RAB3 GTPase Activating Protein Subunit 2 (RAB3GAP2)

Members of the RAB3 protein family are implicated in Ca(2+)-dependent exocytosis. RAB3GAP, which is involved in regulation of RAB3 activity, is a heterodimeric complex consisting a 130-kD catalytic subunit (RAB3GAP1) and a 150-kD noncatalytic subunit (RAB3GAP2). RAB3GAP2 contains 1,393 amino acids. Northern blot analysis detected a 7.5-kb transcript in all human tissues examined. Western blot analysis of subcellular fractionated rat brain detected p150 enriched in the synaptic soluble fraction.p150 did not show GAP activity, and the interaction between p150 and p130 did not alter the activity of p130 or the subcellular distribution of the 2 proteins.RT-PCR ELISA detected highest expression in brain, followed by kidney, ovary, and heart. Intermediate expression was detected in all other tissues examined.