Is predicted to encode a protein with the following domains: Rab3GAP regulatory subunit, C-terminal; Rab3 GTPase-activating protein regulatory subunit N-terminus; Rab3GAP regulatory subunit; Rab3-GAP regulatory subunit, N-terminal; and Rab3 GTPase-activating protein regulatory subunit C-terminus. Is an ortholog of C. elegans rbg-2.