Acts as an A-kinase anchoring protein by binding to the type II regulatory subunit of protein kinase A and anchoring it to the mitochondrion. Also involved in synchronization of mitochondrial fission . Plays a role in the maturation of phagosomes that engulf pathogens, such as S.aureus and M.tuberculosis . Plays an important role in the control of melanin production and melanosome biogenesis . In concert with RAB38, regulates the proper trafficking of melanogenic enzymes TYR, TYRP1 and DCT/TYRP2 to melanosomes in melanocytes (By similarity).
Subcellular locations: Mitochondrion, Mitochondrion outer membrane, Cytoplasmic vesicle, Phagosome, Cytoplasmic vesicle, Phagosome membrane, Melanosome, Melanosome membrane
Recruited to phagosomes containing S.aureus or M.tuberculosis . The BLOC-3 complex, a heterodimer of HPS1 and HPS4 promotes its membrane localization .
Widely expressed with high levels in heart, liver, kidney, bone marrow, testis, colon and fetal lung.