Enables protein transmembrane transporter activity. Involved in anterograde synaptic vesicle transport. Acts upstream of or within several processes, including positive regulation of natural killer cell activation; secretion of lysosomal enzymes; and vesicle organization. Located in cytosol. Part of BLOC-1 complex. Used to study Hermansky-Pudlak syndrome 8. Human ortholog(s) of this gene implicated in Hermansky-Pudlak syndrome 8. Orthologous to human BLOC1S3 (biogenesis of lysosomal organelles complex 1 subunit 3). [provided by Alliance of Genome Resources, Apr 2022]