GTPase-activating protein for the ADP ribosylation factor family (Potential). GTPase which may be involved in the degradation of expanded polyglutamine proteins through the ubiquitin-proteasome pathway. GTPase activity is stimulated by oxidative stress. Interacts with PML. Interacts with expanded polyglutamine proteins. In cells upon oxidative stress or in brains of Machado-Joseph disease patients, translocates to PML nuclear bodies. Widely expressed. Belongs to the centaurin gamma-like family.