GTPase-activating protein (GAP) for ARF1 and ARF2. Involved in intracellular vesicular transport. Required for transport from the trans-Golgi network. Implicated in the regulation of retrograde transport from the Golgi to the ER and in actin cytoskeletal organization. May be involved in the maintenance of mitochondrial morphology, possibly through organizing the actin cytoskeleton in Saccharomyces. Found also in the mitochondria and in the perinuclear region. Present with 9560 molecules/cell in log phase SD medium.