1
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Davey R, Donahue C, Kesari A, Thakur N, Wang L, Hulsey-Stubbs S, Williams C, Kirby C, Leung D, Aryal U, Basler C, LaCount D. A protein-proximity screen reveals Ebola virus co-opts the mRNA decapping complex through the scaffold protein EDC4. RESEARCH SQUARE 2024:rs.3.rs-3838220. [PMID: 38352529 PMCID: PMC10862950 DOI: 10.21203/rs.3.rs-3838220/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The interaction of host and Ebola virus (EBOV) proteins is required for establishing infection of the cell. To identify protein binding partners, a proximity-dependent protein interaction screen was performed for six EBOV proteins. Hits were computationally mapped onto a human protein-protein interactome and then annotated with viral proteins to reveal known and previously undescribed EBOV-host protein interactions and processes. Importantly, this approach efficiently arranged proteins into functional complexes associated with single viral proteins. Focused characterization of interactions between EBOV VP35 and the mRNA decapping complex demonstrated that VP35 binds the scaffold protein EDC4 through the C-terminal subdomain, with each protein found associated in EBOV-infected cells. Mechanistically, depletion of three components of the complex each similarly inhibited viral replication by reducing early viral RNA synthesis. Overall, we demonstrate successful identification of EBOV protein interaction with entire cellular machines, providing a deeper understanding of replication mechanism for therapeutic intervention.
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2
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Wu K, Fu Y, Ren Y, Liu L, Zhang X, Ruan M. Turnip crinkle virus-encoded suppressor of RNA silencing suppresses mRNA decay by interacting with Arabidopsis XRN4. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:744-755. [PMID: 37522642 DOI: 10.1111/tpj.16402] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/06/2023] [Accepted: 07/17/2023] [Indexed: 08/01/2023]
Abstract
Plant cells employ intricate defense mechanisms, including mRNA decay pathways, to counter viral infections. Among the RNA quality control (RQC) mechanisms, nonsense-mediated decay (NMD), no-go decay (NGD), and nonstop decay (NSD) pathways play critical roles in recognizing and cleaving aberrant mRNA molecules. Turnip crinkle virus (TCV) is a plant virus that triggers mRNA decay pathways, but it has also evolved strategies to evade this antiviral defense. In this study, we investigated the activation of mRNA decay during TCV infection and its impact on TCV RNA accumulation. We found that TCV infection induced the upregulation of essential mRNA decay factors, indicating their involvement in antiviral defense and the capsid protein (CP) of TCV, a well-characterized viral suppressor of RNA silencing (VSR), also compromised the mRNA decay-based antiviral defense by targeting AtXRN4. This interference with mRNA decay was supported by the observation that TCV CP stabilized a reporter transcript with a long 3' untranslated region (UTR). Moreover, TCV CP suppressed the decay of known NMD target transcripts, further emphasizing its ability to modulate host RNA control mechanisms. Importantly, TCV CP physically interacted with AtXRN4, providing insight into the mechanism of viral interference with mRNA decay. Overall, our findings reveal an alternative strategy employed by TCV, wherein the viral coat protein suppresses the mRNA decay pathway to facilitate viral infection.
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Affiliation(s)
- Kunxin Wu
- National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
- Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agriculture Resources, Haikou, 571101, China
| | - Yan Fu
- National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
- Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agriculture Resources, Haikou, 571101, China
| | - Yanli Ren
- School of Biological and Geographical Sciences, Yili Normal University, Yili, 835000, China
| | - Linyu Liu
- National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
- Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agriculture Resources, Haikou, 571101, China
- School of Biological and Geographical Sciences, Yili Normal University, Yili, 835000, China
| | - Xiuchun Zhang
- National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
- Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agriculture Resources, Haikou, 571101, China
- Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Sanya, 572025, China
| | - Mengbin Ruan
- National Key Laboratory for Tropical Crop Breeding, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
- Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agriculture Resources, Haikou, 571101, China
- Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Sanya, 572025, China
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3
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Horlacher M, Wagner N, Moyon L, Kuret K, Goedert N, Salvatore M, Ule J, Gagneur J, Winther O, Marsico A. Towards in silico CLIP-seq: predicting protein-RNA interaction via sequence-to-signal learning. Genome Biol 2023; 24:180. [PMID: 37542318 PMCID: PMC10403857 DOI: 10.1186/s13059-023-03015-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 07/17/2023] [Indexed: 08/06/2023] Open
Abstract
We present RBPNet, a novel deep learning method, which predicts CLIP-seq crosslink count distribution from RNA sequence at single-nucleotide resolution. By training on up to a million regions, RBPNet achieves high generalization on eCLIP, iCLIP and miCLIP assays, outperforming state-of-the-art classifiers. RBPNet performs bias correction by modeling the raw signal as a mixture of the protein-specific and background signal. Through model interrogation via Integrated Gradients, RBPNet identifies predictive sub-sequences that correspond to known and novel binding motifs and enables variant-impact scoring via in silico mutagenesis. Together, RBPNet improves imputation of protein-RNA interactions, as well as mechanistic interpretation of predictions.
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Affiliation(s)
- Marc Horlacher
- Computational Health Center, Helmholtz Center Munich, Munich, Germany.
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
- Department of Informatics, Technical University of Munich, Garching, Germany.
- Helmholtz Association - Munich School for Data Science (MUDS), Munich, Germany.
| | - Nils Wagner
- Department of Informatics, Technical University of Munich, Garching, Germany
- Helmholtz Association - Munich School for Data Science (MUDS), Munich, Germany
| | - Lambert Moyon
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Klara Kuret
- National Institute of Chemistry, Ljubljana, Slovenia
- The Francis Crick Institute, London, UK
- Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Nicolas Goedert
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Marco Salvatore
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jernej Ule
- National Institute of Chemistry, Ljubljana, Slovenia
- The Francis Crick Institute, London, UK
| | - Julien Gagneur
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
- Department of Informatics, Technical University of Munich, Garching, Germany
- Helmholtz Association - Munich School for Data Science (MUDS), Munich, Germany
| | - Ole Winther
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Annalisa Marsico
- Computational Health Center, Helmholtz Center Munich, Munich, Germany.
- Helmholtz Association - Munich School for Data Science (MUDS), Munich, Germany.
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4
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Horlacher M, Oleshko S, Hu Y, Ghanbari M, Cantini G, Schinke P, Vergara EE, Bittner F, Mueller NS, Ohler U, Moyon L, Marsico A. A computational map of the human-SARS-CoV-2 protein-RNA interactome predicted at single-nucleotide resolution. NAR Genom Bioinform 2023; 5:lqad010. [PMID: 36814457 PMCID: PMC9940458 DOI: 10.1093/nargab/lqad010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/10/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
RNA-binding proteins (RBPs) are critical host factors for viral infection, however, large scale experimental investigation of the binding landscape of human RBPs to viral RNAs is costly and further complicated due to sequence variation between viral strains. To fill this gap, we investigated the role of RBPs in the context of SARS-CoV-2 by constructing the first in silico map of human RBP-viral RNA interactions at nucleotide-resolution using two deep learning methods (pysster and DeepRiPe) trained on data from CLIP-seq experiments on more than 100 human RBPs. We evaluated conservation of RBP binding between six other human pathogenic coronaviruses and identified sites of conserved and differential binding in the UTRs of SARS-CoV-1, SARS-CoV-2 and MERS. We scored the impact of mutations from 11 variants of concern on protein-RNA interaction, identifying a set of gain- and loss-of-binding events, as well as predicted the regulatory impact of putative future mutations. Lastly, we linked RBPs to functional, OMICs and COVID-19 patient data from other studies, and identified MBNL1, FTO and FXR2 RBPs as potential clinical biomarkers. Our results contribute towards a deeper understanding of how viruses hijack host cellular pathways and open new avenues for therapeutic intervention.
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Affiliation(s)
- Marc Horlacher
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Svitlana Oleshko
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Yue Hu
- Computational Health Center, Helmholtz Center Munich, Munich, Germany,Informatics 12 Chair of Bioinformatics, Technical University Munich, Garching, Germany
| | - Mahsa Ghanbari
- Institutes of Biology and Computer Science, Humboldt University, Berlin, Germany,Max Delbruck Center, Computational Regulatory Genomics, Berlin, Germany
| | - Giulia Cantini
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Patrick Schinke
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | | | | | | | - Uwe Ohler
- Institutes of Biology and Computer Science, Humboldt University, Berlin, Germany,Max Delbruck Center, Computational Regulatory Genomics, Berlin, Germany
| | - Lambert Moyon
- To whom correspondence should be addressed. Tel: +49 89318749193;
| | - Annalisa Marsico
- Correspondence may also be addressed to Annalisa Marsico. Tel: +49 89318743073;
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5
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Moll T, Odon V, Harvey C, Collins MO, Peden A, Franklin J, Graves E, Marshall JN, Dos Santos Souza C, Zhang S, Castelli L, Hautbergue G, Azzouz M, Gordon D, Krogan N, Ferraiuolo L, Snyder MP, Shaw PJ, Rehwinkel J, Cooper-Knock J. Low expression of EXOSC2 protects against clinical COVID-19 and impedes SARS-CoV-2 replication. Life Sci Alliance 2023; 6:e202201449. [PMID: 36241425 PMCID: PMC9585911 DOI: 10.26508/lsa.202201449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 12/15/2022] Open
Abstract
New therapeutic targets are a valuable resource for treatment of SARS-CoV-2 viral infection. Genome-wide association studies have identified risk loci associated with COVID-19, but many loci are associated with comorbidities and are not specific to host-virus interactions. Here, we identify and experimentally validate a link between reduced expression of EXOSC2 and reduced SARS-CoV-2 replication. EXOSC2 was one of the 332 host proteins examined, all of which interact directly with SARS-CoV-2 proteins. Aggregating COVID-19 genome-wide association studies statistics for gene-specific eQTLs revealed an association between increased expression of EXOSC2 and higher risk of clinical COVID-19. EXOSC2 interacts with Nsp8 which forms part of the viral RNA polymerase. EXOSC2 is a component of the RNA exosome, and here, LC-MS/MS analysis of protein pulldowns demonstrated interaction between the SARS-CoV-2 RNA polymerase and most of the human RNA exosome components. CRISPR/Cas9 introduction of nonsense mutations within EXOSC2 in Calu-3 cells reduced EXOSC2 protein expression and impeded SARS-CoV-2 replication without impacting cellular viability. Targeted depletion of EXOSC2 may be a safe and effective strategy to protect against clinical COVID-19.
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Affiliation(s)
- Tobias Moll
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Valerie Odon
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Calum Harvey
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Mark O Collins
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Andrew Peden
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - John Franklin
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily Graves
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jack Ng Marshall
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Sai Zhang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Lydia Castelli
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Guillaume Hautbergue
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Mimoun Azzouz
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - David Gordon
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA, USA
- Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI) COVID-19 Research Group (QCRG), San Francisco, CA, USA
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Michael P Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Johnathan Cooper-Knock
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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6
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Moll T, Odon V, Harvey C, Collins MO, Peden A, Franklin J, Graves E, Marshall JN, Souza CDS, Zhang S, Azzouz M, Gordon D, Krogan N, Ferraiuolo L, Snyder MP, Shaw PJ, Rehwinkel J, Cooper-Knock J. Low expression of EXOSC2 protects against clinical COVID-19 and impedes SARS-CoV-2 replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.03.06.483172. [PMID: 35291294 PMCID: PMC8923113 DOI: 10.1101/2022.03.06.483172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
New therapeutic targets are a valuable resource in the struggle to reduce the morbidity and mortality associated with the COVID-19 pandemic, caused by the SARS-CoV-2 virus. Genome-wide association studies (GWAS) have identified risk loci, but some loci are associated with co-morbidities and are not specific to host-virus interactions. Here, we identify and experimentally validate a link between reduced expression of EXOSC2 and reduced SARS-CoV-2 replication. EXOSC2 was one of 332 host proteins examined, all of which interact directly with SARS-CoV-2 proteins; EXOSC2 interacts with Nsp8 which forms part of the viral RNA polymerase. Lung-specific eQTLs were identified from GTEx (v7) for each of the 332 host proteins. Aggregating COVID-19 GWAS statistics for gene-specific eQTLs revealed an association between increased expression of EXOSC2 and higher risk of clinical COVID-19 which survived stringent multiple testing correction. EXOSC2 is a component of the RNA exosome and indeed, LC-MS/MS analysis of protein pulldowns demonstrated an interaction between the SARS-CoV-2 RNA polymerase and the majority of human RNA exosome components. CRISPR/Cas9 introduction of nonsense mutations within EXOSC2 in Calu-3 cells reduced EXOSC2 protein expression, impeded SARS-CoV-2 replication and upregulated oligoadenylate synthase ( OAS) genes, which have been linked to a successful immune response against SARS-CoV-2. Reduced EXOSC2 expression did not reduce cellular viability. OAS gene expression changes occurred independent of infection and in the absence of significant upregulation of other interferon-stimulated genes (ISGs). Targeted depletion or functional inhibition of EXOSC2 may be a safe and effective strategy to protect at-risk individuals against clinical COVID-19.
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Affiliation(s)
- Tobias Moll
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Valerie Odon
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Calum Harvey
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Mark O Collins
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Andrew Peden
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - John Franklin
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily Graves
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jack N.G. Marshall
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Sai Zhang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Mimoun Azzouz
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - David Gordon
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, USA
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Michael P Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Johnathan Cooper-Knock
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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7
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Iselin L, Palmalux N, Kamel W, Simmonds P, Mohammed S, Castello A. Uncovering viral RNA-host cell interactions on a proteome-wide scale. Trends Biochem Sci 2022; 47:23-38. [PMID: 34509361 PMCID: PMC9187521 DOI: 10.1016/j.tibs.2021.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/12/2021] [Accepted: 08/06/2021] [Indexed: 01/14/2023]
Abstract
RNA viruses interact with a wide range of cellular RNA-binding proteins (RBPs) during their life cycle. The prevalence of these host-virus interactions has been highlighted by new methods that elucidate the composition of viral ribonucleoproteins (vRNPs). Applied to 11 viruses so far, these approaches have revealed hundreds of cellular RBPs that interact with viral (v)RNA in infected cells. However, consistency across methods is limited, raising questions about methodological considerations when designing and interpreting these studies. Here, we discuss these caveats and, through comparing available vRNA interactomes, describe RBPs that are consistently identified as vRNP components and outline their potential roles in infection. In summary, these novel approaches have uncovered a new universe of host-virus interactions holding great therapeutic potential.
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Affiliation(s)
- Louisa Iselin
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, OX1 3SY, UK,Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK
| | - Natasha Palmalux
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, Scotland, (UK)
| | - Wael Kamel
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK,MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, Scotland, (UK)
| | - Peter Simmonds
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, OX1 3SY, UK
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK,Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK,The Rosalind Franklin Institute, Oxfordshire, OX11 0FA, UK
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK,MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, Scotland, (UK),Correspondence:
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8
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RNA Structure Protects the 5'-end of an Uncapped Tombusvirus RNA Genome from Xrn Digestion. J Virol 2021; 95:e0103421. [PMID: 34346764 DOI: 10.1128/jvi.01034-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One of the many challenges faced by RNA viruses is the maintenance of their genomes during infections of host cells. Members of the family Tombusviridae are plus-strand RNA viruses with unmodified triphosphorylated genomic 5'-termini. The tombusvirus Carnation Italian ringspot virus was used to investigate how it protects its RNA genome from attack by 5'-end-targeting degradation enzymes. In vivo and in vitro assays were employed to determine the role of genomic RNA structure in conferring protection from the 5'-to-3' exoribonuclease Xrn. The results revealed that (i) the CIRV RNA genome is more resistant to Xrn than its sg mRNAs, (ii) the genomic 5'UTR folds into a compact RNA structure that effectively and independently prevents Xrn access, (iii) the RNA structure limiting 5'-access is formed by secondary and tertiary interactions that function cooperatively, (iv) the structure is also able to block access of RNA pyrophosphohydrolase to the genomic 5'-terminus, and (v) the RNA structure does not stall an actively digesting Xrn. Based on its proficiency at impeding Xrn 5'-access, we have termed this 5'-terminal structure an Xrn-evading RNA or xeRNA. These and other findings demonstrate that the 5'UTR of the CIRV RNA genome folds into a complex structural conformation that helps to protect its unmodified 5'-terminus from enzymatic decay during infections. IMPORTANCE The plus-strand RNA genomes of plant viruses in the large family Tombusviridae are not 5'-capped. Here we explored how a species in the type genus Tombusvirus protects its genomic 5'-end from cellular nuclease attack. Our results revealed that the 5'-terminal sequence of the CIRV genome folds into a complex RNA structure that limits access of the 5'-to-3' exoribonuclease Xrn, thereby protecting it from processive degradation. The RNA conformation also impeded access of RNA pyrophosphohydrolase, which converts 5'-triphosphorylated RNA termini into 5'-monophosphorylated forms, the preferred substrate for Xrn. This study represents the first report of a genome-encoded higher-order RNA structure independently conferring resistance to cellular 5'-end-attacking enzymes in an RNA plant virus.
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9
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Xu T, Wang J, Hu B, Zhang G, Zhou W, Zheng M, Shen B, Sun B, Zhang Y, Chen Y, Yu J, Liang M, Pan J, Chen C, Chen H, Jiang M, Xu L, Qu J, Chen JF. Identification of the RNase-binding site of SARS-CoV-2 RNA for anchor primer-PCR detection of viral loading in 306 COVID-19 patients. Brief Bioinform 2021; 22:1215-1224. [PMID: 32935831 PMCID: PMC7543284 DOI: 10.1093/bib/bbaa193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 01/08/2023] Open
Abstract
The pandemic of coronavirus disease 2019 (COVID-19) urgently calls for more sensitive molecular diagnosis to improve sensitivity of current viral nuclear acid detection. We have developed an anchor primer (AP)-based assay to improve viral RNA stability by bioinformatics identification of RNase-binding site of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and implementing AP dually targeting the N gene of SARS-CoV-2 RNA and RNase 1, 3, 6. The arbitrarily primed polymerase chain reaction (AP-PCR) improvement of viral RNA integrity was supported by (a) the AP increased resistance of the targeted gene (N gene) of SARS-CoV-2 RNA to RNase treatment; (b) the detection of SARS-CoV-2 RNA by AP-PCR with lower cycle threshold values (-2.7 cycles) compared to two commercially available assays; (c) improvement of the viral RNA stability of the ORF gene upon targeting of the N gene and RNase. Furthermore, the improved sensitivity by AP-PCR was demonstrated by detection of SARS-CoV-2 RNA in 70-80% of sputum, nasal, pharyngeal swabs and feces and 36% (4/11) of urine of the confirmed cases (n = 252), 7% convalescent cases (n = 54) and none of 300 negative cases. Lastly, AP-PCR analysis of 306 confirmed and convalescent cases revealed prolonged presence of viral loading for >20 days after the first positive diagnosis. Thus, the AP dually targeting SARS-CoV-2 RNA and RNase improves molecular detection by preserving SARS-CoV-2 RNA integrity and reveals the prolonged viral loading associated with older age and male gender in COVID-19 patients.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Jia Qu
- Corresponding authors: Jiang-Fan Chen, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China. Tel: +86-577-88067966; Fax: +86-577-88067966; E-mail: ; Jia Qu, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China. Tel: +86-577-88075566; Fax: +86-577-88075566; E-mail:
| | - Jiang-Fan Chen
- Corresponding authors: Jiang-Fan Chen, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China. Tel: +86-577-88067966; Fax: +86-577-88067966; E-mail: ; Jia Qu, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China. Tel: +86-577-88075566; Fax: +86-577-88075566; E-mail:
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10
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Girardi E, Pfeffer S, Baumert TF, Majzoub K. Roadblocks and fast tracks: How RNA binding proteins affect the viral RNA journey in the cell. Semin Cell Dev Biol 2021; 111:86-100. [PMID: 32847707 PMCID: PMC7443355 DOI: 10.1016/j.semcdb.2020.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 12/12/2022]
Abstract
As obligate intracellular parasites with limited coding capacity, RNA viruses rely on host cells to complete their multiplication cycle. Viral RNAs (vRNAs) are central to infection. They carry all the necessary information for a virus to synthesize its proteins, replicate and spread and could also play essential non-coding roles. Regardless of its origin or tropism, vRNA has by definition evolved in the presence of host RNA Binding Proteins (RBPs), which resulted in intricate and complicated interactions with these factors. While on one hand some host RBPs recognize vRNA as non-self and mobilize host antiviral defenses, vRNA must also co-opt other host RBPs to promote viral infection. Focusing on pathogenic RNA viruses, we will review important scenarios of RBP-vRNA interactions during which host RBPs recognize, modify or degrade vRNAs. We will then focus on how vRNA hijacks the largest ribonucleoprotein complex (RNP) in the cell, the ribosome, to selectively promote the synthesis of its proteins. We will finally reflect on how novel technologies are helping in deepening our understanding of vRNA-host RBPs interactions, which can be ultimately leveraged to combat everlasting viral threats.
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Affiliation(s)
- Erika Girardi
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France
| | - Sebastien Pfeffer
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, 67000, Strasbourg, France; Pole Hépatodigestif, Institut Hopitalo-universitaire, Hopitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - Karim Majzoub
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, 67000, Strasbourg, France.
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11
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Dicker K, Järvelin AI, Garcia-Moreno M, Castello A. The importance of virion-incorporated cellular RNA-Binding Proteins in viral particle assembly and infectivity. Semin Cell Dev Biol 2021; 111:108-118. [PMID: 32921578 PMCID: PMC7482619 DOI: 10.1016/j.semcdb.2020.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/14/2022]
Abstract
RNA is a central molecule in RNA virus biology due to its dual function as messenger and genome. However, the small number of proteins encoded by viral genomes is insufficient to enable virus infection. Hence, viruses hijack cellular RNA-binding proteins (RBPs) to aid replication and spread. In this review we discuss the 'knowns' and 'unknowns' regarding the contribution of host RBPs to the formation of viral particles and the initial steps of infection in the newly infected cell. Through comparison of the virion proteomes of ten different human RNA viruses, we confirm that a pool of cellular RBPs are typically incorporated into viral particles. We describe here illustrative examples supporting the important functions of these RBPs in viral particle formation and infectivity and we propose that the role of host RBPs in these steps can be broader than previously anticipated. Understanding how cellular RBPs regulate virus infection can lead to the discovery of novel therapeutic targets against viruses.
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Affiliation(s)
- Kate Dicker
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Aino I Järvelin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Manuel Garcia-Moreno
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK; MRC-University of Glasgow Centre for Virus Research, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK.
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12
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Lai HC, James A, Luff J, De Souza P, Quek H, Ho U, Lavin MF, Roberts TL. Regulation of RNA degradation pathways during the lipopolysaccharide response in Macrophages. J Leukoc Biol 2021; 109:593-603. [PMID: 32829531 DOI: 10.1002/jlb.2ab0420-151rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 04/01/2020] [Accepted: 05/26/2020] [Indexed: 11/09/2022] Open
Abstract
The innate immune response to LPS is highly dynamic yet tightly regulated. The majority of studies of gene expression have focussed on transcription. However, it is also important to understand how post-transcriptional pathways are regulated in response to inflammatory stimuli as the rate of RNA degradation relative to new transcription is important for overall expression. RNA decay pathways include nonsense-mediated decay, the RNA decay exosome, P-body localized deadenylation, decapping and degradation, and AU-rich element targeted decay mediated by tristetraprolin. Here, bone marrow-derived Mϕs were treated with LPS over a time course of 0, 2, 6, and 24 h and the transcriptional profiles were analyzed by RNA sequencing. The data show that components of RNA degradation pathways are regulated during an LPS response. Processing body associated decapping enzyme DCP2 and regulatory subunit DCP1A, and 5' exonuclease XRN1 and sequence specific RNA decay pathways were upregulated. Nonsense mediated decay was also increased in response to LPS induced signaling, initially by increased activation and at later timepoints at the mRNA and protein levels. This leads to increased nonsense mediated decay efficiency across the 24 h following LPS treatment. These findings suggest that LPS activation of Mϕs results in targeted regulation of RNA degradation pathways in order to change how subsets of mRNAs are degraded during an inflammatory response.
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Affiliation(s)
- Hui-Chi Lai
- Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia
- South West Sydney Clinical School, UNSW Australia, Liverpool, New South Wales, Australia
| | - Alexander James
- Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia
| | - John Luff
- The University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Paul De Souza
- Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia
- Medical Oncology Department, Liverpool Hospital, Liverpool, New South Wales, Australia
- School of Medicine, Western Sydney University, Macarthur, New South Wales, Australia
| | - Hazel Quek
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Uda Ho
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Martin F Lavin
- The University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Tara L Roberts
- Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia
- South West Sydney Clinical School, UNSW Australia, Liverpool, New South Wales, Australia
- The University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- School of Medicine, Western Sydney University, Macarthur, New South Wales, Australia
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13
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Torabi SF, Vaidya AT, Tycowski KT, DeGregorio SJ, Wang J, Shu MD, Steitz TA, Steitz JA. RNA stabilization by a poly(A) tail 3'-end binding pocket and other modes of poly(A)-RNA interaction. Science 2021; 371:science.abe6523. [PMID: 33414189 DOI: 10.1126/science.abe6523] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/20/2020] [Indexed: 12/16/2022]
Abstract
Polyadenylate [poly(A)] tail addition to the 3' end of a wide range of RNAs is a highly conserved modification that plays a central role in cellular RNA function. Elements for nuclear expression (ENEs) are cis-acting RNA elements that stabilize poly(A) tails by sequestering them in RNA triplex structures. A crystal structure of a double ENE from a rice hAT transposon messenger RNA complexed with poly(A)28 at a resolution of 2.89 angstroms reveals multiple modes of interaction with poly(A), including major-groove triple helices, extended minor-groove interactions with RNA double helices, a quintuple-base motif that transitions poly(A) from minor-groove associations to major-groove triple helices, and a poly(A) 3'-end binding pocket. Our findings both expand the repertoire of motifs involved in long-range RNA interactions and provide insights into how polyadenylation can protect an RNA's extreme 3' end.
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Affiliation(s)
- Seyed-Fakhreddin Torabi
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Anand T Vaidya
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA.,TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500046, India
| | - Kazimierz T Tycowski
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Suzanne J DeGregorio
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Mei-Di Shu
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Thomas A Steitz
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA.,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Joan A Steitz
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536, USA. .,Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA
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14
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Abstract
Here we review data suggestive of a role for RNA-binding proteins in vertebrate immunity. We focus on the products of genes found in the class III region of the Major Histocompatibility Complex. Six of these genes, DDX39B (aka BAT1), DXO, LSM2, NELFE, PRRC2A (aka BAT2), and SKIV2L, encode RNA-binding proteins with clear roles in post-transcriptional gene regulation and RNA surveillance. These genes are likely to have important functions in immunity and are associated with autoimmune diseases.
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Affiliation(s)
- Geraldine Schott
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Biochemistry and Molecular Biology Graduate Program, University of Texas Medical Branch, Galveston, Texas, USA
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Programme in Infectious Diseases, Duke-NUS Medical School, Singapore.,Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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15
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Declercq M, Biquand E, Karim M, Pietrosemoli N, Jacob Y, Demeret C, Barbezange C, van der Werf S. Influenza A virus co-opts ERI1 exonuclease bound to histone mRNA to promote viral transcription. Nucleic Acids Res 2020; 48:10428-10440. [PMID: 32960265 PMCID: PMC7544206 DOI: 10.1093/nar/gkaa771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/18/2020] [Accepted: 09/10/2020] [Indexed: 12/25/2022] Open
Abstract
Cellular exonucleases involved in the processes that regulate RNA stability and quality control have been shown to restrict or to promote the multiplication cycle of numerous RNA viruses. Influenza A viruses are major human pathogens that are responsible for seasonal epidemics, but the interplay between viral proteins and cellular exonucleases has never been specifically studied. Here, using a stringent interactomics screening strategy and an siRNA-silencing approach, we identified eight cellular factors among a set of 75 cellular proteins carrying exo(ribo)nuclease activities or involved in RNA decay processes that support influenza A virus multiplication. We show that the exoribonuclease ERI1 interacts with the PB2, PB1 and NP components of the viral ribonucleoproteins and is required for viral mRNA transcription. More specifically, we demonstrate that the protein-protein interaction is RNA dependent and that both the RNA binding and exonuclease activities of ERI1 are required to promote influenza A virus transcription. Finally, we provide evidence that during infection, the SLBP protein and histone mRNAs co-purify with vRNPs alongside ERI1, indicating that ERI1 is most probably recruited when it is present in the histone pre-mRNA processing complex in the nucleus.
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Affiliation(s)
- Marion Declercq
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Elise Biquand
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Marwah Karim
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Natalia Pietrosemoli
- Bioinformatics and Biostatistics Hub, Department of Computational Biology, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Yves Jacob
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Caroline Demeret
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Cyril Barbezange
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
| | - Sylvie van der Werf
- Unité Génétique Moléculaire des Virus à ARN, UMR3569 CNRS, Université de Paris, Département de Virologie, Institut Pasteur, Paris, France
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16
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Weick EM, Lima CD. RNA helicases are hubs that orchestrate exosome-dependent 3'-5' decay. Curr Opin Struct Biol 2020; 67:86-94. [PMID: 33147539 DOI: 10.1016/j.sbi.2020.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 01/10/2023]
Abstract
The RNA exosome is a conserved complex of proteins that mediates 3'-5' RNA processing and decay. Its functions range from processing of non-coding RNAs such as ribosomal RNAs and decay of aberrant transcripts in the nucleus to cytoplasmic mRNA turnover and quality control. Ski2-like RNA helicases translocate substrates to exosome-associated ribonucleases and interact with the RNA exosome either directly or as part of multi-subunit helicase-containing complexes that identify and target RNA substrates for decay. Recent structures of these helicases with their RNA-binding partners or the RNA exosome have advanced our understanding of a system of modular and mutually exclusive contacts between the exosome and exosome-associated helicase complexes that shape the transcriptome by orchestrating exosome-dependent 3'-5' decay.
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Affiliation(s)
- Eva-Maria Weick
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Howard Hughes Medical Institute, 1275 York Avenue, New York, NY 10065, USA.
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17
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Freire MÁ. Viral silencing suppressors and cellular proteins partner with plant RRP6-like exoribonucleases. Virus Genes 2020; 56:621-631. [PMID: 32519287 DOI: 10.1007/s11262-020-01775-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/02/2020] [Indexed: 10/24/2022]
Abstract
RNA silencing and RNA decay are functionally interlaced, regulate gene expression and play a pivotal role in antiviral responses. As a counter-defensive strategy, many plant and mammalian viruses encode suppressors which interfere with both mechanisms. However, the protein interactions that connect these pathways remain elusive. Previous work reported that RNA silencing suppressors from different potyviruses, together with translation initiation factors EIF(iso)4E, interacted with the C-terminal region of the tobacco exoribonuclease RRP6-like 2, a component of the RNA decay exosome complex. Here, we investigate whether other viral silencing suppressors and cellular proteins might also bind RRP6-like exoribonucleases. A candidate search approach based on yeast two-hybrid protein interaction assays showed that three other unrelated viral suppressors, two from plant viruses and one from a mammalian virus, bound the C-terminus of the tobacco RRP6-like 2, the full-length of the Arabidopsis RRP6L1 protein and its C-terminal region. In addition, RRP6-like proteins were found to interact with members of the cellular double-stranded RNA-binding protein (DRB) family involved in RNA silencing. The C-terminal regions of RRP6L proteins are engaged in homotypic and heterotypic interactions and were predicted to be disordered. Collectively, these results suggest a protein interaction network that connects components of RNA decay and RNA silencing that is targeted by viral silencing suppressors.
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Affiliation(s)
- Miguel Ángel Freire
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Universidad Nacional de Córdoba (UNC), Av. Vélez Sarsfield 299, CC 495, 5000, Córdoba, Argentina.
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18
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Insulin Potentiates JAK/STAT Signaling to Broadly Inhibit Flavivirus Replication in Insect Vectors. Cell Rep 2020; 29:1946-1960.e5. [PMID: 31722209 PMCID: PMC6871768 DOI: 10.1016/j.celrep.2019.10.029] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/03/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022] Open
Abstract
The World Health Organization estimates that more than half of the world’s population is at risk for vector-borne diseases, including arboviruses. Because many arboviruses are mosquito borne, investigation of the insect immune response will help identify targets to reduce the spread of arboviruses. Here, we use a genetic screening approach to identify an insulin-like receptor as a component of the immune response to arboviral infection. We determine that vertebrate insulin reduces West Nile virus (WNV) replication in Drosophila melanogaster as well as WNV, Zika, and dengue virus titers in mosquito cells. Mechanistically, we show that insulin signaling activates the JAK/STAT, but not RNAi, pathway via ERK to control infection in Drosophila cells and Culex mosquitoes through an integrated immune response. Finally, we validate that insulin priming of adult female Culex mosquitoes through a blood meal reduces WNV infection, demonstrating an essential role for insulin signaling in insect antiviral responses to human pathogens. The world’s population is at risk for infection with several flaviviruses. Ahlers et al. use a living library of insects to determine that an insulin-like receptor controls West Nile virus infection. Insulin signaling is antiviral via the JAK/STAT pathway in both fly and mosquito models and against a range of flaviviruses.
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19
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Bartok E, Hartmann G. Immune Sensing Mechanisms that Discriminate Self from Altered Self and Foreign Nucleic Acids. Immunity 2020; 53:54-77. [PMID: 32668228 PMCID: PMC7359798 DOI: 10.1016/j.immuni.2020.06.014] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/19/2022]
Abstract
All lifeforms have developed highly sophisticated systems equipped to detect altered self and non-self nucleic acids (NA). In vertebrates, NA-sensing receptors safeguard the integrity of the organism by detecting pathogens, dyshomeostasis and damage, and inducing appropriate responses to eliminate pathogens and reconstitute homeostasis. Effector mechanisms include i) immune signaling, ii) restriction of NA functions such as inhibition of mRNA translation, and iii) cell death pathways. An appropriate effector response is necessary for host defense, but dysregulated NA-sensing can lead to devastating autoimmune and autoinflammatory disease. Their inherent biochemical similarity renders the reliable distinction between self NA under homeostatic conditions and altered or exogenous NA particularly challenging. In this review, we provide an overview of recent progress in our understanding of the closely coordinated and regulated network of innate immune receptors, restriction factors, and nucleases to effectively respond to pathogens and maintain host integrity.
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Affiliation(s)
- Eva Bartok
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Gunther Hartmann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
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20
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Amari K, Niehl A. Nucleic acid-mediated PAMP-triggered immunity in plants. Curr Opin Virol 2020; 42:32-39. [DOI: 10.1016/j.coviro.2020.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/11/2020] [Accepted: 04/16/2020] [Indexed: 12/22/2022]
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21
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Denzer L, Schroten H, Schwerk C. From Gene to Protein-How Bacterial Virulence Factors Manipulate Host Gene Expression During Infection. Int J Mol Sci 2020; 21:ijms21103730. [PMID: 32466312 PMCID: PMC7279228 DOI: 10.3390/ijms21103730] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023] Open
Abstract
Bacteria evolved many strategies to survive and persist within host cells. Secretion of bacterial effectors enables bacteria not only to enter the host cell but also to manipulate host gene expression to circumvent clearance by the host immune response. Some effectors were also shown to evade the nucleus to manipulate epigenetic processes as well as transcription and mRNA procession and are therefore classified as nucleomodulins. Others were shown to interfere downstream with gene expression at the level of mRNA stability, favoring either mRNA stabilization or mRNA degradation, translation or protein stability, including mechanisms of protein activation and degradation. Finally, manipulation of innate immune signaling and nutrient supply creates a replicative niche that enables bacterial intracellular persistence and survival. In this review, we want to highlight the divergent strategies applied by intracellular bacteria to evade host immune responses through subversion of host gene expression via bacterial effectors. Since these virulence proteins mimic host cell enzymes or own novel enzymatic functions, characterizing their properties could help to understand the complex interactions between host and pathogen during infections. Additionally, these insights could propose potential targets for medical therapy.
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22
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Zhang L, Xu W, Gao X, Li W, Qi S, Guo D, Ajayi OE, Ding SW, Wu Q. lncRNA Sensing of a Viral Suppressor of RNAi Activates Non-canonical Innate Immune Signaling in Drosophila. Cell Host Microbe 2020; 27:115-128.e8. [PMID: 31917956 DOI: 10.1016/j.chom.2019.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/10/2019] [Accepted: 11/18/2019] [Indexed: 12/30/2022]
Abstract
Antiviral immunity in insects is mediated by the RNA interference (RNAi) pathway. Viruses evade antiviral RNAi by expressing virulence factors known as viral suppressors of RNAi (VSR). Here, we report the identification of VINR, a Drosophila VSR-interacting long non-coding (lnc) RNA that activates non-canonical innate immune signaling upon detection of the dsRNA-binding VSR of Drosophila C virus (DCV). VINR is required for the induction of antimicrobial peptide (AMP) genes but dispensable for antiviral RNAi. VINR functions by preventing the ubiquitin proteasome-dependent degradation of Cactin, a coiled-coil and arginine-serine-rich domain-containing protein that regulates a non-cannonical antimicrobial pathway for AMP induction. CRISPR-Cas9 knockout of VINR in Drosophila cells enhances DCV replication independently of antiviral RNAi, and VINR-knockout adult flies exhibit enhanced disease susceptibility to DCV and bacteria. Our findings reveal a counter counter-defense strategy activated by a lncRNA in response to the viral suppression of the primary antiviral RNAi immunity.
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Affiliation(s)
- Liqin Zhang
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Wen Xu
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Xinlei Gao
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Wenjie Li
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Shuishui Qi
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Dongyang Guo
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Olugbenga Emmanuel Ajayi
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Shou-Wei Ding
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside CA, USA
| | - Qingfa Wu
- Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
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23
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Langeberg CJ, Welch WRW, McGuire JV, Ashby A, Jackson AD, Chapman EG. Biochemical Characterization of Yeast Xrn1. Biochemistry 2020; 59:1493-1507. [PMID: 32251580 DOI: 10.1021/acs.biochem.9b01035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Messenger RNA degradation is an important component of overall gene expression. During the final step of eukaryotic mRNA degradation, exoribonuclease 1 (Xrn1) carries out 5' → 3' processive, hydrolytic degradation of RNA molecules using divalent metal ion catalysis. To initiate studies of the 5' → 3' RNA decay machinery in our lab, we expressed a C-terminally truncated version of Saccharomyces cerevisiae Xrn1 and explored its enzymology using a second-generation, time-resolved fluorescence RNA degradation assay. Using this system, we quantitatively explored Xrn1's preference for 5'-monophosphorylated RNA substrates, its pH dependence, and the importance of active site mutations in the molecule's conserved catalytic core. Furthermore, we explore Xrn1's preference for RNAs containing a 5' single-stranded region both in an intermolecular hairpin structure and in an RNA-DNA hybrid duplex system. These results both expand and solidify our understanding of Xrn1, a centrally important enzyme whose biochemical properties have implications in numerous RNA degradation and processing pathways.
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Affiliation(s)
- Conner J Langeberg
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - William R W Welch
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - John V McGuire
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Alison Ashby
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Alexander D Jackson
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Erich G Chapman
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
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24
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Avey S, Mohanty S, Chawla DG, Meng H, Bandaranayake T, Ueda I, Zapata HJ, Park K, Blevins TP, Tsang S, Belshe RB, Kaech SM, Shaw AC, Kleinstein SH. Seasonal Variability and Shared Molecular Signatures of Inactivated Influenza Vaccination in Young and Older Adults. THE JOURNAL OF IMMUNOLOGY 2020; 204:1661-1673. [PMID: 32060136 DOI: 10.4049/jimmunol.1900922] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/08/2020] [Indexed: 01/01/2023]
Abstract
The seasonal influenza vaccine is an important public health tool but is only effective in a subset of individuals. The identification of molecular signatures provides a mechanism to understand the drivers of vaccine-induced immunity. Most previously reported molecular signatures of human influenza vaccination were derived from a single age group or season, ignoring the effects of immunosenescence or vaccine composition. Thus, it remains unclear how immune signatures of vaccine response change with age across multiple seasons. In this study we profile the transcriptional landscape of young and older adults over five consecutive vaccination seasons to identify shared signatures of vaccine response as well as marked seasonal differences. Along with substantial variability in vaccine-induced signatures across seasons, we uncovered a common transcriptional signature 28 days postvaccination in both young and older adults. However, gene expression patterns associated with vaccine-induced Ab responses were distinct in young and older adults; for example, increased expression of killer cell lectin-like receptor B1 (KLRB1; CD161) 28 days postvaccination positively and negatively predicted vaccine-induced Ab responses in young and older adults, respectively. These findings contribute new insights for developing more effective influenza vaccines, particularly in older adults.
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Affiliation(s)
- Stefan Avey
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
| | - Subhasis Mohanty
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520
| | - Daniel G Chawla
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511
| | - Hailong Meng
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520
| | - Thilinie Bandaranayake
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520
| | - Ikuyo Ueda
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520
| | - Heidi J Zapata
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520
| | - Koonam Park
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520; and
| | - Tamara P Blevins
- Division of Infectious Diseases, Department of Medicine, Saint Louis University School of Medicine, St. Louis, MO 63104
| | - Sui Tsang
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520
| | - Robert B Belshe
- Division of Infectious Diseases, Department of Medicine, Saint Louis University School of Medicine, St. Louis, MO 63104
| | - Susan M Kaech
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520; and
| | - Albert C Shaw
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520;
| | - Steven H Kleinstein
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06511; .,Department of Pathology, Yale School of Medicine, New Haven, CT 06520.,Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520; and
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25
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Regulation of long non-coding RNAs and genome dynamics by the RNA surveillance machinery. Nat Rev Mol Cell Biol 2020; 21:123-136. [PMID: 32020081 DOI: 10.1038/s41580-019-0209-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
Abstract
Much of the mammalian genome is transcribed, generating long non-coding RNAs (lncRNAs) that can undergo post-transcriptional surveillance whereby only a subset of the non-coding transcripts is allowed to attain sufficient stability to persist in the cellular milieu and control various cellular functions. Paralleling protein turnover by the proteasome complex, lncRNAs are also likely to exist in a dynamic equilibrium that is maintained through constant monitoring by the RNA surveillance machinery. In this Review, we describe the RNA surveillance factors and discuss the vital role of lncRNA surveillance in orchestrating various biological processes, including the protection of genome integrity, maintenance of pluripotency of embryonic stem cells, antibody-gene diversification, coordination of immune cell activation and regulation of heterochromatin formation. We also discuss examples of human diseases and developmental defects associated with the failure of RNA surveillance mechanisms, further highlighting the importance of lncRNA surveillance in maintaining cell and organism functions and health.
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26
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Gunawardene CD, Newburn LR, White K. A 212-nt long RNA structure in the Tobacco necrosis virus-D RNA genome is resistant to Xrn degradation. Nucleic Acids Res 2019; 47:9329-9342. [PMID: 31392982 PMCID: PMC6755097 DOI: 10.1093/nar/gkz668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 06/26/2019] [Accepted: 07/25/2019] [Indexed: 12/16/2022] Open
Abstract
Plus-strand RNA viruses can accumulate viral RNA degradation products during infections. Some of these decay intermediates are generated by the cytosolic 5'-to-3' exoribonuclease Xrn1 (mammals and yeast) or Xrn4 (plants) and are formed when the enzyme stalls on substrate RNAs upon encountering inhibitory RNA structures. Many Xrn-generated RNAs correspond to 3'-terminal segments within the 3'-UTR of viral genomes and perform important functions during infections. Here we have investigated a 3'-terminal small viral RNA (svRNA) generated by Xrn during infections with Tobacco necrosis virus-D (family Tombusviridae). Our results indicate that (i) unlike known stalling RNA structures that are compact and modular, the TNV-D structure encompasses the entire 212 nt of the svRNA and is not functionally transposable, (ii) at least two tertiary interactions within the RNA structure are required for effective Xrn blocking and (iii) most of the svRNA generated in infections is derived from viral polymerase-generated subgenomic mRNA1. In vitro and in vivo analyses allowed for inferences on roles for the svRNA. Our findings provide a new and distinct addition to the growing list of Xrn-resistant viral RNAs and stalling structures found associated with different plant and animal RNA viruses.
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Affiliation(s)
| | - Laura R Newburn
- Department of Biology, York University, Toronto, Ontario, M3J 1P3, Canada
| | - K Andrew White
- Department of Biology, York University, Toronto, Ontario, M3J 1P3, Canada
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27
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Sofia MJ. The Discovery and Development of Daclatasvir: An Inhibitor of the Hepatitis C Virus NS5A Replication Complex. ACTA ACUST UNITED AC 2019. [PMCID: PMC7122418 DOI: 10.1007/7355_2018_47] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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28
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Paquette DR, Tibble RW, Daifuku TS, Gross JD. Control of mRNA decapping by autoinhibition. Nucleic Acids Res 2019; 46:6318-6329. [PMID: 29618050 PMCID: PMC6158755 DOI: 10.1093/nar/gky233] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 03/19/2018] [Indexed: 12/11/2022] Open
Abstract
5′ mediated cytoplasmic RNA decay is a conserved cellular process in eukaryotes. While the functions of the structured core domains in this pathway are well-studied, the role of abundant intrinsically disordered regions (IDRs) is lacking. Here we reconstitute the Dcp1:Dcp2 complex containing a portion of the disordered C-terminus and show its activity is autoinhibited by linear interaction motifs. Enhancers of decapping (Edc) 1 and 3 cooperate to activate decapping by different mechanisms: Edc3 alleviates autoinhibition by binding IDRs and destabilizing an inactive form of the enzyme, whereas Edc1 stabilizes the transition state for catalysis. Both activators are required to fully stimulate an autoinhibited Dcp1:Dcp2 as Edc1 alone cannot overcome the decrease in activity attributed to the C-terminal extension. Our data provide a mechanistic framework for combinatorial control of decapping by protein cofactors, a principle that is likely conserved in multiple 5′ mRNA decay pathways.
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Affiliation(s)
- David R Paquette
- Integrative Program in Quantitative Biology, Graduate Group in Biophysics, University of California, San Francisco, CA 94158, USA.,Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Ryan W Tibble
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA.,Program in Chemistry and Chemical Biology, University of California, San Francisco, CA 94158, USA
| | - Tristan S Daifuku
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - John D Gross
- Integrative Program in Quantitative Biology, Graduate Group in Biophysics, University of California, San Francisco, CA 94158, USA.,Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA.,Program in Chemistry and Chemical Biology, University of California, San Francisco, CA 94158, USA
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29
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Lukhovitskaya N, Ryabova LA. Cauliflower mosaic virus transactivator protein (TAV) can suppress nonsense-mediated decay by targeting VARICOSE, a scaffold protein of the decapping complex. Sci Rep 2019; 9:7042. [PMID: 31065034 PMCID: PMC6504953 DOI: 10.1038/s41598-019-43414-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/12/2019] [Indexed: 01/09/2023] Open
Abstract
During pathogenesis, viruses hijack the host cellular machinery to access molecules and sub-cellular structures needed for infection. We have evidence that the multifunctional viral translation transactivator/viroplasmin (TAV) protein from Cauliflower mosaic virus (CaMV) can function as a suppressor of nonsense-mediated mRNA decay (NMD). TAV interacts specifically with a scaffold protein of the decapping complex VARICOSE (VCS) in the yeast two-hybrid system, and co-localizes with components of the decapping complex in planta. Notably, plants transgenic for TAV accumulate endogenous NMD-elicited mRNAs, while decay of AU-rich instability element (ARE)-signal containing mRNAs are not affected. Using an agroinfiltration-based transient assay we confirmed that TAV specifically stabilizes mRNA containing a premature termination codon (PTC) in a VCS-dependent manner. We have identified a TAV motif consisting of 12 of the 520 amino acids in the full-length sequence that is critical for both VCS binding and the NMD suppression effect. Our data suggest that TAV can intercept NMD by targeting the decapping machinery through the scaffold protein VARICOSE, indicating that 5'-3' mRNA decapping is a late step in NMD-related mRNA degradation in plants.
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Affiliation(s)
- Nina Lukhovitskaya
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Lyubov A Ryabova
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
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30
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Helicase-Dependent RNA Decay Illuminated by a Cryo-EM Structure of a Human Nuclear RNA Exosome-MTR4 Complex. Cell 2019; 173:1663-1677.e21. [PMID: 29906447 DOI: 10.1016/j.cell.2018.05.041] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/26/2018] [Accepted: 05/17/2018] [Indexed: 01/08/2023]
Abstract
The ribonucleolytic RNA exosome interacts with RNA helicases to degrade RNA. To understand how the 3' to 5' Mtr4 helicase engages RNA and the nuclear exosome, we reconstituted 14-subunit Mtr4-containing RNA exosomes from Saccharomyces cerevisiae, Schizosaccharomyces pombe, and human and show that they unwind structured substrates to promote degradation. We loaded a human exosome with an optimized DNA-RNA chimera that stalls MTR4 during unwinding and determined its structure to an overall resolution of 3.45 Å by cryoelectron microscopy (cryo-EM). The structure reveals an RNA-engaged helicase atop the non-catalytic core, with RNA captured within the central channel and DIS3 exoribonuclease active site. MPP6 tethers MTR4 to the exosome through contacts to the RecA domains of MTR4. EXOSC10 remains bound to the core, but its catalytic module and cofactor C1D are displaced by RNA-engaged MTR4. Competition for the exosome core may ensure that RNA is committed to degradation by DIS3 when engaged by MTR4.
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31
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Garcia-Moreno M, Noerenberg M, Ni S, Järvelin AI, González-Almela E, Lenz CE, Bach-Pages M, Cox V, Avolio R, Davis T, Hester S, Sohier TJM, Li B, Heikel G, Michlewski G, Sanz MA, Carrasco L, Ricci EP, Pelechano V, Davis I, Fischer B, Mohammed S, Castello A. System-wide Profiling of RNA-Binding Proteins Uncovers Key Regulators of Virus Infection. Mol Cell 2019; 74:196-211.e11. [PMID: 30799147 PMCID: PMC6458987 DOI: 10.1016/j.molcel.2019.01.017] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 12/18/2018] [Accepted: 01/11/2019] [Indexed: 12/23/2022]
Abstract
The compendium of RNA-binding proteins (RBPs) has been greatly expanded by the development of RNA-interactome capture (RIC). However, it remained unknown if the complement of RBPs changes in response to environmental perturbations and whether these rearrangements are important. To answer these questions, we developed “comparative RIC” and applied it to cells challenged with an RNA virus called sindbis (SINV). Over 200 RBPs display differential interaction with RNA upon SINV infection. These alterations are mainly driven by the loss of cellular mRNAs and the emergence of viral RNA. RBPs stimulated by the infection redistribute to viral replication factories and regulate the capacity of the virus to infect. For example, ablation of XRN1 causes cells to be refractory to SINV, while GEMIN5 moonlights as a regulator of SINV gene expression. In summary, RNA availability controls RBP localization and function in SINV-infected cells. A quarter of the RBPome changes upon SINV infection Alterations in RBP activity are largely explained by changes in RNA availability Altered RBPs are crucial for viral infection efficacy GEMIN5 binds to the 5′ end of SINV RNAs and regulates viral gene expression
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Affiliation(s)
| | - Marko Noerenberg
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Shuai Ni
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Aino I Järvelin
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Esther González-Almela
- Centro de Biologia Molecular "Severo Ochoa," Universidad Autonoma de Madrid, 28049 Madrid, Spain
| | - Caroline E Lenz
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Marcel Bach-Pages
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Victoria Cox
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Rosario Avolio
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK; Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Thomas Davis
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Svenja Hester
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Thibault J M Sohier
- Université de Lyon, ENSL, UCBL, CNRS, INSERM, LBMC, 46 Allée d'Italie, 69007 Lyon, France
| | - Bingnan Li
- SciLifeLab, Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, 17165 Solna, Sweden
| | - Gregory Heikel
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Edinburgh EH9 3BF, UK; Division of Infection and Pathway Medicine, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Gracjan Michlewski
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Edinburgh EH9 3BF, UK; Division of Infection and Pathway Medicine, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK; Zhejiang University-University of Edinburgh Institute, Zhejiang University, 718 East Haizhou Road, Haining, Zhejiang 314400, People's Republic of China
| | - Miguel A Sanz
- Centro de Biologia Molecular "Severo Ochoa," Universidad Autonoma de Madrid, 28049 Madrid, Spain
| | - Luis Carrasco
- Centro de Biologia Molecular "Severo Ochoa," Universidad Autonoma de Madrid, 28049 Madrid, Spain
| | - Emiliano P Ricci
- Université de Lyon, ENSL, UCBL, CNRS, INSERM, LBMC, 46 Allée d'Italie, 69007 Lyon, France
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, 17165 Solna, Sweden
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK
| | - Bernd Fischer
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK; Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, UK.
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32
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Ruiz JC, Hunter OV, Conrad NK. Kaposi's sarcoma-associated herpesvirus ORF57 protein protects viral transcripts from specific nuclear RNA decay pathways by preventing hMTR4 recruitment. PLoS Pathog 2019; 15:e1007596. [PMID: 30785952 PMCID: PMC6398867 DOI: 10.1371/journal.ppat.1007596] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/04/2019] [Accepted: 01/25/2019] [Indexed: 12/15/2022] Open
Abstract
Nuclear RNAs are subject to a number of RNA decay pathways that serve quality control and regulatory functions. As a result, any virus that expresses its genes in the nucleus must have evolved mechanisms that avoid these pathways, but the how viruses evade nuclear RNA decay remains largely unknown. The multifunctional Kaposi’s sarcoma-associated herpesvirus (KSHV) ORF57 (Mta) protein is required for the nuclear stability of viral transcripts. In the absence of ORF57, we show that viral transcripts are subject to degradation by two specific nuclear RNA decay pathways, PABPN1 and PAPα/γ-mediated RNA decay (PPD) in which decay factors are recruited through poly(A) tails, and an ARS2-mediated RNA decay pathway dependent on the 5ʹ RNA cap. In transcription pulse chase assays, ORF57 appears to act primarily by inhibiting the ARS2-mediated RNA decay pathway. In the context of viral infection in cultured cells, inactivation of both decay pathways by RNAi is necessary for the restoration of ORF57-dependent viral genes produced from an ORF57-null bacmid. Mechanistically, we demonstrate that ORF57 protects viral transcripts by preventing the recruitment of the exosome co-factor hMTR4. In addition, our data suggest that ORF57 recruitment of ALYREF inhibits hMTR4 association with some viral RNAs, whereas other KSHV transcripts are stabilized by ORF57 in an ALYREF-independent fashion. In conclusion, our studies show that KSHV RNAs are subject to nuclear degradation by two specific host pathways, PPD and ARS2-mediated decay, and ORF57 protects viral transcripts from decay by inhibiting hMTR4 recruitment. Eukaryotic cells contain numerous nuclear RNA quality control (QC) systems that ensure transcriptome fidelity by detecting and degrading aberrant RNAs. Some viral RNAs are also predicted to be degraded by these RNA QC systems, so viruses have evolved mechanisms that counter host RNA QC pathways. Previous studies showed that the Kaposi’s sarcoma-associated herpesvirus (KSHV) expresses the ORF57 protein to protect its RNAs from nuclear decay. However, neither the specific host pathways that degrade KSHV RNAs nor the mechanisms describing ORF57 protection of viral RNAs were known. Our data suggest that ORF57 protects viral RNAs from two different nuclear RNA QC pathways, PABPN1 and PAPα/γ-mediated RNA decay (PPD) and an ARS2-mediated RNA decay pathway. Mechanistically, we show that ORF57 binds directly to viral RNAs and prevents the recruitment of hMTR4, a cellular factor whose function is to recruit the exosome, the complex responsible for RNA decay, to the transcript. We conclude that by preventing hMTR4 recruitment, ORF57 protects viral RNAs from degradation resulting in robust expression of viral genes.
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Affiliation(s)
- Julio C. Ruiz
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Olga V. Hunter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Nicholas K. Conrad
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas
- * E-mail:
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Abstract
Zika virus (ZIKV) is a significant global health threat, as infection has been linked to serious neurological complications, including microcephaly. Using a human stem cell-derived neural progenitor model system, we find that a critical cellular quality control process called the nonsense-mediated mRNA decay (NMD) pathway is disrupted during ZIKV infection. Importantly, disruption of the NMD pathway is a known cause of microcephaly and other neurological disorders. We further identify an interaction between the capsid protein of ZIKV and up-frameshift protein 1 (UPF1), the master regulator of NMD, and show that ZIKV capsid targets UPF1 for degradation. Together, these results offer a new mechanism for how ZIKV infection can cause neuropathology in the developing brain. Zika virus (ZIKV) infection of neural progenitor cells (NPCs) in utero is associated with neurological disorders, such as microcephaly, but a detailed molecular understanding of ZIKV-induced pathogenesis is lacking. Here we show that in vitro ZIKV infection of human cells, including NPCs, causes disruption of the nonsense-mediated mRNA decay (NMD) pathway. NMD is a cellular mRNA surveillance mechanism that is required for normal brain size in mice. Using affinity purification-mass spectrometry, we identified multiple cellular NMD factors that bind to the viral capsid protein, including the central NMD regulator up-frameshift protein 1 (UPF1). Endogenous UPF1 interacted with the ZIKV capsid protein in coimmunoprecipitation experiments, and capsid expression posttranscriptionally downregulated UPF1 protein levels, a process that we confirmed occurs during ZIKV infection. Cellular fractionation studies show that the ZIKV capsid protein specifically targets nuclear UPF1 for degradation via the proteasome. A further decrease in UPF1 levels by RNAi significantly enhanced ZIKV infection in NPC cultures, consistent with a model in which NMD restricts ZIKV infection in the fetal brain. We propose that ZIKV, via the capsid protein, has evolved a strategy to lower UPF1 levels and dampen antiviral activities of NMD, which in turn contributes to neuropathology in vivo.
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Brunkard JO, Baker B. A Two-Headed Monster to Avert Disaster: HBS1/SKI7 Is Alternatively Spliced to Build Eukaryotic RNA Surveillance Complexes. FRONTIERS IN PLANT SCIENCE 2018; 9:1333. [PMID: 30258456 PMCID: PMC6143672 DOI: 10.3389/fpls.2018.01333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 08/24/2018] [Indexed: 05/19/2023]
Abstract
The cytosolic RNA exosome, a 3'→5' exoribonuclease complex, contributes to mRNA degradation in eukaryotes, limiting the accumulation of poorly-translated, improperly translated, or aberrant mRNA species. Disruption of cytosolic RNA exosome activity allows aberrant RNA species to accumulate, which can then be detected by host antiviral immune systems as a signature of pathogen infection, activating antiviral defenses. SKI7 is a critical component of the cytosolic RNA exosome in yeast, bridging the catalytic exoribonuclease core with the SKI2/SKI3/SKI8 adaptor complex that guides aberrant RNA substrates into the exosome. The ortholog of SKI7 was only recently identified in humans as an alternative splice form of the HBS1 gene, which encodes a decoding factor translational GTPase that rescues stalled ribosomes. Here, we identify the plant orthologs of HBS1/SKI7. We found that HBS1 and SKI7 are typically encoded by alternative splice forms of a single locus, although some plant lineages have evolved subfunctionalized genes that apparently encode only HBS1 or only SKI7. In all plant lineages examined, the SKI7 gene is subject to regulation by alternative splicing that can yield unproductive transcripts, either by removing deeply conserved SKI7 coding sequences, or by introducing premature stop codons that render SKI7 susceptible to nonsense-mediated decay. Taking a comparative, evolutionary approach, we define crucial features of the SKI7 protein shared by all eukaryotes, and use these deeply conserved features to identify SKI7 proteins in invertebrate lineages. We conclude that SKI7 is a conserved cytosolic RNA exosome subunit across eukaryotic lineages, and that SKI7 is consistently regulated by alternative splicing, suggesting broad coordination of nuclear and cytosolic RNA metabolism.
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Affiliation(s)
- Jacob O. Brunkard
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- Plant Gene Expression Center, USDA Agricultural Research Service, Albany, CA, United States
| | - Barbara Baker
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- Plant Gene Expression Center, USDA Agricultural Research Service, Albany, CA, United States
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35
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Garcia-Moreno M, Järvelin AI, Castello A. Unconventional RNA-binding proteins step into the virus-host battlefront. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1498. [PMID: 30091184 PMCID: PMC7169762 DOI: 10.1002/wrna.1498] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/01/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022]
Abstract
The crucial participation of cellular RNA‐binding proteins (RBPs) in virtually all steps of virus infection has been known for decades. However, most of the studies characterizing this phenomenon have focused on well‐established RBPs harboring classical RNA‐binding domains (RBDs). Recent proteome‐wide approaches have greatly expanded the census of RBPs, discovering hundreds of proteins that interact with RNA through unconventional RBDs. These domains include protein–protein interaction platforms, enzymatic cores, and intrinsically disordered regions. Here, we compared the experimentally determined census of RBPs to gene ontology terms and literature, finding that 472 proteins have previous links with viruses. We discuss what these proteins are and what their roles in infection might be. We also review some of the pioneering examples of unorthodox RBPs whose RNA‐binding activity has been shown to be critical for virus infection. Finally, we highlight the potential of these proteins for host‐based therapies against viruses. This article is categorized under:
RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
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Affiliation(s)
| | - Aino I Järvelin
- Department of Biochemistry, University of Oxford, Oxford, UK
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36
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RNA triphosphatase DUSP11 enables exonuclease XRN-mediated restriction of hepatitis C virus. Proc Natl Acad Sci U S A 2018; 115:8197-8202. [PMID: 30038017 DOI: 10.1073/pnas.1802326115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Seventy percent of people infected with hepatitis C virus (HCV) will suffer chronic infection, putting them at risk for liver disease, including hepatocellular carcinoma. The full range of mechanisms that render some people more susceptible to chronic infection and liver disease is still being elucidated. XRN exonucleases can restrict HCV replication and may help to resolve HCV infections. However, it is unknown how 5' triphosphorylated HCV transcripts, primary products of the viral polymerase, become susceptible to attack by 5' monophosphate-specific XRNs. Here, we show that the 5' RNA triphosphatase DUSP11 acts on HCV transcripts, rendering them susceptible to XRN-mediated attack. Cells lacking DUSP11 show substantially enhanced HCV replication, and this effect is diminished when XRN expression is reduced. MicroRNA-122 (miR-122), a target of current phase II anti-HCV drugs, is known to protect HCV transcripts against XRNs. We show that HCV replication is less dependent on miR-122 in cells lacking DUSP11. Combined, these results implicate DUSP11 as an important component of XRN-mediated restriction of HCV.
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37
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Flobinus A, Chevigny N, Charley PA, Seissler T, Klein E, Bleykasten-Grosshans C, Ratti C, Bouzoubaa S, Wilusz J, Gilmer D. Beet Necrotic Yellow Vein Virus Noncoding RNA Production Depends on a 5'→3' Xrn Exoribonuclease Activity. Viruses 2018; 10:v10030137. [PMID: 29562720 PMCID: PMC5869530 DOI: 10.3390/v10030137] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/28/2018] [Accepted: 03/17/2018] [Indexed: 12/27/2022] Open
Abstract
The RNA3 species of the beet necrotic yellow vein virus (BNYVV), a multipartite positive-stranded RNA phytovirus, contains the 'core' nucleotide sequence required for its systemic movement in Beta macrocarpa. Within this 'core' sequence resides a conserved "coremin" motif of 20 nucleotides that is absolutely essential for long-distance movement. RNA3 undergoes processing steps to yield a noncoding RNA3 (ncRNA3) possessing "coremin" at its 5' end, a mandatory element for ncRNA3 accumulation. Expression of wild-type (wt) or mutated RNA3 in Saccharomyces cerevisiae allows for the accumulation of ncRNA3 species. Screening of S.cerevisiae ribonuclease mutants identified the 5'-to-3' exoribonuclease Xrn1 as a key enzyme in RNA3 processing that was recapitulated both in vitro and in insect cell extracts. Xrn1 stalled on ncRNA3-containing RNA substrates in these decay assays in a similar fashion as the flavivirus Xrn1-resistant structure (sfRNA). Substitution of the BNYVV-RNA3 'core' sequence by the sfRNA sequence led to the accumulation of an ncRNA species in yeast in vitro but not in planta and no viral long distance occurred. Interestingly, XRN4 knockdown reduced BNYVV RNA accumulation suggesting a dual role for the ribonuclease in the viral cycle.
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Affiliation(s)
- Alyssa Flobinus
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
| | - Nicolas Chevigny
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
| | - Phillida A Charley
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523-168, USA.
| | - Tanja Seissler
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
| | - Elodie Klein
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
- SESVanderHave, B3300 Tienen, Belgium.
| | | | - Claudio Ratti
- DipSA-Plant Pathology, University of Bologna, 40127 Bologna, Italy.
| | - Salah Bouzoubaa
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523-168, USA.
| | - David Gilmer
- Institut de biologie moléculaire des plantes, CNRS UPR2357, Université de Strasbourg, 67084 Strasbourg, France.
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Abstract
The power and ease of Drosophila genetics and the medical relevance of mosquito-transmitted viruses have made dipterans important model organisms in antiviral immunology. Studies of virus-host interactions at the molecular and population levels have illuminated determinants of resistance to virus infection. Here, we review the sources and nature of variation in antiviral immunity and virus susceptibility in model dipteran insects, specifically the fruit fly Drosophila melanogaster and vector mosquitoes of the genera Aedes and Culex. We first discuss antiviral immune mechanisms and describe the virus-specificity of these responses. In the following sections, we review genetic and microbiota-dependent variation in antiviral immunity. In the final sections, we explore less well-studied sources of variation, including abiotic factors, sexual dimorphism, infection history, and endogenous viral elements. We borrow from work on other pathogen types and non-dipteran species when it parallels or complements studies in dipterans. Understanding natural variation in virus-host interactions may lead to the identification of novel restriction factors and immune mechanisms and shed light on the molecular determinants of vector competence.
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Affiliation(s)
- William H Palmer
- Institute of Evolutionary Biology and Centre for Infection, Evolution and Immunity, University of Edinburgh, Edinburgh EH9 3FL UK.
| | - Finny S Varghese
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, Nijmegen 6500 HB, The Netherlands.
- Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands.
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, P.O. Box 9101, Nijmegen 6500 HB, The Netherlands.
- Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands.
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Charley PA, Wilusz CJ, Wilusz J. Identification of phlebovirus and arenavirus RNA sequences that stall and repress the exoribonuclease XRN1. J Biol Chem 2017; 293:285-295. [PMID: 29118186 DOI: 10.1074/jbc.m117.805796] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/06/2017] [Indexed: 12/22/2022] Open
Abstract
Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay machinery to establish a productive infection. One way for RNA viruses to accomplish this is to target the cellular exoribonuclease XRN1, because this enzyme is accessible in the cytoplasm and plays a major role in mRNA decay. Members of the Flaviviridae use RNA structures in their 5'- or 3'-untranslated regions to stall and repress XRN1, effectively stabilizing viral RNAs while also causing significant dysregulation of host cell mRNA stability. Here, we use a series of biochemical assays to demonstrate that the 3'-terminal portion of the nucleocapsid (N) mRNA of Rift Valley fever virus, a phlebovirus of the Bunyaviridae family, also can effectively stall and repress XRN1. The region responsible for impeding XRN1 includes a G-rich portion that likely forms a G-quadruplex structure. The 3'-terminal portions of ambisense-derived transcripts of multiple arenaviruses also stalled XRN1. Therefore, we conclude that RNAs from two additional families of mammalian RNA viruses stall and repress XRN1. This observation. emphasizes the importance and commonality of this viral strategy to interfere with the 5'-to-3'-exoribonuclease component of the cytoplasmic RNA decay machinery.
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Affiliation(s)
- Phillida A Charley
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523.
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Zhao M, Wang L, Li S. Influenza A Virus-Host Protein Interactions Control Viral Pathogenesis. Int J Mol Sci 2017; 18:ijms18081673. [PMID: 28763020 PMCID: PMC5578063 DOI: 10.3390/ijms18081673] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 07/27/2017] [Accepted: 07/28/2017] [Indexed: 12/20/2022] Open
Abstract
The influenza A virus (IAV), a member of the Orthomyxoviridae family, is a highly transmissible respiratory pathogen and represents a continued threat to global health with considerable economic and social impact. IAV is a zoonotic virus that comprises a plethora of strains with different pathogenic profiles. The different outcomes of viral pathogenesis are dependent on the engagement between the virus and the host cellular protein interaction network. The interactions may facilitate virus hijacking of host molecular machinery to fulfill the viral life cycle or trigger host immune defense to eliminate the virus. In recent years, much effort has been made to discover the virus–host protein interactions and understand the underlying mechanisms. In this paper, we review the recent advances in our understanding of IAV–host interactions and how these interactions contribute to host defense and viral pathogenesis.
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Affiliation(s)
- Mengmeng Zhao
- 156 McElroy Hall, Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Lingyan Wang
- 156 McElroy Hall, Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Shitao Li
- 156 McElroy Hall, Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
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