Organelle-specific signaling of cGAS-STING.

Abstract

Innate immune sensing through cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) surveils cytosolic DNA from invading pathogens or damaged organelles and initiates a spectrum of immune responses. It is well established that upon 2'3'-cyclic GMP-AMP (cGAMP) binding, STING exits the endoplasmic reticulum (ER), traverses the Golgi to trigger interferon programs, and finally reaches lysosomes for signal resolution through degradation, revealing a tightly choreographed itinerary for cytokine-driven immunity. However, emerging studies reveal additional layers of spatiotemporal complexity: ER-resident STING tunes in messenger RNA translation and Ca²⁺ efflux, Golgi-localized STING functions as a proton channel that initiates H⁺-dependent autophagy and transcription factor EB-directed programs for organelle homeostasis, and various mechanisms for metabolic remodeling and cell fate determination. This review synthesizes emerging organelle-specific mechanisms of cGAS-STING, delineates their roles in physiology and disease, and discusses how an organelle-centric perspective may inform selective, context-sensitive immunotherapies.