Probable GTPase-activating protein which stimulates the GTP hydrolysis rate by GYP5 of YPT1 and SEC4. Involved in ER to Golgi trafficking and polarized exocytosis. Interacts with GYP5 and RVS167. Is part of SEC4-containing complexes. Present with 2010 molecules/cell in log phase SD medium. Belongs to the GYP5 family.