Adapter protein that regulates and/or fission of intracellular vesicles such as lysosomes (PubMed:11984006, PubMed:25216107). Might regulate trafficking of effectors involved in exocytosis (PubMed:25425525). In cytotoxic T-cells and natural killer (NK) cells, has role in the regulation of size, number and exocytosis of lytic granules (PubMed:26478006). In macrophages and dendritic cells, regulates phagosome maturation by controlling the conversion of early phagosomal compartments into late phagosomes (By similarity). In macrophages and dendritic cells, specifically involved in TLR3- and TLR4-induced production of pro-inflammatory cytokines by regulating the endosomal TLR3- TICAM1/TRIF and TLR4- TICAM1/TRIF signaling pathways (PubMed:27881733). Interacts with CENPJ, LIP8 and ZNF521. Additional isoforms seem to exist. Abundantly expressed in adult and fetal thymus, peripheral blood leukocytes, bone marrow and several regions of the adult brain. The disease is caused by variants affecting the gene represented in this entry. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. LYST mutation db Retina International's Scientific Newsletter LYST mutations