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Xue L, Chang T, Li Z, Wang C, Zhao H, Li M, Tang P, Wen X, Yu M, Wu J, Bao X, Wang X, Gong P, He J, Chen X, Xiong X. Cryo-EM structures of Thogoto virus polymerase reveal unique RNA transcription and replication mechanisms among orthomyxoviruses. Nat Commun 2024; 15:4620. [PMID: 38816392 PMCID: PMC11139864 DOI: 10.1038/s41467-024-48848-3] [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: 11/30/2023] [Accepted: 05/13/2024] [Indexed: 06/01/2024] Open
Abstract
Influenza viruses and thogotoviruses account for most recognized orthomyxoviruses. Thogotoviruses, exemplified by Thogoto virus (THOV), are capable of infecting humans using ticks as vectors. THOV transcribes mRNA without the extraneous 5' end sequences derived from cap-snatching in influenza virus mRNA. Here, we report cryo-EM structures to characterize THOV polymerase RNA synthesis initiation and elongation. The structures demonstrate that THOV RNA transcription and replication are able to start with short dinucleotide primers and that the polymerase cap-snatching machinery is likely non-functional. Triggered by RNA synthesis, asymmetric THOV polymerase dimers can form without the involvement of host factors. We confirm that, distinctive from influenza viruses, THOV-polymerase RNA synthesis is weakly dependent of the host factors ANP32A/B/E in human cells. This study demonstrates varied mechanisms in RNA synthesis and host factor utilization among orthomyxoviruses, providing insights into the mechanisms behind thogotoviruses' broad-infectivity range.
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Affiliation(s)
- Lu Xue
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Tiancai Chang
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Zimu Li
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Chenchen Wang
- College of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Heyu Zhao
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Mei Li
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Peng Tang
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xin Wen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Mengmeng Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jiqin Wu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Xichen Bao
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Jun He
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xinwen Chen
- Guangzhou National Laboratory, Guangzhou, Guangdong, China.
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China.
| | - Xiaoli Xiong
- State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangdong Provincial Key Laboratory of Biocomputing, GIBH-CUHK Joint Research Laboratory on Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
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2
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Zhang L, Shao Y, Wang Y, Yang Q, Guo J, Gao GF, Deng T. Twenty natural amino acid substitution screening at the last residue 121 of influenza A virus NS2 protein reveals the critical role of NS2 in promoting virus genome replication by coordinating with viral polymerase. J Virol 2024; 98:e0116623. [PMID: 38054704 PMCID: PMC10804943 DOI: 10.1128/jvi.01166-23] [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: 08/02/2023] [Accepted: 11/20/2023] [Indexed: 12/07/2023] Open
Abstract
Both influenza A virus genome transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA), catalyzed by the influenza RNA polymerase (FluPol), are dynamically regulated across the virus life cycle. It has been reported that the last amino acid I121 of the viral NS2 protein plays a critical role in promoting viral genome replication in influenza mini-replicon systems. Here, we performed a 20 natural amino acid substitution screening at residue NS2-I121 in the context of virus infection. We found that the hydrophobicity of the residue 121 is essential for virus survival. Interestingly, through serial passage of the rescued mutant viruses, we further identified adaptive mutations PA-K19E and PB1-S713N on FluPol which could effectively compensate for the replication-promoting defect caused by NS2-I121 mutation in the both mini-replicon and virus infection systems. Structural analysis of different functional states of FluPol indicates that PA-K19E and PB1-S713N could stabilize the replicase conformation of FluPol. By using a cell-based NanoBiT complementary reporter assay, we further demonstrate that both wild-type NS2 and PA-K19E/PB1-S713N could enhance FluPol dimerization, which is necessary for genome replication. These results reveal the critical role NS2 plays in promoting viral genome replication by coordinating with FluPol.IMPORTANCEThe intrinsic mechanisms of influenza RNA polymerase (FluPol) in catalyzing viral genome transcription and replication have been largely resolved. However, the mechanisms of how transcription and replication are dynamically regulated remain elusive. We recently reported that the last amino acid of the viral NS2 protein plays a critical role in promoting viral genome replication in an influenza mini-replicon system. Here, we conducted a 20 amino acid substitution screening at the last residue 121 in virus rescue and serial passage. Our results demonstrate that the replication-promoting function of NS2 is important for virus survival and efficient multiplication. We further show evidence that NS2 and NS2-I121 adaptive mutations PA-K19E/PB1-S713N regulate virus genome replication by promoting FluPol dimerization. This work highlights the coordination between NS2 and FluPol in fulfilling efficient genome replication. It further advances our understanding of the regulation of viral RNA synthesis for influenza A virus.
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Affiliation(s)
- Lei Zhang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- />Institute of Pediatrics, Shenzhen Children’s Hospital, Shenzhen, China
| | - Yuekun Shao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yingying Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qiuxian Yang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jiamei Guo
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - George F. Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tao Deng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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3
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Arragain B, Pelosse M, Thompson A, Cusack S. Structural and functional analysis of the minimal orthomyxovirus-like polymerase of Tilapia Lake Virus from the highly diverged Amnoonviridae family. Nat Commun 2023; 14:8145. [PMID: 38066000 PMCID: PMC10709604 DOI: 10.1038/s41467-023-44044-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Tilapia Lake Virus (TiLV), a recently discovered pathogen of tilapia fish, belongs to the Amnoonviridae family from the Articulavirales order. Its ten genome segments have characteristic conserved ends and encode proteins with no known homologues, apart from the segment 1, which encodes an orthomyxo-like RNA-dependent-RNA polymerase core subunit. Here we show that segments 1-3 encode respectively the PB1, PB2 and PA-like subunits of an active heterotrimeric polymerase that maintains all domains found in the distantly related influenza polymerase, despite an unprecedented overall size reduction of 40%. Multiple high-resolution cryo-EM structures of TiLV polymerase in pre-initiation, initiation and active elongation states, show how it binds the vRNA and cRNA promoters and performs RNA synthesis, with both transcriptase and replicase configurations being characterised. However, the highly truncated endonuclease-like domain appears inactive and the putative cap-binding domain is autoinhibited, emphasising that many functional aspects of TiLV polymerase remain to be elucidated.
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Affiliation(s)
- Benoit Arragain
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042, Grenoble, Cedex 9, France
| | - Martin Pelosse
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042, Grenoble, Cedex 9, France
| | - Albert Thompson
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042, Grenoble, Cedex 9, France
- The Francis Crick Institute, London, UK
| | - Stephen Cusack
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042, Grenoble, Cedex 9, France.
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4
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Saka N, Ohta K, Kolakofsky D, Nishio M. The bipartite promoter of Orthonairovirus hazaraense large segment. J Virol 2023; 97:e0091823. [PMID: 37916836 PMCID: PMC10688357 DOI: 10.1128/jvi.00918-23] [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: 06/21/2023] [Accepted: 10/03/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE The realization that segmented negative-strand RNA virus genome ribonucleoproteins are never free as their RNA ends are always bound to the viral polymerase has highlighted the problem of how these genome segments are replicated and express their mRNAs while their RNA ends remain associated with the polymerase throughout the cycles of RNA synthesis. This study of the length and nucleotide composition of the Orthonairovirus hazaraense L segment-specific double-stranded RNA (dsRNA) promoter element (the promoter duplex) provides insight into how its mRNA might be initiated and suggests that this promoter element acts via its separated single strands as well as via dsRNA.
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Affiliation(s)
- Naoki Saka
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Keisuke Ohta
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Daniel Kolakofsky
- Department of Microbiology and Molecular Medicine, University of Geneva School of Medicine, Geneva, Switzerland
| | - Machiko Nishio
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
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5
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Gilbertson B, Duncan M, Subbarao K. Role of the viral polymerase during adaptation of influenza A viruses to new hosts. Curr Opin Virol 2023; 62:101363. [PMID: 37672875 DOI: 10.1016/j.coviro.2023.101363] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 09/08/2023]
Abstract
As a group, influenza-A viruses (IAV) infect a wide range of animal hosts, however, they are constrained to infecting selected host species by species-specific interactions between the host and virus, that are required for efficient replication of the viral RNA genome. When IAV cross the species barrier, they acquire mutations in the viral genome to enable interactions with the new host factors, or to compensate for their loss. The viral polymerase genes polymerase basic 1, polymerase basic 2, and polymerase-acidic are important sites of host adaptation. In this review, we discuss why the viral polymerase is so vital to the process of host adaptation, look at some of the known viral mutations, and host factors involved in adaptation, particularly of avian IAV to mammalian hosts.
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Affiliation(s)
- Brad Gilbertson
- Department of Microbiology and Immunology, University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Melanie Duncan
- WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Kanta Subbarao
- Department of Microbiology and Immunology, University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
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6
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Peng Q, Yuan B, Cheng J, Wang M, Gao S, Bai S, Zhao X, Qi J, Gao GF, Shi Y. Molecular mechanism of de novo replication by the Ebola virus polymerase. Nature 2023; 622:603-610. [PMID: 37699521 DOI: 10.1038/s41586-023-06608-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
Non-segmented negative-strand RNA viruses, including Ebola virus (EBOV), rabies virus, human respiratory syncytial virus and pneumoviruses, can cause respiratory infections, haemorrhagic fever and encephalitis in humans and animals, and are considered a substantial health and economic burden worldwide1. Replication and transcription of the viral genome are executed by the large (L) polymerase, which is a promising target for the development of antiviral drugs. Here, using the L polymerase of EBOV as a representative, we show that de novo replication of L polymerase is controlled by the specific 3' leader sequence of the EBOV genome in an enzymatic assay, and that formation of at least three base pairs can effectively drive the elongation process of RNA synthesis independent of the specific RNA sequence. We present the high-resolution structures of the EBOV L-VP35-RNA complex and show that the 3' leader RNA binds in the template entry channel with a distinctive stable bend conformation. Using mutagenesis assays, we confirm that the bend conformation of the RNA is required for the de novo replication activity and reveal the key residues of the L protein that stabilize the RNA conformation. These findings provide a new mechanistic understanding of RNA synthesis for polymerases of non-segmented negative-strand RNA viruses, and reveal important targets for the development of antiviral drugs.
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Affiliation(s)
- Qi Peng
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Bin Yuan
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinlong Cheng
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Min Wang
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Siwei Gao
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Suran Bai
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xuejin Zhao
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jianxun Qi
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Beijing Life Science Academy, Beijing, China.
| | - George F Gao
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Beijing Life Science Academy, Beijing, China.
- Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China.
| | - Yi Shi
- International Institute of Vaccine Research and Innovation (iVac), Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Beijing Life Science Academy, Beijing, China.
- Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China.
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7
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Camacho-Zarco AR, Yu L, Krischuns T, Dedeoglu S, Maurin D, Bouvignies G, Crépin T, Ruigrok RWH, Cusack S, Naffakh N, Blackledge M. Multivalent Dynamic Colocalization of Avian Influenza Polymerase and Nucleoprotein by Intrinsically Disordered ANP32A Reveals the Molecular Basis of Human Adaptation. J Am Chem Soc 2023; 145:20985-21001. [PMID: 37707433 PMCID: PMC10540212 DOI: 10.1021/jacs.3c06965] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Indexed: 09/15/2023]
Abstract
Adaptation of avian influenza RNA polymerase (FluPol) to human cells requires mutations on the 627-NLS domains of the PB2 subunit. The E627K adaptive mutation compensates a 33-amino-acid deletion in the acidic intrinsically disordered domain of the host transcription regulator ANP32A, a deletion that restricts FluPol activity in mammalian cells. The function of ANP32A in the replication transcription complex and in particular its role in host restriction remains poorly understood. Here we characterize ternary complexes formed between ANP32A, FluPol, and the viral nucleoprotein, NP, supporting the putative role of ANP32A in shuttling NP to the replicase complex. We demonstrate that while FluPol and NP can simultaneously bind distinct linear motifs on avian ANP32A, the deletion in the shorter human ANP32A blocks this mode of colocalization. NMR reveals that NP and human-adapted FluPol, containing the E627 K mutation, simultaneously bind the identical extended linear motif on human ANP32A in an electrostatically driven, highly dynamic and multivalent ternary complex. This study reveals a probable molecular mechanism underlying host adaptation, whereby E627K, which enhances the basic surface of the 627 domain, is selected to confer the necessary multivalent properties to allow ANP32A to colocalize NP and FluPol in human cells.
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Affiliation(s)
- Aldo R. Camacho-Zarco
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Lefan Yu
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Tim Krischuns
- Institut
Pasteur, Université Paris Cité,
CNRS UMR3569, Unité Biologie des ARN et Virus Influenza, 75015 Paris, France
| | - Selin Dedeoglu
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Damien Maurin
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Guillaume Bouvignies
- Laboratoire
des Biomolécules, Département de Chimie, École
Normale Supérieur, UPMC Université Paris 06, CNRS, PSL Research University, 24 rue Lhomond, 75005 Paris, France
| | - Thibaut Crépin
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Rob W. H. Ruigrok
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
| | - Stephan Cusack
- European
Molecular Biology Laboratory, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Nadia Naffakh
- Institut
Pasteur, Université Paris Cité,
CNRS UMR3569, Unité Biologie des ARN et Virus Influenza, 75015 Paris, France
| | - Martin Blackledge
- Institut
de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS
UMR5075, 71 Avenue des
Martyrs, 38000 Grenoble, France
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8
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Li H, Wu Y, Li M, Guo L, Gao Y, Wang Q, Zhang J, Lai Z, Zhang X, Zhu L, Lan P, Rao Z, Liu Y, Liang H. An intermediate state allows influenza polymerase to switch smoothly between transcription and replication cycles. Nat Struct Mol Biol 2023; 30:1183-1192. [PMID: 37488357 DOI: 10.1038/s41594-023-01043-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/23/2023] [Indexed: 07/26/2023]
Abstract
Influenza polymerase (FluPol) transcribes viral mRNA at the beginning of the viral life cycle and initiates genome replication after viral protein synthesis. However, it remains poorly understood how FluPol switches between its transcription and replication states, especially given that the structural bases of these two functions are fundamentally different. Here we propose a mechanism by which FluPol achieves functional switching between these two states through a previously unstudied conformation, termed an 'intermediate state'. Using cryo-electron microscopy, we obtained a structure of the intermediate state of H5N1 FluPol at 3.7 Å, which is characterized by a blocked cap-binding domain and a contracted core region. Structural analysis results suggest that the intermediate state may allow FluPol to transition smoothly into either the transcription or replication state. Furthermore, we show that the formation of the intermediate state is required for both the transcription and replication activities of FluPol, leading us to conclude that the transcription and replication cycles of FluPol are regulated via this intermediate state.
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Affiliation(s)
- Huanhuan Li
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
- Department of General Surgery, Guangdong Institute of Gastroenterology, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yixi Wu
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
| | - Minke Li
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
| | - Lu Guo
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yaqi Gao
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
| | - Quan Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jihua Zhang
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
| | - Zhaohua Lai
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China
| | - Xing Zhang
- Departments of Biophysics and Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Center of Cryo Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
| | - Lixin Zhu
- Department of General Surgery, Guangdong Institute of Gastroenterology, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ping Lan
- Department of General Surgery, Guangdong Institute of Gastroenterology, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zihe Rao
- Laboratory of Structural Biology, Tsinghua University, Beijing, China
| | - Yingfang Liu
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China.
- Department of General Surgery, Guangdong Institute of Gastroenterology, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
| | - Huanhuan Liang
- Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-Sen University, Sun Yat-Sen University, Shenzhen, China.
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9
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Durieux Trouilleton Q, Barata-García S, Arragain B, Reguera J, Malet H. Structures of active Hantaan virus polymerase uncover the mechanisms of Hantaviridae genome replication. Nat Commun 2023; 14:2954. [PMID: 37221161 DOI: 10.1038/s41467-023-38555-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/04/2023] [Indexed: 05/25/2023] Open
Abstract
Hantaviruses are causing life-threatening zoonotic infections in humans. Their tripartite negative-stranded RNA genome is replicated by the multi-functional viral RNA-dependent RNA-polymerase. Here we describe the structure of the Hantaan virus polymerase core and establish conditions for in vitro replication activity. The apo structure adopts an inactive conformation that involves substantial folding rearrangement of polymerase motifs. Binding of the 5' viral RNA promoter triggers Hantaan virus polymerase reorganization and activation. It induces the recruitment of the 3' viral RNA towards the polymerase active site for prime-and-realign initiation. The elongation structure reveals the formation of a template/product duplex in the active site cavity concomitant with polymerase core widening and the opening of a 3' viral RNA secondary binding site. Altogether, these elements reveal the molecular specificities of Hantaviridae polymerase structure and uncover the mechanisms underlying replication. They provide a solid framework for future development of antivirals against this group of emerging pathogens.
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Affiliation(s)
| | | | - Benoît Arragain
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000, Grenoble, France
- European Molecular Biology Laboratory (EMBL), Grenoble, France
| | - Juan Reguera
- Aix-Marseille Université, CNRS, AFMB UMR, 7257, Marseille, France.
- INSERM, AFMB UMR, 7257, Marseille, France.
| | - Hélène Malet
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000, Grenoble, France.
- Institut Universitaire de France (IUF), Paris, France.
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10
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Liu L, Madhugiri R, Saul VV, Bacher S, Kracht M, Pleschka S, Schmitz ML. Phosphorylation of the PA subunit of influenza polymerase at Y393 prevents binding of the 5'-termini of RNA and polymerase function. Sci Rep 2023; 13:7042. [PMID: 37120635 PMCID: PMC10148841 DOI: 10.1038/s41598-023-34285-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/27/2023] [Indexed: 05/01/2023] Open
Abstract
The influenza A virus (IAV) polymerase is a multifunctional machine that can adopt alternative configurations to perform transcription and replication of the viral RNA genome in a temporally ordered manner. Although the structure of polymerase is well understood, our knowledge of its regulation by phosphorylation is still incomplete. The heterotrimeric polymerase can be regulated by posttranslational modifications, but the endogenously occurring phosphorylations at the PA and PB2 subunits of the IAV polymerase have not been studied. Mutation of phosphosites in PB2 and PA subunits revealed that PA mutants resembling constitutive phosphorylation have a partial (S395) or complete (Y393) defect in the ability to synthesize mRNA and cRNA. As PA phosphorylation at Y393 prevents binding of the 5' promoter of the genomic RNA, recombinant viruses harboring such a mutation could not be rescued. These data show the functional relevance of PA phosphorylations to control the activity of viral polymerase during the influenza infectious cycle.
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Affiliation(s)
- Lu Liu
- Institute of Biochemistry, Justus Liebig University Giessen, Member of the German Center for Lung Research (DZL), Giessen, Germany
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - Ramakanth Madhugiri
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - Vera Vivian Saul
- Institute of Biochemistry, Justus Liebig University Giessen, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Susanne Bacher
- Institute of Biochemistry, Justus Liebig University Giessen, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Michael Kracht
- Rudolf-Buchheim-Institute of Pharmacology, Justus Liebig University, Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Stephan Pleschka
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research (DZIF), Partner Site Giessen, Giessen, Germany
| | - M Lienhard Schmitz
- Institute of Biochemistry, Justus Liebig University Giessen, Member of the German Center for Lung Research (DZL), Giessen, Germany.
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11
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Ishida H, Murakami S, Kamiki H, Matsugo H, Katayama M, Sekine W, Ohira K, Takenaka-Uema A, Horimoto T. Generation of a recombinant temperature-sensitive influenza D virus. Sci Rep 2023; 13:3806. [PMID: 36882459 PMCID: PMC9992382 DOI: 10.1038/s41598-023-30942-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/03/2023] [Indexed: 03/09/2023] Open
Abstract
Influenza D virus (IDV) is a causative agent of the bovine respiratory disease complex (BRDC), which is the most common and costly disease affecting the cattle industry. For developing a candidate vaccine virus against IDV, we sought to produce a temperature-sensitive strain, similar to the live attenuated, cold-adapted vaccine strain available against the influenza A virus (IAV). To this end, we produced a recombinant IDV (designated rD/OK-AL) strain by introducing mutations responsible for the adaptation of the IAV vaccine strain to cold conditions and conferring sensitivity to high temperatures into PB2 and PB1 proteins using reverse genetics. The rD/OK-AL strain grew efficiently at 33 °C but did not grow at 37 °C in the cell culture, indicating its high-temperature sensitivity. In mice, rD/OK-AL was attenuated following intranasal inoculation. It mediated the production of high levels of antibodies against IDV in the serum. When the rD/OK-AL-inoculated mice were challenged with the wild-type virus, the virus was not detected in respiratory organs after the challenge, indicating complete protection against IDV. These results imply that the rD/OK-AL might be a potential candidate for the development of live attenuated vaccines for IDV that can be used to control BRDC.
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Affiliation(s)
- Hiroho Ishida
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shin Murakami
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
| | - Haruhiko Kamiki
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiromichi Matsugo
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Misa Katayama
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Wataru Sekine
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kosuke Ohira
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Akiko Takenaka-Uema
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Horimoto
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
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12
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A structural understanding of influenza virus genome replication. Trends Microbiol 2023; 31:308-319. [PMID: 36336541 DOI: 10.1016/j.tim.2022.09.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/27/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Influenza virus contains a single-stranded negative-sense RNA genome. Replication of the genome is carried out by the viral RNA-dependent RNA polymerase in the context of the viral ribonucleoprotein (RNP) complex, through a positive-sense complementary RNA intermediate. Genome replication is tightly controlled through interactions with accessory viral and host factors. Propelled by developments in recombinant protein expression, and technical improvements in X-ray crystallography and cryo-electron microscopy, snapshots of the replication process have been captured. Here, we review how recent structural data shed light on the molecular mechanisms of influenza virus genome replication, in particular, encapsidation of nascent RNA, de novo RNP assembly, and regulation of replication initiation through interactions with host and viral cues.
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13
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Williams HM, Thorkelsson SR, Vogel D, Milewski M, Busch C, Cusack S, Grünewald K, Quemin EJ, Rosenthal M. Structural insights into viral genome replication by the severe fever with thrombocytopenia syndrome virus L protein. Nucleic Acids Res 2023; 51:1424-1442. [PMID: 36651274 PMCID: PMC9943659 DOI: 10.1093/nar/gkac1249] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/29/2022] [Accepted: 12/14/2022] [Indexed: 01/19/2023] Open
Abstract
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a phenuivirus that has rapidly become endemic in several East Asian countries. The large (L) protein of SFTSV, which includes the RNA-dependent RNA polymerase (RdRp), is responsible for catalysing viral genome replication and transcription. Here, we present 5 cryo-electron microscopy (cryo-EM) structures of the L protein in several states of the genome replication process, from pre-initiation to late-stage elongation, at a resolution of up to 2.6 Å. We identify how the L protein binds the 5' viral RNA in a hook-like conformation and show how the distal 5' and 3' RNA ends form a duplex positioning the 3' RNA terminus in the RdRp active site ready for initiation. We also observe the L protein stalled in the early and late stages of elongation with the RdRp core accommodating a 10-bp product-template duplex. This duplex ultimately splits with the template binding to a designated 3' secondary binding site. The structural data and observations are complemented by in vitro biochemical and cell-based mini-replicon assays. Altogether, our data provide novel key insights into the mechanism of viral genome replication by the SFTSV L protein and will aid drug development against segmented negative-strand RNA viruses.
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Affiliation(s)
| | | | - Dominik Vogel
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Morlin Milewski
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Carola Busch
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | | | - Kay Grünewald
- Centre for Structural Systems Biology, Leibniz Institute of Virology, Hamburg, Germany,University of Hamburg, Hamburg, Germany
| | - Emmanuelle R J Quemin
- Centre for Structural Systems Biology, Leibniz Institute of Virology, Hamburg, Germany
| | - Maria Rosenthal
- To whom correspondence should be addressed. Tel: +49 40 285380 930;
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14
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Takashita E, Murakami S, Matsuzaki Y, Fujisaki S, Morita H, Nagata S, Katayama M, Mizuta K, Nishimura H, Watanabe S, Horimoto T, Hasegawa H. Antiviral Susceptibilities of Distinct Lineages of Influenza C and D Viruses. Viruses 2023; 15:244. [PMID: 36680284 PMCID: PMC9861540 DOI: 10.3390/v15010244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/10/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
The emergence and spread of antiviral-resistant influenza viruses are of great concern. To minimize the public health risk, it is important to monitor antiviral susceptibilities of influenza viruses. Analyses of the antiviral susceptibilities of influenza A and B viruses have been conducted globally; however, those of influenza C and D viruses are limited. Here, we determined the susceptibilities of influenza C viruses representing all six lineages (C/Taylor, C/Yamagata, C/Sao Paulo, C/Aichi, C/Kanagawa, and C/Mississippi) and influenza D viruses representing four lineages (D/OK, D/660, D/Yama2016, and D/Yama2019) to RNA polymerase inhibitors (baloxavir and favipiravir) by using a focus reduction assay. All viruses tested were susceptible to both drugs. We then performed a genetic analysis to check for amino acid substitutions associated with baloxavir and favipiravir resistance and found that none of the viruses tested possessed these substitutions. Use of the focus reduction assay with the genotypic assay has proven valuable for monitoring the antiviral susceptibilities of influenza C and D viruses as well as influenza A and B viruses. Antiviral susceptibility monitoring of all influenza virus types should continue in order to assess the public health risks posed by these viruses.
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Affiliation(s)
- Emi Takashita
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Shin Murakami
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan
| | - Yoko Matsuzaki
- Department of Infectious Diseases, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan
| | - Seiichiro Fujisaki
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Hiroko Morita
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Shiho Nagata
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Misa Katayama
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan
| | - Katsumi Mizuta
- Department of Microbiology, Yamagata Prefectural Institute of Public Health, Yamagata 990-0031, Japan
| | - Hidekazu Nishimura
- Virus Research Center, Clinical Research Division, Sendai Medical Center, Sendai 983-8520, Japan
| | - Shinji Watanabe
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Taisuke Horimoto
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan
| | - Hideki Hasegawa
- Research Center for Influenza and Respiratory Viruses, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
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15
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Revisiting Viral RNA-Dependent RNA Polymerases: Insights from Recent Structural Studies. Viruses 2022; 14:v14102200. [PMID: 36298755 PMCID: PMC9612308 DOI: 10.3390/v14102200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/29/2022] [Accepted: 10/02/2022] [Indexed: 11/07/2022] Open
Abstract
RNA-dependent RNA polymerases (RdRPs) represent a distinctive yet versatile class of nucleic acid polymerases encoded by RNA viruses for the replication and transcription of their genome. The structure of the RdRP is comparable to that of a cupped right hand consisting of fingers, palm, and thumb subdomains. Despite the presence of a common structural core, the RdRPs differ significantly in the mechanistic details of RNA binding and polymerization. The present review aims at exploring these incongruities in light of recent structural studies of RdRP complexes with diverse cofactors, RNA moieties, analogs, and inhibitors.
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16
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Zhao X, Lin X, Li P, Chen Z, Zhang C, Manicassamy B, Rong L, Cui Q, Du R. Expanding the tolerance of segmented Influenza A Virus genome using a balance compensation strategy. PLoS Pathog 2022; 18:e1010756. [PMID: 35926068 PMCID: PMC9380948 DOI: 10.1371/journal.ppat.1010756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/16/2022] [Accepted: 07/21/2022] [Indexed: 12/17/2022] Open
Abstract
Reporter viruses provide powerful tools for both basic and applied virology studies, however, the creation and exploitation of reporter influenza A viruses (IAVs) have been hindered by the limited tolerance of the segmented genome to exogenous modifications. Interestingly, our previous study has demonstrated the underlying mechanism that foreign insertions reduce the replication/transcription capacity of the modified segment, impairing the delicate balance among the multiple segments during IAV infection. In the present study, we developed a “balance compensation” strategy by incorporating additional compensatory mutations during initial construction of recombinant IAVs to expand the tolerance of IAV genome. As a proof of concept, promoter-enhancing mutations were introduced within the modified segment to rectify the segments imbalance of a reporter influenza PR8-NS-Gluc virus, while directed optimization of the recombinant IAV was successfully achieved. Further, we generated recombinant IAVs expressing a much larger firefly luciferase (Fluc) by coupling with a much stronger compensatory enhancement, and established robust Fluc-based live-imaging mouse models of IAV infection. Our strategy feasibly expands the tolerance for foreign gene insertions in the segmented IAV genome, which opens up better opportunities to develop more versatile reporter IAVs as well as live attenuated influenza virus-based vaccines for other important human pathogens.
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Affiliation(s)
- Xiujuan Zhao
- Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiaojing Lin
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ping Li
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zinuo Chen
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Chengcheng Zhang
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Balaji Manicassamy
- Department of Microbiology and Immunology, University of Iowa, Iowa, United States of America
| | - Lijun Rong
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, United States of America
- * E-mail: (LR); (QC); (RD)
| | - Qinghua Cui
- Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Qingdao Academy of Chinese Medicinal Sciences, Shandong University of Traditional Chinese Medicine, Qingdao, China
- * E-mail: (LR); (QC); (RD)
| | - Ruikun Du
- Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Qingdao Academy of Chinese Medicinal Sciences, Shandong University of Traditional Chinese Medicine, Qingdao, China
- * E-mail: (LR); (QC); (RD)
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17
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Li B, Su G, Xiao C, Zhang J, Li H, Sun N, Lao G, Yu Y, Ren X, Qi W, Wang X, Liao M. The PB2 co-adaptation of H10N8 avian influenza virus increases the pathogenicity to chickens and mice. Transbound Emerg Dis 2022; 69:1794-1803. [PMID: 34008327 DOI: 10.1111/tbed.14157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/06/2021] [Accepted: 05/14/2021] [Indexed: 12/18/2022]
Abstract
Avian influenza (AI) is an important zoonotic disease, which can be transmitted across species barriers to other hosts, especially humans, posing a serious threat to the poultry industry and public health. In recent years, human cases infected with the H10N8, H9N2, and H7N9 of avian influenza viruses (AIVs) have been identified frequently as have the internal genes of H7N9 and H10N8, which are derived from H9N2 viruses. The adaptive mutation of the PB2 gene is an important way for the H10N8, H9N2, and H7N9 AIVs to spread across species to adapt to new hosts. Several well-known adaptive mutations in the PB2 gene, such as E627K, D701N, and A588V, significantly enhanced the virulence of the AIVs in mammals. However, the co-adaptation of AIVs to avian and mammalian hosts is rarely studied. In this study, we found that the mutations of PB2-I292V, PB2-R389K, PB2-A588V, PB2-T598M/V, PB2-L648V, and PB2-T676M substitutions significantly increased after 2012. In addition, in our previous studies, we found that the human-origin and avian-origin of H10N8 AIVs with very high homology also have these six mutation differences in PB2 gene, and the avian-origin H10N8 strain known as JX102 with all the key amino acids on the PB2 protein in the pre-evolutionary stage, so JX102 was chosen as a model strain. Among them, PB2-A588V significantly enhanced the activity of polymerase in avian and mammalian cells. Notably, animal experiments showed that PB2-A588V substitution increased the pathogenicity and transmissibility in chickens and the virulence of mice. The combined mutations of PB2-F6 (including PB2-I292V, PB2-R389K, PB2-A588V, PB2-T598M, PB2-L648V, and PB2-T676M) obtained higher adaptability of AIVs in avians and mammals than that of the single mutation of PB2-A588V, which suggested that the PB2 588 site is a key co-adaptation site and that synergies with other mutation sites can further enhance this co-adaptability. The results of this study show that the emergence of co-adaptation not only increases the threat to avians and mammals but may also contribute to a pandemic among avians and cross the interspecies barrier to mammals.
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Affiliation(s)
- Bo Li
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Key Laboratory of Zoonoses, Ministry of Agricultural and Rural Affairs of the People's Republic of China, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, National Development and Reform Commission of the People's Republic of China, Guangzhou, China
- Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Guanming Su
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Chencheng Xiao
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jiahao Zhang
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Key Laboratory of Zoonoses, Ministry of Agricultural and Rural Affairs of the People's Republic of China, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, National Development and Reform Commission of the People's Republic of China, Guangzhou, China
- Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Huanan Li
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Key Laboratory of Zoonoses, Ministry of Agricultural and Rural Affairs of the People's Republic of China, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, National Development and Reform Commission of the People's Republic of China, Guangzhou, China
- Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Na Sun
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Guangjie Lao
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yuandi Yu
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xingxing Ren
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Wenbao Qi
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Key Laboratory of Zoonoses, Ministry of Agricultural and Rural Affairs of the People's Republic of China, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, National Development and Reform Commission of the People's Republic of China, Guangzhou, China
- Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Xiuhui Wang
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Hebei Province Poultry Engineering Technology Research Center, Hebei University of Engineering, Handan, People's Republic of China
| | - Ming Liao
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Key Laboratory of Zoonoses, Ministry of Agricultural and Rural Affairs of the People's Republic of China, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, National Development and Reform Commission of the People's Republic of China, Guangzhou, China
- Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
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18
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The C-terminal domains of the PB2 subunit of the influenza A virus RNA polymerase directly interact with cellular GTPase Rab11a. J Virol 2022; 96:e0197921. [PMID: 35019720 PMCID: PMC8906434 DOI: 10.1128/jvi.01979-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Influenza A virus (IAV) contains a segmented RNA genome that is transcribed and replicated by the viral RNA polymerase in the cell nucleus. Replicated RNA segments are assembled with viral polymerase and oligomeric nucleoprotein into viral ribonucleoprotein (vRNP) complexes which are exported from the nucleus and transported across the cytoplasm to be packaged into progeny virions. Host GTPase Rab11a associated with recycling endosomes is believed to contribute to this process by mediating the cytoplasmic transport of vRNPs. However, how vRNPs interact with Rab11a remains poorly understood. In this study, we utilised a combination of biochemical, proteomic, and biophysical approaches to characterise the interaction between the viral polymerase and Rab11a. Using pull-down assays we show that vRNPs but not cRNPs from infected cell lysates bind to Rab11a. We also show that the viral polymerase directly interacts with Rab11a and that the C-terminal two thirds of the PB2 polymerase subunit (PB2-C) comprising the cap-binding, mid-link, 627 and nuclear localization signal (NLS) domains mediate this interaction. Small-angle X-ray scattering (SAXS) experiments confirmed that PB2-C associates with Rab11a in solution forming a compact folded complex with a 1:1 stoichiometry. Furthermore, we demonstrate that the switch I region of Rab11a, that has been shown to be important for binding Rab11 family interacting proteins (Rab11-FIPs), is also important for PB2-C binding suggesting that IAV polymerase and Rab11-FIPs compete for the same binding site. Our findings expand our understanding of the interaction between the IAV polymerase and Rab11a in the cytoplasmic transport of vRNPs. Importance The influenza virus RNA genome segments are replicated in the cell nucleus and are assembled into viral ribonucleoprotein (vRNP) complexes with viral RNA polymerase and nucleoprotein (NP). Replicated vRNPs need to be exported from the nucleus and trafficked across the cytoplasm to the cell membrane where virion assembly takes place. The host GTPase Rab11a plays a role in vRNP trafficking. In this study we show that the viral polymerase directly interacts with Rab11a mediating the interaction between vRNPs and Rab11a. We map this interaction to the C-terminal domains of the PB2 polymerase subunit and the switch I region of Rab11a. Identifying the exact site of Rab11a binding on the viral polymerase could uncover a novel target site for the development of an influenza antiviral drug.
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19
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Mapping inhibitory sites on the RNA polymerase of the 1918 pandemic influenza virus using nanobodies. Nat Commun 2022; 13:251. [PMID: 35017564 PMCID: PMC8752864 DOI: 10.1038/s41467-021-27950-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 12/21/2021] [Indexed: 11/26/2022] Open
Abstract
Influenza A viruses cause seasonal epidemics and global pandemics, representing a considerable burden to healthcare systems. Central to the replication cycle of influenza viruses is the viral RNA-dependent RNA polymerase which transcribes and replicates the viral RNA genome. The polymerase undergoes conformational rearrangements and interacts with viral and host proteins to perform these functions. Here we determine the structure of the 1918 influenza virus polymerase in transcriptase and replicase conformations using cryo-electron microscopy (cryo-EM). We then structurally and functionally characterise the binding of single-domain nanobodies to the polymerase of the 1918 pandemic influenza virus. Combining these functional and structural data we identify five sites on the polymerase which are sensitive to inhibition by nanobodies. We propose that the binding of nanobodies at these sites either prevents the polymerase from assuming particular functional conformations or interactions with viral or host factors. The polymerase is highly conserved across the influenza A subtypes, suggesting these sites as effective targets for potential influenza antiviral development. Influenza viruses carry their own RNAdependent RNA-polymerase that is highly conserved and a promising anti-viral target. Combining functional and structural data, Keown et al. characterise the inhibitory effect of nanobodies on 1918 pandemic H1N1 influenza strain polymerase complex and identify sensitive sites interfering with polymerase activity in vitro.
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Pyle JD, Whelan SPJ, Bloyet LM. Structure and function of negative-strand RNA virus polymerase complexes. Enzymes 2021; 50:21-78. [PMID: 34861938 DOI: 10.1016/bs.enz.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Viruses with negative-strand RNA genomes (NSVs) include many highly pathogenic and economically devastating disease-causing agents of humans, livestock, and plants-highlighted by recent Ebola and measles virus epidemics, and continuously circulating influenza virus. Because of their protein-coding orientation, NSVs face unique challenges for efficient gene expression and genome replication. To overcome these barriers, NSVs deliver a large and multifunctional RNA-dependent RNA polymerase into infected host cells. NSV-encoded polymerases contain all the enzymatic activities required for transcription and replication of their genome-including RNA synthesis and mRNA capping. Here, we review the structures and functions of NSV polymerases with a focus on key domains responsible for viral replication and gene expression. We highlight shared and unique features among polymerases of NSVs from the Mononegavirales, Bunyavirales, and Articulavirales orders.
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Affiliation(s)
- Jesse D Pyle
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States; Ph.D. Program in Virology, Harvard Medical School, Boston, MA, United States
| | - Sean P J Whelan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States.
| | - Louis-Marie Bloyet
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States.
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21
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Conformational changes in Lassa virus L protein associated with promoter binding and RNA synthesis activity. Nat Commun 2021; 12:7018. [PMID: 34857749 PMCID: PMC8639829 DOI: 10.1038/s41467-021-27305-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/08/2021] [Indexed: 11/08/2022] Open
Abstract
Lassa virus is endemic in West Africa and can cause severe hemorrhagic fever. The viral L protein transcribes and replicates the RNA genome via its RNA-dependent RNA polymerase activity. Here, we present nine cryo-EM structures of the L protein in the apo-, promoter-bound pre-initiation and active RNA synthesis states. We characterize distinct binding pockets for the conserved 3' and 5' promoter RNAs and show how full-promoter binding induces a distinct pre-initiation conformation. In the apo- and early elongation states, the endonuclease is inhibited by two distinct L protein peptides, whereas in the pre-initiation state it is uninhibited. In the early elongation state, a template-product duplex is bound in the active site cavity together with an incoming non-hydrolysable nucleotide and the full C-terminal region of the L protein, including the putative cap-binding domain, is well-ordered. These data advance our mechanistic understanding of how this flexible and multifunctional molecular machine is activated.
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22
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Wang Y, Sun W, Wang Z, Zhao M, Zhang X, Kong Y, Wang X, Feng N, Wang T, Yan F, Zhao Y, Xia X, Yang S, Gao Y. Amino acid sites related to the PB2 subunits of IDV affect polymerase activity. Virol J 2021; 18:230. [PMID: 34809668 PMCID: PMC8607657 DOI: 10.1186/s12985-021-01703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/15/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND In 2011, a new influenza virus, named Influenza D Virus (IDV), was isolated from pigs, and then cattle, presenting influenza-like symptoms. IDV is one of the causative agents of Bovine Respiratory Disease (BRD), which causes high morbidity and mortality in feedlot cattle worldwide. To date, the molecular mechanisms of IDV pathogenicity are unknown. Recent IDV outbreaks in cattle, along with serological and genetic evidence of IDV infection in humans, have raised concerns regarding the zoonotic potential of this virus. Influenza virus polymerase is a determining factor of viral pathogenicity to mammals. METHODS Here we take a prospective approach to this question by creating a random mutation library about PB2 subunit of the IDV viral polymerase to test which amino acid point mutations will increase viral polymerase activity, leading to increased pathogenicity of the virus. RESULTS Our work shows some exact sites that could affect polymerase activities in influenza D viruses. For example, two single-site mutations, PB2-D533S and PB2-G603Y, can independently increase polymerase activity. The PB2-D533S mutation alone can increase the polymerase activity by 9.92 times, while the PB2-G603Y mutation increments the activity by 8.22 times. CONCLUSION Taken together, our findings provide important insight into IDV replication fitness mediated by the PB2 protein, increasing our understanding of IDV replication and pathogenicity and facilitating future studies.
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Affiliation(s)
- Yutian Wang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Weiyang Sun
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Zhenfei Wang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
- Jilin Agricultural University, Changchun, 130118, China
| | - Menglin Zhao
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Xinghai Zhang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Yunyi Kong
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Xuefeng Wang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Na Feng
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Tiecheng Wang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Feihu Yan
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Yongkun Zhao
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Xianzhu Xia
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China
| | - Songtao Yang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China.
| | - Yuwei Gao
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, 130000, China.
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Staller E, Barclay WS. Host Cell Factors That Interact with Influenza Virus Ribonucleoproteins. Cold Spring Harb Perspect Med 2021; 11:a038307. [PMID: 32988980 PMCID: PMC8559542 DOI: 10.1101/cshperspect.a038307] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Influenza viruses hijack host cell factors at each stage of the viral life cycle. After host cell entry and endosomal escape, the influenza viral ribonucleoproteins (vRNPs) are released into the cytoplasm where the classical cellular nuclear import pathway is usurped for nuclear translocation of the vRNPs. Transcription takes place inside the nucleus at active host transcription sites, and cellular mRNA export pathways are subverted for export of viral mRNAs. Newly synthesized RNP components cycle back into the nucleus using various cellular nuclear import pathways and host-encoded chaperones. Replication of the negative-sense viral RNA (vRNA) into complementary RNA (cRNA) and back into vRNA requires complex interplay between viral and host factors. Progeny vRNPs assemble at the host chromatin and subsequently exit from the nucleus-processes orchestrated by sets of host and viral proteins. Finally, several host pathways appear to play a role in vRNP trafficking from the nuclear envelope to the plasma membrane for egress.
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Affiliation(s)
- Ecco Staller
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, St. Mary's Campus, London W2 1NY, United Kingdom
| | - Wendy S Barclay
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, St. Mary's Campus, London W2 1NY, United Kingdom
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24
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Staller E, Sheppard CM, Baillon L, Frise R, Peacock TP, Sancho-Shimizu V, Barclay WS. A natural variant in ANP32B impairs influenza virus replication in human cells. J Gen Virol 2021; 102. [PMID: 34524075 PMCID: PMC8567425 DOI: 10.1099/jgv.0.001664] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Viruses require host factors to support their replication, and genetic variation in such factors can affect susceptibility to infectious disease. Influenza virus replication in human cells relies on ANP32 proteins, which are involved in assembly of replication-competent dimeric influenza virus polymerase (FluPol) complexes. Here, we investigate naturally occurring single nucleotide variants (SNV) in the human Anp32A and Anp32B genes. We note that variant rs182096718 in Anp32B is found at a higher frequency than other variants in either gene. This SNV results in a D130A substitution in ANP32B, which is less able to support FluPol activity than wild-type ANP32B and binds FluPol with lower affinity. Interestingly, ANP32B-D130A exerts a dominant negative effect over wild-type ANP32B and interferes with the functionally redundant paralogue ANP32A. FluPol activity and virus replication are attenuated in CRISPR-edited cells expressing wild-type ANP32A and mutant ANP32B-D130A. We propose a model in which the D130A mutation impairs FluPol dimer formation, thus resulting in compromised replication. We suggest that both homozygous and heterozygous carriers of rs182096718 may have some genetic protection against influenza viruses.
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Affiliation(s)
- Ecco Staller
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK.,Present address: Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Carol M Sheppard
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK
| | - Laury Baillon
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK
| | - Rebecca Frise
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK
| | - Thomas P Peacock
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK
| | | | - Wendy S Barclay
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, UK
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25
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Abstract
Influenza polymerase (FluPol) plays a key role in the viral infection cycle by transcribing and replicating the viral genome. FluPol is a multifunctional, heterotrimeric enzyme with cap-binding, endonuclease, RNA-dependent RNA polymerase and polyadenylation activities. It performs its functions in the context of the viral ribonucleoprotein particle (RNP), wherein the template viral RNA is coated by multiple copies of viral nucleoprotein. Moreover, it interacts with a number of host proteins that are essential cofactors and, consequently, adaptive mutations in the polymerase are required for crossing the avian-human species barrier. In this review, we show how mechanistic understanding of how FluPol performs its multiple functions has greatly advanced over the last decade through determination of high-resolution structures by X-ray crystallography and cryo-electron microscopy. These have revealed not only the detailed architecture of FluPol but highlighted the remarkably conformational flexibility that is inherent to its functioning as a dynamic RNA synthesis machine. Structural studies are also underpinning current attempts to develop next-generation anti-influenza drugs that directly target FluPol.
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Affiliation(s)
- Joanna M Wandzik
- European Molecular Biology Laboratory, Grenoble 38042-Cedex 9, France
| | - Tomas Kouba
- European Molecular Biology Laboratory, Grenoble 38042-Cedex 9, France
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble 38042-Cedex 9, France
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26
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Identification of One Critical Amino Acid Residue of the Nucleoprotein as a Determinant for In Vitro Replication Fitness of Influenza D Virus. J Virol 2021; 95:e0097121. [PMID: 34190601 DOI: 10.1128/jvi.00971-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The newly identified influenza D virus (IDV) of the Orthomyxoviridae family has a wide host range with a broad geographical distribution. Despite the first appearance in U.S. pig herds in 2011, subsequent studies demonstrated that IDV is widespread in global cattle populations, supporting a theory that IDV utilizes bovines as a primary reservoir. Our investigation of the two reference influenza D viruses, D/swine/Oklahoma/1334/2011 (OK/11), isolated from swine, and D/Bovine/Oklahoma/660/2013 (660/13), isolated from cattle, revealed that 660/13 replicated to titers approximately 100-fold higher than those for OK/11 in multiple cell lines. By using a recently developed IDV reverse-genetics system derived from low-titer OK/11, we generated recombinant chimeric OK/11 viruses in which one of the seven genome segments was replaced with its counterpart from high-titer 660/13 virus. Further characterization demonstrated that the replication level of the chimeric OK/11 virus was significantly increased only when harboring the 660/13 nucleoprotein (NP) segment. Finally, through both gain-of-function and loss-of-function experiments, we identified that one amino acid residue at position 381, located in the body domain of NP protein, was a key determinant for the replication difference between the low-titer OK/11 virus and the high-titer 660/13 virus. Taken together, our findings provide important insight into IDV replication fitness mediated by the NP protein, which should facilitate future study of the infectious virus particle production mechanism of IDV. IMPORTANCE Little is known about the virus infection and production mechanism for newly discovered influenza D virus (IDV), which utilizes bovines as a primary reservoir, with frequent spillover to new hosts, including swine. In this study, we showed that of two well-characterized IDVs, 660/13 replicated more efficiently (approximately 100-fold higher) than OK/11. Using a recently developed IDV reverse-genetics system, we identified viral nucleoprotein (NP) as a primary determinant of the different replication capacities observed between these two nearly identical viruses. Mechanistic investigation further revealed that a mutation at NP position 381 evidently modulated virus fitness. Taken together, these observations indicate that IDV NP protein performs a critical role in infectious virus particle production. Our study thus illustrates an NP-based mechanism for efficient IDV infection and production in vitro.
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27
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Xu X, Zhang L, Chu JTS, Wang Y, Chin AWH, Chong TH, Dai Z, Poon LLM, Cheung PPH, Huang X. A novel mechanism of enhanced transcription activity and fidelity for influenza A viral RNA-dependent RNA polymerase. Nucleic Acids Res 2021; 49:8796-8810. [PMID: 34379778 PMCID: PMC8421151 DOI: 10.1093/nar/gkab660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
During RNA elongation, the influenza A viral (IAV) RNA-dependent RNA polymerase (RdRp) residues in the active site interact with the triphosphate moiety of nucleoside triphosphate (NTP) for catalysis. The molecular mechanisms by which they control the rate and fidelity of NTP incorporation remain elusive. Here, we demonstrated through enzymology, virology and computational approaches that the R239 and K235 in the PB1 subunit of RdRp are critical to controlling the activity and fidelity of transcription. Contrary to common beliefs that high-fidelity RdRp variants exert a slower incorporation rate, we discovered a first-of-its-kind, single lysine-to-arginine mutation on K235 exhibited enhanced fidelity and activity compared with wild-type. In particular, we employed a single-turnover NTP incorporation assay for the first time on IAV RdRp to show that K235R mutant RdRp possessed a 1.9-fold increase in the transcription activity of the cognate NTP and a 4.6-fold increase in fidelity compared to wild-type. Our all-atom molecular dynamics simulations further elucidated that the higher activity is attributed to the shorter distance between K235R and the triphosphate moiety of NTP compared with wild-type. These results provide novel insights into NTP incorporation and fidelity control mechanisms, which lay the foundation for the rational design of IAV vaccine and antiviral targets.
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Affiliation(s)
- Xinzhou Xu
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Julie Tung Sem Chu
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yuqing Wang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Bioengineering Graduate Program, Department of Biological and Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Alex Wing Hong Chin
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Tin Hang Chong
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Zixi Dai
- Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Leo Lit Man Poon
- School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,HKU-Pasteur Research Pole, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Centre for Immunity and Infection, Hong Kong Science Park, Hong Kong, China
| | - Peter Pak-Hang Cheung
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.,Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.,Li Ka Shing Institute of Health Sciences, Li Ka Shing Medical Sciences Building, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xuhui Huang
- The Hong Kong University of Science and Technology-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China.,Department of Chemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
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28
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Ultrastructure of influenza virus ribonucleoprotein complexes during viral RNA synthesis. Commun Biol 2021; 4:858. [PMID: 34244608 PMCID: PMC8271009 DOI: 10.1038/s42003-021-02388-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/23/2021] [Indexed: 11/16/2022] Open
Abstract
The single-stranded, negative-sense, viral genomic RNA (vRNA) of influenza A virus is encapsidated by viral nucleoproteins (NPs) and an RNA polymerase to form a ribonucleoprotein complex (vRNP) with a helical, rod-shaped structure. The vRNP is responsible for transcription and replication of the vRNA. However, the vRNP conformation during RNA synthesis is not well understood. Here, using high-speed atomic force microscopy and cryo-electron microscopy, we investigated the native structure of influenza A vRNPs during RNA synthesis in vitro. Two distinct types of vRNPs were observed in association with newly synthesized RNAs: an intact, helical rod-shaped vRNP connected with a folded RNA and a deformed vRNP associated with a looped RNA. Interestingly, the looped RNA was a double-stranded RNA, which likely comprises a nascent RNA and the template RNA detached from NPs of the vRNP. These results suggest that while some vRNPs keep their helical structures during RNA synthesis, for the repeated cycle of RNA synthesis, others accidentally become structurally deformed, which likely results in failure to commence or continue RNA synthesis. Thus, our findings provide the ultrastructural feature of vRNPs during RNA synthesis. Nakano et al. use high-speed AFM and cryo-EM to study influenza virus RNA synthesis in vitro. They observe the synthesis of two types of RNA: folded single stranded RNA associated to an intact viral ribonucleoprotein (vRNP) and looped, double stranded RNA associated with a partially rearranged vRNP structure.
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29
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Takashita E. Influenza Polymerase Inhibitors: Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a038687. [PMID: 32122918 PMCID: PMC8091960 DOI: 10.1101/cshperspect.a038687] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The influenza virus RNA-dependent RNA polymerase is highly conserved among influenza A, B, C, and D viruses. It comprises three subunits: polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), and polymerase acidic protein (PA) in influenza A and B viruses or polymerase 3 protein (P3) in influenza C and D viruses. Because this polymerase is essential for influenza virus replication, it has been considered as a target for antiviral agents. Recently, several polymerase inhibitors that target each subunit have been developed. This review discusses the mechanism of action, antiviral activity, and emergence of resistance to three inhibitors approved for the treatment of influenza or in late-phase clinical trials: the PB1 inhibitor favipiravir, the PB2 inhibitor pimodivir, and the PA inhibitor baloxavir marboxil.
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Affiliation(s)
- Emi Takashita
- Influenza Virus Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan
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30
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Weis S, te Velthuis AJW. Influenza Virus RNA Synthesis and the Innate Immune Response. Viruses 2021; 13:v13050780. [PMID: 33924859 PMCID: PMC8146608 DOI: 10.3390/v13050780] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/25/2021] [Accepted: 04/25/2021] [Indexed: 12/25/2022] Open
Abstract
Infection with influenza A and B viruses results in a mild to severe respiratory tract infection. It is widely accepted that many factors affect the severity of influenza disease, including viral replication, host adaptation, innate immune signalling, pre-existing immunity, and secondary infections. In this review, we will focus on the interplay between influenza virus RNA synthesis and the detection of influenza virus RNA by our innate immune system. Specifically, we will discuss the generation of various RNA species, host pathogen receptors, and host shut-off. In addition, we will also address outstanding questions that currently limit our knowledge of influenza virus replication and host adaption. Understanding the molecular mechanisms underlying these factors is essential for assessing the pandemic potential of future influenza virus outbreaks.
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31
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Fearns R. Negative‐strand RNA Viruses. Virology 2021. [DOI: 10.1002/9781119818526.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Krischuns T, Lukarska M, Naffakh N, Cusack S. Influenza Virus RNA-Dependent RNA Polymerase and the Host Transcriptional Apparatus. Annu Rev Biochem 2021; 90:321-348. [PMID: 33770447 DOI: 10.1146/annurev-biochem-072820-100645] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Influenza virus RNA-dependent RNA polymerase (FluPol) transcribes the viral RNA genome in the infected cell nucleus. In the 1970s, researchers showed that viral transcription depends on host RNA polymerase II (RNAP II) activity and subsequently that FluPol snatches capped oligomers from nascent RNAP II transcripts to prime its own transcription. Exactly how this occurs remains elusive. Here, we review recent advances in the mechanistic understanding of FluPol transcription and early events in RNAP II transcription that are relevant to cap-snatching. We describe the known direct interactions between FluPol and the RNAP II C-terminal domain and summarize the transcription-related host factors that have been found to interact with FluPol. We also discuss open questions regarding how FluPol may be targeted to actively transcribing RNAP II and the exact context and timing of cap-snatching, which is presumed to occur after cap completion but before the cap is sequestered by the nuclear cap-binding complex.
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Affiliation(s)
- Tim Krischuns
- Unité Biologie des ARN et Virus Influenza, Département de Virologie, Institut Pasteur, CNRS UMR 3569, F-75015 Paris, France; ,
| | - Maria Lukarska
- European Molecular Biology Laboratory, 38042 Grenoble CEDEX 9, France; .,Current affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA;
| | - Nadia Naffakh
- Unité Biologie des ARN et Virus Influenza, Département de Virologie, Institut Pasteur, CNRS UMR 3569, F-75015 Paris, France; ,
| | - Stephen Cusack
- European Molecular Biology Laboratory, 38042 Grenoble CEDEX 9, France;
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33
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Gregor J, Radilová K, Brynda J, Fanfrlík J, Konvalinka J, Kožíšek M. Structural and Thermodynamic Analysis of the Resistance Development to Pimodivir (VX-787), the Clinical Inhibitor of Cap Binding to PB2 Subunit of Influenza A Polymerase. Molecules 2021; 26:molecules26041007. [PMID: 33673017 PMCID: PMC7917969 DOI: 10.3390/molecules26041007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/20/2021] [Accepted: 02/12/2021] [Indexed: 01/06/2023] Open
Abstract
Influenza A virus (IAV) encodes a polymerase composed of three subunits: PA, with endonuclease activity, PB1 with polymerase activity and PB2 with host RNA five-prime cap binding site. Their cooperation and stepwise activation include a process called cap-snatching, which is a crucial step in the IAV life cycle. Reproduction of IAV can be blocked by disrupting the interaction between the PB2 domain and the five-prime cap. An inhibitor of this interaction called pimodivir (VX-787) recently entered the third phase of clinical trial; however, several mutations in PB2 that cause resistance to pimodivir were observed. First major mutation, F404Y, causing resistance was identified during preclinical testing, next the mutation M431I was identified in patients during the second phase of clinical trials. The mutation H357N was identified during testing of IAV strains at Centers for Disease Control and Prevention. We set out to provide a structural and thermodynamic analysis of the interactions between cap-binding domain of PB2 wild-type and PB2 variants bearing these mutations and pimodivir. Here we present four crystal structures of PB2-WT, PB2-F404Y, PB2-M431I and PB2-H357N in complex with pimodivir. We have thermodynamically analysed all PB2 variants and proposed the effect of these mutations on thermodynamic parameters of these interactions and pimodivir resistance development. These data will contribute to understanding the effect of these missense mutations to the resistance development and help to design next generation inhibitors.
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Affiliation(s)
- Jiří Gregor
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
- First Faculty of Medicine, Charles University, Kateřinská 1660/32, 12108 Prague 2, Czech Republic
| | - Kateřina Radilová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
- First Faculty of Medicine, Charles University, Kateřinská 1660/32, 12108 Prague 2, Czech Republic
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
| | - Jindřich Fanfrlík
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague 2, Czech Republic
- Correspondence: (J.K.); (M.K.); Tel.: +420-220-183-218 (J.K.)
| | - Milan Kožíšek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Gilead Sciences and IOCB Research Center, Flemingovo n. 2, 16610 Prague 6, Czech Republic; (J.G.); (K.R.); (J.B.); (J.F.)
- Correspondence: (J.K.); (M.K.); Tel.: +420-220-183-218 (J.K.)
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Abstract
RNA viruses include many important human and animal pathogens, such as the influenza viruses, respiratory syncytial virus, Ebola virus, measles virus and rabies virus. The genomes of these viruses consist of single or multiple RNA segments that assemble with oligomeric viral nucleoprotein into ribonucleoprotein complexes. Replication and transcription of the viral genome is performed by ~250-450 kDa viral RNA-dependent RNA polymerases that also contain capping or cap-snatching activity. In this Review, we compare recent high-resolution X-ray and cryoelectron microscopy structures of RNA polymerases of negative-sense RNA viruses with segmented and non-segmented genomes, including orthomyxoviruses, peribunyaviruses, phenuiviruses, arenaviruses, rhabdoviruses, pneumoviruses and paramyxoviruses. In addition, we discuss how structural insights into these enzymes contribute to our understanding of the molecular mechanisms of viral transcription and replication, and how we can use these insights to identify targets for antiviral drug design.
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Carrique L, Fan H, Walker AP, Keown JR, Sharps J, Staller E, Barclay WS, Fodor E, Grimes JM. Host ANP32A mediates the assembly of the influenza virus replicase. Nature 2020; 587:638-643. [PMID: 33208942 PMCID: PMC7116770 DOI: 10.1038/s41586-020-2927-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 09/01/2020] [Indexed: 12/11/2022]
Abstract
Aquatic birds represent a vast reservoir from which new pandemic influenza A viruses can emerge1. Influenza viruses contain a negative-sense segmented RNA genome that is transcribed and replicated by the viral heterotrimeric RNA polymerase (FluPol) in the context of viral ribonucleoprotein complexes2,3. RNA polymerases of avian influenza A viruses (FluPolA) replicate viral RNA inefficiently in human cells because of species-specific differences in acidic nuclear phosphoprotein 32 (ANP32), a family of essential host proteins for FluPol activity4. Host-adaptive mutations, particularly a glutamic-acid-to-lysine mutation at amino acid residue 627 (E627K) in the 627 domain of the PB2 subunit, enable avian FluPolA to overcome this restriction and efficiently replicate viral RNA in the presence of human ANP32 proteins. However, the molecular mechanisms of genome replication and the interplay with ANP32 proteins remain largely unknown. Here we report cryo-electron microscopy structures of influenza C virus polymerase (FluPolC) in complex with human and chicken ANP32A. In both structures, two FluPolC molecules form an asymmetric dimer bridged by the N-terminal leucine-rich repeat domain of ANP32A. The C-terminal low-complexity acidic region of ANP32A inserts between the two juxtaposed PB2 627 domains of the asymmetric FluPolA dimer, suggesting a mechanism for how the adaptive PB2(E627K) mutation enables the replication of viral RNA in mammalian hosts. We propose that this complex represents a replication platform for the viral RNA genome, in which one of the FluPol molecules acts as a replicase while the other initiates the assembly of the nascent replication product into a viral ribonucleoprotein complex.
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Affiliation(s)
- Loïc Carrique
- Division of Structural Biology, University of Oxford, Oxford, UK
| | - Haitian Fan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | | | - Jeremy R Keown
- Division of Structural Biology, University of Oxford, Oxford, UK
| | - Jane Sharps
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ecco Staller
- Section of Molecular Virology, Imperial College London, London, UK
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Wendy S Barclay
- Section of Molecular Virology, Imperial College London, London, UK
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| | - Jonathan M Grimes
- Division of Structural Biology, University of Oxford, Oxford, UK.
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK.
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Hashimoto T, Baba K, Inoue K, Okane M, Hata S, Shishido T, Naito A, Wildum S, Omoto S. Comprehensive assessment of amino acid substitutions in the trimeric RNA polymerase complex of influenza A virus detected in clinical trials of baloxavir marboxil. Influenza Other Respir Viruses 2020; 15:389-395. [PMID: 33099886 PMCID: PMC8051730 DOI: 10.1111/irv.12821] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/01/2020] [Accepted: 10/04/2020] [Indexed: 01/18/2023] Open
Abstract
Background Baloxavir marboxil (BXM) is an approved drug that selectively targets cap‐dependent endonuclease on PA subunit in the RNA polymerase complex of influenza A and B viruses. Amino acid substitutions at position 38 in the PA subunit were identified as a major pathway for reduced susceptibility to baloxavir acid (BXA), the active form of BXM. Additionally, substitutions found at positions E23, A37, and E199 in the PA subunit impact BXA susceptibility by less than 10‐fold. Methods We comprehensively evaluated the impact of novel amino acid substitutions identified in PA, PB1, and PB2 subunits in BXM clinical trials and influenza sequence databases by means of drug susceptibility and replicative capacity. Results PA/I38N in A(H1N1)pdm09 and PA/I38R in A(H3N2) were newly identified as treatment‐emergent substitutions in the CAPSTONE‐2 study. The I38N substitution conferred reduced susceptibility by 24‐fold, whereas replicative capacity of the I38N‐substituted virus was impaired compared with the wild‐type. The I38R‐substituted virus was not viable in cell culture. All other mutations assessed in this extensive study did not significantly affect BXA susceptibility (< 2.4‐fold change). Conclusion These results provide additional information on the impact of amino acid substitutions in the trimeric viral polymerase complex to BXA susceptibility and will further support influenza surveillance.
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Affiliation(s)
- Takashi Hashimoto
- Shionogi & Co., Ltd., Osaka, Japan.,Shionogi Techno Advance Research, Co., Ltd., Osaka, Japan
| | | | - Kae Inoue
- Shionogi Techno Advance Research, Co., Ltd., Osaka, Japan
| | - Miyako Okane
- Shionogi Techno Advance Research, Co., Ltd., Osaka, Japan
| | - Satoshi Hata
- Shionogi Techno Advance Research, Co., Ltd., Osaka, Japan
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Dawson AR, Wilson GM, Freiberger EC, Mondal A, Coon JJ, Mehle A. Phosphorylation controls RNA binding and transcription by the influenza virus polymerase. PLoS Pathog 2020; 16:e1008841. [PMID: 32881973 PMCID: PMC7494117 DOI: 10.1371/journal.ppat.1008841] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/16/2020] [Accepted: 07/25/2020] [Indexed: 12/03/2022] Open
Abstract
The influenza virus polymerase transcribes and replicates the viral genome. The proper timing and balance of polymerase activity is important for successful replication. Genome replication is controlled in part by phosphorylation of NP that regulates assembly of the replication machinery. However, it remains unclear whether phosphorylation directly regulated polymerase activity. Here we identified polymerase phosphosites that control its function. Mutating phosphosites in the catalytic subunit PB1 altered polymerase activity and virus replication. Biochemical analyses revealed phosphorylation events that disrupted global polymerase function by blocking the NTP entry channel or preventing RNA binding. We also identified a regulatory site that split polymerase function by specifically suppressing transcription. These experiments show that host kinases phospho-regulate viral RNA synthesis directly by modulating polymerase activity and indirectly by controlling assembly of replication machinery. Further, they suggest polymerase phosphorylation may bias replication versus transcription at discrete times or locations during the infectious cycle. The influenza virus polymerase is a multifunctional enzyme directing viral gene expression and genome replication. Immediately following infection, the polymerase primarily performs transcription to make the viral mRNAs that program the replication cycle. The polymerase then shifts output to produce more copies of the viral genome at later stages of infection. The balance between transcription and replication is critical for successful infection. Here we identify phosphorylation sites within the viral polymerase and describe how these post-translational modifications control polymerase activity. Cellular kinases modify the viral polymerase. We identified a phosphorylation site in the catalytic subunit PB1 that selectively disables transcription, but not replication. We also describe a phosphorylation site in PB1 that disrupts binding to viral RNAs, disabling all activities of the polymerase. These modifications may establish polymerases with specialized function, and help regulate the balance between transcription and replication throughout the viral life cycle.
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Affiliation(s)
- Anthony R. Dawson
- Department of Medical Microbiology & Immunology, University of Wisconsin–Madison, Madison, WI, United States of America
| | - Gary M. Wilson
- Department of Chemistry, University of Wisconsin–Madison, Madison, WI, United States of America
| | - Elyse C. Freiberger
- Department of Biomolecular Chemistry, University of Wisconsin–Madison, Madison, WI, United States of America
| | - Arindam Mondal
- Department of Medical Microbiology & Immunology, University of Wisconsin–Madison, Madison, WI, United States of America
| | - Joshua J. Coon
- Department of Chemistry, University of Wisconsin–Madison, Madison, WI, United States of America
- Department of Biomolecular Chemistry, University of Wisconsin–Madison, Madison, WI, United States of America
| | - Andrew Mehle
- Department of Medical Microbiology & Immunology, University of Wisconsin–Madison, Madison, WI, United States of America
- * E-mail:
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38
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Fodor E, Te Velthuis AJW. Structure and Function of the Influenza Virus Transcription and Replication Machinery. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a038398. [PMID: 31871230 DOI: 10.1101/cshperspect.a038398] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Transcription and replication of the influenza virus RNA genome is catalyzed by the viral heterotrimeric RNA-dependent RNA polymerase in the context of viral ribonucleoprotein (vRNP) complexes. Atomic resolution structures of the viral RNA synthesis machinery have offered insights into the initiation mechanisms of viral transcription and genome replication, and the interaction of the viral RNA polymerase with host RNA polymerase II, which is required for the initiation of viral transcription. Replication of the viral RNA genome by the viral RNA polymerase depends on host ANP32A, and host-specific sequence differences in ANP32A underlie the poor activity of avian influenza virus polymerases in mammalian cells. A failure to faithfully copy the viral genome segments can lead to the production of aberrant viral RNA products, such as defective interfering (DI) RNAs and mini viral RNAs (mvRNAs). Both aberrant RNA types have been implicated in innate immune responses against influenza virus infection. This review discusses recent insights into the structure-function relationship of the viral RNA polymerase and its role in determining host range and virulence.
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Affiliation(s)
- Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Aartjan J W Te Velthuis
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 2QQ, United Kingdom
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Molecular basis of host-adaptation interactions between influenza virus polymerase PB2 subunit and ANP32A. Nat Commun 2020; 11:3656. [PMID: 32694517 PMCID: PMC7374565 DOI: 10.1038/s41467-020-17407-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022] Open
Abstract
Avian influenza polymerase undergoes host adaptation in order to efficiently replicate in human cells. Adaptive mutants are localised on the C-terminal (627-NLS) domains of the PB2 subunit. In particular, mutation of PB2 residue 627 from E to K rescues polymerase activity in mammalian cells. A host transcription regulator ANP32A, comprising a long C-terminal intrinsically disordered domain (IDD), is responsible for this adaptation. Human ANP32A IDD lacks a 33 residue insertion compared to avian ANP32A, and this deletion restricts avian influenza polymerase activity. We used NMR to determine conformational ensembles of E627 and K627 forms of 627-NLS of PB2 in complex with avian and human ANP32A. Human ANP32A IDD transiently binds to the 627 domain, exploiting multivalency to maximise affinity. E627 interrupts the polyvalency of the interaction, an effect compensated by an avian-unique motif in the IDD. The observed binding mode is maintained in the context of heterotrimeric influenza polymerase, placing ANP32A in the immediate vicinity of known host-adaptive PB2 mutants. Avian influenza polymerase undergoes host adaptation in order to efficiently replicate in human cells. Here, the authors use NMR spectroscopy and quantitative ensemble modelling to describe the highly dynamic assemblies formed by the human-adapted or avian-adapted C-terminal domains with the respective ANP32A host proteins.
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40
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Mutation of an Influenza Virus Polymerase 3' RNA Promoter Binding Site Inhibits Transcription Elongation. J Virol 2020; 94:JVI.00498-20. [PMID: 32295915 DOI: 10.1128/jvi.00498-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022] Open
Abstract
Influenza viruses encode a viral RNA-dependent RNA polymerase (FluPol), which is responsible for transcribing and replicating the negative-sense viral RNA (vRNA) genome. FluPol transcribes vRNA using a host-capped mRNA primer and replicates it by synthesizing a positive-sense cRNA intermediate, which is copied back into vRNA. To carry out these functions, FluPol interacts with vRNA and cRNA using conserved promoter elements at the 5' and 3' termini. Recent structural studies have identified a new surface binding site for the 3' vRNA and cRNA promoters on FluPol, referred to as the mode B site. However, the role of this binding site in FluPol function is unknown. In this study, we used a combination of cell-based and biochemical assays to show that the mode B site is important for both viral genome transcription and replication in influenza A virus. Furthermore, we show that the mode B site is not needed for initiating transcription in vitro but is required to synthesize a full-length product. This is consistent with a model in which the 3' terminus of the vRNA template binds in the mode B site during elongation. Our data provide the first functional insights into the role of the mode B site on FluPol, which advances our understanding of FluPol function and influenza virus replication.IMPORTANCE Influenza viruses are responsible for up to 650,000 deaths per year through seasonal epidemics, and pandemics have caused tens of millions of deaths in the past. Most current therapeutics suffer from widespread resistance, creating a need for new drug targets against influenza virus. The virus encodes an RNA-dependent RNA polymerase, which replicates and transcribes the vRNA genome. The polymerase interacts with vRNA and the complementary replicative intermediate cRNA using several specific binding sites; however, the functions associated with these binding sites remain unknown. Here, we functionally characterize a binding site for the 3' vRNA and cRNA promoters. Our data offer insight into the mechanism of viral genome transcription by the influenza virus polymerase and may be applicable to other related viruses.
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Suzuki Y, Inoue T, Nishimura M, Kobayashi Y. Putative bundling signals incompatible between influenza C and D viruses. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The ongoing COVID-19 pandemic has made us to consider the emergence of potential viral diseases in the future. Animals can carry vast and diverse virus species, most of which we do not understand yet, and the spillover events of the viruses from the unknown pool in animals to human population always occurred in the past. To effectively prevent and control the emerging viral diseases, we should make efforts to explore the unknown virus species in nature and prepare in advance.
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Affiliation(s)
- Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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43
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Structure of severe fever with thrombocytopenia syndrome virus L protein elucidates the mechanisms of viral transcription initiation. Nat Microbiol 2020; 5:864-871. [PMID: 32341479 DOI: 10.1038/s41564-020-0712-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/19/2020] [Indexed: 02/07/2023]
Abstract
Segmented negative-sense RNA viruses (sNSRVs) encode a single-polypeptide polymerase (L protein) or a heterotrimeric polymerase complex to cannibalize host messenger RNA cap structures serving as primers of transcription, and catalyse RNA synthesis. Here, we report the full-length structure of the severe fever with thrombocytopaenia syndrome virus (SFTSV) L protein, as determined by cryogenic electron microscopy at 3.4 Å, leading to an atomic model harbouring three functional parts (an endonuclease, an RNA-dependent RNA polymerase and a cap-binding domain) and two structural domains (an arm domain with a blocker motif and a carboxy-terminal lariat domain). The SFTSV L protein has a compact architecture in which its cap-binding pocket is surprisingly occupied by an Arg finger of the blocker motif, and the endonuclease active centre faces back towards the cap-binding pocket, suggesting that domain rearrangements are necessary to acquire the pre-initiation state of the active site. Our results provide insight into the complete architecture of sNSRV-encoded L protein and further the understanding of sNSRV transcription initiation.
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Wandzik JM, Kouba T, Karuppasamy M, Pflug A, Drncova P, Provaznik J, Azevedo N, Cusack S. A Structure-Based Model for the Complete Transcription Cycle of Influenza Polymerase. Cell 2020; 181:877-893.e21. [PMID: 32304664 DOI: 10.1016/j.cell.2020.03.061] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/18/2020] [Accepted: 03/26/2020] [Indexed: 11/16/2022]
Abstract
Influenza polymerase uses unique mechanisms to synthesize capped and polyadenylated mRNAs from the genomic viral RNA (vRNA) template, which is packaged inside ribonucleoprotein particles (vRNPs). Here, we visualize by cryoelectron microscopy the conformational dynamics of the polymerase during the complete transcription cycle from pre-initiation to termination, focusing on the template trajectory. After exiting the active site cavity, the template 3' extremity rebinds into a specific site on the polymerase surface. Here, it remains sequestered during all subsequent transcription steps, forcing the template to loop out as it further translocates. At termination, the strained connection between the bound template 5' end and the active site results in polyadenylation by stuttering at uridine 17. Upon product dissociation, further conformational changes release the trapped template, allowing recycling back into the pre-initiation state. Influenza polymerase thus performs transcription while tightly binding to and protecting both template ends, allowing efficient production of multiple mRNAs from a single vRNP.
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Affiliation(s)
- Joanna M Wandzik
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Tomas Kouba
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Manikandan Karuppasamy
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Alexander Pflug
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Petra Drncova
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Jan Provaznik
- European Molecular Biology Laboratory, GeneCore, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Nayara Azevedo
- European Molecular Biology Laboratory, GeneCore, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Stephen Cusack
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France.
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Isel C, Chen KY, Naffakh N. La dimérisation, une nouvelle propriété de l’ARN polymérase des virus influenza. Med Sci (Paris) 2020; 36:332-335. [DOI: 10.1051/medsci/2020053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Swale C, Da Costa B, Sedano L, Garzoni F, McCarthy AA, Berger I, Bieniossek C, Ruigrok RWH, Delmas B, Crépin T. X-ray Structure of the Human Karyopherin RanBP5, an Essential Factor for Influenza Polymerase Nuclear Trafficking. J Mol Biol 2020; 432:3353-3359. [PMID: 32222384 DOI: 10.1016/j.jmb.2020.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/16/2020] [Accepted: 03/22/2020] [Indexed: 12/15/2022]
Abstract
Here, we describe the crystal structures of two distinct isoforms of ligand-free human karyopherin RanBP5 and investigate its global propensity to interact with influenza A virus polymerase. Our results confirm the general architecture and mechanism of the IMB3 karyopherin-β subfamily whilst also highlighting differences with the yeast orthologue Kap121p. Moreover, our results provide insight into the structural flexibility of β-importins in the unbound state. Based on docking of a nuclear localisation sequence, point mutations were designed, which suppress influenza PA-PB1 subcomplex binding to RanBP5 in a binary protein complementation assay.
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Affiliation(s)
- Christopher Swale
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France; EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Bruno Da Costa
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Laura Sedano
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Frédéric Garzoni
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Andrew A McCarthy
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Imre Berger
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France; Max Planck Centre for Minimal Biology, University of Bristol, Clifton BS8 1TD, United Kingdom
| | - Christoph Bieniossek
- Roche Innovation Centre, Basel, Switzerland F. Hoffmann-La Roche AG, Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | - Rob W H Ruigrok
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France
| | - Bernard Delmas
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Thibaut Crépin
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France.
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Peng R, Xu X, Jing J, Wang M, Peng Q, Liu S, Wu Y, Bao X, Wang P, Qi J, Gao GF, Shi Y. Structural insight into arenavirus replication machinery. Nature 2020; 579:615-619. [PMID: 32214249 DOI: 10.1038/s41586-020-2114-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 01/14/2020] [Indexed: 01/10/2023]
Abstract
Arenaviruses can cause severe haemorrhagic fever and neurological diseases in humans and other animals, exemplified by Lassa mammarenavirus, Machupo mammarenavirus and lymphocytic choriomeningitis virus, posing great threats to public health1-4. These viruses encode a large multi-domain RNA-dependent RNA polymerase for transcription and replication of the viral genome5. Viral polymerases are one of the leading antiviral therapeutic targets. However, the structure of arenavirus polymerase is not yet known. Here we report the near-atomic resolution structures of Lassa and Machupo virus polymerases in both apo and promoter-bound forms. These structures display a similar overall architecture to influenza virus and bunyavirus polymerases but possess unique local features, including an arenavirus-specific insertion domain that regulates the polymerase activity. Notably, the ordered active site of arenavirus polymerase is inherently switched on, without the requirement for allosteric activation by 5'-viral RNA, which is a necessity for both influenza virus and bunyavirus polymerases6,7. Moreover, dimerization could facilitate the polymerase activity. These findings advance our understanding of the mechanism of arenavirus replication and provide an important basis for developing antiviral therapeutics.
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Affiliation(s)
- Ruchao Peng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Xin Xu
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Jiamei Jing
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Min Wang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Peng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China
- Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China
| | - Sheng Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ying Wu
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Xichen Bao
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Peiyi Wang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - George F Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China.
- Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.
| | - Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China.
- Center for Influenza Research and Early-warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, China.
- College of Basic Medicine, Jilin University, Changchun, China.
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Insight into the multifunctional RNA synthesis machine of rabies virus. Proc Natl Acad Sci U S A 2020; 117:3895-3897. [PMID: 31992635 DOI: 10.1073/pnas.2000120117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Gao S, Zhang W, Lu C, Cao M, Cen S, Peng Y, Deng T. Identification of a Type-Specific Promoter Element That Differentiates between Influenza A and B Viruses. J Virol 2019; 93:e01164-19. [PMID: 31534045 PMCID: PMC6854497 DOI: 10.1128/jvi.01164-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 09/05/2019] [Indexed: 11/20/2022] Open
Abstract
Type A and type B influenza viruses (FluA and FluB viruses) are two major human pathogens that share common structural and functional features. FluA and FluB viruses can reassort within each type but never between the types. Here, we bioinformatically analyzed all promoter sequences of FluA and FluB viruses and confirmed the presence of the type-specific promoter elements. We then studied the promoter elements with cell-based in vivo assays and an in vitro replication initiation assay. Our results identified, for the first time, a type-specific promoter element-the nucleotide at position 5 in the 3' end of the viral RNA (vRNA)-that plays a key role(s) in modulating polymerase activity in a type-specific manner. Interestingly, swapping the promoter element between FluA and FluB recombinant viruses showed different tolerances: the replacement of FluA virus-specific U5 with FluB virus-specific C5 in influenza virus A/WSN/33 (H1N1) could be reverted to U5 after 2 to 3 passages, while the replacement of FluB virus-specific C5 with FluA virus-specific U5 in influenza virus B/Yamagata/88 could be maintained, but with significantly reduced replication efficiency. Therefore, our findings indicate that the nucleotide variation at position 5 in the 3' end of the vRNA promoter between FluA and FluB viruses contributes to their RNP incompatibility, which may shed new light on the mechanisms of intertypic exclusion of reassortment between FluA and FluB viruses.IMPORTANCE Genetic reassortment of influenza virus plays a key role in virus evolution and the emergence of pandemic strains. The reassortment occurs extensively within either FluA or FluB viruses but never between them. Here, we bioinformatically compared available promoter sequences of FluA and FluB viruses and confirmed the presence of the type-specific promoter elements. Our in vivo and in vitro mutagenesis studies showed that a type-specific promoter element-the nucleotide at position 5 in the 3' end of vRNA promoters-plays key roles in modulating polymerase activity. Interestingly, FluA and FluB viruses showed different tolerances upon key promoter element swapping in the context of virus infections. We concluded that the nucleotide at position 5 in the 3' end of the vRNA promoters of FluA and FluB viruses is a critical type-specific determinant. This work has implications for further elucidating the mechanisms of the intertypic exclusion of reassortment between FluA and FluB viruses.
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Affiliation(s)
- Shuman Gao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Wenyu Zhang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Congyu Lu
- College of Biology, Hunan University, Changsha, People's Republic of China
| | - Mengmeng Cao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical School, Beijing, People's Republic of China
| | - Yousong Peng
- College of Biology, Hunan University, Changsha, People's Republic of China
| | - Tao Deng
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
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50
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Chen KY, Santos Afonso ED, Enouf V, Isel C, Naffakh N. Influenza virus polymerase subunits co-evolve to ensure proper levels of dimerization of the heterotrimer. PLoS Pathog 2019; 15:e1008034. [PMID: 31581279 PMCID: PMC6776259 DOI: 10.1371/journal.ppat.1008034] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/18/2019] [Indexed: 12/18/2022] Open
Abstract
The influenza A virus RNA-dependent RNA polymerase complex consists in three subunits, PB2, PB1 and PA, that perform transcription and replication of the viral genome through very distinct mechanisms. Biochemical and structural studies have revealed that the polymerase can adopt multiple conformations and form oligomers. However so far it remained unclear whether the available oligomeric crystal structures represent a functional state of the polymerase. Here we gained new insights into this question, by investigating the incompatibility between non-cognate subunits of influenza polymerase brought together through genetic reassortment. We observed that a 7:1 reassortant virus whose PB2 segment derives from the A/WSN/33 (WSN) virus in an otherwise A/PR/8/34 (PR8) backbone is attenuated, despite a 97% identity between the PR8-PB2 and WSN-PB2 proteins. Independent serial passages led to the selection of phenotypic revertants bearing distinct second-site mutations on PA, PB1 and/or PB2. The constellation of mutations present on one revertant virus was studied extensively using reverse genetics and cell-based reconstitution of the viral polymerase. The PA-E349K mutation appeared to play a major role in correcting the initial defect in replication (cRNA -> vRNA) of the PR8xWSN-PB2 reassortant. Strikingly the PA-E349K mutation, and also the PB2-G74R and PB1-K577G mutations present on other revertants, are located at a dimerization interface of the polymerase. All three restore wild-type-like polymerase activity in a minigenome assay while decreasing the level of polymerase dimerization. Overall, our data show that the polymerase subunits co-evolve to ensure not only optimal inter-subunit interactions within the heterotrimer, but also proper levels of dimerization of the heterotrimer which appears to be essential for efficient viral RNA replication. Our findings point to influenza polymerase dimerization as a feature that is controlled by a complex interplay of genetic determinants, can restrict genetic reassortment, and could become a target for antiviral drug development.
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Affiliation(s)
- Kuang-Yu Chen
- Unité de Génétique Moléculaire des Virus à ARN, Institut Pasteur, UMR 3569 CNRS, Paris, France
- Unité de Génétique Moléculaire des Virus à ARN, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Vincent Enouf
- Unité de Génétique Moléculaire des Virus à ARN, Institut Pasteur, UMR 3569 CNRS, Paris, France
- Unité de Génétique Moléculaire des Virus à ARN, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Unité de Génétique Moléculaire des Virus à ARN, Centre National de Référence des Virus des Infections Respiratoires, Institut Pasteur, Paris, France
- Pasteur International Bioresources network (PIBnet), Plateforme de Microbiologie Mutualisée (P2M), Institut Pasteur, Paris, France
| | - Catherine Isel
- Unité de Génétique Moléculaire des Virus à ARN, Institut Pasteur, UMR 3569 CNRS, Paris, France
- Unité de Génétique Moléculaire des Virus à ARN, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Nadia Naffakh
- Unité de Génétique Moléculaire des Virus à ARN, Institut Pasteur, UMR 3569 CNRS, Paris, France
- Unité de Génétique Moléculaire des Virus à ARN, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- * E-mail:
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