Exo1 is a cell-permeable, reversible inhibitor of exocytosis (IC50 = 20 μM). It interferes with protein trafficking and secretion mediated by the Golgi apparatus and endoplasmic reticulum by dissociating the GTPase activator ADP-ribosylation factor (ARF1) from Golgi membranes, which leads to a consequent collapse of the Golgi apparatus.
