Protein involved in various processes, such as stress granule formation and innate immunity. Plays an essential role in stress granule formation. Stress granules are membraneless compartments that store mRNAs and proteins, such as stalled translation pre-initiation complexes, in response to stress. Promotes formation of stress granules phase-separated membraneless compartment by undergoing liquid-liquid phase separation (LLPS) upon unfolded RNA-binding: functions as a molecular switch that triggers RNA-dependent LLPS in response to a rise in intracellular free RNA concentrations. Also acts as an ATP- and magnesium-dependent helicase: unwinds DNA/DNA, RNA/DNA, and RNA/RNA substrates with comparable efficiency. Acts unidirectionally by moving in the 5' to 3' direction along the bound single-stranded DNA. Unwinds preferentially partial DNA and RNA duplexes having a 17 bp annealed portion and either a hanging 3' tail or hanging tails at both 5'- and 3'-ends. Plays an essential role in innate immunity by promoting CGAS and RIGI activity. Participates in the DNA-triggered cGAS/STING pathway by promoting the DNA binding and activation of CGAS. Triggers the condensation of cGAS, a process probably linked to the formation of membrane-less organelles.Enhances also RIGI-induced type I interferon production probably by helping RIGI at sensing pathogenic RNA. May also act as a phosphorylation-dependent sequence-specific endoribonuclease in vitro: Cleaves exclusively between cytosine and adenine and cleaves MYC mRNA preferentially at the 3'-UTR.
Subcellular locations: Cytoplasm, Cytosol, Perikaryon, Cytoplasm, Stress granule, Nucleus
Cytoplasmic in proliferating cells, can be recruited to the plasma membrane in exponentially growing cells. Cytosolic and partially nuclear in resting cells. Recruited to stress granules in response to arsenite treatment. The unphosphorylated form is recruited to stress granules. HRAS signaling contributes to this process by regulating G3BP dephosphorylation.