARPPVRRLA 2887

Ephexin Pleckstrin homology (PH) domain; Ephexin-1 (also called NGEF/ neuronal guanine nucleotide exchange factor) plays a role in the homeostatic modulation of presynaptic neurotransmitter release. Specific functions are still unknown for Ephexin-2 (also called RhoGEF19) and Ephexin-3 (also called Rho guanine nucleotide exchange factor 5/RhoGEF5, Transforming immortalized mammary oncogene/p60 TIM, and NGEF/neuronalGEF). Ephexin-4 (also called RhoGEF16) acts downstream of EphA2 to promote ligand-independent breast cancer cell migration and invasion toward epidermal growth factor through activation of RhoG. This in turn results in the activation of RhoG which recruits ELMO2 and Dock4 to form a complex with EphA2 at the tips of cortactin-rich protrusions in migrating breast cancer cells. Ephexin-5 is the specific GEF for RhoA activation and the regulation of vascular smooth muscle contractility. It interacts with EPHA4 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. The members of the Ephexin family contains a RhoGEF (DH) followed by a PH domain and an SH3 domain. The ephexin PH domain is believed to act with the DH domain in mediating protein-protein interactions. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392 643 KIKPFPLVSSSRWLVKRGELTAYVEDTV--LFSRRTSKQQVYFFLFNDVLIITKKKSEESYNVNDYSLRDQLLVESCDNE 720
Cdd:cd01221    1 KIKAFPLISSSRWLVKRGELTELVEDGGslTFRKKFSKTPVYLFLFNDLLLITKKKSEERYLVLDYAPRNLVQVEEVEDP 80

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 354459392 721 ELNSSPGknsstmlysrqssASHLFTLTVLSNHANEKVEMLLGAETQSERARWITALGHSS 781
Cdd:cd01221   81 LQLPQPL-------------GKNLFLLTLLENHEGKTVELLLSAESESDRERWLSALSPPK 128

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 354459392   443 AIFEVISSEHSYLLSLEILIRMF-KNSKELSDTMTKTERHHLFSNITDVCEASKKFFIELEARHQN-NIFIDDISDIVEK 520
Cdd:smart00325   1 VLKELLQTERNYVRDLKLLVEVFlKPLKKELKLLSPNELETLFGNIEEIYEFHRDFLDELEERIEEwDDSVERIGDVFLK 80

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392   521 HtASTFDPYVKYCTNEVYQQRTLQKLlATNPSFKEVLSRIESHEDCRNLPMISFLILPMQRVTRLPLLMDTICQKTPKDS 600
Cdd:smart00325  81 L-EEFFKIYSEYCSNHPDALELLKKL-KKNPRFQKFLKEIESSPQCRRLTLESLLLKPVQRLTKYPLLLKELLKHTPEDH 158

                          170       180
                   ....*....|....*....|..
gi 354459392   601 PKYEVCKRALKEVSKLVRLCNE 622
Cdd:smart00325 159 EDREDLKKALKAIKELANQVNE 180

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF16 and ARHGEF26; ARHGEF16, also called ephexin-4, acts as a GEF for RhoG, activating it by exchanging bound GDP for free GTP. RhoG is a small GTPase that is a crucial regulator of Rac in migrating cells. ARHGEF16 interacts directly with the ephrin receptor EphA2 and mediates cell migration and invasion in breast cancer cells by activating RhoG. ARHGEF26, also called SGEF (SH3 domain-containing guanine exchange factor), also activates RhoG. It is highly expressed in liver and may play a role in regulating membrane dynamics. ARHGEF16 and ARHGEF26 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH 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        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 354459392 793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMECAKE 847
Cdd:cd11938    1 QVEIIKAYTAKQPDELSLQQADVVLVLQTESDGWYYGERLRDGERGWFPSSCAKE 55

RhoGEF, Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392  427 KGLSQTVSQEERKRQEAIFEVISSEHSYLLSLEIL----IRMFKNSKELSDTMTKTERHHLFSNITDVCEASKKFFIELE 502
Cdd:COG5422   472 KEVWESLPKQEIKRQEAIYEVIYTERDFVKDLEYLrdtwIKPLEESNIIPENARRNFIKHVFANINEIYAVNSKLLKALT 551

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392  503 ARHQNNIFIDDISDIVEKHTaSTFDPYVKYCTNEVYQQRTLQKLLATNPSFKEVLSRIESHEDCRNLPMISFLILPMQRV 582
Cdd:COG5422   552 NRQCLSPIVNGIADIFLDYV-PKFEPFIKYGASQPYAKYEFEREKSVNPNFARFDHEVERLDESRKLELDGYLTKPTTRL 630

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392  583 TRLPLLMDTICQKTPKDSPKYEVCKRALKEVSKLVRLCNEGARKMERTEMMYTINSQLEFKIKPFPL--VSSSRWLVKRG 660
Cdd:COG5422   631 ARYPLLLEEVLKFTDPDNPDTEDIPKVIDMLREFLSRLNFESGKAENRGDLFHLNQQLLFKPEYVNLglNDEYRKIIFKG 710

                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392  661 ELTayvEDTVLFSRRTSKQQVYFFLFNDVLIITKKKSEESYNVNDYSLRD--QLLVESC---DNEELNSSPGKNSSTMLY 735
Cdd:COG5422   711 VLK---RKAKSKTDGSLRGDIQFFLLDNMLLFCKAKAVNKWRQHKVFQRPipLELLFISpdeDSPDRAEYLKPAPSADVL 787

                         330       340       350       360
                  ....*....|....*....|....*....|....*....|
gi 354459392  736 SRQSSASHLFTLTVLSNHAN-EKVEMLLGAETQSERARWI 774
Cdd:COG5422   788 DPAYNTKPPKNAYGFELYGNgQRYQITLYAETHAGRDTWL 827

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH 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        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 354459392 793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPME 843
Cdd:cd11940    1 QVQCIRSYKAQENDELTLEKADIIMVRQQSSDGWLEGVRLSDGERGWFPQS 51

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 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGeRLRDGERGWFP 841
Cdd:cd00174    7 DYEAQDDDELSFKKGDIITVLEKDDDGWWEG-ELNGGREGLFP 48

Src homology 3 domain of JNK-interacting proteins 1 and 2, and similar domains; JNK-interacting proteins (JIPs) function as scaffolding proteins for c-Jun N-terminal kinase (JNK) signaling pathways. They bind to components of Mitogen-activated protein kinase (MAPK) pathways such as JNK, MKK, and several MAP3Ks such as MLK and DLK. There are four JIPs (JIP1-4); all contain a JNK binding domain. JIP1 and JIP2 also contain SH3 and Phosphotyrosine-binding (PTB) domains. Both are highly expressed in the brain and pancreatic beta-cells. JIP1 functions as an adaptor linking motor to cargo during axonal transport and also is involved in regulating insulin secretion. JIP2 form complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. The SH3 domain of JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. 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 354459392 800 FTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMECAKE 847
Cdd:cd11801    8 FIPRHEDEIELDIGDPVYVEQEADDLWCEGTNLRTGQRGIFPAAYVVE 55

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGErLRdGERGWFP 841
Cdd:cd11823    7 SYTANREDELSLQPGDIIEVHEKQDDGWWLGE-LN-GKKGIFP 47

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11766    7 NYEAQREDELSLRKGDRVLVLEKSSDGWWRGE--CNGQVGWFP 47

Src homology 3 domain of Growth Arrest Specific protein 7; GAS7 is mainly expressed in the brain and is required for neurite outgrowth. It may also play a role in the protection and migration of embryonic stem cells. Treatment-related acute myeloid leukemia (AML) has been reported resulting from mixed-lineage leukemia (MLL)-GAS7 translocations as a complication of primary cancer treatment. GAS7 contains an N-terminal SH3 domain, followed by a WW domain, and a central F-BAR 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 354459392 800 FTAKQPDE-LSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11829    8 FTGEQHQQgLSFEAGELIRVLQAPDGGWWEGE--KDGLRGWFP 48

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. 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 354459392 794 VEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERlRDGERGWFP 841
Cdd:cd11770    2 YEALSDFQAEQEGDLSFKKGEVLRIISKRADGWWLAEN-SKGNRGLVP 48

Src homology 3 domain of JNK-interacting protein 2; JNK-interacting protein 2 (JIP2) is also called Mitogen-activated protein kinase 8-interacting protein 2 (MAPK8IP2) or Islet-brain-2 (IB2). It is widely expressed in the brain, where it forms complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. JIP2 is enriched in postsynaptic densities and may play a role in motor and cognitive function. In addition to a JNK binding domain, JIP2 also contains SH3 and Phosphotyrosine-binding (PTB) domains. The SH3 domain of the related protein JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. 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 354459392 797 VRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMECAKE 847
Cdd:cd11942    5 VFRFIPRHEDELELDVDDPLLVEAEEDDYWYRGYNMRTGERGIFPAFYAHE 55

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 354459392 800 FTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11873    8 YDAEEPDELTLKVGDIITNVKKMEEGWWEGT--LNGKRGMFP 47

Src homology 3 domain of Slit-Robo GTPase Activating Proteins; Slit-Robo GTPase Activating Proteins (srGAPs) are Rho GAPs that interact with Robo1, the transmembrane receptor of Slit proteins. Slit proteins are secreted proteins that control axon guidance and the migration of neurons and leukocytes. Vertebrates contain three isoforms of srGAPs (srGAP1-3), all of which are expressed during embryonic and early development in the nervous system but with different localization and timing. A fourth member has also been reported (srGAP4, also called ARHGAP4). srGAPs contain an N-terminal F-BAR domain, a Rho GAP domain, and a C-terminal SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 354459392 800 FTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11809    8 YTGRSERELSFKKGDSLTLYRQVSDDWWRGQ--LNGQDGLVP 47

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 354459392 800 FTAKQPDELSLQVADVVLIYQRVSD--GWYEGErlRDGERGWFP 841
Cdd:cd11875    8 YEAENEDELTLREGDIVTILSKDCEdkGWWKGE--LNGKRGVFP 49

Third Src Homology 3 domain of SH3 domain containing ring finger 2; SH3RF2 is also called POSHER (POSH-eliminating RING protein) or HEPP1 (heart protein phosphatase 1-binding protein). It acts as an anti-apoptotic regulator of the JNK pathway by binding to and promoting the degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal RING finger domain and three SH3 domains. This model represents the third SH3 domain, located in the middle, of SH3RF2. 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 354459392 796 IVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFPMEC 844
Cdd:cd11784    4 ALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLSLVTGRVGIFPSNY 52

Src Homology 3 domain of fungal BOI-like proteins; This subfamily includes the Saccharomyces cerevisiae proteins BOI1 and BOI2, and similar proteins. They contain an N-terminal SH3 domain, a Sterile alpha motif (SAM), and a Pleckstrin homology (PH) domain at the C-terminus. BOI1 and BOI2 interact with the SH3 domain of Bem1p, a protein involved in bud formation. They promote polarized cell growth and participates in the NoCut signaling pathway, which is involved in the control of cytokinesis. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 354459392 794 VEIVRSFTAKQPDELSLQVADVVLIYQR---VSDGWYEGERLRDGERGWFP 841
Cdd:cd11886    2 LIVIHDFNARSEDELTLKPGDKIELIEDdeeFGDGWYLGRNLRTGETGLFP 52

C-terminal (or second) Src Homology 3 domain of the p67phox subunit of NADPH oxidase; p67phox, also called Neutrophil cytosol factor 2 (NCF-2), is a cytosolic subunit of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) which plays a crucial role in the cellular response to bacterial infection. NADPH oxidase catalyzes the transfer of electrons from NADPH to oxygen during phagocytosis forming superoxide and reactive oxygen species. p67phox plays a regulatory role and contains N-terminal TPR, first SH3 (or N-terminal or central SH3), PB1, and C-terminal SH3 domains. It binds, via its C-terminal SH3 domain, to a proline-rich region of p47phox and upon activation, this complex assembles with flavocytochrome b558, the Nox2-p22phox heterodimer. Concurrently, RacGTP translocates to the membrane and interacts with the TPR domain of p67phox, which leads to the activation of NADPH oxidase. The PB1 domain of p67phox binds to its partner PB1 domain in p40phox, and this facilitates the assembly of p47phox-p67phox at the membrane. 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 354459392 793 QVEIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd12046    1 QVVALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQ--CKGKIGIFP 47

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 354459392 800 FTAKQPDELSLQVADVVLIYQRVSD-GWYEGErlRDGERGWFP 841
Cdd:cd11830    8 FCARDMRELSLKEGDVVKIYNKKGQqGWWRGE--INGRIGWFP 48

Second 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 second SH3 domain of Nck appears to prefer ligands containing the APxxPxR motif. SH3 domains are protein interaction domains that usually bind to proline-rich ligands with moderate affinity and selectivity, preferentially a PxxP motif. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11901    9 NYTAEREDELSLVKGTKVIVMEKCSDGWWRGS--YNGQVGWFP 49

Third (or C-terminal) Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the third SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. 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 354459392 797 VRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGERGWFP 841
Cdd:cd11780    5 LYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSERTGLFGTFP 49

Second Src Homology 3 domain (SH3B) of CD2-associated protein and similar proteins; This subfamily is composed of the second SH3 domain (SH3B) of CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and similar domains. CD2AP and CIN85 are adaptor proteins that bind to protein partners and assemble complexes that have been implicated in T cell activation, kidney function, and apoptosis of neuronal cells. They also associate with endocytic proteins, actin cytoskeleton components, and other adaptor proteins involved in receptor tyrosine kinase (RTK) signaling. CD2AP and the main isoform of CIN85 contain three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP and CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. SH3B of both proteins have been shown to bind to Cbl. In the case of CD2AP, its SH3B binds to Cbl at a site distinct from the c-Cbl/SH3A binding site. The CIN85 SH3B also binds ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11874    7 SYTPQNEDELELKVGDTIEVLGEVEEGWWEGK--LNGKVGVFP 47

First Src Homology 3 domain of Sorbin and SH3 domain containing 1 (Sorbs1), also called ponsin; Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl associated protein). It is an adaptor protein containing one sorbin homology (SoHo) and three SH3 domains. It binds Cbl and plays a major role in regulating the insulin signaling pathway by enhancing insulin-induced phosphorylation of Cbl. Sorbs1, like vinexin, localizes at cell-ECM and cell-cell adhesion sites where it binds vinculin, paxillin, and afadin. It may function in the control of cell motility. Other interaction partners of Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7, filamin C, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 354459392 800 FTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11919    9 FKAQTLKELPLQKGDIVYIYKQIDQNWYEGE--HHGRVGIFP 48

Fourth Src homology 3 domain (or SH3D) of Intersectin-1; Intersectin-1 (ITSN1) is an adaptor protein that functions in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. It plays a role in clathrin-coated pit (CCP) formation. It binds to many proteins through its multidomain structure and facilitate the assembly of multimeric complexes. ITSN1 localizes in membranous organelles, CCPs, the Golgi complex, and may be involved in the cell membrane trafficking system. It exists in alternatively spliced short and long isoforms. The short isoform contains two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoform, in addition, contains RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. The fourth SH3 domain (or SH3D) of ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and N-WASP. 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 354459392 795 EIVRSFTAKQPDELSLQVADVVLIYQRVSDGWYEGERLRDGER---GWFPMECAK 846
Cdd:cd11993    7 QVIASYTATGPEQLTLAPGQLILIRKKNPGGWWEGELQARGKKrqiGWFPANYVK 61

First Src homology 3 domain (or SH3A) of Intersectin; Intersectins (ITSNs) are adaptor proteins that function in exo- and endocytosis, actin cytoskeletal reorganization, and signal transduction. They are essential for initiating clathrin-coated pit formation. They bind to many proteins through their multidomain structure and facilitate the assembly of multimeric complexes. Vertebrates contain two ITSN proteins, ITSN1 and ITSN2, which exist in alternatively spliced short and long isoforms. The short isoforms contain two Eps15 homology domains (EH1 and EH2), a coiled-coil region and five SH3 domains (SH3A-E), while the long isoforms, in addition, contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin homology (PH) and C2 domains. ITSN1 and ITSN2 are both widely expressed, with variations depending on tissue type and stage of development. The first SH3 domain (or SH3A) of ITSN1 has been shown to bind many proteins including Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 354459392 799 SFTAKQPDELSLQVADVVLIY--QRVSDGWYEGErlRDGERGWFP 841
Cdd:cd11836    7 AFEARNPDEISFQPGDIIQVDesQVAEPGWLAGE--LKGKTGWFP 49

Pleckstrin homology (PH) domain; PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 354459392 655 WLVKRGELTayvedtvlfsrRTSKQQVYFFLFNDVLIITKKKSEESYN-VNDYSLRDQLLVESCDNEELNsspgknsstm 733
Cdd:cd00821    4 YLLKRGGGG-----------LKSWKKRWFVLFEGVLLYYKSKKDSSYKpKGSIPLSGILEVEEVSPKERP---------- 62

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....
gi 354459392 734 lysrqssasHLFTLTvlsnHANEKVeMLLGAETQSERARWITAL 777
Cdd:cd00821   63 ---------HCFELV----TPDGRT-YYLQADSEEERQEWLKAL 92

Second Src Homology 3 domain of Sorbin and SH3 domain containing (Sorbs) proteins and similar domains; This family, also called the vinexin family, is composed predominantly of adaptor proteins containing one sorbin homology (SoHo) and three SH3 domains. Members include the second SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and similar domains. They are involved in the regulation of cytoskeletal organization, cell adhesion, and growth factor signaling. Members of this family bind multiple partners including signaling molecules like c-Abl, c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules such as vinculin and afadin. They may have overlapping functions. 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 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGErlRDGERGWFPME 843
Cdd:cd11782    7 NFNADTGVELSFRKGDVITLTRRVDENWYEGR--IGGRQGIFPVS 49

Second Src Homology 3 domain (SH3B) of Cbl-interacting protein of 85 kDa; CIN85, also called SH3 domain-containing kinase-binding protein 1 (SH3KBP1) or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor protein that is involved in the downregulation of receptor tyrosine kinases by facilitating endocytosis through interaction with endophilin-associated ubiquitin ligase Cbl proteins. It is also important in many other cellular processes including vesicle-mediated transport, cytoskeletal remodelling, apoptosis, cell adhesion and migration, and viral infection, among others. CIN85 exists as multiple variants from alternative splicing; the main variant contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CIN85 to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CIN85. SH3B has been shown to bind Cbl proline-rich peptides and ubiquitin. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 354459392 799 SFTAKQPDELSLQVADVVLIYQRVSDGWYEGerLRDGERGWFPMECAKE 847
Cdd:cd12055    7 SYLPQNEDELELKVGDIIEVVGEVEEGWWEG--VLNGKTGMFPSNFIKE 53

Second Src Homology 3 domain (SH3B) of CD2-associated protein; CD2AP, also called CMS (Cas ligand with Multiple SH3 domains) or METS1 (Mesenchyme-to-Epithelium Transition protein with SH3 domains), is a cytosolic adaptor protein that plays a role in regulating the cytoskeleton. It is critical in cell-to-cell union necessary for kidney function. It also stabilizes the contact between a T cell and antigen-presenting cells. It is primarily expressed in podocytes at the cytoplasmic face of the slit diaphragm and serves as a linker anchoring podocin and nephrin to the actin cytoskeleton. CD2AP contains three SH3 domains, a proline-rich region, and a C-terminal coiled-coil domain. All of these domains enable CD2AP to bind various protein partners and assemble complexes that have been implicated in many different functions. This alignment model represents the second SH3 domain (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR is the core binding motif) distinct from the c-Cbl/SH3A binding site. 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.