6bzh

Structural highlights

Function

RIGI_MOUSE Innate immune receptor that senses cytoplasmic viral nucleic acids and activates a downstream signaling cascade leading to the production of type I interferons and pro-inflammatory cytokines. Forms a ribonucleoprotein complex with viral RNAs on which it homooligomerizes to form filaments. The homooligomerization allows the recruitment of RNF135 an E3 ubiquitin-protein ligase that activates and amplifies the RIG-I-mediated antiviral signaling in an RNA length-dependent manner through ubiquitination-dependent and -independent mechanisms. Upon activation, associates with mitochondria antiviral signaling protein (MAVS/IPS1) that activates the IKK-related kinases TBK1 and IKBKE which in turn phosphorylate the interferon regulatory factors IRF3 and IRF7, activating transcription of antiviral immunological genes including the IFN-alpha and IFN-beta interferons. Ligands include: 5'-triphosphorylated ssRNA and dsRNA and short dsRNA (<1 kb in length). In addition to the 5'-triphosphate moiety, blunt-end base pairing at the 5'-end of the RNA is very essential. Overhangs at the non-triphosphorylated end of the dsRNA RNA have no major impact on its activity. A 3'overhang at the 5'triphosphate end decreases and any 5'overhang at the 5' triphosphate end abolishes its activity. Detects both positive and negative strand RNA viruses including members of the families Paramyxoviridae: Sendai virus (SeV), Rhabdoviridae and Flaviviridae. It also detects rotavirus and orthoreovirus. Also involved in antiviral signaling in response to viruses containing a dsDNA genome. Detects dsRNA produced from non-self dsDNA by RNA polymerase III. May play important roles in granulocyte production and differentiation, bacterial phagocytosis and in the regulation of cell migration.^{[1] [2] [3] [4] [5] [6]}

References

1. ↑ Kato H, Sato S, Yoneyama M, Yamamoto M, Uematsu S, Matsui K, Tsujimura T, Takeda K, Fujita T, Takeuchi O, Akira S. Cell type-specific involvement of RIG-I in antiviral response. Immunity. 2005 Jul;23(1):19-28. PMID:16039576 doi:http://dx.doi.org/S1074-7613(05)00142-1
2. ↑ Kato H, Takeuchi O, Sato S, Yoneyama M, Yamamoto M, Matsui K, Uematsu S, Jung A, Kawai T, Ishii KJ, Yamaguchi O, Otsu K, Tsujimura T, Koh CS, Reis e Sousa C, Matsuura Y, Fujita T, Akira S. Differential roles of MDA5 and RIG-I helicases in the recognition of RNA viruses. Nature. 2006 May 4;441(7089):101-5. Epub 2006 Apr 9. PMID:16625202 doi:http://dx.doi.org/nature04734
3. ↑ Loo YM, Fornek J, Crochet N, Bajwa G, Perwitasari O, Martinez-Sobrido L, Akira S, Gill MA, Garcia-Sastre A, Katze MG, Gale M Jr. Distinct RIG-I and MDA5 signaling by RNA viruses in innate immunity. J Virol. 2008 Jan;82(1):335-45. Epub 2007 Oct 17. PMID:17942531 doi:http://dx.doi.org/10.1128/JVI.01080-07
4. ↑ Schlee M, Roth A, Hornung V, Hagmann CA, Wimmenauer V, Barchet W, Coch C, Janke M, Mihailovic A, Wardle G, Juranek S, Kato H, Kawai T, Poeck H, Fitzgerald KA, Takeuchi O, Akira S, Tuschl T, Latz E, Ludwig J, Hartmann G. Recognition of 5' triphosphate by RIG-I helicase requires short blunt double-stranded RNA as contained in panhandle of negative-strand virus. Immunity. 2009 Jul 17;31(1):25-34. doi: 10.1016/j.immuni.2009.05.008. Epub 2009, Jul 2. PMID:19576794 doi:10.1016/j.immuni.2009.05.008
5. ↑ Ablasser A, Bauernfeind F, Hartmann G, Latz E, Fitzgerald KA, Hornung V. RIG-I-dependent sensing of poly(dA:dT) through the induction of an RNA polymerase III-transcribed RNA intermediate. Nat Immunol. 2009 Oct;10(10):1065-72. doi: 10.1038/ni.1779. Epub 2009 Jul 16. PMID:19609254 doi:10.1038/ni.1779
6. ↑ Chiu YH, Macmillan JB, Chen ZJ. RNA polymerase III detects cytosolic DNA and induces type I interferons through the RIG-I pathway. Cell. 2009 Aug 7;138(3):576-91. doi: 10.1016/j.cell.2009.06.015. Epub 2009 Jul, 23. PMID:19631370 doi:10.1016/j.cell.2009.06.015
7. ↑ D'Cruz AA, Kershaw NJ, Hayman TJ, Linossi EM, Chiang JJ, Wang MK, Dagley LF, Kolesnik TB, Zhang JG, Masters SL, Griffin MD, Gack MU, Murphy JM, Nicola NA, Babon JJ, Nicholson SE. Identification of a second binding site on the TRIM25 B30.2 domain. Biochem J. 2017 Dec 19. pii: BCJ20170427. doi: 10.1042/BCJ20170427. PMID:29259080 doi:http://dx.doi.org/10.1042/BCJ20170427