Fig. 1

STING activation pathways. The endoplasmic reticulum (ER) adaptor STING is activated via recognition of bacteria-secreted 3′-5′ bond cyclic dinucleotides or DNA sensor cGAS-catalyzed 2′-5′ cGAMP. Cytoplasmic DNA, released from DNA viruses or reverse transcribed from the RNA viral genome, can induce direct interaction between STING and DNA sensors (in red) such as DDX41, IFI16, and DAI. Alternatively, RNA viruses also induce the RIG-I dependent MAVS activation which alters mitochondrial dynamics and indirectly induce STING activation. Mitochondrial stress can result in the release of mitochondrial DNA (mtDNA) which also induces DNA sensor activation (not shown) and STING-mediated signalling. RNA polymerase III (RNA Pol III) can convert dsDNA into dsRNA which activates RIG-I/ MAVS axis which has been shown to induce STING activation