Function
Probably functions as cargo-recognition protein that couples cytoplasmic vesicles to the transport machinery (PubMed:22940130, PubMed:22275436, PubMed:30174147). Plays a role in hair pigmentation, a process that involves shedding of melanosome-containing vesicles from melanocytes, followed by phagocytosis of the melanosome-containing vesicles by keratinocytes (PubMed:15550542, PubMed:3410303, PubMed:22753477). Functions on melanosomes as receptor for RILP and the complex formed by RILP and DCTN1, and thereby contributes to retrograde melanosome transport from the cell periphery to the center (PubMed:22940130, PubMed:22275436). Overexpression causes accumulation of late endosomes and/or lysosomes at the microtubule organising center (MTOC) at the center of the cell (PubMed:19240024, PubMed:30174147). Probably binds cholesterol and requires the presence of cholesterol in membranes to function in microtubule-mediated retrograde organelle transport (PubMed:30174147). Binds phosphatidylinositol 3-phosphate, phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate and phosphatidylinositol 3,5-bisphosphate, but not phosphatidylinositol 3,4-bisphosphate or phosphatidylinositol 4,5-bisphosphate (PubMed:19240024). Required for normal phagosome clearing and normal activation of lysosomal enzymes in lysosomes from retinal pigment epithelium cells (PubMed:19240024). Required for normal degradation of the lipofuscin component N-retinylidene-N-retinylethanolamine (A2E) in the eye (PubMed:19240024). May function in membrane fusion and regulate the biogenesis of disk membranes of photoreceptor rod cells (Probable).