Rabphilin-3A is a protein that in humans is encoded by the RPH3A gene.

Exocytosis of neurotransmitters and hormones is fundamental to synaptic neurotransmission and cell-cell communication. RAB3A (MIM 179390) is a small G protein that is thought to act at late stages of exocytosis, and RPH3A is a RAB3A effector (Lin et al., 2007 [PubMed 17149709]).[supplied by OMIM, Jul 2008].
Function: Protein transport. Probably involved with Ras-related protein Rab-3A in synaptic vesicle traffic and/or synaptic vesicle fusion. Could play a role in neurotransmitter release by regulating membrane flow in the nerve terminal (By similarity).