Component of the AP-4 complex, a novel type of clathrin-or non-clathrin-associated protein coat involved in targeting proteins from the trans-Golgi network(TGN) to the endosomal-lysosomal system. Plays a role in the intracellular trafficking of APP from the trans-Golgi network(TGN) to endosomes, and thereby inhibits amyloidogenic processing of APP.
