REGULATION OF NEUROTRANSMITTER RELEASE KINETICS BY NSF

NSF (N-ethylmaleimide-sensitive factor) is an adenosine triphosphatase (ATPase) that contributes to a protein complex essential for membrane fusion. The synaptic function of this protein was investigated by inj ecting, into the giant presynaptic terminal of squid, peptides that in hibit the ATPase activity of NSF stimulated by the soluble NSF attachm ent protein (SNAP). These peptides reduced the amount and slowed the k inetics of neurotransmitter release as a result of actions that requir ed vesicle turnover and occurred at a step subsequent to vesicle docki ng. These results define NSF as an essential participant in synaptic v esicle exocytosis that regulates the kinetics of neurotransmitter rele ase and, thereby, the integrative properties of synapses.