The ADP-ribosylation factor (ARF) family of small GTP-binding proteins are involved in vesicular transport regulation and in controlling cytoskeletal organization and cell adhesion. The Centaurin GTPase-activating protein family comprise a subset of ARF regulatory molecules that transduce PI 3-kinase activation into coordinated control of ARF-dependent pathways. This family includes ASAP1, ACAP1, ACAP2, AGAP1, ARAP1, ARAP2, Centaurin a1, Centaurin g3 and the recently discovered Centaurin a2. Expressed in a wide variety of tissues such as fat, heart and skeletal muscle, Centaurin a2 is thought to negatively regulate ARF-mediated actin rearrangement by binding activated PI 3-kinase. Although the exact function of Centaurin a2 is not yet known, its high sequence similarity with Centaurin a1 suggests that it may also act as an ARF6 GTPase.
