Vacuolar fusion protein MON1 homolog A (Mon1a)

Plays an important role in membrane trafficking through the secretory apparatus. Not included in endocytic trafficking to lysosomes (PubMed:17632513).

Acts in concert with CCZ1, as a guanine exchange factor (GEF) for RAB7, promotes the exchange of GDP to GTP, converting it from an inactive GDP-bound form into an energetic GTP-bound form (By similarity). .