title: The viral RNA recognition sensor RIG-I is degraded during encephalomyocarditis virus (EMCV) infection.
abstract: RNA helicase-like receptors MDA-5 but not RIG-I has been shown to be essential for triggering innate immune responses against picornaviruses. However, virus-host co-evolution has selected for viruses capable of replicating despite host cells antiviral defences. In this report, we demonstrate that RIG-I is degraded during encephalomyocarditis virus (EMCV) infection. This effect is mediated by both the viral-encoded 3C protease and caspase proteinase. In addition, we show that RIG-I overexpression confers IFN-beta promoter activation during EMCV infection, in MDA-5 knockout (MDA-5(-/-)) mouse embryo fibroblasts. This induction is followed by a strong inhibition reflecting the ability of EMCV to disrupt RIG-I signalling. Taken together, our data strongly suggest that during evolution RIG-I has been involved for triggering innate immune response to picornavirus infections.
authors.affiliation: Université Montpellier 1, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), F-34095 Montpellier, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Papon
authors.forename: Alexandra
authors.initials: A
authors.lastname: Oteiza
authors.forename: Tadaatsu
authors.initials: T
authors.lastname: Imaizumi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.forename: Emiliana
authors.initials: E
authors.lastname: Brocchi
authors.forename: T Glen
authors.initials: TG
authors.lastname: Lawson
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
authors.forename: Nadir
authors.initials: N
authors.lastname: Mechti
mesh_terms: D000086042:3C Viral Proteases; D000818:Animals; D018188:Cardiovirus Infections / Q000276:immunology* / Q000821:virology; D020169:Caspases / Q000276:immunology / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000276:immunology / Q000378:metabolism; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000276:immunology / Q000378:metabolism*; D004686:Encephalomyocarditis virus / Q000276:immunology* / Q000378:metabolism; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007113:Immunity, Innate; D000072640:Interferon-Induced Helicase, IFIH1; D016899:Interferon-beta / Q000276:immunology*; D051379:Mice; D011401:Promoter Regions, Genetic; D014764:Viral Proteins / Q000276:immunology / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D016899:Interferon-beta; D020169:Caspases; D003546:Cysteine Endopeptidases; D000086042:3C Viral Proteases; C503356:Ddx58 protein, mouse; C510592:Ifih1 protein, mouse; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1