Involved in synaptic vesicle budding from endosome. Predicted to be located in axon and postsynapse. Predicted to be part of AP-3 adaptor complex. Predicted to be active in endosome; glutamatergic synapse; and terminal bouton. Human ortholog(s) of this gene implicated in Hermansky-Pudlak syndrome. Orthologous to human AP3D1 (adaptor related protein complex 3 subunit delta 1). [provided by Alliance of Genome Resources, Apr 2022]