The Bin/Amphiphysin/Rvs (BAR) domain of SH3-domain Binding Protein 1
BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. SH3-domain binding protein 1 (SH3BP1 or 3BP-1) is a Rac GTPase activating protein that inhibits Rac-mediated platelet-derived growth factor (PDGF)-induced membrane ruffling. SH3BP1 contains an N-terminal BAR domain followed by a GAP domain for Rho and Rac GTPases and a C-terminal proline-rich domain. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions.