Acts as a regulator of DDX58/RIG-I and IFIH1/MDA5 mediatedantiviral signaling. Cannot initiate antiviral signaling as it lacksthe CARD domain required for activating MAVS/IPS1-dependent signalingevents. Can have both negative and positive regulatory functionsrelated to DDX58/RIG-I and IFIH1/MDA5 signaling and this role inregulating signaling may be complex and could probably depend oncharacteristics of the infecting virus or target cells, or both. Itsinhibitory action on DDX58/RIG-I signaling may involve the followingmechanisms: competition with DDX58/RIG-I for binding to the viral RNA, binding to DDX58/RIG-I and inhibiting its dimerization and interactionwith MAVS/IPS1, competing with IKBKE in its binding to MAVS/IPS1thereby inhibiting activation of interferon regulatory factor 3 (IRF3). Its positive regulatory role may involve unwinding or strippingnucleoproteins of viral RNA thereby facilitating their recognition byDDX58/RIG-I and IFIH1/MDA5. Involved in the innate immune response tovarious RNA viruses and some DNA viruses such as poxviruses andcoronavirus SARS-CoV-2, and also to the bacterial pathogen Listeriamonocytogenes. Can bind both ssRNA and dsRNA, with ahigher affinity for dsRNA. Shows a preference to 5'-triphosphorylatedRNA, although it can recognize RNA lacking a 5'-triphosphate. [1-11]

MELRSYQWEVIMPALEGKNIIIWLPTGAGKTRAAAYVAKRHLETVDGAKVVVLVNRVHLVTQHGEEFRRMLDGRWTVTTLSGDMGPRAGFGHLARCHDLLICTAELLQMALTSPEEEEHVELTVFSLIVVDECHHTHKDTVYNVIMSQYLELKLQRAQPLPQVLGLTASPGTGGASKLDGAINHVLQLCANLDTWCIMSPQNCCPQLQEHSQQPCKQYNLCHRRSQDPFGDLLKKLMDQIHDHLEMPELSRKFGTQMYEQQVVKLSEAAALAGLQEQRVYALHLRRYNDALLIHDTVRAVDALAALQDFYHREHVTKTQILCAERRLLALFDDRKNELAHLATHGPENPKLEMLEKILQRQFSSSNSPRGIIFTRTRQSAHSLLLWLQQQQGLQTVDIRAQLLIGAGNSSQSTHMTQRDQQEVIQKFQDGTLNLLVATSVAEEGLDIPHCNVVVRYGLLTNEISMVQARGRARADQSVYAFVATEGSRELKRELINEALETLMEQAVAAVQKMDQAEYQAKIRDLQQAALTKRAAQAAQRENQRQQFPVEHVQLLCINCMVAVGHGSDLRKVEGTHHVNVNPNFSNYYNVSRDPVVINKVFKDWKPGGVISCRNCGEVWGLQMIYKSVKLPVLKVRSMLLETPQGRIQAKKWSRVPFSVPDFDFLQHCAENLSDLSLD