The Emp24 complex recruits a specific cargo molecule into endoplasmic reticulum-derived vesicles

Abstract

Members of the yeast p24 family, including Emp24p and Erv25p, form a heteromeric complex re- quired for the efficient transport of selected proteins from the endoplasmic reticulum (ER) to the Golgi ap- paratus. The specific functions and sites of action of this complex are unknown. We show that Emp24p is di- rectly required for efficient packaging of a lumenal cargo protein, Gas1p, into ER-derived vesicles. Emp24p and Erv25p can be directly cross-linked to Gas1p in ER-derived vesicles. Gap1p, which was not af- fected by emp24 mutation, was not cross-linked. These results suggest that the Emp24 complex acts as a cargo receptor in vesicle biogenesis from the ER