Small G proteins such as RAP and RAB proteins are the key molecules in intracellular signal transduction and vesicle transportation. A novel protein family small G protein signaling modulator (SGSM) consisting of three members SGSM1-3 bind to RAP and RAB family proteins. All three SGSM proteins possess both a RUN domain and a TBC domain. Little is known of the exact function of SGSM3.Synonyms: MAP, Merlin-associated protein, RABGAPLP, RUN and TBC1 domain-containing protein 3, RUTBC3, Rab-GTPase-activating protein-like protein, Small G protein signaling modulator 3