Description
Innate DNA sensing via the cGAS-STING pathway surveys both microbial invasion and cellular damage, constituting a ubiquitous mechanism for host defense and tissue homeostasis. However, very little is known about the signaling mechanism(s) and physiological impacts downstream of cGAS-STING signaling and independent of the classical TBK1-IRF3-IFN cascade. Here, we identified an unrecognized STING-PERK-eIF2 signaling axis that was specific and controlled cap-dependent translation, a fundamental cellular process. STING, upon activation by 2'3’-cyclic GMP-AMP (cGAMP), robustly bound and directly activated the endoplasmic reticulum (ER)-located kinase PERK, and this process was upstream of IRF3 activation and independent of the unfolded protein response (UPR) and TBK1/IKK. Innate DNA sensing suppressed global translation programs but selectively ensured the activation of some pathways by PERK-mediated eIF2 phosphorylation and the rapid regulation of protein synthesis, enabling translational modulation of immune responses. Notably, the STING-PERK-eIF2 axis is an evolutionarily primitive component of STING-TBKI-IRF3-IFN signaling and is physiologically critical in pulmonary and renal fibrosis as well as in the regulation of cellular senescence. Therefore, these findings establish the first noncanonical pathway of the cGAS-STING mechanism and demonstrate the physiological importance of this STING-triggered selective translation, which we propose as a promising therapeutic target for fibrotic diseases.
Overall Design
HEK293 cells transfected with Vector/STING for two replicates are performed Polysome sequencing.
Curator
xm_li