RAB EFFECTOR DOMAIN PEPTIDES STIMULATE THE RELEASE OF NEUROTRANSMITTER FROM CELL CULTURED SYNAPSES

The involvement of the small GTP-binding protein rab3A in synaptic transmission was tested by presynaptic microinjection of guanine nucleotides and peptides corresponding to the effector domain of rab3A. When GTPgammaS injection was paired with presynaptic action potentials, the frequency of MIPSCs was increased and the evoked synaptic current was reduced in magnitude. To more specifically manipulate mb proteins, peptides were microinjected. Injection of the peptide rab3AL(33-48) or rab3(29-48) stimulated an increase in the frequency of MIPSC with little effect on action potential evoked synaptic transmission supporting a role for rab proteins in regulating synaptic transmission.