The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Formin Binding Protein 17; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Formin Binding Protein 17 (FBP17), also called FormiN Binding Protein 1 (FNBP1), is involved in dynamin-mediated endocytosis. It is recruited to clathrin-coated pits late in the endocytosis process and may play a role in the invagination and scission steps. FBP17 binds in vivo to tankyrase, a protein involved in telomere maintenance and mitogen activated protein kinase (MAPK) signaling. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958   5 TELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTACKAFLSTLNEMNDYA 84
Cdd:cd07676    1 TELWDQFDNLEKHTQWGIEVLEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTSCRAFLMTLNEMNDYA 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  85 GQHEVISENMTSQITVDLMRYVQELKQERKSNFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 164
Cdd:cd07676   81 GQHEVISENLASQIIVELTRYVQELKQERKSHFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 160

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 165 TKADVEKARQQAQIRQQMAEDSKADYSLILQRFNQEQWEYYHTHIPNIFQKIQEMEERRIVRIGESMKTYAEVDRQVIPI 244
Cdd:cd07676  161 TKADVEKARQQAQIRHQMAEDSKAEYSSYLQKFNKEQHEHYYTHIPNIFQKIQEMEERRIGRVGESMKTYAEVDRQVIPI 240

                        250
                 ....*....|...
gi 568912958 245 IGKCLDGIVKAAE 257
Cdd:cd07676  241 IGKCLDGITKAAE 253

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568912958 547 GTCKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEVY 603
Cdd:cd12071    1 GTCKALYPFEGQNEGTISVAEGEMLYVIEEDKGDGWTRIRRNEDEEGYVPTSYIEVY 57

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Formin Binding Protein 17; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Formin Binding Protein 17 (FBP17), also called FormiN Binding Protein 1 (FNBP1), is involved in dynamin-mediated endocytosis. It is recruited to clathrin-coated pits late in the endocytosis process and may play a role in the invagination and scission steps. FBP17 binds in vivo to tankyrase, a protein involved in telomere maintenance and mitogen activated protein kinase (MAPK) signaling. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958   5 TELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTACKAFLSTLNEMNDYA 84
Cdd:cd07676    1 TELWDQFDNLEKHTQWGIEVLEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTSCRAFLMTLNEMNDYA 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  85 GQHEVISENMTSQITVDLMRYVQELKQERKSNFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 164
Cdd:cd07676   81 GQHEVISENLASQIIVELTRYVQELKQERKSHFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 160

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 165 TKADVEKARQQAQIRQQMAEDSKADYSLILQRFNQEQWEYYHTHIPNIFQKIQEMEERRIVRIGESMKTYAEVDRQVIPI 244
Cdd:cd07676  161 TKADVEKARQQAQIRHQMAEDSKAEYSSYLQKFNKEQHEHYYTHIPNIFQKIQEMEERRIGRVGESMKTYAEVDRQVIPI 240

                        250
                 ....*....|...
gi 568912958 245 IGKCLDGIVKAAE 257
Cdd:cd07676  241 IGKCLDGITKAAE 253

Src Homology 3 domain of Formin Binding Protein 17; Formin Binding Protein 17 (FBP17), also called FormiN Binding Protein 1 (FNBP1), is involved in dynamin-mediated endocytosis. It is recruited to clathrin-coated pits late in the endocytosis process and may play a role in the invagination and scission steps. FBP17 binds in vivo to tankyrase, a protein involved in telomere maintenance and mitogen activated protein kinase (MAPK) signaling. It contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, a Cdc42-binding HR1 domain, and a C-terminal SH3 domain. The SH3 domain of the related protein, CIP4, associates with Gapex-5, a Rab31 GEF. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 568912958 547 GTCKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEVY 603
Cdd:cd12071    1 GTCKALYPFEGQNEGTISVAEGEMLYVIEEDKGDGWTRIRRNEDEEGYVPTSYIEVY 57

Fes/CIP4 homology domain; Alignment extended from original report. Highly alpha-helical. Also known as the RAEYL motif or the S. pombe Cdc15 N-terminal domain.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958     1 MSWGTELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKkyQPKKNSKEEEEYKYTAcKAFLSTLNEM 80
Cdd:smart00055   1 MGFWSELDDGFEALLSRLKNGLRLLEDLKKFMRERAKIEEEYAKKLQKLSK--KLRAVRDTEPEYGSLS-KAWEVLLSET 77

                   ....*...
gi 568912958    81 NDYAGQHE 88
Cdd:smart00055  78 DALAKQHL 85

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

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 568912958  550 KALYTFEGQNEGTISVVEGETLSVIeEDKGDGWTRIRRNEDEEGYVPT 597
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVL-EKSEDGWWKGRNKGGKEGLIPS 47

SH3 domain protein; Members of this protein family have a signal peptide, a strongly conserved SH3 domain, a variable region, and then a C-terminal hydrophobic transmembrane alpha helix region.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 568912958  564 SVVEGETLSVIEEDkGDGWTRIRRNEDEEGYVPTSYV 600
Cdd:TIGR04211  23 SLKSGTPVTVLERS-EDGYSRVRTPKGREGWVLSRYL 58

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Formin Binding Protein 17; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Formin Binding Protein 17 (FBP17), also called FormiN Binding Protein 1 (FNBP1), is involved in dynamin-mediated endocytosis. It is recruited to clathrin-coated pits late in the endocytosis process and may play a role in the invagination and scission steps. FBP17 binds in vivo to tankyrase, a protein involved in telomere maintenance and mitogen activated protein kinase (MAPK) signaling. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958   5 TELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTACKAFLSTLNEMNDYA 84
Cdd:cd07676    1 TELWDQFDNLEKHTQWGIEVLEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEYKYTSCRAFLMTLNEMNDYA 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  85 GQHEVISENMTSQITVDLMRYVQELKQERKSNFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 164
Cdd:cd07676   81 GQHEVISENLASQIIVELTRYVQELKQERKSHFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 160

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 165 TKADVEKARQQAQIRQQMAEDSKADYSLILQRFNQEQWEYYHTHIPNIFQKIQEMEERRIVRIGESMKTYAEVDRQVIPI 244
Cdd:cd07676  161 TKADVEKARQQAQIRHQMAEDSKAEYSSYLQKFNKEQHEHYYTHIPNIFQKIQEMEERRIGRVGESMKTYAEVDRQVIPI 240

                        250
                 ....*....|...
gi 568912958 245 IGKCLDGIVKAAE 257
Cdd:cd07676  241 IGKCLDGITKAAE 253

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Formin Binding Protein 1-Like; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. FormiN Binding Protein 1-Like (FNBP1L), also known as Toca-1 (Transducer of Cdc42-dependent actin assembly), forms a complex with neural Wiskott-Aldrich syndrome protein (N-WASP). The FNBP1L/N-WASP complex induces the formation of filopodia and endocytic vesicles. FNBP1L is required for Cdc42-induced actin assembly and is essential for autophagy of intracellular pathogens. It contains an N-terminal F-BAR domain, a central Cdc42-binding HR1 domain, and a C-terminal SH3 domain. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958   5 TELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEyKYTACKAFLSTLNEMNDYA 84
Cdd:cd07675    1 TELWDQFDNLDKHTQWGIDFLERYAKFVKERLEIEQNYAKQLRNLVKKYCPKRSSKDEEP-RFTSCLSFYNILNELNDYA 79

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  85 GQHEVISENMTSQITVDLMRYVQELKQERKSNFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINV 164
Cdd:cd07675   80 GQREVVAEEMGHRVYGELMRYSHDLKGERKMHLQEGRKAQQYLDMCWKQMDNSKKKFERECREAEKAQQSYERLDNDTNA 159

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 165 TKADVEKARQQAQIRQQMAEDSKADYSLILQRFNQEQWEYYHTHIPNIFQKIQEMEERRIVRIGESMKTYAEVDRQVIPI 244
Cdd:cd07675  160 TKSDVEKAKQQLNLRTHMADESKNEYAAQLQNFNGEQHKHFYIVIPQIYKQLQEMDERRTVKLSECYRGFADSERKVIPI 239

                        250
                 ....*....|...
gi 568912958 245 IGKCLDGIVKAAE 257
Cdd:cd07675  240 ISKCLEGMVLAAK 252

Protein kinase C-related kinase homology region 1 (HR1) Rho-binding domain of vertebrate Cdc42-Interacting Protein 4 and FormiN Binding Protein 1-Like; CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. FNBP1L, also called Toca-1 (Transducer of Cdc42-dependent actin assembly 1), forms a complex with neural WASP; the complex induces the formation of filopodia and endocytic vesicles. FNBP1L is required for Cdc42-induced actin assembly and is essential for autophagy of intracellular pathogens. CIP4 may also play a role in phagocytosis. It functions downstream of Cdc42 in PDGF-dependent actin reorganization and cell migration, and also regulates the activity of PDGFRbeta. It uses Src as a substrate in regulating the invasiveness of breast tumor cells. CIP4 may also play a role in the pathogenesis of Huntington's disease. CIP4 and FNBP1L contain an N-terminal F-BAR domain, a central HR1 domain, and a C-terminal SH3 domain. HR1 domains are anti-parallel coiled-coil (ACC) domains that bind small GTPases from the Rho family; the HR1 domain of CIP4 binds Cdc42 and TC10. Translocation of CIP4 is facilitated by its binding to TC10 at the plasma membrane.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 400 PPEQRRKKLQQKVDDLNREIQKETDQRDAITKMKDVYLKNPQMGDPASLDQKLTEVTQNIEKLRLEAQKFEAWLAEVEGR 479
Cdd:cd11628    1 PPEQRRKRLQQKIDELSRELQKEMDQSEALMKMKDVYEKNPQMGDPASLQPQIAETASNIDRLRGELHKYEAWLAEAEGR 80

Protein kinase C-related kinase homology region 1 (HR1) Rho-binding domain of Cdc42-Interacting Protein 4 and similar proteins; This subfamily is composed of Cdc42-Interacting Protein 4 (CIP4), Formin Binding Protein 17 (FBP17), FormiN Binding Protein 1-Like (FNBP1L), and similar proteins. CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. CIP4 and FBP17 bind to the Fas ligand and may be implicated in the inflammatory response. CIP4 may also play a role in phagocytosis. It functions downstream of Cdc42 in PDGF-dependent actin reorganization and cell migration, and also regulates the activity of PDGFRbeta. It uses Src as a substrate in regulating the invasiveness of breast tumor cells. CIP4 may also play a role in the pathogenesis of Huntington's disease. Members of this subfamily typically contain an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, central HR1 domain, and a C-terminal SH3 domain. HR1 domains are anti-parallel coiled-coil (ACC) domains that bind small GTPases from the Rho family; the HR1 domain of CIP4 binds Cdc42 and TC10. Translocation of CIP4 is facilitated by its binding to TC10 at the plasma membrane.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 568912958 401 PEQRRKKLQQKVDDLNREIQKETDQRDAITKMKDVYLKNPQMGDPASLDQKLTEVTQNIEKLRLEAQKFEAWLAEVE 477
Cdd:cd11619    1 PEQRRKKLQQKIDELEKEIEKETKSRDGLMKMKGVYEQNPQLGDPASVEGQLAEYAKKLDKLREELQKYQGYLAEAE 77

The Extended FES-CIP4 Homology (FCH) or F-BAR (FCH and Bin/Amphiphysin/Rvs) domain, a dimerization module that binds and bends membranes; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. F-BAR domain containing proteins, also known as Pombe Cdc15 homology (PCH) family proteins, include Fes and Fer tyrosine kinases, PACSINs/Syndapins, FCHO, PSTPIP, CIP4-like proteins and srGAPs. Many members also contain an SH3 domain and play roles in endocytosis. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules. These tubules have diameters larger than those observed with N-BARs. The F-BAR domains of some members such as NOSTRIN and Rgd1 are important for the subcellular localization of the protein.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  10 QFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKnskeeeEYKYTACKAFLSTLNEMNDYAGQHEV 89
Cdd:cd07610    1 GFELLEKRTELGLDLLKDLREFLKKRAAIEEEYAKNLQKLAKKFSKKP------ESGKTSLGTSWNSLREETESAATVHE 74

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  90 ISENMTSQITVDLMRYVQEL-KQERKSNFHDGRKAQQHIETCWKQLESSKrrferdckeadraqqyfekmdadinvtkad 168
Cdd:cd07610   75 ELSEKLSQLIREPLEKVKEDkEQARKKELAEGEKLKKKLQELWAKLAKKA------------------------------ 124

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 169 vekarqqaqirqqmaedsKADYSLILQRFNQEQWEYYHTHIPNIfQKIQEMEERRIVRIGESMKTYAEVDRQVIPIIGKC 248
Cdd:cd07610  125 ------------------DEEYREQVEKLNPAQSEYEEEKLNKI-QAEQEREEERLEILKDNLKNYINAIKEIPQKIQQE 185

                 ....*.
gi 568912958 249 LDGIVK 254
Cdd:cd07610  186 LEQSIN 191

Src Homology 3 domain of Cdc42-Interacting Protein 4, Bzz1 and similar domains; This subfamily is composed of Cdc42-Interacting Protein 4 (CIP4) and similar proteins such as Formin Binding Protein 17 (FBP17) and FormiN Binding Protein 1-Like (FNBP1L), as well as yeast Bzz1 (or Bzz1p). CIP4 and FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich syndrome protein (WASP) and function in endocytosis. CIP4 and FBP17 bind to the Fas ligand and may be implicated in the inflammatory response. CIP4 may also play a role in phagocytosis. Bzz1 is also a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Members of this subfamily contain an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain as well as at least one C-terminal SH3 domain. Bzz1 contains a second SH3 domain at the C-terminus. 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 568912958 549 CKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEV 602
Cdd:cd11777    2 CKALYAFVGSSEGTISMTEGEKLSLVEEDKGDGWTRVRRDTGEEGYVPTSYIRI 55

Fes/CIP4, and EFC/F-BAR homology domain; Alignment extended from. Highly alpha-helical. The cytosolic endocytic adaptor proteins in fungi carry this domain at the N-terminus; several of these have been referred to as muniscin proteins. These N-terminal BAR, N-BAR, and EFC/F-BAR domains are found in proteins that regulate membrane trafficking events by inducing membrane tubulation. The domain dimerizes into a curved structure that binds to liposomes and either senses or induces the curvature of the membrane bilayer to cause biophysical changes to the shape of the bilayer; it also thereby recruits other trafficking factors, such as the GTPase dynamin. Most EFC/F-BAR domain-family members localize to actin-rich structures.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 568912958   10 QFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEykYTACKAFLSTLNEMNDYAGQHE 88
Cdd:pfam00611   1 GFKVLLKRLKQGIKLLEELASFLKERAEIEEEYAKKLQKLAKKFLKKKKKPEDDG--GTLKKAWDELLTETEQLAKQHL 77

Fes/CIP4 homology domain; Alignment extended from original report. Highly alpha-helical. Also known as the RAEYL motif or the S. pombe Cdc15 N-terminal domain.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958     1 MSWGTELWDQFDNLEKHTQWGIDILEKYIKFVKERTEIELSYAKQLRNLSKkyQPKKNSKEEEEYKYTAcKAFLSTLNEM 80
Cdd:smart00055   1 MGFWSELDDGFEALLSRLKNGLRLLEDLKKFMRERAKIEEEYAKKLQKLSK--KLRAVRDTEPEYGSLS-KAWEVLLSET 77

                   ....*...
gi 568912958    81 NDYAGQHE 88
Cdd:smart00055  78 DALAKQHL 85

Src Homology 3 domain of Sorting Nexin 9 and similar proteins; Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. This subfamily consists of SH3 domain containing SNXs including SNX9, SNX18, SNX33, and similar proteins. SNX9 is localized to plasma membrane endocytic sites and acts primarily in clathrin-mediated endocytosis, while SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. 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 568912958 549 CKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEV 602
Cdd:cd11763    2 VRALYDFDSQPSGELSLRAGEVLTITRQDVGDGWLEGRNSRGEVGLFPSSYVEI 55

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 568912958 548 TCKALYTFEGQNEGTISVVEGETLSVIEEDkGDGWTRIRRNEDEEGYVPTSY 599
Cdd:cd00174    1 YARALYDYEAQDDDELSFKKGDIITVLEKD-DDGWWEGELNGGREGLFPANY 51

Src homology 3 domains of the p47phox subunit of NADPH oxidase and similar domains; This family is composed of the tandem SH3 domains of p47phox subunit of NADPH oxidase and Nox Organizing protein 1 (NoxO1), the four SH3 domains of Tks4 (Tyr kinase substrate with four SH3 domains), the five SH3 domains of Tks5, the SH3 domain of obscurin, Myosin-I, and similar domains. Most members of this group also contain Phox homology (PX) domains, except for obscurin and Myosin-I. p47phox and NoxO1 are regulators of the phagocytic NADPH oxidase complex (also called Nox2 or gp91phox) and nonphagocytic NADPH oxidase Nox1, respectively. They play roles in the activation of their respective NADPH oxidase, which catalyzes the transfer of electrons from NADPH to molecular oxygen to form superoxide. Tks proteins are Src substrates and scaffolding proteins that play important roles in the formation of podosomes and invadopodia, the dynamic actin-rich structures that are related to cell migration and cancer cell invasion. Obscurin is a giant muscle protein that plays important roles in the organization and assembly of the myofibril and the sarcoplasmic reticulum. Type I myosins (Myosin-I) are actin-dependent motors in endocytic actin structures and actin patches. They play roles in membrane traffic in endocytic and secretory pathways, cell motility, and mechanosensing. Myosin-I contains an N-terminal actin-activated ATPase, a phospholipid-binding TH1 (tail homology 1) domain, and a C-terminal extension which includes an F-actin-binding TH2 domain, an SH3 domain, and an acidic peptide that participates in activating the Arp2/3complex. The SH3 domain of myosin-I is required for myosin-I-induced actin polymerization. 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 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDKGdGWTRIrRNEDEEGYVPTSYVE 601
Cdd:cd11856    4 AIADYEAQGDDEISLQEGEVVEVLEKNDS-GWWYV-RKGDKEGWVPASYLE 52

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. They bind both dynamin and Wiskott-Aldrich syndrome protein (WASP), and may provide direct links between the actin cytoskeletal machinery through WASP and dynamin-dependent endocytosis. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSINs contain an N-terminal F-BAR domain and a C-terminal SH3 domain. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  28 YIKFVKERTEIELSYAKQLRNLSKKYQPKKNSKEEEEykyTACKAFLSTLNEMNDYAGQHEVISENMTSQItvdlmryVQ 107
Cdd:cd07655   24 LMKMVQERAEIEKAYAKKLKEWAKKWRDLIEKGPEYG---TLETAWKGLLSEAERLSELHLSIRDKLLNDV-------VE 93

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 108 ELKQERKSNFH--------------DG-RKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINVTKADVEKA 172
Cdd:cd07655   94 EVKTWQKENYHksmmggfketkeaeDGfAKAQKPWAKLLKKVEKAKKAYHAACKAEKSAQKQENNAKSDTSLSPDQVKKL 173

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 173 RQQAQIRQQMAEDSKADYSLILQRFNQEQwEYYHTHIPNIFQKIQEMEERRIVRIGESMKTYaevdrqvipiiGKCLDGI 252
Cdd:cd07655  174 QDKVEKCKQEVSKTKDKYEKALEDLNKYN-PRYMEDMEQVFDKCQEFEEKRLDFFKEILLSY-----------HRHLDLS 241

                 ...
gi 568912958 253 VKA 255
Cdd:cd07655  242 TNP 244

Src Homology 3 domain of Sorting nexin 18; SNX18 is localized to peripheral endosomal structures, and acts in a trafficking pathway that is clathrin-independent but relies on AP-1 and PACS1. It binds FIP5 and is required for apical lumen formation. It may also play a role in axonal elongation. SNXs are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNX18 also contains BAR and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 568912958 550 KALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEV 602
Cdd:cd11897    3 RALYDFRSENPGEISLREHEVLSLCSEQDIEGWLEGVNSRGDRGLFPASYVEV 55

Second Src Homology 3 domain of Bzz1 and similar domains; Bzz1 (or Bzz1p) is a WASP/Las17-interacting protein involved in endocytosis and trafficking to the vacuole. It physically interacts with type I myosins and functions in the early steps of endocytosis. Together with other proteins, it induces membrane scission in yeast. Bzz1 contains an N-terminal F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a central coiled-coil, and two C-terminal SH3 domains. This model represents the second 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        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 568912958 548 TCKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNeDEEGYVPTSY 599
Cdd:cd11778    1 YVEALYDYEAQGDDEISIRVGDRIAVIRGDDGSGWTYGEIN-GVKGLFPTSY 51

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of Protein kinase C and Casein kinase Substrate in Neurons 1 (PACSIN1); F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. Protein kinase C and Casein kinase Substrate in Neurons (PACSIN) proteins, also called Synaptic dynamin-associated proteins (Syndapins), act as regulators of cytoskeletal and membrane dynamics. Vetebrates harbor three isoforms with distinct expression patterns and specific functions. PACSIN 1 or Syndapin I is expressed specifically in the brain and is localized in neurites and synaptic boutons. It binds the brain-specific proteins dynamin I, synaptojanin, synapsin I, and neural Wiskott-Aldrich syndrome protein (nWASP), and functions as a link between the cytoskeletal machinery and synaptic vesicle endocytosis. PACSIN 1 interacts with huntingtin and may be implicated in the neuropathology of Huntington's disease. It contains an N-terminal F-BAR domain and a C-terminal SH3 domain. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  32 VKERTEIELSYAKQLRNLSKKYQ------PKKNSKEeeeykytacKAFLSTLNEMNDYAGQHEVISENMTSQitvDLmry 105
Cdd:cd07680   28 VQERAKIEKAYGQQLTDWAKRWRqliekgPQYGSLE---------RAWGAIMTEADKVSELHQEVKNNLLNE---DL--- 92

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 106 vQELKQERKSNFH--------------DG-RKAQQHIETCWKQLESSKRRFERDCKEADRAQQYFEKMDADINVTKADVE 170
Cdd:cd07680   93 -EKVKNWQKDAYHkqimggfketkeaeDGfRKAQKPWAKKMKELEAAKKAYHLACKEEKLAMTREANSKAEQSVTPEQQK 171

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 568912958 171 KARQQAQIRQQMAEDSKADYSLILQRFNQEQWEYYHThIPNIFQKIQEMEERRIVRIGE 229
Cdd:cd07680  172 KLQDKVDKCKQDVQKTQEKYEKVLDDVGKTTPQYMEN-MEQVFEQCQQFEEKRLVFLKE 229

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 568912958 548 TCKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWT-RIRRnedEEGYVPTSYVE 601
Cdd:cd11827    1 QCKALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTgRLRG---KEGLFPGNYVE 52

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDkGDGWTRIRRNeDEEGYVPTSYVE 601
Cdd:cd11824    4 VLYDYTAQEDDELSISKGDVVAVIEKG-EDGWWTVERN-GQKGLVPGTYLE 52

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 568912958 548 TCKALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYVEV 602
Cdd:cd11769    3 ECIAKYNFNGASEEDLPFKKGDILTIVAVTKDPNWYKAKNKDGREGMIPANYVQK 57

Src Homology 3 domain of Tec-like Protein Tyrosine Kinases; The Tec (Tyrosine kinase expressed in hepatocellular carcinoma) subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) tyr kinases containing Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Most Tec subfamily members (except Rlk) also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. The function of Tec kinases in lymphoid cells have been studied extensively. They play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. 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 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEeDKGDGWTRIRRNEDEEGYVPTSYVE 601
Cdd:cd11768    4 ALYDFQPIEPGDLPLEKGEEYVVLD-DSNEHWWRARDKNGNEGYIPSNYVT 53

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        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 568912958 549 CKALYTFEGQNEGTISVVEGETLSVIEEDKGD-GWTRIRRNEdEEGYVPTSYVE 601
Cdd:cd11836    2 YRALYAFEARNPDEISFQPGDIIQVDESQVAEpGWLAGELKG-KTGWFPANYVE 54

Src homology 3 domain of Srms Protein Tyrosine Kinase; Src-related kinase lacking C-terminal regulatory tyrosine and N-terminal myristoylation sites (Srms) is a cytoplasmic (or non-receptor) PTK with limited homology to Src kinases. Src kinases in general contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr; they are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Srms lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYV 600
Cdd:cd11846    4 ALYDFTARSTHELSVEQGDKLCVIEEEGDYIFARKLTGNPESGLVPASYV 53

Bacterial SH3 domain;

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 568912958  564 SVVEGETLSVIEEDkGDGWTRIRRNEDEEGYVPTSYVE 601
Cdd:pfam08239  18 TLPKGEKVEVLEEQ-GGGWYKVRTYDGYEGWVSSSYLS 54

Src homology 3 domain of Endophilin-A; Endophilins play roles in synaptic vesicle formation, virus budding, mitochondrial morphology maintenance, receptor-mediated endocytosis inhibition, and endosomal sorting. They are classified into two types, A and B. Vertebrates contain three endophilin-A isoforms (A1, A2, and A3). Endophilin-A proteins are enriched in the brain and play multiple roles in receptor-mediated endocytosis. They tubulate membranes and regulate calcium influx into neurons to trigger the activation of the endocytic machinery. They are also involved in the sorting of plasma membrane proteins, actin filament assembly, and the uncoating of clathrin-coated vesicles for fusion with endosomes. Endophilins contain an N-terminal N-BAR domain (BAR domain with an additional N-terminal amphipathic helix), followed by a variable region containing proline clusters, 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        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 568912958 549 CKALYTFEGQNEGTISVVEGETLSVIEE-DkgDGWTRIRRNeDEEGYVPTSYVEV 602
Cdd:cd11803    3 CRALYDFEPENEGELGFKEGDIITLTNQiD--ENWYEGMVN-GQSGFFPVNYVEV 54

Variant SH3 domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 568912958  551 ALYTFEGQNEGTISVVEGETLSVIEEDkGDGWTRIRRNEdEEGYVPTSYVE 601
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIEES-EDGWWEGINTG-RTGLVPANYVE 49

Src homology 3 domain of Fyn and Yrk Protein Tyrosine Kinases; Fyn and Yrk (Yes-related kinase) are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Fyn, together with Lck, plays a critical role in T-cell signal transduction by phosphorylating ITAM (immunoreceptor tyr activation motif) sequences on T-cell receptors, ultimately leading to the proliferation and differentiation of T-cells. In addition, Fyn is involved in the myelination of neurons, and is implicated in Alzheimer's and Parkinson's diseases. Yrk has been detected only in chickens. It is primarily found in neuronal and epithelial cells and in macrophages. It may play a role in inflammation and in response to injury. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYV 600
Cdd:cd12006    5 ALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGETGYIPSNYV 54

The F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain of FCH domain Only 2 protein; F-BAR domains are dimerization modules that bind and bend membranes and are found in proteins involved in membrane dynamics and actin reorganization. The specific function of FCH domain Only 2 (FCHO2) is still unknown. It contains an N-terminal F-BAR domain and a C-terminal domain of unknown function named SAFF which is also present in FCHO1 and endophilin interacting protein 1. F-BAR domains form banana-shaped dimers with a positively-charged concave surface that binds to negatively-charged lipid membranes. They can induce membrane deformation in the form of long tubules.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958  31 FVKERTEIELSYAKQLRNLSKKyqpkknskeeeeykytackafLSTLNEMNDYAGQHEVI--SENMTSQITVDLMRYVQE 108
Cdd:cd07673   34 FIRERATIEEAYSRSMTKLAKS---------------------ASNYSQLGTFAPVWDVFktSTEKLANCHLELVRKLQE 92

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 109 LKQE--------------RKSNFHDGRKAQQHIETCWKQLESSKRRFERDCKEADRAQQYfekmdadiNVTKADVEKARQ 174
Cdd:cd07673   93 LIKEvqkygeeqvkshkkTKEEVAGTLEAVQNIQSITQALQKSKENYNAKCLEQERLKKE--------GATQREIEKAAV 164

                        170       180       190       200       210       220       230       240
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568912958 175 QAQIRQQMAEDSKADYSLILQRFNQEQWEyyhthipnIFQKIQEMEERRIVRIGESMKTYAEVDRQVIPIIGKCLDGIVK 254
Cdd:cd07673  165 KSKKATESYKLYVEKYALAKADFEQKMTE--------TAQKFQDIEETHLIRIKEIIGSYSNSVKEIHIQIGQVHEEFIN 236

                        250       260       270
                 ....*....|....*....|....*....|..
gi 568912958 255 AAESIDQKNDSQLVVEAYKSGFEPPGDIEFED 286
Cdd:cd07673  237 NMANTTVESLIQKFAESKGTGKERPGPIEFEE 268

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYV 600
Cdd:cd12007    5 ALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGKNGYIPSNYV 54

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 568912958 548 TCKALYTFEGQNEGTISVVEGETLSVIEEDKGD-GWTRIRRNEDEEGYVPTSYVEV 602
Cdd:cd11904    2 VVQALYPFSSSNDEELNFEKGEVMDVIEKPENDpEWWKCRKANGQVGLVPKNYVTV 57

Src homology 3 domain of Src Protein Tyrosine Kinase; Src (or c-Src) is a cytoplasmic (or non-receptor) PTK and is the vertebrate homolog of the oncogenic protein (v-Src) from Rous sarcoma virus. Together with other Src subfamily proteins, it is involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. Src also play a role in regulating cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Elevated levels of Src kinase activity have been reported in a variety of human cancers. Several inhibitors of Src have been developed as anti-cancer drugs. Src is also implicated in acute inflammatory responses and osteoclast function. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 568912958 551 ALYTFEGQNEGTISVVEGETLSVIEEDKGDGWTRIRRNEDEEGYVPTSYV 600
Cdd:cd12008    4 ALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQTGYIPSNYV 53