GTPase-activating protein for ARF1 and, to a lesser extent, ARF5. Directly and specifically regulates the adapter protein 3 (AP-3)-dependent trafficking of proteins in the endosomal-lysosomal system. GAP activity stimulated by phosphatidylinositol 3,4,5-trisphosphate (PIP3) and, to a lesser extent, by phosphatidylinositol 4,5-bisphosphate (PIP2). Phosphatidic acid potentiates PIP2 stimulation. Homodimer. Interacts with several subunits of the AP-3 protein complex: AP3M1, AP3S1 and AP3S2. Interacts with GUCY1A3 and GUCY1B3. Associates with the endocytic compartment. Widely expressed. The PH domain mediates AP-3 binding. Phosphorylated on tyrosines. Belongs to the centaurin gamma-like family. A 4-nucleotides insertion of unknown origin disrupts the reading frame. Extended N-terminus. Truncated N-terminus.