Interaction of Rabphilin3 with synaptic vesicles through multiple regions.

Rabphilin3 is a downstream target protein of Rab3A small G protein, implicated in neurotransmitter release. We have previously reported that about 4 molecules of Rabphilin3 are associated with one synaptic vesicle through a vesicle anchoring protein(s). We have shown here that Rabphilin3 interacts with rat synaptic vesicles through at least three regions: the N-terminal region (1-280 amino acids (aa)), the C-terminal region containing the two C2 domains (440-704 aa), and an unidentified region. A model for the interaction of Rabphilin3 with the vesicles is discussed.