cGAS Protein, Mouse

cGAS Protein, a nucleotidyltransferase, plays a pivotal role in innate immunity by catalyzing the formation of cyclic GMP-AMP (2',3'-cGAMP) from ATP and GTP. Acting as a key DNA sensor, cGAS directly binds double-stranded DNA (dsDNA), inducing the synthesis of 2',3'-cGAMP, a second messenger that activates STING1, leading to the production of type-I interferon and triggering immune responses. Recognizing curved long dsDNAs, cGAS acts as a foreign DNA sensor, detecting the presence of DNA from viruses, retroviruses, bacteria, and neutrophil extracellular traps (NETs). Moreover, cGAS responds to endogenous DNA released during cellular stress, contributing to sterile inflammation. It regulates cellular senescence by binding to cytosolic chromatin fragments and participates in the inflammatory response to genome instability and double-stranded DNA breaks. cGAS is also implicated in sensing translation stress, and its activation inhibits homologous recombination repair in response to DNA damage. Human cGAS exhibits species-specific mechanisms of DNA recognition, allowing a more finely tuned response to pathogens.