The Bin/Amphiphysin/Rvs (BAR) domain of ArfGAP with SH3 domain, ANK repeat and PH domain containing protein 1BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. ASAP1 (ArfGAP with SH3 domain, ANK repeat and PH domain containing protein 1) is also known as DDEF1 (Development and Differentiation Enhancing Factor 1), AMAP1, centaurin beta-4, or PAG2. ASAP1 is an Arf GTPase activating protein (GAP) with activity towards Arf1 and Arf5 but not Arf6 However, it has been shown to bind GTP-Arf6 stably without GAP activity. It has been implicated in cell growth, migration, and survival, as well as in tumor invasion and malignancy. It binds paxillin and cortactin, two components of invadopodia which are essential for tumor invasiveness. It also binds focal adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL. ASAP1 contains an N-terminal BAR domain, followed by a Pleckstrin homology (PH) domain, an Arf GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3 domain. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions. The BAR domain of ASAP1 mediates membrane bending, is essential for function, and autoinhibits GAP activity by interacting with the PH and/or Arf GAP domains.