The Bin/Amphiphysin/Rvs (BAR) domain of Sorting Nexin 8
BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. Sorting nexins (SNXs) are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. A subset of SNXs also contain BAR domains. The PX-BAR structural unit determines the specific membrane targeting of SNXs. SNX8 and the yeast counterpart Mvp1p are involved in sorting and delivery of late-Golgi proteins, such as carboxypeptidase Y, to vacuoles. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions.