Exo1

Description: Exo-1 is a novel and reversible inhibitor of exocytosis which is used as a chemical inhibitor of the exocytic pathway. It acts by activating Golgi ARF 1 (ADP-Ribosylation Factor) GTPase. Exo1 induces a rapid collapse of the Golgi to the endoplasmic reticulum, thus acutely inhibiting the traffic emanating from the endoplasmic reticulum. Like Brefeldin A (BFA), Exo1 induces the rapid release of ADP-ribosylation factor (ARF) 1 from Golgi membranes but has less effect on the organization of the trans-Golgi network. Exo1 acts by a different mechanism from BFA. Unlike BFA, Exo1 does not induce the ADP-ribosylation of CtBP/Bars50 and does not interfere with the activity of guanine nucleotide exchange factors specific for Golgi-based ARFs. Thus, Exo1 allows the fatty acid exchange activity of Bars50 to be distinguished from ARF1 activity in the control of Golgi tubulation.

References: Proc Natl Acad Sci U S A. 2003 May 27; 100(11):6469-74.