Involved in the recruitment of clathrin to the Golgi network and endosomes to form clathrin coated vesicles. Plays a role in the trafficking of clathrin between the Golgi network and endosomes. Binds to membranes enriched in phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P2) and, in association with VPS27, is involved in protein sorting at the multivesicular body (MVB). Interacts with the clathrin adapter GGA2 and the clathrin adapter complex AP-1. Found predominantly on endosomal structures. Present with 8100 molecules/cell in log phase SD medium.