Vacuolar protein sorting-associated protein 5, PX domain (IPR037868)

Short name: PX_Vps5

Overlapping homologous superfamilies

Domain relationships


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 [PMID: 15634208, PMID: 22193161]. 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 [PMID: 25148684, PMID: 22168438, PMID: 12181349].

Vsp5 is the yeast counterpart of human SNX1 and is part of the retromer complex, which functions in the endosome-to-Golgi retrieval of vacuolar protein sorting receptor Vps10, the Golgi-resident membrane protein A-ALP, and endopeptidase Kex2. The PX domain of Vps5 binds phosphatidylinositol-3-phosphate (PI3P). Similar to SNX1, Vps5 contains 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 [PMID: 12181349].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.