Kinetic discrimination of self/non-self RNA by the ATPase activity of RIG-I and MDA5

Autor: Louber, Jade, Brunel, Joanna, Uchikawa, Emiko, Cusack, Stephen, Gerlier, Denis
Přispěvatelé: Immunobiologie des infections virales – Immunobiology of Viral Infections (IbIV), Centre International de Recherche en Infectiologie - UMR (CIRI), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Unit for Virus Host-Cell Interactions [Grenoble] (UVHCI), Centre National de la Recherche Scientifique (CNRS)-European Molecular Biology Laboratory [Grenoble] (EMBL)-Université Joseph Fourier - Grenoble 1 (UJF), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-European Molecular Biology Laboratory [Grenoble] (EMBL)-Centre National de la Recherche Scientifique (CNRS), BMC, BMC
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: BMC Biology
BMC Biology, BioMed Central, 2015, 13 (1), pp.54. ⟨10.1186/s12915-015-0166-9⟩
BMC Biology, 2015, 13 (1), pp.54. ⟨10.1186/s12915-015-0166-9⟩
ISSN: 1741-7007
DOI: 10.1186/s12915-015-0166-9⟩
Popis: Background The cytoplasmic RIG-like receptors are responsible for the early detection of viruses and other intracellular microbes by activating the innate immune response mediated by type I interferons (IFNs). RIG-I and MDA5 detect virus-specific RNA motifs with short 5′-tri/diphosphorylated, blunt-end double-stranded RNA (dsRNA) and >0.5–2 kb long dsRNA as canonical agonists, respectively. However, in vitro, they can bind to many RNA species, while in cells there is an activation threshold. As SF2 helicase/ATPase family members, ATP hydrolysis is dependent on co-operative RNA and ATP binding. Whereas simultaneous ATP and cognate RNA binding is sufficient to activate RIG-I by releasing autoinhibition of the signaling domains, the physiological role of the ATPase activity of RIG-I and MDA5 remains controversial. Results A cross-analysis of a rationally designed panel of RNA binding and ATPase mutants and truncated receptors, using type I IFN promoter activation as readout, allows us to refine our understanding of the structure-function relationships of RIG-I and MDA5. RNA activation of RIG-I depends on multiple critical RNA binding sites in its helicase domain as confirmed by functional evidence using novel mutations. We found that RIG-I or MDA5 mutants with low ATP hydrolysis activity exhibit constitutive activity but this was fully reverted when associated with mutations preventing RNA binding to the helicase domain. We propose that the turnover kinetics of the ATPase domain enables the discrimination of self/non-self RNA by both RIG-I and MDA5. Non-cognate, possibly self, RNA binding would lead to fast ATP turnover and RNA disassociation and thus insufficient time for the caspase activation and recruitment domains (CARDs) to promote downstream signaling, whereas tighter cognate RNA binding provides a longer time window for downstream events to be engaged. Conclusions The exquisite fine-tuning of RIG-I and MDA5 RNA-dependent ATPase activity coupled to CARD release allows a robust IFN response from a minor subset of non-self RNAs within a sea of cellular self RNAs. This avoids the eventuality of deleterious autoimmunity effects as have been recently described to arise from natural gain-of-function alleles of RIG-I and MDA5. Electronic supplementary material The online version of this article (doi:10.1186/s12915-015-0166-9) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
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