RIGI
RIGI encodes RIG-I, a cytoplasmic innate immune receptor that senses viral nucleic acids and triggers production of type I interferons and pro-inflammatory cytokines. The protein is also known as DDX58, RIG-1 and RIG1, and belongs to the RLR subfamily of helicases. Browse Assay Genie's current range of RIGI research reagents below, or read on for the biology behind the target.
RIG-I is an innate immune receptor that detects viral nucleic acids in the cytoplasm and activates a signalling cascade leading to type I interferons and pro-inflammatory cytokines. It forms a ribonucleoprotein complex with viral RNA, on which it homo-oligomerises into filaments. This allows recruitment of RNF135, an E3 ubiquitin-protein ligase that amplifies RIG-I-mediated antiviral signalling in an RNA length-dependent manner. Once activated, RIG-I associates with the mitochondrial antiviral signalling protein MAVS (IPS1), which activates the IKK-related kinases TBK1 and IKBKE. These phosphorylate the transcription factors IRF3 and IRF7, driving expression of antiviral genes including IFN-alpha and IFN-beta.
Ligand recognition is specific. Ligands include 5'-triphosphorylated single-stranded and double-stranded RNAs, as well as short dsRNAs. Beyond the 5'-triphosphate, blunt-end base pairing at the 5' end is essential; a 3' overhang at the triphosphate end reduces activity and any 5' overhang abolishes it. RIG-I detects both positive and negative strand RNA viruses, including influenza A and B virus, measles virus, vesicular stomatitis virus, hepatitis C virus, dengue virus, Japanese encephalitis virus and west Nile virus, as well as rotaviruses and reoviruses. It binds SARS-CoV-2 RNAs, an interaction inhibited by m6A RNA modification, and responds to Epstein-Barr virus through dsRNA made from dsDNA by RNA polymerase III. It may also contribute to granulocyte production and differentiation, bacterial phagocytosis and the regulation of cell migration.
The RIGI gene encodes a protein with DEAD-box RNA helicase motifs and a caspase recruitment domain (CARD), and was formerly named DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 or DExD/H-box helicase 58. UniProt records localisation in the cytoplasm, ruffle membrane, cytoskeleton and tight junctions. Mutations in the gene are associated with Singleton-Merten syndrome 2. A mouse ortholog, Rigi, is annotated.
RIG-I senses cytoplasmic viral RNA from many RNA virus families and initiates interferon production, making it central to studies of early antiviral defence.
Signalling runs from RIG-I through MAVS, TBK1, IKBKE and IRF3/IRF7 to IFN-alpha and IFN-beta, providing a defined axis for pathway analysis.
RIG-I discriminates RNA by 5'-triphosphate and blunt-end base pairing, which makes it a model for how innate receptors distinguish viral from self RNA.
Mutations in the RIGI gene are associated with Singleton-Merten syndrome 2, linking RNA sensing to inherited disease.
RIG-I is a cytoplasmic receptor that senses viral RNA and activates signalling through MAVS, TBK1, IKBKE and IRF3/IRF7. This drives transcription of antiviral genes, including IFN-alpha and IFN-beta, and production of pro-inflammatory cytokines.
The protein is called RIG-I, RIG-1 or RIG1, and the gene is also known as DDX58, FLJ13599 and DKFZp434J1111. Earlier names were DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 and DExD/H-box helicase 58. HGNC now uses RNA sensor RIG-I.
Mutations in the RIGI gene are associated with Singleton-Merten syndrome 2. A mouse ortholog, Rigi, is annotated, so mouse models can be used to study its function. Check the datasheet of any product for its validated reactivity.
Other RLR pathway components, interferon regulatory factors, kinases and interferons involved in antiviral innate immune signalling.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O95786; product specifications from Assay Genie datasheets.