Uncoating of clathrin-coated vesicles in presynaptic terminals: Roles for Hsc70 and auxilin

We have examined the roles of Hsc70 and auxilin in the uncoating of clathri n-coated vesicles (CCVs) during neuronal endocytosis. We identified two pep tides that inhibit the ability of Hsc70 and auxilin to uncoat CCVs in vitro . When injected into nerve terminals, these peptides inhibited both synapti c transmission and CCV uncoating. Mutation of a conserved HPD motif within the J domain of auxilin prevented binding to Hsc70 in vitro and injecting t his mutant protein inhibited CCV uncoating in vivo, demonstrating that the interaction of auxilin with Hsc70 is critical for CCV uncoating. These stud ies establish that auxilin and Hsc70 participate in synaptic vesicle recycl ing in neurons and that an interaction between these proteins is required f or CCV uncoating.