1. Antagonism of ALAS1 by the Measles Virus V protein contributes to degradation of the mitochondrial network and promotes interferon response
- Author
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Pierre Khalfi, Rodolphe Suspène, Kyle A. Raymond, Vincent Caval, Grégory Caignard, Noémie Berry, Valérie Thiers, Chantal Combredet, Claude Rufie, Stéphane Rigaud, Amine Ghozlane, Stevenn Volant, Anastassia V. Komarova, Frédéric Tangy, Jean-Pierre Vartanian, Virus et stress cellulaire / Virus and cellular stress, Institut Pasteur [Paris] (IP), ED 515 - Complexité du vivant, Sorbonne Université (SU), Virologie UMR1161 (VIRO), École nationale vétérinaire - Alfort (ENVA)-Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d’innovation : vaccins – Innovation lab : vaccines, Institut Pasteur [Paris] (IP)-Université Paris Cité (UPCité), Hub d'analyse d'images - Image Analysis Hub (Platform) (IAH), Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB, Interactomique, ARN et immunité / Interactomics, RNA and immunity, and This work was supported by the Institut Pasteur and by the Centre National de la Recherche Scientifique (CNRS). PK is a PhD fellow supported by la Ligue contre le Cancer (IP/SC-15364), KAR is a PhD fellow supported by the Ministère de l’Enseignement Supérieur et de la Recherche.
- Subjects
Virology ,Immunology ,[SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,Genetics ,Parasitology ,[INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM] ,Molecular Biology ,Microbiology - Abstract
Viruses have evolved countless mechanisms to subvert and impair the host innate immune response. Measles virus (MeV), an enveloped, non-segmented, negative-strand RNA virus, alters the interferon response through different mechanisms, yet no viral protein has been described as directly targeting mitochondria. Among the crucial mitochondrial enzymes, 5′-aminolevulinate synthase (ALAS) is an enzyme that catalyzes the first step in heme biosynthesis, generating 5′-aminolevulinate from glycine and succinyl-CoA. In this work, we demonstrate that MeV impairs the mitochondrial network through the V protein, which antagonizes the mitochondrial enzyme ALAS1 and sequesters it to the cytosol. This re-localization of ALAS1 leads to a decrease in mitochondrial volume and impairment of its metabolic potential, a phenomenon not observed in MeV deficient for the V gene. This perturbation of the mitochondrial dynamics demonstrated both in culture and in infected IFNAR−/− hCD46 transgenic mice, causes the release of mitochondrial double-stranded DNA (mtDNA) in the cytosol. By performing subcellular fractionation post infection, we demonstrate that the most significant source of DNA in the cytosol is of mitochondrial origin. Released mtDNA is then recognized and transcribed by the DNA-dependent RNA polymerase III. The resulting double-stranded RNA intermediates will be captured by RIG-I, ultimately initiating type I interferon production. Deep sequencing analysis of cytosolic mtDNA editing divulged an APOBEC3A signature, primarily analyzed in the 5’TpCpG context. Finally, in a negative feedback loop, APOBEC3A an interferon inducible enzyme will orchestrate the catabolism of mitochondrial DNA, decrease cellular inflammation, and dampen the innate immune response.
- Published
- 2023
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