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 2462554796   2 LVWPVPELPGKSTFFGTSDE-FIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQSQ 56
Cdd:cd06898    58 LLIQLPSLPPKNLFGRFNNEgFIEERQQGLQDFLEKVLQTPLLLSDSRLHLFLQTQ 113

The phosphoinositide binding Phox Homology domain of Sorting Nexin 10; 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. SNX10 may be involved in the regulation of endosome homeostasis. Its expression induces the formation of giant vacuoles in mammalian cells.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 2462554796   2 LVWPVPELPGKSTFFGTSDE-FIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQSQ 56
Cdd:cd06898    58 LLIQLPSLPPKNLFGRFNNEgFIEERQQGLQDFLEKVLQTPLLLSDSRLHLFLQTQ 113

PhoX homologous domain, present in p47phox and p40phox; Eukaryotic domain of unknown function present in phox proteins, PLD isoforms, a PI3K isoform.

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                   ....*....|....*....|....*....|....*....|....*....|....*
gi 2462554796    4 WPVPELPGKSTFFGT---SDEFIEKRRQGLQHFLEKVLQSVVLLSDS-QLHLFLQ 54
Cdd:smart00312  51 SILPPLPGKKLFGRLnnfSEEFIEKRRRGLEKYLQSLLNHPELINHSeVVLEFLE 105

The phosphoinositide binding Phox Homology domain of Sorting Nexin 10; 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. SNX10 may be involved in the regulation of endosome homeostasis. Its expression induces the formation of giant vacuoles in mammalian cells.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 2462554796   2 LVWPVPELPGKSTFFGTSDE-FIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQSQ 56
Cdd:cd06898    58 LLIQLPSLPPKNLFGRFNNEgFIEERQQGLQDFLEKVLQTPLLLSDSRLHLFLQTQ 113

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 2462554796   6 VPELPGKSTFFGTSDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQS 55
Cdd:cd06093    57 LPPLPPKKLFGNLDPEFIEERRKQLEQYLQSLLNHPELRNSEELKEFLEL 106

PhoX homologous domain, present in p47phox and p40phox; Eukaryotic domain of unknown function present in phox proteins, PLD isoforms, a PI3K isoform.

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gi 2462554796    4 WPVPELPGKSTFFGT---SDEFIEKRRQGLQHFLEKVLQSVVLLSDS-QLHLFLQ 54
Cdd:smart00312  51 SILPPLPGKKLFGRLnnfSEEFIEKRRRGLEKYLQSLLNHPELINHSeVVLEFLE 105

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 2462554796   6 VPELPGKSTF-------FgtSDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQS 55
Cdd:cd06863    63 VPPLPDKHRLeyitgdrF--SPEFITRRAQSLQRFLRRISLHPVLSQSKILHQFLES 117

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 2462554796   6 VPELPGKS-----TFFGTS----DEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQSQ 56
Cdd:cd06894    62 VPPLPGKAlkrqlPFRGDDgifeEEFIEERRKGLETFINKVAGHPLAQNEKCLHMFLQEE 121

The phosphoinositide binding Phox Homology domain of SNX-like 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. Some SNXs are localized in early endosome structures such as clathrin-coated pits, while others are located in late structures of the endocytic pathway. This subfamily is composed of uncharacterized proteins, predominantly from plants, with similarity to sorting nexins. A few members show a similar domain architecture as a subfamily of sorting nexins, containing a Bin/Amphiphysin/Rvs (BAR) domain, which detects membrane curvature, C-terminal to the PX domain. The PX-BAR structural unit is known to determine specific membrane localization.

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gi 2462554796   6 VPELPGKSTFFGT---SDEFIEKRRQGLQHFLEK-VLQSVVLLSDsQLHLFLQSQ 56
Cdd:cd06865    67 VPPRPDKSVVESQvmqSAEFIEQRRVALEKYLNRlAAHPVIGLSD-ELRVFLTLQ 120

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 2462554796   6 VPELPGKSTFFGTSDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFL 53
Cdd:cd06866    55 VPALPPKRIGGSADREFLEARRRGLSRFLNLVARHPVLSEDELVRTFL 102

The phosphoinositide binding Phox Homology domain of Sorting Nexin 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. SNX2 is a component 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 efficient cargo sorting by facilitating proper membrane localization of the cargo-recognition subcomplex. Similar to SNX1, SNX2 contains a Bin/Amphiphysin/Rvs (BAR) domain, which detects membrane curvature, C-terminal to the PX domain. The PX domain of SNX2 preferentially binds phosphatidylinositol-3-phosphate (PI3P), but not PI(3,4,5)P3. Studies on mice deficient with SNX1 and/or SNX2 suggest that they provide an essential function in embryogenesis and are functionally redundant.

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gi 2462554796   6 VPELPGKSTFFGT----------SDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQS 55
Cdd:cd07282    64 VPPAPEKSIVGMTkvkvgkedssSTEFVEKRRAALERYLQRTVKHPTLLQDPDLRQFLES 123

The phosphoinositide binding Phox Homology domain of fungal Grd19; 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. Grd19 is involved in the localization of late Golgi membrane proteins in yeast. 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 2462554796   6 VPELPGKSTFFGTSDEFIEKRRQGLQHFLEKVLQSVVLLSDSQ-LHLFLQS 55
Cdd:cd07295    63 IPPLPGKIFTNRFSDEVIEERRQGLETFLQSVAGHPLLQTGSKvLAAFLQD 113

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 2462554796   9 LPGKSTFFGTSDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQS 55
Cdd:cd06877    72 LPSRRIFGPKSYEFLESKREIFEEFLQKLLQKPELRGSELLYDFLSP 118

The phosphoinositide binding Phox Homology domain of Sorting Nexin 7; 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. SNX7 harbors a Bin/Amphiphysin/Rvs (BAR) domain, which detects membrane curvature, C-terminal to the PX domain, similar to the sorting nexins SNX1-2, SNX4-6, SNX8, SNX30, and SNX32. Both domains have been shown to determine the specific membrane-targeting of SNX1. The specific function of SNX7 has yet to be elucidated.

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gi 2462554796   6 VPELPGKSTFFGT----SDEFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQSQ 56
Cdd:cd07284    62 IPPLPEKFVMKGMverfNEDFIETRRKALHKFLNRIADHPTLTFNEDFKIFLTAQ 116

The phosphoinositide binding Phox Homology domain of Sorting Nexin 15-like proteins; 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. Members of this subfamily have similarity to sorting nexin 15 (SNX15), which contains an N-terminal PX domain and a C-terminal Microtubule Interacting and Trafficking (MIT) 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. SNX15 plays a role in protein trafficking processes in the endocytic pathway and the trans-Golgi network. The PX domain of SNX15 interacts with the PDGF receptor and is responsible for the membrane association of the protein. Other members of this subfamily contain an additional C-terminal kinase domain, similar to human RPK118, which binds sphingosine kinase and the antioxidant peroxiredoxin-3 (PRDX3). RPK118 may be involved in the transport of proteins such as PRDX3 from the cytoplasm to its site of function in the mitochondria.

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gi 2462554796   5 PVPELPgKSTFFGTSDE-FIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFLQ 54
Cdd:cd06881    66 SFPPFP-KGKYFGRFDAaVIEERRQAILELLDFVGNHPALYQSSAFQQFFE 115

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 2462554796   9 LPGKStFFGTSD-EFIEKRRQGLQHFLEKVLQSVVLLSDSQLHLFL 53
Cdd:cd06871    63 LPPKK-LIGNMDrEFIAERQQGLQNYLNVILMNPILASCLPVKKFL 107

The phosphoinositide binding Phox Homology domain of Sorting Nexins 9 and 18; 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 SNX9, SNX18, and similar proteins. They contain an N-terminal Src Homology 3 (SH3) domain, a PX domain, and a C-terminal Bin/Amphiphysin/Rvs (BAR) domain. 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.

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gi 2462554796   5 PVPELPGKSTFFGTSDEFIEKRRQGLQHFLEKVLQSVVlLSDSQ-LHLFLQSQ 56
Cdd:cd06862    56 AIPPLPEKQVTGRFEEDFIEKRRERLELWMNRLARHPV-LSQSEvFRHFLTCT 107