Small G protein signaling modulator 2 (SGSM2)

Possesses GTPase activator activity towards RAB32, RAB33B and RAB38 (PubMed:26620560, PubMed:21808068).

Regulates the trafficking of melanogenic enzymes TYR, TYRP1 and DCT/TYRP2 to melanosomes in melanocytes by inactivating RAB32 and RAB38.

Inhibits RAB32 and RAB38 activation both directly by boosting their GTPase activity and indirectly by disrupting the RAB9A-HPS4 interaction that's needed for RAB32/38 activation (PubMed:26620560). .