A ROLE FOR THE HINGE EAR DOMAIN OF THE BETA-CHAINS IN THE INCORPORATION OF AP COMPLEXES INTO CLATHRIN-COATED PITS AND COATED VESICLES/

The clathrin-associated adaptor protein (AP) complexes drive the polym erization of clathrin in coated pits to form coated vesicles. It has p reviously been shown that the carboxyl-terminal hinge/ear domain of th e beta 2 chain contains a binding site for clathrin and that removal o f this domain from APs or from isolated beta 2 chains abrogates their ability to form clathrin coats in vitro. We show here that the hinge/e ar domain is necessary for efficient incorporation of AP complexes int o coated pits and coated vesicles in cells, a result that is consisten t with the view that the beta chains indeed provide an important inter action between the AP complexes and clathrin.