UNIPROT #

Q86WV6

PROTEIN NAME

Stimulator of interferon genes protein

GENE NAME

STING1

SYNONYMS

hSTING, ERIS, hMITA, TMEM173, ERIS, MITA, STING

SEQUENCE SIMILARITIES

Belongs to the STING family.

TISSUE SPECIFICITY

Ubiquitously expressed. Expressed in skin endothelial cells, alveolar type 2 pneumocytes, bronchial epithelium and alveolar macrophages.

POST-TRANSLATIONAL MODIFICATION

Phosphorylation by TBK1 leads to activation and production of IFN-beta. Following cyclic nucleotide (c-di-GMP or cGAMP)-binding, activation and translocation from the endoplasmic reticulum, STING1 is phosphorylated by TBK1 at Ser-366 in the pLxIS motif. The phosphorylated pLxIS motif constitutes an IRF3-binding motif, leading to recruitment of the transcription factor IRF3 to induce type-I interferons and other cytokines. Phosphorylated on tyrosine residues upon MHC-II aggregation (By similarity).; Ubiquitinated. Ubiquitinated via 'Lys-63'-linked ubiquitin chains in response to double-stranded DNA treatment, leading to relocalization to autophagosomes and subsequent degradation; this process is dependent on SQSTM1 (By similarity). 'Lys-63'-linked ubiquitination mediated by TRIM56 at Lys-150 promotes homodimerization and recruitment of the antiviral kinase TBK1 and subsequent production of IFN-beta. 'Lys-48'-linked polyubiquitination at Lys-150 occurring after viral infection is mediated by RNF5 and leads to proteasomal degradation. 'Lys-11'-linked polyubiquitination at Lys-150 by RNF26 leads to stabilize STING1: it protects STING1 from RNF5-mediated 'Lys-48'-linked polyubiquitination.

SUBCELLULAR LOCATION

Endoplasmic reticulum membrane; Multi-pass membrane protein. Cytoplasm, perinuclear region. Endoplasmic reticulum-Golgi intermediate compartment membrane; Multi-pass membrane protein; Multi-pass membrane protein; Multi-pass membrane protein.

FUNCTION

Facilitator of innate immune signaling that acts as a sensor of cytosolic DNA from bacteria and viruses and promotes the production of type I interferon (IFN-alpha and IFN-beta). Innate immune response is triggered in response to non-CpG double-stranded DNA from viruses and bacteria delivered to the cytoplasm. Acts by binding cyclic dinucleotides: recognizes and binds cyclic di-GMP (c-di-GMP), a second messenger produced by bacteria, and cyclic GMP-AMP (cGAMP), a messenger produced by CGAS in response to DNA virus in the cytosol. Upon binding of c-di-GMP or cGAMP, STING1 oligomerizes, translocates from the endoplasmic reticulum and is phosphorylated by TBK1 on the pLxIS motif, leading to recruitment and subsequent activation of the transcription factor IRF3 to induce expression of type I interferon and exert a potent anti-viral state. In addition to promote the production of type I interferons, plays a direct role in autophagy. Following cGAMP-binding, STING1 buds from the endoplasmic reticulum into COPII vesicles, which then form the endoplasmic reticulum-Golgi intermediate compartment (ERGIC). The ERGIC serves as the membrane source for WIPI2 recruitment and LC3 lipidation, leading to formation of autophagosomes that target cytosolic DNA or DNA viruses for degradation by the lysosome. The autophagy- and interferon-inducing activities can be uncoupled and autophagy induction is independent of TBK1 phosphorylation. Autophagy is also triggered upon infection by bacteria: following c-di-GMP-binding, which is produced by live Gram-positive bacteria, promotes reticulophagy (By similarity). Exhibits 2',3' phosphodiester linkage-specific ligand recognition: can bind both 2'-3' linked cGAMP (2'-3'-cGAMP) and 3'-3' linked cGAMP but is preferentially activated by 2'-3' linked cGAMP. The preference for 2'-3'-cGAMP, compared to other linkage isomers is probably due to the ligand itself, whichs adopts an organized free-ligand conformation that resembles the STING1-bound conformation and pays low energy costs in changing into the active conformation. May be involved in translocon function, the translocon possibly being able to influence the induction of type I interferons. May be involved in transduction of apoptotic signals via its association with the major histocompatibility complex class II (MHC-II) (By similarity).; (Microbial infection) Antiviral activity is antagonized by oncoproteins, such as papillomavirus (HPV) protein E7 and adenovirus early E1A protein. Such oncoproteins prevent the ability to sense cytosolic DNA.