Sorting nexins are a large family of evolutionarily conserved phosphoinositide-binding proteins that have roles in cargo sorting through the endosomal netwrok. Sorting nexins contain at least a PX domain (a phospholipid-binding motif). Some nexins contain a few additional domains. Proteins in the sorting nexin 9 subfamily includes SNX9, SNX18 and SNX33. They are characterised by the presence of an N-terminal SH3 domain , a PX domain that is a phosphoinositide-binding module , and a Bin/Amphiphysin/Rvs (BAR) domain at the C terminus, which allows membrane binding and bending. They are required for progression and completion of mitosis. SNX33 plays a role in maintaining cell shape and cell cycle progression through its interaction with WASp (Wiskott-Aldrich syndrome protein). It interferes with cellular prion protein (PrP) formation by modulation of its shedding. It may also promote the formation of macropinosomes (large endocytic organelles). This entry represents the BAR domain of SNX33. BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions.