Stimulator of interferon genes
Stimulator of interferon genes (STING), also known as transmembrane protein 173 (TMEM173) and MPYS/MITA/ERIS is a protein that in humans is encoded by the STING1 gene. STING plays an important role in innate immunity. STING induces type I interferon production when cells are infected with intracellular pathogens, such as viruses, mycobacteria and intracellular parasites. Type I interferon, mediated by STING, protects infected cells and nearby cells from local infection by binding to the same cell that secretes it (autocrine signaling) and nearby cells (paracrine signaling.) It thus plays an important role, for instance, in controlling norovirus infection. STING works as both a direct cytosolic DNA sensor (CDS) and an adaptor protein in Type I interferon signaling through different molecular mechanisms. It has been shown to activate downstream transcription factors STAT6 and IRF3 through TBK1, which are responsible for antiviral response and innate immune response against intracellular pathogen. Structure Amino acids 1–379 of human STING include the 4 transmembrane regions (TMs) and a C-terminal domain. The C-terminal domain (CTD: amino acids 138–379) contains the dimerization domain (DD) and the carboxy-terminal tail (CTT: amino acids 340–379). The STING forms a symmetrical dimer in the cell. STING dimer resembles a butterfly, with a