Background:

IC50: about 20 μM for exocytosis

Exo1 is a chemical inhibitor of the exocytic pathway.

The development of a cellular organism is mainly controlled at the transcriptional level but it was also shown to require the transport of membrane and proteins via the exocytic pathway to the plasma membrane and the extracellular medium.

In vitro: A Previous study using phenotypic screen to search for drug-like molecules that could interfere with specific steps in membrane traffic. Screening resulted in the identification of Exo1, which could induce a rapid collapse of the Golgi to the endoplasmic reticulum, therefore inhibiting the traffic emanating from the endoplasmic reticulum acutely. In addition, similar to Brefeldin A (BFA), Exo1 could induce the quick release of ADP-ribosylation factor (ARF) 1 from Golgi membranes but had minimal effect on the organization of the trans-Golgi network. These data suggested that Exo1 acted by a different mechanism from BFA. However, unlike BFA, Exo1 could not induce the ADP-ribosylation of CtBPBars50 and could not interfere with the activity of guanine nucleotide exchange factors neither. Thererfore, Exo1 allowed the fatty acid exchange activity of Bars50 to be distinguished from ARF1 activity [1].

In vivo: Currently, there is no animal data reported.

Clinical trial: Up to now, Exo1 is still in the preclinical development stage.

Reference:
[1] Feng Y,Yu S,Lasell TK,Jadhav AP,Macia E,Chardin P,Melancon P,Roth M,Mitchison T,Kirchhausen T.  Exo1: a new chemical inhibitor of the exocytic pathway. Proc Natl Acad Sci U S A.2003 May 27;100(11):6469-74.