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. 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. The BLOC-1 complex, in association with SNARE proteins, is also proposed to be involved in neurite extension. 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. May play a role in cell proliferation. 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. The BLOC-1 complex associates with the AP-3 protein complex and membrane protein cargos. Component of the BLOC-one-related complex (BORC) which is composed of BLOC1S1, BLOC1S2, BORCS5, BORCS6, BORCS7, BORCS8, KXD1 and SNAPIN. Interacts with gamma-tubulin. Interacts with IFT57. Localizes to the centrosomes in a microtubule-dependent manner. Widely expressed. Highly expressed in most brain regions, spinal cord, kidney and ovary. In the brain, expressed in the frontal cortex and the superior thalamic radiation, with the strongest expression in the granule cells of hippocampal CA1, CA3 and dentate gyrus regions. In the spinal cord, mainly expressed in the gray matter. Expression level is high in laminae I-II and V-VI small sensory neurons in the dorsal horn, as well as in the large motor neurons of the ventral horn. Overexpressed in injured nerves. Belongs to the BLOC1S2 family.