PX domain; PX domains bind to phosphoinositides.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 564346802   40 SMCFTMKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLFFNMnNRQHVDQRRQGLEDFLRKVLQN 108
Cdd:pfam00787   1 LPTFSLEEWSVRRRYSDFVELHKKLLRKFPSVIIPPLPPKRWLGRY-NEEFIEKRRKGLEQYLQRLLQH 68

Phox homology (PX) domain protein [Intracellular trafficking and secretion / General function prediction only];

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  29 YIDYEICIHTNSMCFTMKTSC---VRRRYREFVWLRQRLQSNALLVQLPELPSK----NLFFNMNNRQHVDQRRQGLEDF 101
Cdd:COG5391  151 HTSYEIITVTNLPSFQLRESRplvVRRRYSDFESLHSILIKLLPLCAIPPLPSKksnsEYYGDRFSDEFIEERRQSLQNF 230

                 ....
gi 564346802 102 LRKV 105
Cdd:COG5391  231 LRRV 234

The Phox Homology domain, a phosphoinositide binding module; The PX domain is a phosphoinositide (PI) binding module involved in targeting proteins to membranes. Proteins containing PX domains interact with PIs and have been implicated in highly diverse functions such as cell signaling, vesicular trafficking, protein sorting, lipid modification, cell polarity and division, activation of T and B cells, and cell survival. Many members of this superfamily bind phosphatidylinositol-3-phosphate (PI3P) but in some cases, other PIs such as PI4P or PI(3,4)P2, among others, are the preferred substrates. In addition to protein-lipid interaction, the PX domain may also be involved in protein-protein interaction, as in the cases of p40phox, p47phox, and some sorting nexins (SNXs). The PX domain is conserved from yeast to humans and is found in more than 100 proteins. The majority of PX domain-containing proteins are SNXs, which play important roles in endosomal sorting.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  12 SVWVRDPRiQKEDFWHSYIDYEICIHTNSMcftmKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLFFNMnNRQHV 91
Cdd:cd06093    1 SVSIPDYE-KVKDGGKKYVVYIIEVTTQGG----EEWTVYRRYSDFEELHEKLKKKFPGVILPPLPPKKLFGNL-DPEFI 74

                         90
                 ....*....|....*..
gi 564346802  92 DQRRQGLEDFLRKVLQN 108
Cdd:cd06093   75 EERRKQLEQYLQSLLNH 91

The phosphoinositide binding Phox Homology domain of Sorting Nexins 1 and 2; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. This subfamily consists of SNX1, SNX2, and similar proteins. They harbor a Bin/Amphiphysin/Rvs (BAR) domain, which detects membrane curvature, C-terminal to the PX domain. Both domains have been shown to determine the specific membrane-targeting of SNX1. SNX1 and SNX2 are components of the retromer complex, a membrane coat multimeric complex required for endosomal retrieval of lysosomal hydrolase receptors to the Golgi. The retromer consists of a cargo-recognition subcomplex and a subcomplex formed by a dimer of sorting nexins (SNX1 and/or SNX2), which ensures effcient cargo sorting by facilitating proper membrane localization of the cargo-recognition subcomplex.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  28 SYIDYEICIHTNSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLF--FNMNNRqHVDQRRQGLEDFLRKV 105
Cdd:cd06859   17 AYVVYRVTTKTNLPDFKKSEFSVLRRYSDFLWLYERLVEKYPGRIVPPPPEKQAVgrFKVKFE-FIEKRRAALERFLRRI 95

                 ...
gi 564346802 106 LQN 108
Cdd:cd06859   96 AAH 98

The phosphoinositide binding Phox Homology domain of Sorting Nexin 3; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. SNX3 associates with early endosomes through a PX domain-mediated interaction with phosphatidylinositol-3-phosphate (PI3P). It associates with the retromer complex, a membrane coat multimeric complex required for endosomal retrieval of lysosomal hydrolase receptors to the Golgi, and functions as a cargo-specific adaptor for the retromer. SNX3 is required for the formation of multivesicular bodies, which function as transport intermediates to late endosomes. It also promotes cell surface expression of the amiloride-sensitive epithelial Na+ channel (ENaC), which is critical in sodium homeostasis and maintenance of extracellular fluid volume.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  29 YIDYEICIHTNSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVqLPELPSKNLFFNMNNR--------QHVDQRRQGLED 100
Cdd:cd07293   19 FTTYEIRLKTNLPIFKLKESTVRRRYSDFEWLRSELERESKVV-VPPLPGKALFRQLPFRgddgifddSFIEERKQGLEQ 97

                 ....*
gi 564346802 101 FLRKV 105
Cdd:cd07293   98 FLNKV 102

The phosphoinositide binding Phox Homology domain of Sorting Nexin 3 and related proteins; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. This subfamily is composed of SNX3, SNX12, and fungal Grd19. Grd19 is involved in the localization of late Golgi membrane proteins in yeast. SNX3/Grp19 associates with the retromer complex, a membrane coat multimeric complex required for endosomal retrieval of lysosomal hydrolase receptors to the Golgi, and functions as a cargo-specific adaptor for the retromer.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  29 YIDYEICIHTNSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVqLPELPSKNLFFNMNNR--------QHVDQRRQGLED 100
Cdd:cd06894   19 FTDYEVRMRTNLPVFKKKESSVRRRYSDFEWLRSELERDSKIV-VPPLPGKALKRQLPFRgddgifeeEFIEERRKGLET 97

                 ....*
gi 564346802 101 FLRKV 105
Cdd:cd06894   98 FINKV 102

The phosphoinositide binding Phox Homology domain of the fungal protein YPT35; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions such as cell signaling, vesicular trafficking, protein sorting, and lipid modification, among others. This subfamily is composed of YPT35 proteins from the fungal subkingdom Dikarya. The PX domain is involved in targeting of proteins to PI-enriched membranes, and may also be involved in protein-protein interaction. The PX domain of YPT35 binds to phosphatidylinositol 3-phosphate (PI3P). It also serves as a protein interaction domain, binding to members of the Yip1p protein family, which localize to the ER and Golgi. YPT35 is mainly associated with endosomes and together with Yip1p proteins, may be involved in a specific function in the endocytic pathway.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  28 SYIDYEICIHTNSMCFTMKTScvRRRYREFVWLRQRLQS---NALLVQLPELPSKNLFF----NMNnRQHVDQRRQGLED 100
Cdd:cd07280   21 AYVVWKITIETKDLIGSSIVA--YKRYSEFVQLREALLDefpRHKRNEIPQLPPKVPWYdsrvNLN-KAWLEKRRRGLQY 97

                 ....*...
gi 564346802 101 FLRKVLQN 108
Cdd:cd07280   98 FLNCVLLN 105

The phosphoinositide binding Phox Homology domain of Sorting Nexin 12; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. Some SNXs are localized in early endosome structures such as clathrin-coated pits, while others are located in late structures of the endocytic pathway. The specific function of SNX12 has yet to be elucidated.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 564346802  29 YIDYEICIHTNSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVqLPELPSKNLFFNMNNR--------QHVDQRRQGLED 100
Cdd:cd07294   21 FTTYEVRMRTNLPIFKLKESCVRRRYSDFEWLKNELERDSKIV-VPPLPGKALKRQLPFRgdegifeeSFIEERRQGLEQ 99

                 ....*
gi 564346802 101 FLRKV 105
Cdd:cd07294  100 FINKI 104

The phosphoinositide binding Phox Homology domain of yeast Atg24p, an autophagic degradation protein; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. The yeast Atg24p is a sorting nexin (SNX) which is involved in membrane fusion events at the vacuolar surface during pexophagy. This is facilitated via binding of Atg24p to phosphatidylinositol 3-phosphate (PI3P) through its PX domain. SNXs make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway.

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gi 564346802  15 VRDPRIQKEDFWHSYIDYEICIHTNSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSK-NLFFNMNNRQH--- 90
Cdd:cd06863    5 VSDPQKELDGSSDTYISYLITTKTNLPSFSRKEFKVRRRYSDFVFLHECLSNDFPACVVPPLPDKhRLEYITGDRFSpef 84

                         90
                 ....*....|....*..
gi 564346802  91 VDQRRQGLEDFLRKVLQ 107
Cdd:cd06863   85 ITRRAQSLQRFLRRISL 101

The phosphoinositide binding Phox Homology domain of Sorting Nexin 8 and yeast Mvp1p; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. Some SNXs are localized in early endosome structures such as clathrin-coated pits, while others are located in late structures of the endocytic pathway. SNX8 and the yeast counterpart Mvp1p are involved in sorting and delivery of late-Golgi proteins, such as carboxypeptidase Y, to vacuoles.

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gi 564346802  22 KEDFWHSYIDYEIcihTNSMcftmKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLFFNMnNRQHVDQRRQGLEDF 101
Cdd:cd06866   11 KKGLFLKHVEYEV---SSKR----FKSTVYRRYSDFVWLHEYLLKRYPYRMVPALPPKRIGGSA-DREFLEARRRGLSRF 82

                 ....
gi 564346802 102 LRKV 105
Cdd:cd06866   83 LNLV 86

The phosphoinositide binding Phox Homology domain of SNARE proteins from fungi; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions such as cell signaling, vesicular trafficking, protein sorting, and lipid modification, among others. This subfamily is composed of fungal proteins similar to Saccharomyces cerevisiae Vam7p. They contain an N-terminal PX domain and a C-terminal SNARE domain. The SNARE (Soluble NSF attachment protein receptor) family of proteins are integral membrane proteins that serve as key factors for vesicular trafficking. Vam7p is anchored at the vacuolar membrane through the specific interaction of its PX domain with phosphatidylinositol-3-phosphate (PI3P) present in bilayers. It plays an essential role in vacuole fusion. The PX domain is involved in targeting of proteins to PI-enriched membranes, and may also be involved in protein-protein interaction.

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gi 564346802  50 VRRRYREFVWLRQRLQSNALLVQLPELPSKNLFFNMNNRQHV-DQRRQGLEDFLRKVL 106
Cdd:cd06897   31 VSRRYSEFVALHKQLESEVGIEPPYPLPPKSWFLSTSSNPKLvEERRVGLEAFLRALL 88

The phosphoinositide binding Phox Homology domain of Sorting Nexin 19; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. SNX19 contains an N-terminal PXA domain, a central PX domain, and a C-terminal domain that is conserved in some SNXs. These domains are also found in SNX13 and SNX14, which also contain a regulator of G protein signaling (RGS) domain in between the PXA and PX domains. SNX19 interacts with IA-2, a major autoantigen found in type-1 diabetes. It inhibits the conversion of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] to PI(3,4,5)P3, which leads in the decrease of protein phosphorylation in the Akt signaling pathway, resulting in apoptosis. SNX19 may also be implicated in coronary heart disease and thyroid oncocytic tumors.

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gi 564346802  39 NSMCFTMKTSCVRRRYREFVWLRQRLQSNALLVQ----------LPELPSKNLffnmnNRQHVDQRRQGLEDFLRKV 105
Cdd:cd06893   42 AASEQPLATHTVNRRFREFLTLQTRLEENPKFRKimnvkgppkrLFDLPFGNM-----DKDKIEARRGLLETFLRQL 113

The phosphoinositide binding Phox Homology domain of Modulator of Na,K-ATPase; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions such as cell signaling, vesicular trafficking, protein sorting, and lipid modification, among others. MONaKA (Modulator of Na,K-ATPase) binds the plasma membrane ion transporter, Na,K-ATPase, and modulates its enzymatic and ion pump activities. It modulates brain Na,K-ATPase and may be involved in regulating electrical excitability and synaptic transmission. MONaKA contains an N-terminal PX domain and a C-terminal catalytic kinase domain. The PX domain interacts with PIs and plays a role in targeting proteins to PI-enriched membranes.

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gi 564346802  50 VRRRYREFVWLRQRLQSNALlvQLPeLPSKNLFFNMnNRQHVDQRRQGLEDFLRKVLQN 108
Cdd:cd06871   40 VIRRYNDFDLLNASLQISGI--SLP-LPPKKLIGNM-DREFIAERQQGLQNYLNVILMN 94

The phosphoinositide binding Phox Homology domain of Sorting Nexin 27; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. SNX27 contains an N-terminal PDZ domain followed by a PX domain and a Ras-Associated (RA) domain. It binds G protein-gated potassium (Kir3) channels, which play a role in neuronal excitability control, through its PDZ domain. SNX27 downregulates Kir3 channels by promoting their movement in the endosome, reducing surface expression and increasing degradation. SNX27 also associates with 5-hydroxytryptamine type 4 receptor (5-HT4R), cytohesin associated scaffolding protein (CASP), and diacylglycerol kinase zeta, and may play a role in their intracellular trafficking and endocytic recycling. The SNX27 PX domain preferentially binds to phosphatidylinositol-3-phosphate (PI3P) and is important for targeting to the early endosome.

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gi 564346802  52 RRYREFVWLRQRLQSNALLVQLPELPSKNLFfnMNNRQHVDQRRQGLEDFLRKV 105
Cdd:cd06886   36 RRYREFANLHQNLKKEFPDFQFPKLPGKWPF--SLSEQQLDARRRGLEQYLEKV 87

The phosphoinositide binding Phox Homology domain of fungal Sorting Nexins 41 and 42; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. Some SNXs are localized in early endosome structures such as clathrin-coated pits, while others are located in late structures of the endocytic pathway. SNX41 and SNX42 (also called Atg20p) form dimers with SNX4, and are required in protein recycling from the sorting endosome (post-Golgi endosome) back to the late Golgi in yeast.

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gi 564346802  28 SYIDYEIcihtnsmcfTMKTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLFF--------NMNNRQHVDQRRQGLE 99
Cdd:cd06867   17 SYIVYVI---------RLGGSEVKRRYSEFESLRKNLTRLYPTLIIPPIPEKHSLKdyakkpskAKNDAKIIERRKRMLQ 87

                 ....*....
gi 564346802 100 DFLRKVLQN 108
Cdd:cd06867   88 RFLNRCLQH 96

The phosphoinositide binding Phox Homology domain of Sorting Nexin 14; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. Sorting nexins (SNXs) make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway. SNX14 may be involved in recruiting other proteins to the membrane via protein-protein and protein-ligand interaction. It is expressed in the embryonic nervous system of mice, and is co-expressed in the motoneurons and the anterior pituary with Islet-1. SNX14 shows a similar domain architecture as SNX13, containing an N-terminal PXA domain, a regulator of G protein signaling (RGS) domain, a PX domain, and a C-terminal domain that is conserved in some SNXs.

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                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 564346802  49 CVRRRYREFVWLRQRLQSNALLVQLPELPSKNlFFNMNNRQHVDQRRQGLEDFLRKVLQ 107
Cdd:cd06877   45 SVLRRYNEFYVLESKLTEFHGEFPDAPLPSRR-IFGPKSYEFLESKREIFEEFLQKLLQ 102

The phosphoinositide binding Phox Homology domain of yeast MDM1p; The PX domain is a phosphoinositide binding (PI) module present in many proteins with diverse functions such as cell signaling, vesicular trafficking, protein sorting, and lipid modification, among others. Yeast MDM1p is a filament-like protein localized in punctate structures distributed throughout the cytoplasm. It plays an important role in nuclear and mitochondrial transmission to daughter buds. Members of this subfamily show similar domain architectures as some sorting nexins (SNXs). Some members are similar to SNX19 in that they contain an N-terminal PXA domain, a central PX domain, and a C-terminal domain that is conserved in some SNXs. Others are similar to SNX13 and SNX14, which also harbor these three domains as well as a regulator of G protein signaling (RGS) domain in between the PXA and PX domains. SNXs make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. The PX domain of SNXs binds PIs and targets the protein to PI-enriched membranes. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 564346802  50 VRRRYREFVWLRQRLQSNALLVQLPELPSK-NLFFNMNNRQHVDQRRQGLEDFLRKVLQ 107
Cdd:cd06876   59 VARRYSEFLELHKYLKKRYPGVLKLDFPQKrKISLKYSKTLLVEERRKALEKYLQELLK 117

The phosphoinositide binding Phox Homology domain of the Imidazoline Receptor Antisera-Selected; The PX domain is a phosphoinositide binding (PI) module present in many proteins with diverse functions such as cell signaling, vesicular trafficking, protein sorting, and lipid modification, among others. Imidazoline Receptor Antisera-Selected (IRAS), also called nischarin, contains an N-terminal PX domain, leucine rich repeats, and a predicted coiled coil domain. The PX domain of IRAS binds to phosphatidylinositol-3-phosphate in membranes. Together with the coiled coil domain, it is essential for the localization of IRAS to endosomes. IRAS has been shown to interact with integrin and inhibit cell migration. Its interaction with alpha5 integrin causes a redistribution of the receptor from the cell surface to endosomal structures, suggesting that IRAS may function as a sorting nexin (SNX) which regulates the endosomal trafficking of integrin. SNXs make up the largest group among PX domain containing proteins. They are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in PI-binding specificity and affinity, and the presence of other protein-protein interaction domains, which help determine subcellular localization and specific function in the endocytic pathway.

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gi 564346802  15 VRDPRIQKEDfwhSYIDYEICIHTNSMCFTmktscVRRRYREFVWLRQRL-QSNALLVQLpeLPSKNLFFNMNnRQHVDQ 93
Cdd:cd06875    6 IRIPSAETVE---GYTVYIIEVKVGSVEWT-----VKHRYSDFAELHDKLvAEHKVDKDL--LPPKKLIGNKS-PSFVEK 74

                         90
                 ....*....|...
gi 564346802  94 RRQGLEDFLRKVL 106
Cdd:cd06875   75 RRKELEIYLQTLL 87

The phosphoinositide binding Phox Homology Domain of Class II Phosphoinositide 3-Kinases; The PX domain is a phosphoinositide (PI) binding module present in many proteins with diverse functions. The Phosphoinositide 3-Kinase (PI3K) family of enzymes catalyzes the phosphorylation of the 3-hydroxyl group of the inositol ring of phosphatidylinositol. PI3Ks play an important role in a variety of fundamental cellular processes, including cell motility, the Ras pathway, vesicle trafficking and secretion, immune cell activation and apoptosis. They are also involved in the regulation of clathrin-mediated membrane trafficking as well as ATP-dependent priming of neurosecretory granule exocytosis. PI3Ks are divided into three main classes (I, II, and III) based on their substrate specificity, regulation, and domain structure. Class II PI3Ks preferentially use PI as a substrate to produce PI3P, but can also phosphorylate PI4P to produce PI(3,4)P2. They function as monomers and do not associate with any regulatory subunits. Class II enzymes contain an N-terminal Ras binding domain, a lipid binding C2 domain, a PI3K homology domain of unknown function, an ATP-binding cataytic domain, a PX domain, and a second C2 domain at the C-terminus. Class II PI3Ks include three vertebrate isoforms (alpha, beta, and gamma), the Drosophila PI3K_68D, and similar proteins.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 564346802  46 KTSCVRRRYREFVWLRQRLQSNALLVQLPELPSKNLFFNMNNRQHVDQRRQGLEDFLRKVL 106
Cdd:cd06883   30 EPSFVFRTFEEFQELHNKLSLLFPSLKLPSFPARVVLGRSHIKQVAERRKIELNSYLKSLF 90