Predicted to enable protein dimerization activity. Predicted to contribute to guanyl-nucleotide exchange factor activity. Involved in lipid homeostasis and protein secretion. Acts upstream of or within with a negative effect on gene expression. Acts upstream of or within several processes, including cellular zinc ion homeostasis; positive regulation of natural killer cell activation; and secretion of lysosomal enzymes. Predicted to be located in cytoplasmic vesicle. Predicted to be part of BLOC-3 complex. Used to study Hermansky-Pudlak syndrome 1 and platelet storage pool deficiency. Human ortholog(s) of this gene implicated in Hermansky-Pudlak syndrome 1 and oculocutaneous albinism. Orthologous to human HPS1 (HPS1 biogenesis of lysosomal organelles complex 3 subunit 1). [provided by Alliance of Genome Resources, Apr 2022]