Component of the BLOC-1 complex, a complex that is required for normal biogenesis of lysosome-related organelles (LRO), such as platelet dense granules and melanosomes (By similarity). In concert with the AP-3 complex, the BLOC-1 complex is required to target membrane protein cargos into vesicles assembled at cell bodies for delivery into neurites and nerve terminals (PubMed:16760431, PubMed:21998198). The BLOC-1 complex, in association with SNARE proteins, is also proposed to be involved in neurite extension (PubMed:19546860). As part of the BORC complex may play a role in lysosomes movement and localization at the cell periphery. Associated with the cytosolic face of lysosomes, the BORC complex may recruit ARL8B and couple lysosomes to microtubule plus-end-directed kinesin motor (By similarity). Component of the biogenesis of lysosome-related organelles complex 1 (BLOC-1) composed of BLOC1S1, BLOC1S2, BLOC1S3, BLOC1S4, BLOC1S5, BLOC1S6, DTNBP1/BLOC1S7 and SNAPIN/BLOC1S8. Octamer composed of one copy each BLOC1S1, BLOC1S2, BLOC1S3, BLOC1S4, BLOC1S5, BLOC1S6, DTNBP1/BLOC1S7 and SNAPIN/BLOC1S8. Interacts directly with BLOC1S1, BLOC1S3, BLOC1S4, BLOC1S5 and SNAPIN (PubMed:15102850). The BLOC-1 complex associates with the AP-3 protein complex and membrane protein cargos (PubMed:21998198). Component of the BLOC-one-related complex (BORC) which is composed of BLOC1S1, BLOC1S2, BORCS5, BORCS6, BORCS7, BORCS8, KXD1 and SNAPIN (By similarity). Interacts with gamma-tubulin (By similarity). Interacts with IFT57 (PubMed:18188704). Localizes to the centrosomes in a microtubule-dependent manner. Belongs to the BLOC1S2 family. Truncated N-terminus.