New fashions in vesicle coats

Clathrin-coated vesicles are responsible for the sorting and selective transport of membrane proteins within cells. Their coat is composed of the self-assembling-protein clathrin, and adaptor molecules that interact with the vesicle cargo and localize clathrin to membranes. Recently, novel clathrin-like and adaptor-like proteins have been identified. Here, Frances Brodsky discusses various implications of these findings, including the possibility that the novel proteins have expanded functions beyond the conventional roles of their homologues in coated-vesicle formation. In this context, the mechanism by which coats influence vesicle formation is reconsidered.