Regulating synaptic membrane exocytosis protein 1 is a protein that in humans is encoded by the RIMS1 gene.

The protein encoded by this gene is a RAS gene superfamily member that regulates synaptic vesicle exocytosis. The encoded protein may be part of the protein scaffold of the cell. Defects in this gene are a cause of cone-rod dystrophy type 7 (CORD7). Several transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Dec 2009].
Function: Rab effector involved in exocytosis. May act as scaffold protein that regulates neurotransmitter release at the active zone. Essential for maintaining normal probability of neurotransmitter release and for regulating release during short-term synaptic plasticity (By similarity).