Predicted to enable GTP-dependent protein binding activity and protein phosphatase binding activity. Involved in anterograde synaptic vesicle transport and synaptic vesicle budding from endosome. Acts upstream of or within with a negative effect on mRNA transcription by RNA polymerase II and regulation of catalytic activity. Acts upstream of or within several processes, including animal organ development; establishment of protein localization to organelle; and vesicle organization. Predicted to be located in trans-Golgi network. Predicted to be part of AP-3 adaptor complex and clathrin adaptor complex. Used to study Hermansky-Pudlak syndrome 2 and platelet storage pool deficiency. Human ortholog(s) of this gene implicated in Hermansky-Pudlak syndrome; Hermansky-Pudlak syndrome 2; interstitial lung disease; neutropenia; and pulmonary fibrosis. Orthologous to human AP3B1 (adaptor related protein complex 3 subunit beta 1). [provided by Alliance of Genome Resources, Apr 2022]