RIG-I (retinoic acid-inducible gene I) is a RIG-I-like receptordsRNAhelicaseenzyme that is encoded (in humans) by the DDX58gene. RIG-I is part of the RIG-I-like receptor family, which also includes MDA5 and LGP2, and functions as a pattern recognition receptor that is a sensor for viruses such as influenza A, Sendai virus, and flavivirus. Certain retroviruses, such as HIV-1, encode a protease that directs RIG-I to the lysosome for degradation, and thereby evade RIG-I mediated signaling. RIG-I typically recognizes short (< 4000 nt) 5′triphosphate uncapped double stranded or single stranded RNA. RIG-I and MDA5 are involved in activating MAVS and triggering an antiviral response. RIG-I is also able to detect non-self 5′-triphosphorylated dsRNA transcribed from AT-rich dsDNA by DNA-dependent RNA polymerase III (Pol III). For many viruses, effective RIG-I-mediated antiviral responses are dependent on functionally active LGP2.
DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases which are implicated in a number of cellular processes involving RNA binding and alteration of RNA secondary structure. RIG-I contains a RNA helicase-DEAD box motifs and a caspase recruitment domain (CARD). RIG-I is involved in viral double-stranded (ds) RNA recognition and the regulation of immune response.
^Pichlmair A, Schulz O, Tan CP, Näslund TI, Liljeström P, Weber F, Reis e Sousa C (Nov 2006). "RIG-I-mediated antiviral responses to single-stranded RNA bearing 5'-phosphates". Science. 314 (5801): 997–1001. doi:10.1126/science.1132998. PMID17038589.
^Yoneyama M, Kikuchi M, Natsukawa T, Shinobu N, Imaizumi T, Miyagishi M, Taira K, Akira S, Fujita T (Jul 2004). "The RNA helicase RIG-I has an essential function in double-stranded RNA-induced innate antiviral responses". Nature Immunology. 5 (7): 730–7. doi:10.1038/ni1087. PMID15208624.
Imaizumi T, Aratani S, Nakajima T, Carlson M, Matsumiya T, Tanji K, Ookawa K, Yoshida H, Tsuchida S, McIntyre TM, Prescott SM, Zimmerman GA, Satoh K (Mar 2002). "Retinoic acid-inducible gene-I is induced in endothelial cells by LPS and regulates expression of COX-2". Biochemical and Biophysical Research Communications. 292 (1): 274–9. doi:10.1006/bbrc.2002.6650. PMID11890704.
Cui XF, Imaizumi T, Yoshida H, Borden EC, Satoh K (Jun 2004). "Retinoic acid-inducible gene-I is induced by interferon-gamma and regulates the expression of interferon-gamma stimulated gene 15 in MCF-7 cells". Biochemistry and Cell Biology. 82 (3): 401–5. doi:10.1139/o04-041. PMID15181474.
Yoneyama M, Kikuchi M, Natsukawa T, Shinobu N, Imaizumi T, Miyagishi M, Taira K, Akira S, Fujita T (Jul 2004). "The RNA helicase RIG-I has an essential function in double-stranded RNA-induced innate antiviral responses". Nature Immunology. 5 (7): 730–7. doi:10.1038/ni1087. PMID15208624.
Imaizumi T, Yagihashi N, Hatakeyama M, Yamashita K, Ishikawa A, Taima K, Yoshida H, Inoue I, Fujita T, Yagihashi S, Satoh K (Jul 2004). "Expression of retinoic acid-inducible gene-I in vascular smooth muscle cells stimulated with interferon-gamma". Life Sciences. 75 (10): 1171–80. doi:10.1016/j.lfs.2004.01.030. PMID15219805.
Imaizumi T, Yagihashi N, Hatakeyama M, Yamashita K, Ishikawa A, Taima K, Yoshida H, Yagihashi S, Satoh K (Aug 2004). "Upregulation of retinoic acid-inducible gene-I in T24 urinary bladder carcinoma cells stimulated with interferon-gamma". The Tohoku Journal of Experimental Medicine. 203 (4): 313–8. doi:10.1620/tjem.203.313. PMID15297736.
Imaizumi T, Hatakeyama M, Yamashita K, Yoshida H, Ishikawa A, Taima K, Satoh K, Mori F, Wakabayashi K (2004). "Interferon-gamma induces retinoic acid-inducible gene-I in endothelial cells". Endothelium. 11 (3–4): 169–73. doi:10.1080/10623320490512156. PMID15370293.
Sakaki H, Imaizumi T, Matsumiya T, Kusumi A, Nakagawa H, Kubota K, Nishi N, Nakamura T, Hirashima M, Satoh K, Kimura H (Feb 2005). "Retinoic acid-inducible gene-I is induced by interleukin-1beta in cultured human gingival fibroblasts". Oral Microbiology and Immunology. 20 (1): 47–50. doi:10.1111/j.1399-302X.2005.00181.x. PMID15612946.
Li K, Chen Z, Kato N, Gale M, Lemon SM (Apr 2005). "Distinct poly(I-C) and virus-activated signaling pathways leading to interferon-beta production in hepatocytes". The Journal of Biological Chemistry. 280 (17): 16739–47. doi:10.1074/jbc.M414139200. PMID15737993.
Yoneyama M, Kikuchi M, Matsumoto K, Imaizumi T, Miyagishi M, Taira K, Foy E, Loo YM, Gale M, Akira S, Yonehara S, Kato A, Fujita T (Sep 2005). "Shared and unique functions of the DExD/H-box helicases RIG-I, MDA5, and LGP2 in antiviral innate immunity". Journal of Immunology. 175 (5): 2851–8. doi:10.4049/jimmunol.175.5.2851. PMID16116171.
Seth RB, Sun L, Ea CK, Chen ZJ (Sep 2005). "Identification and characterization of MAVS, a mitochondrial antiviral signaling protein that activates NF-kappaB and IRF 3". Cell. 122 (5): 669–82. doi:10.1016/j.cell.2005.08.012. PMID16125763.
Kawai T, Takahashi K, Sato S, Coban C, Kumar H, Kato H, Ishii KJ, Takeuchi O, Akira S (Oct 2005). "IPS-1, an adaptor triggering RIG-I- and Mda5-mediated type I interferon induction". Nature Immunology. 6 (10): 981–8. doi:10.1038/ni1243. PMID16127453.
Xu LG, Wang YY, Han KJ, Li LY, Zhai Z, Shu HB (Sep 2005). "VISA is an adapter protein required for virus-triggered IFN-beta signaling". Molecular Cell. 19 (6): 727–40. doi:10.1016/j.molcel.2005.08.014. PMID16153868.
Meylan E, Curran J, Hofmann K, Moradpour D, Binder M, Bartenschlager R, Tschopp J (Oct 2005). "Cardif is an adaptor protein in the RIG-I antiviral pathway and is targeted by hepatitis C virus". Nature. 437 (7062): 1167–72. doi:10.1038/nature04193. PMID16177806.