Centaurin gamma (CENTG) GTPase; The centaurins (alpha, beta, gamma, and delta) are large, multi-domain proteins that all contain an ArfGAP domain and ankyrin repeats, and in some cases, numerous additional domains. Centaurin gamma contains an additional GTPase domain near its N-terminus. The specific function of this GTPase domain has not been well characterized, but centaurin gamma 2 (CENTG2) may play a role in the development of autism. Centaurin gamma 1 is also called PIKE (phosphatidyl inositol (PI) 3-kinase enhancer) and centaurin gamma 2 is also known as AGAP (ArfGAP protein with a GTPase-like domain, ankyrin repeats and a Pleckstrin homology domain) or GGAP. Three isoforms of PIKE have been identified. PIKE-S (short) and PIKE-L (long) are brain-specific isoforms, with PIKE-S restricted to the nucleus and PIKE-L found in multiple cellular compartments. A third isoform, PIKE-A was identified in human glioblastoma brain cancers and has been found in various tissues. GGAP has been shown to have high GTPase activity due to a direct intramolecular interaction between the N-terminal GTPase domain and the C-terminal ArfGAP domain. In human tissue, AGAP mRNA was detected in skeletal muscle, kidney, placenta, brain, heart, colon, and lung. Reduced expression levels were also observed in the spleen, liver, and small intestine.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  71 LRLGVLGDVRSGKSSLIHRFLTGSYQVLEKPESEQYKKEMLVDGQTHLVLIREEAGAPDAKFSGWADAVIFVFSLEDESS 150
Cdd:cd04103    1 LKLGIVGNLRSGKSALVHRYLTGSYVQLESPEGGRFKKEVLVDGQSHLLLIRDEGGAPDAQFAGWVDAVIFVFSLEDEAS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 151 FQAVSHLHGQLISLRgeGRGGLALALVGTQDRISASSPRVVGDARARALCTDMKRCSYYETCATYGLNVDRVFQEVAQKV 230
Cdd:cd04103   81 FQTVYRLYHQLSSYR--NISEIPLILVGTQDAISASNPRVIDDARARQLCADMKRCSYYETCATYGLNVERVFQEAAQKI 158

Arf-GAP with GTPase, ANK repeat and PH domain-containing protein Pleckstrin homology (PH) domain; AGAP (also called centaurin gamma; PIKE/Phosphatidylinositol-3-kinase enhancer) reside mainly in the nucleus and are known to activate phosphoinositide 3-kinase, a key regulator of cell proliferation, motility and vesicular trafficking. There are 3 isoforms of AGAP (PIKE-A, PIKE-L, and PIKE-S) the longest of which PIKE-L consists of N-terminal proline rich domains (PRDs), followed by a GTPase domain, a split PH domain (PHN and PHC), an ArfGAP domain and two ankyrin repeats. PIKE-S terminates after the PHN domain and PIKE-A is missing the PRD region. Centaurin binds phosphatidlyinositol (3,4,5)P3. 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 564359681 338 RAIPIKQSFLLKRSGNSLNKEWKKKYVTLSSNGFLLYHPSINDYIHSTHGKEMDLLRTTVKVPGKRPPRAISAfgpsasi 417
Cdd:cd01250    1 RAIPIKQGYLYKRSSKSLNKEWKKKYVTLCDDGRLTYHPSLHDYMENVHGKEIDLLRTTVKVPGKRPPRASSK------- 73

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 418 nglvkdmstvqmgegpeastpmpspspspsslqlptdqtskhllkpdrnlaralstdctpsgdlsplsrepppspmvkkq 497
Cdd:cd01250      --------------------------------------------------------------------------------

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 564359681 498 rrkklstpsktegsavqaeeENFEFLIVSSTGQTWHFEAASFEERDAWVQAIESQILASLQ 558
Cdd:cd01250   74 --------------------SAFEFIIVSLDGKQWHFEAASSEERDEWVQAIEQQILASLQ 114

Centaurin gamma (CENTG) GTPase; The centaurins (alpha, beta, gamma, and delta) are large, multi-domain proteins that all contain an ArfGAP domain and ankyrin repeats, and in some cases, numerous additional domains. Centaurin gamma contains an additional GTPase domain near its N-terminus. The specific function of this GTPase domain has not been well characterized, but centaurin gamma 2 (CENTG2) may play a role in the development of autism. Centaurin gamma 1 is also called PIKE (phosphatidyl inositol (PI) 3-kinase enhancer) and centaurin gamma 2 is also known as AGAP (ArfGAP protein with a GTPase-like domain, ankyrin repeats and a Pleckstrin homology domain) or GGAP. Three isoforms of PIKE have been identified. PIKE-S (short) and PIKE-L (long) are brain-specific isoforms, with PIKE-S restricted to the nucleus and PIKE-L found in multiple cellular compartments. A third isoform, PIKE-A was identified in human glioblastoma brain cancers and has been found in various tissues. GGAP has been shown to have high GTPase activity due to a direct intramolecular interaction between the N-terminal GTPase domain and the C-terminal ArfGAP domain. In human tissue, AGAP mRNA was detected in skeletal muscle, kidney, placenta, brain, heart, colon, and lung. Reduced expression levels were also observed in the spleen, liver, and small intestine.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  71 LRLGVLGDVRSGKSSLIHRFLTGSYQVLEKPESEQYKKEMLVDGQTHLVLIREEAGAPDAKFSGWADAVIFVFSLEDESS 150
Cdd:cd04103    1 LKLGIVGNLRSGKSALVHRYLTGSYVQLESPEGGRFKKEVLVDGQSHLLLIRDEGGAPDAQFAGWVDAVIFVFSLEDEAS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 151 FQAVSHLHGQLISLRgeGRGGLALALVGTQDRISASSPRVVGDARARALCTDMKRCSYYETCATYGLNVDRVFQEVAQKV 230
Cdd:cd04103   81 FQTVYRLYHQLSSYR--NISEIPLILVGTQDAISASNPRVIDDARARQLCADMKRCSYYETCATYGLNVERVFQEAAQKI 158

Arf-GAP with GTPase, ANK repeat and PH domain-containing protein Pleckstrin homology (PH) domain; AGAP (also called centaurin gamma; PIKE/Phosphatidylinositol-3-kinase enhancer) reside mainly in the nucleus and are known to activate phosphoinositide 3-kinase, a key regulator of cell proliferation, motility and vesicular trafficking. There are 3 isoforms of AGAP (PIKE-A, PIKE-L, and PIKE-S) the longest of which PIKE-L consists of N-terminal proline rich domains (PRDs), followed by a GTPase domain, a split PH domain (PHN and PHC), an ArfGAP domain and two ankyrin repeats. PIKE-S terminates after the PHN domain and PIKE-A is missing the PRD region. Centaurin binds phosphatidlyinositol (3,4,5)P3. 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 564359681 338 RAIPIKQSFLLKRSGNSLNKEWKKKYVTLSSNGFLLYHPSINDYIHSTHGKEMDLLRTTVKVPGKRPPRAISAfgpsasi 417
Cdd:cd01250    1 RAIPIKQGYLYKRSSKSLNKEWKKKYVTLCDDGRLTYHPSLHDYMENVHGKEIDLLRTTVKVPGKRPPRASSK------- 73

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 418 nglvkdmstvqmgegpeastpmpspspspsslqlptdqtskhllkpdrnlaralstdctpsgdlsplsrepppspmvkkq 497
Cdd:cd01250      --------------------------------------------------------------------------------

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 564359681 498 rrkklstpsktegsavqaeeENFEFLIVSSTGQTWHFEAASFEERDAWVQAIESQILASLQ 558
Cdd:cd01250   74 --------------------SAFEFIIVSLDGKQWHFEAASSEERDEWVQAIEQQILASLQ 114

Putative GTPase activating protein for Arf; Putative zinc fingers with GTPase activating proteins (GAPs) towards the small GTPase, Arf. The GAP of ARD1 stimulates GTPase hydrolysis for ARD1 but not ARFs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  577 AIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWE 656
Cdd:pfam01412   3 VLRELLKLPGNKVCADCGAPNPTWASVNLGIFICIDCSGVHRSLGVHISKVRSLTLDTWTDEQLELMKAGGNDRANEFWE 82

                          90       100       110
                  ....*....|....*....|....*....|....
gi 564359681  657 SDTRGRAKPTRDSSREERESWIRAKYEQLLFLAP 690
Cdd:pfam01412  83 ANLPPSYKPPPSSDREKRESFIRAKYVEKKFAKP 116

ADP-ribosylation factor GTPase-activating protein AGD10; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 587 NSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRV-----WESDTRG 661
Cdd:PLN03114  22 NKICFDCNAKNPTWASVTYGIFLCIDCSAVHRSLGVHISFVRSTNLDSWSSEQLKMMIYGGNNRAQVFfkqygWSDGGKT 101

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....
gi 564359681 662 RAKPTRDSSREERE----SWIRAKYEQLLFL--APLGTTEEPLG 699
Cdd:PLN03114 102 EAKYTSRAADLYKQilakEVAKSKAEEELDLppSPPDSTQVPNG 145

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681   75 VLGDVRSGKSSLIHRFLTGSYQvlEKPES----EQYKKEMLVDGQTHLVLIREEAGA------PDAKFSGwADAVIFVFS 144
Cdd:pfam00071   4 LVGDGGVGKSSLLIRFTQNKFP--EEYIPtigvDFYTKTIEVDGKTVKLQIWDTAGQerfralRPLYYRG-ADGFLLVYD 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  145 LEDESSFQAVSHLHGQLISLRGEgrgGLALALVGTQdrISASSPRVVGDARARALCTDMKrCSYYETCATYGLNVDRVFQ 224
Cdd:pfam00071  81 ITSRDSFENVKKWVEEILRHADE---NVPIVLVGNK--CDLEDQRVVSTEEGEALAKELG-LPFMETSAKTNENVEEAFE 154

                  ....*.
gi 564359681  225 EVAQKV 230
Cdd:pfam00071 155 ELAREI 160

GTPase SAR1 family domain [General function prediction only];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  70 ELRLGVLGDVRSGKSSLIHRFLTGSYQvLEKPES----EQYKKEMLVDGQT-HLVLI----REEAGAPDAKFSGW---AD 137
Cdd:COG1100    3 EKKIVVVGTGGVGKTSLVNRLVGDIFS-LEKYLStngvTIDKKELKLDGLDvDLVIWdtpgQDEFRETRQFYARQltgAS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 138 AVIFVFSLEDESSFQAVSHLHGQLISLRGEGRgglaLALVGTQ-DRISAssPRVVGDARARALCTDMKRCSYYETCATYG 216
Cdd:COG1100   82 LYLFVVDGTREETLQSLYELLESLRRLGKKSP----IILVLNKiDLYDE--EEIEDEERLKEALSEDNIVEVVATSAKTG 155

                        170
                 ....*....|..
gi 564359681 217 LNVDRVFQEVAQ 228
Cdd:COG1100  156 EGVEELFAALAE 167

Rab family protein; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  75 VLGDVRSGKSSLIHRFLTGSYQVLEKPESEQYK-KEMLVDGQTHLVLIREEAGAP-----DAKFSGWADAVIFVFSLEDE 148
Cdd:PLN03118  19 LIGDSGVGKSSLLVSFISSSVEDLAPTIGVDFKiKQLTVGGKRLKLTIWDTAGQErfrtlTSSYYRNAQGIILVYDVTRR 98

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 149 SSFQAVSHLHGQLISLRGEGRGGLALaLVGtqDRISASSPRVVGDARARALCTDMKrCSYYETCATYGLNVDRVFQEVAQ 228
Cdd:PLN03118  99 ETFTNLSDVWGKEVELYSTNQDCVKM-LVG--NKVDRESERDVSREEGMALAKEHG-CLFLECSAKTRENVEQCFEELAL 174

                 ...
gi 564359681 229 KVV 231
Cdd:PLN03118 175 KIM 177

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
                   ....*....|....*....|....*....|....*...
gi 564359681   516 EEENFEFLIVSSTGQTWHFEAASFEERDAWVQAIESQI 553
Cdd:smart00233  64 SKKPHCFEIKTSDRKTLLLQAESEEEREKWVEALRKAI 101

Centaurin gamma (CENTG) GTPase; The centaurins (alpha, beta, gamma, and delta) are large, multi-domain proteins that all contain an ArfGAP domain and ankyrin repeats, and in some cases, numerous additional domains. Centaurin gamma contains an additional GTPase domain near its N-terminus. The specific function of this GTPase domain has not been well characterized, but centaurin gamma 2 (CENTG2) may play a role in the development of autism. Centaurin gamma 1 is also called PIKE (phosphatidyl inositol (PI) 3-kinase enhancer) and centaurin gamma 2 is also known as AGAP (ArfGAP protein with a GTPase-like domain, ankyrin repeats and a Pleckstrin homology domain) or GGAP. Three isoforms of PIKE have been identified. PIKE-S (short) and PIKE-L (long) are brain-specific isoforms, with PIKE-S restricted to the nucleus and PIKE-L found in multiple cellular compartments. A third isoform, PIKE-A was identified in human glioblastoma brain cancers and has been found in various tissues. GGAP has been shown to have high GTPase activity due to a direct intramolecular interaction between the N-terminal GTPase domain and the C-terminal ArfGAP domain. In human tissue, AGAP mRNA was detected in skeletal muscle, kidney, placenta, brain, heart, colon, and lung. Reduced expression levels were also observed in the spleen, liver, and small intestine.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  71 LRLGVLGDVRSGKSSLIHRFLTGSYQVLEKPESEQYKKEMLVDGQTHLVLIREEAGAPDAKFSGWADAVIFVFSLEDESS 150
Cdd:cd04103    1 LKLGIVGNLRSGKSALVHRYLTGSYVQLESPEGGRFKKEVLVDGQSHLLLIRDEGGAPDAQFAGWVDAVIFVFSLEDEAS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 151 FQAVSHLHGQLISLRgeGRGGLALALVGTQDRISASSPRVVGDARARALCTDMKRCSYYETCATYGLNVDRVFQEVAQKV 230
Cdd:cd04103   81 FQTVYRLYHQLSSYR--NISEIPLILVGTQDAISASNPRVIDDARARQLCADMKRCSYYETCATYGLNVERVFQEAAQKI 158

ArfGAP with GTPase domain, ANK repeat and PH domain 1; The AGAP subfamily of ADP-ribosylation factor GTPase-activating proteins (Arf GAPs) includes three members: AGAP1-3. In addition to the Arf GAP domain, AGAP proteins contain GTP-binding protein-like, ANK repeat and pleckstrin homology (PH) domains. AGAP1 and AGAP2 have phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-mediated GTPase-activating protein (GAP) activity preferentially toward Arf1, and function in the endocytic system. AGAP1 and AGAP2 independently regulate AP-3 endosomes and AP-1/Rab4 fast recycling endosomes, respectively. AGAP1, via its PH domain, directly interacts with the adapter protein 3 (AP-3), which is a coat protein involved in trafficking in the endosomal-lysosomal system, and regulates AP-3-dependent trafficking. In other hand, AGAP2 specifically binds the clathrin adaptor protein AP-1 and regulates the AP-1/Rab-4 dependent endosomal trafficking. AGAP2 is overexpressed in different human cancers including prostate carcinoma and glioblastoma, and promotes cancer cell invasion. AGAP3 exists as a component of the NMDA receptor complex that regulates Arf6 and Ras/ERK signaling pathways. Moreover, AGAP3 regulates AMPA receptor trafficking through the ArfGAP domain. Together, AGAP3 is believed to involve in linking NMDA receptor activation to AMPA receptor trafficking.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 575 AVAIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRV 654
Cdd:cd08854    1 AVAIQAIRNAKGNSLCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNHMANSI 80

                         90       100
                 ....*....|....*....|....*....
gi 564359681 655 WESDTRGRAKPTRDSSREERESWIRAKYE 683
Cdd:cd08854   81 WESCTQGRTKPAPDSSREERESWIRAKYE 109

ArfGAP with GTPase domain, ANK repeat and PH domain 2; The AGAP subfamily of ADP-ribosylation factor GTPase-activating proteins (Arf GAPs) includes three members: AGAP1-3. In addition to the Arf GAP domain, AGAP proteins contain GTP-binding protein-like, ANK repeat and pleckstrin homology (PH) domains. AGAP1 and AGAP2 have phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-mediated GTPase-activating protein (GAP) activity preferentially toward Arf1, and function in the endocytic system. AGAP1 and AGAP2 independently regulate AP-3 endosomes and AP-1/Rab4 fast recycling endosomes, respectively. AGAP1, via its PH domain, directly interacts with the adapter protein 3 (AP-3), which is a coat protein involved in trafficking in the endosomal-lysosomal system, and regulates AP-3-dependent trafficking. In other hand, AGAP2 specifically binds the clathrin adaptor protein AP-1 and regulates the AP-1/Rab-4 dependent endosomal trafficking. AGAP2 is overexpressed in different human cancers including prostate carcinoma and glioblastoma, and promotes cancer cell invasion. AGAP3 exists as a component of the NMDA receptor complex that regulates Arf6 and Ras/ERK signaling pathways. Moreover, AGAP3 regulates AMPA receptor trafficking through the ArfGAP domain. Together, AGAP3 is believed to involve in linking NMDA receptor activation to AMPA receptor trafficking.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 575 AVAIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRV 654
Cdd:cd08853    1 AMALQSIRNMRGNSHCVDCETQNPKWASLNLGVLMCIECSGIHRNLGTHLSRVRSLDLDDWPVELRKVMSSIGNELANSI 80

                         90       100
                 ....*....|....*....|....*....
gi 564359681 655 WESDTRGRAKPTRDSSREERESWIRAKYE 683
Cdd:cd08853   81 WEGSSQGQTKPSSDSTREEKERWIRAKYE 109

GTPase-activating protein (GAP) for the ADP ribosylation factors (ARFs); ArfGAPs are a family of proteins containing an ArfGAP catalytic domain that induces the hydrolysis of GTP bound to the small guanine nucleotide-binding protein Arf, a member of the Ras superfamily of GTPases. Like all GTP-binding proteins, Arf proteins function as molecular switches, cycling between GTP (active-membrane bound) and GDP (inactive-cytosolic) form. Conversion to the GTP-bound form requires a guanine nucleotide exchange factor (GEF), whereas conversion to the GDP-bound form is catalyzed by a GTPase activating protein (GAP). In that sense, ArfGAPs were originally proposed to function as terminators of Arf signaling, which is mediated by regulating Arf family GTP-binding proteins. However, recent studies suggest that ArfGAPs can also function as Arf effectors, independently of their GAP enzymatic activity to transduce signals in cells. The ArfGAP domain contains a C4-type zinc finger motif and a conserved arginine that is required for activity, within a specific spacing (CX2CX16CX2CX4R). ArfGAPs, which have multiple functional domains, regulate the membrane trafficking and actin cytoskeleton remodeling via specific interactions with signaling lipids such as phosphoinositides and trafficking proteins, which consequently affect cellular events such as cell growth, migration, and cancer invasion. The ArfGAP family, which includes 31 human ArfGAP-domain containing proteins, is divided into 10 subfamilies based on domain structure and sequence similarity. The ArfGAP nomenclature is mainly based on the protein domain structure. For example, ASAP1 contains ArfGAP, SH3, ANK repeat and PH domains; ARAPs contain ArfGAP, Rho GAP, ANK repeat and PH domains; ACAPs contain ArfGAP, BAR (coiled coil), ANK repeat and PH domains; and AGAPs contain Arf GAP, GTP-binding protein-like, ANK repeat and PH domains. Furthermore, the ArfGAPs can be classified into two major types of subfamilies, according to the overall domain structure: the ArfGAP1 type includes 6 subfamilies (ArfGAP1, ArfGAP2/3, ADAP, SMAP, AGFG, and GIT), which contain the ArfGAP domain at the N-terminus of the protein; and the AZAP type includes 4 subfamilies (ASAP, ACAP, AGAP, and ARAP), which contain an ArfGAP domain between the PH and ANK repeat domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 578 IQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWES 657
Cdd:cd08204    1 LEELLKLPGNKVCADCGAPDPRWASINLGVFICIRCSGIHRSLGVHISKVRSLTLDSWTPEQVELMKAIGNARANAYYEA 80

                         90       100
                 ....*....|....*....|....*.
gi 564359681 658 D-TRGRAKPTRDSSREERESWIRAKY 682
Cdd:cd08204   81 NlPPGFKKPTPDSSDEEREQFIRAKY 106

Putative GTPase activating protein for Arf; Putative zinc fingers with GTPase activating proteins (GAPs) towards the small GTPase, Arf. The GAP of ARD1 stimulates GTPase hydrolysis for ARD1 but not ARFs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681  577 AIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWE 656
Cdd:pfam01412   3 VLRELLKLPGNKVCADCGAPNPTWASVNLGIFICIDCSGVHRSLGVHISKVRSLTLDTWTDEQLELMKAGGNDRANEFWE 82

                          90       100       110
                  ....*....|....*....|....*....|....
gi 564359681  657 SDTRGRAKPTRDSSREERESWIRAKYEQLLFLAP 690
Cdd:pfam01412  83 ANLPPSYKPPPSSDREKRESFIRAKYVEKKFAKP 116

ArfGAP domain of ASAP (Arf GAP, SH3, ANK repeat and PH domains) subfamily of ADP-ribosylation factor GTPase-activating proteins; The ArfGAPs are a family of multidomain proteins with a common catalytic domain that promotes the hydrolysis of GTP bound to Arf, thereby inactivating Arf signaling. ASAP-subfamily GAPs include three members: ASAP1, ASAP2, ASAP3. The ASAP subfamily comprises Arf GAP, SH3, ANK repeat and PH domains. From the N-terminus, each member has a BAR, PH, Arf GAP, ANK repeat, and proline rich domains. Unlike ASAP3, ASAP1 and ASAP2 also have an SH3 domain at the C-terminus. ASAP1 and ASAP2 show strong GTPase-activating protein (GAP) activity toward Arf1 and Arf5 and weak activity toward Arf6. ASAP1 is a target of Src and FAK signaling that regulates focal adhesions, circular dorsal ruffles (CDR), invadopodia, and podosomes. ASAP1 GAP activity is synergistically stimulated by phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidic acid. ASAP2 is believed to function as an ArfGAP that controls ARF-mediated vesicle budding when recruited to Golgi membranes. It also functions as a substrate and downstream target for protein tyrosine kinases Pyk2 and Src, a pathway that may be involved in the regulation of vesicular transport. ASAP3 is a focal adhesion-associated ArfGAP that functions in cell migration and invasion. Similar to ASAP1, the GAP activity of ASAP3 is strongly enhanced by PIP2 via PH domain. Like ASAP1, ASAP3 associates with focal adhesions and circular dorsal ruffles. However, unlike ASAP1, ASAP3 does not localize to invadopodia or podosomes. Both ASAP 1 and 3 have been implicated in oncogenesis, as ASAP1 is highly expressed in metastatic breast cancer and ASAP3 in hepatocellular carcinoma.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 578 IQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWES 657
Cdd:cd08834    6 IAEVKRLPGNDVCCDCGSPDPTWLSTNLGILTCIECSGVHRELGVHVSRIQSLTLDNLGTSELLLARNLGNEGFNEIMEA 85

                         90       100
                 ....*....|....*....|....*
gi 564359681 658 DTRGRAKPTRDSSREERESWIRAKY 682
Cdd:cd08834   86 NLPPGYKPTPNSDMEERKDFIRAKY 110

ArfGAP domain of ACAP1 (ArfGAP with Coiled-coil, ANK repeat and PH domains 1); ACAP1 belongs to the ACAP subfamily of GAPs (GTPase-activating proteins) for the small GTPase Arf (ADP-ribosylation factor). ACAP subfamily of ArfGAPs are composed of Coiled coli (BAR, Bin-Amphiphysin-Rvs), PH, ArfGAP and ANK repeats domains. ACAP1 (centaurin beta1) and ACAP2 centaurin beta2) have a GAP (GTPase-activating protein) activity preferentially toward Arf6, which regulates endocytic recycling. Both ACAP1/2 are activated by are activated by the phosphoinositides, PI(4,5)P2 and PI(3,5)P2. ACAP1 binds specifically with recycling cargo proteins such as transferrin receptor (TfR) and cellubrevin. Thus, ACAP1 promotes cargo sorting to enhance TfR recycling from the recycling endosome. In addition, phosphorylation of ACAP by Akt, a serine/threonine protein kinase, regulates the recycling of integrin beta1 to control cell migration. In contrast, ACAP2 does not exhibit a similar interaction with the recycling cargo proteins. It has been shown that ACAP2 functions both as an effector of Ras-related protein Rab35 and as an Arf6-GTPase-activating protein (GAP) during neurite outgrowth of PC12 cells. Moreover, ACAP2, together with Rab35, regulates phagocytosis in mammalian macrophages. ACAP3 also positively regulates neurite outgrowth through its GAP activity specific to Arf6 in mouse hippocampal neurons.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 577 AIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWE 656
Cdd:cd08852    3 AVAQVQSVDGNAQCCDCREPAPEWASINLGVTLCIQCSGIHRSLGVHFSKVRSLTLDSWEPELVKLMCELGNVIINQIYE 82

                         90       100       110
                 ....*....|....*....|....*....|....*..
gi 564359681 657 S--DTRGRAKPTRDSSREERESWIRAKYEQLLFLAPL 691
Cdd:cd08852   83 AriEAMAIKKPGPSSSRQEKEAWIRAKYVEKKFITKL 119

ArfGAP domain of ACAP2 (ArfGAP with Coiled-coil, ANK repeat and PH domains 2); ACAP2 belongs to the ACAP subfamily of GAPs (GTPase-activating proteins) for the small GTPase Arf (ADP-ribosylation factor). ACAP subfamily of ArfGAPs are composed of Coiled coli (BAR, Bin-Amphiphysin-Rvs), PH, ArfGAP and ANK repeats domains. ACAP1 (centaurin beta1) and ACAP2 centaurin beta2) have a GAP (GTPase-activating protein) activity preferentially toward Arf6, which regulates endocytic recycling. Both ACAP1/2 are activated by are activated by the phosphoinositides, PI(4,5)P2 and PI(3,5)P2. ACAP1 binds specifically with recycling cargo proteins such as transferrin receptor (TfR) and cellubrevin. Thus, ACAP1 promotes cargo sorting to enhance TfR recycling from the recycling endosome. In addition, phosphorylation of ACAP by Akt, a serine/threonine protein kinase, regulates the recycling of integrin beta1 to control cell migration. In contrast, ACAP2 does not exhibit a similar interaction with the recycling cargo proteins. It has been shown that ACAP2 functions both as an effector of Ras-related protein Rab35 and as an Arf6-GTPase-activating protein (GAP) during neurite outgrowth of PC12 cells. Moreover, ACAP2, together with Rab35, regulates phagocytosis in mammalian macrophages. ACAP3 also positively regulates neurite outgrowth through its GAP activity specific to Arf6 in mouse hippocampal neurons.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 577 AIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWE 656
Cdd:cd08851    3 ALQRVQCIPGNASCCDCGLADPRWASINLGITLCIECSGIHRSLGVHFSKVRSLTLDTWEPELLKLMCELGNDVINRIYE 82

                         90       100
                 ....*....|....*....|....*...
gi 564359681 657 S--DTRGRAKPTRDSSREERESWIRAKY 682
Cdd:cd08851   83 ArvEKMGAKKPQPGGQRQEKEAYIRAKY 110

GTPase-activating protein that regulates ARFs (ADP-ribosylation factors), involved in ARF-mediated vesicular transport [Intracellular trafficking and secretion];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 570 DSQSEAVAIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGND 649
Cdd:COG5347    3 TKSEDRKLLKLLKSDSSNKKCADCGAPNPTWASVNLGVFLCIDCAGVHRSLGVHISKVKSLTLDNWTEEELRRMEVGGNS 82

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 564359681 650 TANRVWESD-TRGRAKPTR-DSSREERESWIRAKYE 683
Cdd:COG5347   83 NANRFYEKNlLDQLLLPIKaKYDSSVAKKYIRKKYE 118

Arf1 GTPase-activating protein 1; ArfGAP (ADP Ribosylation Factor GTPase Activating Protein) domain is a part of ArfGap1-like proteins that play a crucial role in controlling of membrane trafficking, particularly in the formation of COPI (coat protein complex I)-coated vesicles on Golgi membranes. The ArfGAP1 protein subfamily consists of three members: ArfGAP1 (Gcs1p in yeast), ArfGAP2 and ArfGAP3 (both are homologs of yeast Glo3p). ArfGAP2/3 are closely related, but with little similarity to ArfGAP1, except the catalytic ArfGAP domain. They promote hydrolysis of GTP bound to the small G protein ADP-ribosylation factor 1 (Arf1), which leads to the dissociation of coat proteins from Golgi-derived membranes and vesicles. Dissociation of the coat proteins is required for the fusion of these vesicles with target compartments. Thus, the GAP catalytic activity plays a key role in the formation of COPI vesicles from Golgi membrane. In contrast to ArfGAP1, which displays membrane curvature-dependent ArfGAP activity, ArfGAP2 and ArfGAP3 activities are dependent on coatomer (the core COPI complex) which required for efficient recruitment of ArfGAP2 and ArfGAP3 to the Golgi membrane. Accordingly, ArfGAP2/3 has been implicated in coatomer-mediated protein transport between the Golgi complex and the endoplasmic reticulum. Unlike ArfGAP1, which is controlled by membrane curvature through its amphipathic lipid packing sensor (ALPS) motifs, ArfGAP2/3 do not possess ALPS motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 579 QAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDW-PRELTLvLTAIGNDTANRVWES 657
Cdd:cd08830    6 RELQKLPGNNRCFDCGAPNPQWASVSYGIFICLECSGVHRGLGVHISFVRSITMDSWsEKQLKK-MELGGNAKLREFFES 84

ArfGAP domain of ASAP3 (ArfGAP with ANK repeat and PH domain-containing protein 3); The ArfGAPs are a family of multidomain proteins with a common catalytic domain that promotes the hydrolysis of GTP bound to Arf, thereby inactivating Arf signaling. ASAP-subfamily GAPs include three members: ASAP1, ASAP2, ASAP3. The ASAP subfamily comprises Arf GAP, SH3, ANK repeat and PH domains. From the N-terminus, each member has a BAR, PH, Arf GAP, ANK repeat, and proline rich domains. Unlike ASAP1 and ASAP2, ASAP3 do not have an SH3 domain at the C-terminus. ASAP1 and ASAP2 show strong GTPase-activating protein (GAP) activity toward Arf1 and Arf5 and weak activity toward Arf6. ASAP1 is a target of Src and FAK signaling that regulates focal adhesions, circular dorsal ruffles (CDR), invadopodia, and podosomes. ASAP1 GAP activity is synergistically stimulated by phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidic acid. ASAP2 is believed to function as an ArfGAP that controls ARF-mediated vesicle budding when recruited to Golgi membranes. It also functions as a substrate and downstream target for protein tyrosine kinases Pyk2 and Src, a pathway that may be involved in the regulation of vesicular transport. ASAP3 is a focal adhesion-associated ArfGAP that functions in cell migration and invasion. Similar to ASAP1, the GAP activity of ASAP3 is strongly enhanced by PIP2 via PH domain. Like ASAP1, ASAP3 associates with focal adhesions and circular dorsal ruffles. However, unlike ASAP1, ASAP3 does not localize to invadopodia or podosomes. ASAP 1 and 3 have been implicated in oncogenesis, as ASAP1 is highly expressed in metastatic breast cancer and ASAP3 in hepatocellular carcinoma.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 578 IQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDW-PRELTLVLTaIGNDTANRVWE 656
Cdd:cd17900    6 IAEVKSRPGNSQCCDCGAPDPTWLSTNLGILTCIECSGIHRELGVRYSRIQSLTLDLLsTSELLLAVS-MGNTRFNEVME 84

                         90       100
                 ....*....|....*....|....*...
gi 564359681 657 SD--TRGRAKPTRDSSREERESWIRAKY 682
Cdd:cd17900   85 ATlpAHGGPKPSAESDMGTRKDYIMAKY 112

ArfGAP domain of ASAP1 (ArfGAP with SH3 domain, ANK repeat and PH domain-containing protein 1); The ArfGAPs are a family of multidomain proteins with a common catalytic domain that promotes the hydrolysis of GTP bound to Arf, thereby inactivating Arf signaling. ASAP-subfamily GAPs include three members: ASAP1, ASAP2, ASAP3. The ASAP subfamily comprises Arf GAP, SH3, ANK repeat and PH domains. From the N-terminus, each member has a BAR, PH, Arf GAP, ANK repeat, and proline rich domains. Unlike ASAP3, ASAP1 and ASAP2 also have an SH3 domain at the C-terminus. ASAP1 and ASAP2 show strong GTPase-activating protein (GAP) activity toward Arf1 and Arf5 and weak activity toward Arf6. ASAP1 is a target of Src and FAK signaling that regulates focal adhesions, circular dorsal ruffles (CDR), invadopodia, and podosomes. ASAP1 GAP activity is synergistically stimulated by phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidic acid. ASAP2 is believed to function as an ArfGAP that controls ARF-mediated vesicle budding when recruited to Golgi membranes. It also functions as a substrate and downstream target for protein tyrosine kinases Pyk2 and Src, a pathway that may be involved in the regulation of vesicular transport. ASAP3 is a focal adhesion-associated ArfGAP that functions in cell migration and invasion. Similar to ASAP1, the GAP activity of ASAP3 is strongly enhanced by PIP2 via PH domain. Like ASAP1, ASAP3 associates with focal adhesions and circular dorsal ruffles. However, unlike ASAP1, ASAP3 does not localize to invadopodia or podosomes. ASAP 1 and 3 have been implicated in oncogenesis, as ASAP1 is highly expressed in metastatic breast cancer and ASAP3 in hepatocellular carcinoma.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 578 IQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWES 657
Cdd:cd08848    6 IDDVQRLPGNEVCCDCGSPDPTWLSTNLGILTCIECSGIHREMGVHISRIQSLELDKLGTSELLLAKNVGNNSFNDIMEG 85

                         90       100
                 ....*....|....*....|....*.
gi 564359681 658 DTRG-RAKPTRDSSREERESWIRAKY 682
Cdd:cd08848   86 NLPSpSPKPSPSSDMTARKEYITAKY 111

ADAP1 GTPase activating protein for Arf, with dual PH domains; The ADAP subfamily, ArfGAPs with dual pleckstrin homology (PH) domains, includes two members: ADAP1 and ADAP2. Both ADAP1 (also known as centaurin-alpha1, p42(IP4), or PIP3BP) and ADAP2 (centaurin-alpha2) display a GTPase-activating protein (GAP) activity toward Arf6 (ADP-ribosylation factor 6), which is involved in protein trafficking that regulates endocytic recycling, cytoskeleton remodeling, and neuronal differentiation. ADAP2 has high sequence similarity to the ADAP1 and they both contain a ArfGAP domain at the N-terminus, followed by two PH domains. However, ADAP1, unlike ADAP2, contains a putative N-terminal nuclear localization signal. The PH domains of ADAP1bind to the two second messenger molecules phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) and inositol 1,3,4,5-tetrakisphosphate (I(1,3,4,5)P4) with identical high affinity, whereas those of ADAP2 specifically binds phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2) and PI(3,4,5)P3, which are produced by activated phosphatidylinositol 3-kinase. ADAP1 is predominantly expressed in the brain neurons, while ADAP2 is broadly expressed, including the adipocytes, heart, and skeletal muscle but not in the brain. The limited distribution and high expression of ADAP1 in the brain indicates that ADAP1 is important for neuronal functions. ADAP1 has been shown to highly expressed in the neurons and plagues of Alzheimer's disease patients. In other hand, ADAP2 gene deletion has been shown to cause circulatory deficiencies and heart shape defects in zebrafish, indicating that ADAP2 has a vital role in heart development. Taken together, the hemizygous deletion of ADAP2 gene may be contributing to the cardiovascular malformation in patients with neurofibromatosis type 1 (NF1) microdeletions.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 586 GNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLgTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWESDTRG-RAK 664
Cdd:cd08843   16 GNARCADCGAPDPDWASYTLGVFICLSCSGIHRNI-PQVSKVKSVRLDAWEEAQVEFMASHGNDAARARFESKVPSfYYR 94

                         90
                 ....*....|....*...
gi 564359681 665 PTRDSSREERESWIRAKY 682
Cdd:cd08843   95 PTPSDCQLLREQWIRAKY 112

Stromal membrane-associated protein 2; a subfamily of the ArfGAP family; The SMAP subfamily of Arf GTPase-activating proteins consists of the two structurally-related members, SMAP1 and SMAP2. Each SMAP member exhibits common and distinct functions in vesicle trafficking. They both bind to clathrin heavy chain molecules and are involved in the trafficking of clathrin-coated vesicles. SMAP1 preferentially exhibits GAP toward Arf6, while SMAP2 prefers Arf1 as a substrate. SMAP1 is involved in Arf6-dependent vesicle trafficking, but not Arf6-mediated actin cytoskeleton reorganization, and regulates clathrin-dependent endocytosis of the transferrin receptors and E-cadherin. SMAP2 regulates Arf1-dependent retrograde transport of TGN38/46 from the early endosome to the trans-Golgi network (TGN). SMAP2 has the Clathrin Assembly Lymphoid Myeloid (CALM)-binding domain, but SMAP1 does not.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 587 NSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWES---DTRGRa 663
Cdd:cd08859   10 NKFCADCQSKGPRWASWNIGVFICIRCAGIHRNLGVHISRVKSVNLDQWTQEQIQCMQEMGNGKANRLYEAflpENFRR- 88

                         90       100
                 ....*....|....*....|.
gi 564359681 664 kPTRDSSreeRESWIRAKYEQ 684
Cdd:cd08859   89 -PQTDQA---VEGFIRDKYEK 105

ADAP2 GTPase activating protein for Arf, with dual PH domains; The ADAP subfamily, ArfGAPs with dual pleckstrin homology (PH) domains, includes two members: ADAP1 and ADAP2. Both ADAP1 (also known as centaurin-alpha1, p42(IP4), or PIP3BP) and ADAP2 (centaurin-alpha2) display a GTPase-activating protein (GAP) activity toward Arf6 (ADP-ribosylation factor 6), which is involved in protein trafficking that regulates endocytic recycling, cytoskeleton remodeling, and neuronal differentiation. ADAP2 has high sequence similarity to the ADAP1 and they both contain a ArfGAP domain at the N-terminus, followed by two PH domains. However, ADAP1, unlike ADAP2, contains a putative N-terminal nuclear localization signal. The PH domains of ADAP1bind to the two second messenger molecules phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) and inositol 1,3,4,5-tetrakisphosphate (I(1,3,4,5)P4) with identical high affinity, whereas those of ADAP2 specifically binds phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2) and PI(3,4,5)P3, which are produced by activated phosphatidylinositol 3-kinase. ADAP1 is predominantly expressed in the brain neurons, while ADAP2 is broadly expressed, including the adipocytes, heart, and skeletal muscle but not in the brain. The limited distribution and high expression of ADAP1 in the brain indicates that ADAP1 is important for neuronal functions. ADAP1 has been shown to highly expressed in the neurons and plagues of Alzheimer's disease patients. In other hand, ADAP2 gene deletion has been shown to cause circulatory deficiencies and heart shape defects in zebrafish, indicating that ADAP2 has a vital role in heart development. Taken together, the hemizygous deletion of ADAP2 gene may be contributing to the cardiovascular malformation in patients with neurofibromatosis type 1 (NF1) microdeletions.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 586 GNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLgTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWESDTRG-RAK 664
Cdd:cd08844   16 GNSVCADCGAPDPDWASYTLGIFICLNCSGVHRNL-PDISRVKSIRLDFWEDELVEFMKENGNLKAKAKFEAFVPPfYYR 94

                         90
                 ....*....|....*...
gi 564359681 665 PTRDSSREERESWIRAKY 682
Cdd:cd08844   95 PQANDCDVLKEQWIRAKY 112

ArfGap with Rho-Gap domain, ANK repeat and PH domain-containing protein 3; The ARAP subfamily includes three members, ARAP1-3, and belongs to the ADP-ribosylation factor GTPase-activating proteins (Arf GAPs) family of proteins that promotes the hydrolysis of GTP bound to Arf, thereby inactivating Arf signaling. The function of Arfs is dependent on GAPs and guanine nucleotide exchange factors (GEFs), which allow Arfs to cycle between the GDP-bound and GTP-bound forms. In addition to the Arf GAP domain, ARAPs contain the SAM (sterile-alpha motif) domain, 5 pleckstrin homology (PH) domains, the Rho-GAP domain, the Ras-association domain, and ANK repeats. ARAPs show phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3)-dependent GAP activity toward Arf6. ARAPs play important roles in endocytic trafficking, cytoskeleton reorganization in response to growth factors stimulation, and focal adhesion dynamics. ARAP3 possesses a unique dual-specificity GAP activity for Arf6 and RhoA regulated by PI(3,4,5)P3 and a small GTPase Rap1-GTP. The RhoGAP activity of ARAP3 is enhanced by direct binding of Rap1-GTP to the Ras-association (RA) domain. ARAP3 is involved in regulation of cell shape and adhesion.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 579 QAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDD--WPRELTLVLTAIGNDTANRVWE 656
Cdd:cd17902    5 EKIWSNKANRFCADCHASSPDWASINLCVVICKQCAGQHRSLGSGISKVQSLKLDTsvWSNEIVQLFIVLGNDRANRFWA 84

                         90       100       110
                 ....*....|....*....|....*....|.
gi 564359681 657 SDTRGRAKPTRDSSREERESWIRAKYEQLLF 687
Cdd:cd17902   85 ARLPASEALHPDATPEQRREFISRKYREGRF 115

ArfGAP domain of the AGFG subfamily (ArfGAP domain and FG repeat-containing proteins); The ArfGAP domain and FG repeat-containing proteins (AFGF) subfamily of Arf GTPase-activating proteins consists of the two structurally-related members: AGFG1 and AGFG2. AGFG1 (alias: HIV-1 Rev binding protein, HRB; Rev interacting protein, RIP; Rev/Rex activating domain-binding protein, RAB) and AGFG2 are involved in the maintenance and spread of immunodeficiency virus type 1 (HIV-1) infection. The ArfGAP domain of AGFG is related to nucleoporins, which is a class of proteins that mediate nucleocytoplasmic transport. AGFG plays a role in the Rev export pathway, which mediates the nucleocytoplasmic transfer of proteins and RNAs, possibly together by the nuclear export receptor CRM1. In humans, the presence of the FG repeat motifs (11 in AGFG1 and 7 in AGFG2) are thought to be required for these proteins to act as HIV-1 Rev cofactors. Hence, AGFG promotes movement of Rev-responsive element-containing RNAs from the nuclear periphery to the cytoplasm, which is an essential step for HIV-1 replication.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 586 GNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGtHlsRVRSLDLDDWPRELTLVLTAIGNDTANRVWESDTRGRAKP 665
Cdd:cd08838   12 ENKRCFDCGQRGPTYVNLTFGTFVCTTCSGIHREFN-H--RVKSISMSTFTPEEVEFLQAGGNEVARKIWLAKWDPRTDP 88

                         90       100
                 ....*....|....*....|
gi 564359681 666 TRDSSREER-ESWIRAKYEQ 684
Cdd:cd08838   89 EPDSGDDQKiREFIRLKYVD 108

Arf1 GTPase-activating protein 3; ArfGAP (ADP Ribosylation Factor GTPase Activating Protein) domain is a part of ArfGap1-like proteins that play a crucial role in controlling of membrane trafficking, particularly in the formation of COPI (coat protein complex I)-coated vesicles on Golgi membranes. The ArfGAP1 protein subfamily consists of three members: ArfGAP1 (Gcs1p in yeast), ArfGAP2 and ArfGAP3 (both are homologs of yeast Glo3p). ArfGAP2/3 are closely related, but with little similarity to ArfGAP1, except the catalytic ArfGAP domain. They promote hydrolysis of GTP bound to the small G protein ADP-ribosylation factor 1 (Arf1), which leads to the dissociation of coat proteins from Golgi-derived membranes and vesicles. Dissociation of the coat proteins is required for the fusion of these vesicles with target compartments. Thus, the GAP catalytic activity plays a key role in the formation of COPI vesicles from Golgi membrane. In contrast to ArfGAP1, which displays membrane curvature-dependent ArfGAP activity, ArfGAP2 and ArfGAP3 activities are dependent on coatomer (the core COPI complex) which required for efficient recruitment of ArfGAP2 and ArfGAP3 to the Golgi membrane. Accordingly, ArfGAP2/3 has been implicated in coatomer-mediated protein transport between the Golgi complex and the endoplasmic reticulum. Unlike ArfGAP1, which is controlled by membrane curvature through its amphipathic lipid packing sensor (ALPS) motifs, ArfGAP2/3 do not possess ALPS motif.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 564359681 572 QSEAVAIQAIRNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLD-DW 635
Cdd:cd09028    4 QDIAAIFKRLRSVPTNKVCFDCGAKNPSWASITYGVFLCIDCSGIHRSLGVHLSFIRSTELDsNW 68

GIT1 GTPase activating protein for Arf; The GIT (G-protein coupled receptor kinase-interacting protein) subfamily includes GIT1 and GIT2, which have three ANK repeats, a Spa-homology domain (SHD), a coiled-coil domain and a C-terminal paxillin-binding site (PBS). The GIT1/2 proteins are GTPase-activating proteins that function as an inactivator of Arf signaling, and interact with the PIX/Cool family of Rac/Cdc42 guanine nucleotide exchange factors (GEFs). Unlike other ArfGAPs, GIT and PIX (Pak-interacting exchange factor) proteins are tightly associated to form an oligomeric complex that acts as a scaffold and signal integrator that can be recruited for multiple signaling pathways. The GIT/PIX complex functions as a signaling scaffold by binding to specific protein partners. As a result, the complex is transported to specific cellular locations. For instance, the GIT partners paxillin or integrin-alpha4 (to focal adhesions), piccolo and liprin-alpha (to synapses), and the beta-PIX partner Scribble (to epithelial cell-cell contacts and synapses). Moreover, the GIT/PIT complex functions to integrate signals from multiple GTP-binding protein and protein kinase pathways to regulate the actin cytoskeleton and thus cell polarity, adhesion and migration.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564359681 582 RNAKGNSTCVDCGAPNPTWASLNLGALICIECSGIHRNLGTHLSRVRSLDLDDWPRELTLVLTAIGNDTANRVWE----- 656
Cdd:cd08846    3 RKGPRAEVCADCSAPDPGWASINRGVLICDECCSVHRSLGRHISIVKHLRHSAWPPTLLQMVHTLASNGANSIWEhslld 82

                         90       100       110
                 ....*....|....*....|....*....|
gi 564359681 657 ----SDTRGRAKPtRDSSREERESWIRAKY 682
Cdd:cd08846   83 paqvQSGRRKANP-QDKVHPTKSEFIRAKY 111