Guanine nucleotide exchange factor for Rab-3A (RAB3IL1)

Guanine nucleotide exchange factor (GEF) which may activate RAB3A, a GTPase that regulates synaptic vesicle exocytosis. Promotes the exchange of GDP to GTP, converting inactive GDP-bound Rab proteins in their busy GTP-bound form.

May also activate RAB8A and RAB8B. .