1
|
Staller E, Carrique L, Swann OC, Fan H, Keown JR, Sheppard CM, Barclay WS, Grimes JM, Fodor E. Structures of H5N1 influenza polymerase with ANP32B reveal mechanisms of genome replication and host adaptation. Nat Commun 2024; 15:4123. [PMID: 38750014 PMCID: PMC11096171 DOI: 10.1038/s41467-024-48470-3] [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: 01/05/2024] [Accepted: 05/01/2024] [Indexed: 05/18/2024] Open
Abstract
Avian influenza A viruses (IAVs) pose a public health threat, as they are capable of triggering pandemics by crossing species barriers. Replication of avian IAVs in mammalian cells is hindered by species-specific variation in acidic nuclear phosphoprotein 32 (ANP32) proteins, which are essential for viral RNA genome replication. Adaptive mutations enable the IAV RNA polymerase (FluPolA) to surmount this barrier. Here, we present cryo-electron microscopy structures of monomeric and dimeric avian H5N1 FluPolA with human ANP32B. ANP32B interacts with the PA subunit of FluPolA in the monomeric form, at the site used for its docking onto the C-terminal domain of host RNA polymerase II during viral transcription. ANP32B acts as a chaperone, guiding FluPolA towards a ribonucleoprotein-associated FluPolA to form an asymmetric dimer-the replication platform for the viral genome. These findings offer insights into the molecular mechanisms governing IAV genome replication, while enhancing our understanding of the molecular processes underpinning mammalian adaptations in avian-origin FluPolA.
Collapse
Affiliation(s)
- Ecco Staller
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Loïc Carrique
- Division of Structural Biology, Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Olivia C Swann
- Section of Molecular Virology, Imperial College London, London, UK
| | - Haitian Fan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- School of Basic Medical Sciences, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China
| | - Jeremy R Keown
- Division of Structural Biology, Centre for Human Genetics, University of Oxford, Oxford, UK
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Carol M Sheppard
- Section of Molecular Virology, Imperial College London, London, UK
| | - Wendy S Barclay
- Section of Molecular Virology, Imperial College London, London, UK
| | - Jonathan M Grimes
- Division of Structural Biology, Centre for Human Genetics, University of Oxford, Oxford, UK.
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| |
Collapse
|
2
|
Dupont M, Krischuns T, Gianetto QG, Paisant S, Bonazza S, Brault JB, Douché T, Arragain B, Florez-Prada A, Perez-Perri JI, Hentze MW, Cusack S, Matondo M, Isel C, Courtney DG, Naffakh N. The RBPome of influenza A virus NP-mRNA reveals a role for TDP-43 in viral replication. Nucleic Acids Res 2024:gkae291. [PMID: 38686810 DOI: 10.1093/nar/gkae291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 03/22/2024] [Accepted: 04/05/2024] [Indexed: 05/02/2024] Open
Abstract
Genome-wide approaches have significantly advanced our knowledge of the repertoire of RNA-binding proteins (RBPs) that associate with cellular polyadenylated mRNAs within eukaryotic cells. Recent studies focusing on the RBP interactomes of viral mRNAs, notably SARS-Cov-2, have revealed both similarities and differences between the RBP profiles of viral and cellular mRNAs. However, the RBPome of influenza virus mRNAs remains unexplored. Herein, we identify RBPs that associate with the viral mRNA encoding the nucleoprotein (NP) of an influenza A virus. Focusing on TDP-43, we show that it binds several influenza mRNAs beyond the NP-mRNA, and that its depletion results in lower levels of viral mRNAs and proteins within infected cells, and a decreased yield of infectious viral particles. We provide evidence that the viral polymerase recruits TDP-43 onto viral mRNAs through a direct interaction with the disordered C-terminal domain of TDP-43. Notably, other RBPs found to be associated with influenza virus mRNAs also interact with the viral polymerase, which points to a role of the polymerase in orchestrating the assembly of viral messenger ribonucleoproteins.
Collapse
Affiliation(s)
- Maud Dupont
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| | - Tim Krischuns
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| | - Quentin Giai Gianetto
- Institut Pasteur, Université Paris Cité, CNRS UAR2024, Proteomics Platform, Mass Spectrometry for Biology, Paris, France
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics HUB, Paris, France
| | - Sylvain Paisant
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| | - Stefano Bonazza
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, BelfastBT9 7BL, Northern Ireland
| | - Jean-Baptiste Brault
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| | - Thibaut Douché
- Institut Pasteur, Université Paris Cité, CNRS UAR2024, Proteomics Platform, Mass Spectrometry for Biology, Paris, France
| | - Benoît Arragain
- European Molecular Biology Laboratory, 38042Grenoble, France
| | | | | | | | - Stephen Cusack
- European Molecular Biology Laboratory, 38042Grenoble, France
| | - Mariette Matondo
- Institut Pasteur, Université Paris Cité, CNRS UAR2024, Proteomics Platform, Mass Spectrometry for Biology, Paris, France
| | - Catherine Isel
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| | - David G Courtney
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, BelfastBT9 7BL, Northern Ireland
| | - Nadia Naffakh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology and Influenza Viruses, Paris, France
| |
Collapse
|
3
|
Krischuns T, Arragain B, Isel C, Paisant S, Budt M, Wolff T, Cusack S, Naffakh N. The host RNA polymerase II C-terminal domain is the anchor for replication of the influenza virus genome. Nat Commun 2024; 15:1064. [PMID: 38316757 PMCID: PMC10844641 DOI: 10.1038/s41467-024-45205-2] [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: 08/01/2023] [Accepted: 01/16/2024] [Indexed: 02/07/2024] Open
Abstract
The current model is that the influenza virus polymerase (FluPol) binds either to host RNA polymerase II (RNAP II) or to the acidic nuclear phosphoprotein 32 (ANP32), which drives its conformation and activity towards transcription or replication of the viral genome, respectively. Here, we provide evidence that the FluPol-RNAP II binding interface, beyond its well-acknowledged function in cap-snatching during transcription initiation, has also a pivotal role in replication of the viral genome. Using a combination of cell-based and in vitro approaches, we show that the RNAP II C-terminal-domain, jointly with ANP32, enhances FluPol replication activity. We observe successive conformational changes to switch from a transcriptase to a replicase conformation in the presence of the bound RNPAII C-terminal domain and propose a model in which the host RNAP II is the anchor for transcription and replication of the viral genome. Our data open new perspectives on the spatial coupling of viral transcription and replication and the coordinated balance between these two activities.
Collapse
Affiliation(s)
- Tim Krischuns
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, RNA Biology of Influenza Virus, Paris, France.
| | | | - Catherine Isel
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, RNA Biology of Influenza Virus, Paris, France
| | - Sylvain Paisant
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, RNA Biology of Influenza Virus, Paris, France
| | - Matthias Budt
- Unit 17 "Influenza and other Respiratory Viruses", Robert Koch Institut, Berlin, Germany
| | - Thorsten Wolff
- Unit 17 "Influenza and other Respiratory Viruses", Robert Koch Institut, Berlin, Germany
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble, France.
| | - Nadia Naffakh
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, RNA Biology of Influenza Virus, Paris, France.
| |
Collapse
|
4
|
Li Y, Arcos S, Sabsay KR, te Velthuis AJW, Lauring AS. Deep mutational scanning reveals the functional constraints and evolutionary potential of the influenza A virus PB1 protein. J Virol 2023; 97:e0132923. [PMID: 37882522 PMCID: PMC10688322 DOI: 10.1128/jvi.01329-23] [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: 08/28/2023] [Accepted: 10/08/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE The influenza virus polymerase is important for adaptation to new hosts and, as a determinant of mutation rate, for the process of adaptation itself. We performed a deep mutational scan of the polymerase basic 1 (PB1) protein to gain insights into the structural and functional constraints on the influenza RNA-dependent RNA polymerase. We find that PB1 is highly constrained at specific sites that are only moderately predicted by the global structure or larger domain. We identified a number of beneficial mutations, many of which have been shown to be functionally important or observed in influenza virus' natural evolution. Overall, our atlas of PB1 mutations and their fitness impacts serves as an important resource for future studies of influenza replication and evolution.
Collapse
Affiliation(s)
- Yuan Li
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sarah Arcos
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kimberly R. Sabsay
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Lewis-Sigler Institute, Princeton University, Princeton, New Jersey, USA
| | | | - Adam S. Lauring
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
5
|
Sheppard CM, Goldhill DH, Swann OC, Staller E, Penn R, Platt OK, Sukhova K, Baillon L, Frise R, Peacock TP, Fodor E, Barclay WS. An Influenza A virus can evolve to use human ANP32E through altering polymerase dimerization. Nat Commun 2023; 14:6135. [PMID: 37816726 PMCID: PMC10564888 DOI: 10.1038/s41467-023-41308-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/09/2023] [Indexed: 10/12/2023] Open
Abstract
Human ANP32A and ANP32B are essential but redundant host factors for influenza virus genome replication. While most influenza viruses cannot replicate in edited human cells lacking both ANP32A and ANP32B, some strains exhibit limited growth. Here, we experimentally evolve such an influenza A virus in these edited cells and unexpectedly, after 2 passages, we observe robust viral growth. We find two mutations in different subunits of the influenza polymerase that enable the mutant virus to use a novel host factor, ANP32E, an alternative family member, which is unable to support the wild type polymerase. Both mutations reside in the symmetric dimer interface between two polymerase complexes and reduce polymerase dimerization. These mutations have previously been identified as adapting influenza viruses to mice. Indeed, the evolved virus gains the ability to use suboptimal mouse ANP32 proteins and becomes more virulent in mice. We identify further mutations in the symmetric dimer interface which we predict allow influenza to adapt to use suboptimal ANP32 proteins through a similar mechanism. Overall, our results suggest a balance between asymmetric and symmetric dimers of influenza virus polymerase that is influenced by the interaction between polymerase and ANP32 host proteins.
Collapse
Affiliation(s)
- Carol M Sheppard
- Department of Infectious Disease, Imperial College London, London, UK.
| | - Daniel H Goldhill
- Department of Infectious Disease, Imperial College London, London, UK
- Department of Pathobiology and Population Sciences, Royal Veterinary College, London, UK
| | - Olivia C Swann
- Department of Infectious Disease, Imperial College London, London, UK
| | - Ecco Staller
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rebecca Penn
- Department of Infectious Disease, Imperial College London, London, UK
| | - Olivia K Platt
- Department of Infectious Disease, Imperial College London, London, UK
| | - Ksenia Sukhova
- Department of Infectious Disease, Imperial College London, London, UK
| | - Laury Baillon
- Department of Infectious Disease, Imperial College London, London, UK
| | - Rebecca Frise
- Department of Infectious Disease, Imperial College London, London, UK
| | - Thomas P Peacock
- Department of Infectious Disease, Imperial College London, London, UK
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Wendy S Barclay
- Department of Infectious Disease, Imperial College London, London, UK.
| |
Collapse
|
6
|
Idoko-Akoh A, Goldhill DH, Sheppard CM, Bialy D, Quantrill JL, Sukhova K, Brown JC, Richardson S, Campbell C, Taylor L, Sherman A, Nazki S, Long JS, Skinner MA, Shelton H, Sang HM, Barclay WS, McGrew MJ. Creating resistance to avian influenza infection through genome editing of the ANP32 gene family. Nat Commun 2023; 14:6136. [PMID: 37816720 PMCID: PMC10564915 DOI: 10.1038/s41467-023-41476-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/05/2023] [Indexed: 10/12/2023] Open
Abstract
Chickens genetically resistant to avian influenza could prevent future outbreaks. In chickens, influenza A virus (IAV) relies on host protein ANP32A. Here we use CRISPR/Cas9 to generate homozygous gene edited (GE) chickens containing two ANP32A amino acid substitutions that prevent viral polymerase interaction. After IAV challenge, 9/10 edited chickens remain uninfected. Challenge with a higher dose, however, led to breakthrough infections. Breakthrough IAV virus contained IAV polymerase gene mutations that conferred adaptation to the edited chicken ANP32A. Unexpectedly, this virus also replicated in chicken embryos edited to remove the entire ANP32A gene and instead co-opted alternative ANP32 protein family members, chicken ANP32B and ANP32E. Additional genome editing for removal of ANP32B and ANP32E eliminated all viral growth in chicken cells. Our data illustrate a first proof of concept step to generate IAV-resistant chickens and show that multiple genetic modifications will be required to curtail viral escape.
Collapse
Affiliation(s)
- Alewo Idoko-Akoh
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
| | - Daniel H Goldhill
- Department of Infectious Disease, Imperial College London, London, UK
- Royal Veterinary College, London, UK
| | - Carol M Sheppard
- Department of Infectious Disease, Imperial College London, London, UK
| | | | | | - Ksenia Sukhova
- Department of Infectious Disease, Imperial College London, London, UK
| | - Jonathan C Brown
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Ciara Campbell
- Department of Infectious Disease, Imperial College London, London, UK
| | - Lorna Taylor
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK
| | - Adrian Sherman
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK
| | | | - Jason S Long
- Department of Infectious Disease, Imperial College London, London, UK
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Michael A Skinner
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Helen M Sang
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
| | - Wendy S Barclay
- Department of Infectious Disease, Imperial College London, London, UK.
| | - Mike J McGrew
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Kleinehr J, Schöfbänker M, Daniel K, Günl F, Mohamed FF, Janowski J, Brunotte L, Boergeling Y, Liebmann M, Behrens M, Gerdemann A, Klotz L, Esselen M, Humpf HU, Ludwig S, Hrincius ER. Glycolytic interference blocks influenza A virus propagation by impairing viral polymerase-driven synthesis of genomic vRNA. PLoS Pathog 2023; 19:e1010986. [PMID: 37440521 DOI: 10.1371/journal.ppat.1010986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 06/10/2023] [Indexed: 07/15/2023] Open
Abstract
Influenza A virus (IAV), like any other virus, provokes considerable modifications of its host cell's metabolism. This includes a substantial increase in the uptake as well as the metabolization of glucose. Although it is known for quite some time that suppression of glucose metabolism restricts virus replication, the exact molecular impact on the viral life cycle remained enigmatic so far. Using 2-deoxy-d-glucose (2-DG) we examined how well inhibition of glycolysis is tolerated by host cells and which step of the IAV life cycle is affected. We observed that effects induced by 2-DG are reversible and that cells can cope with relatively high concentrations of the inhibitor by compensating the loss of glycolytic activity by upregulating other metabolic pathways. Moreover, mass spectrometry data provided information on various metabolic modifications induced by either the virus or agents interfering with glycolysis. In the presence of 2-DG viral titers were significantly reduced in a dose-dependent manner. The supplementation of direct or indirect glycolysis metabolites led to a partial or almost complete reversion of the inhibitory effect of 2-DG on viral growth and demonstrated that indeed the inhibition of glycolysis and not of N-linked glycosylation was responsible for the observed phenotype. Importantly, we could show via conventional and strand-specific qPCR that the treatment with 2-DG led to a prolonged phase of viral mRNA synthesis while the accumulation of genomic vRNA was strongly reduced. At the same time, minigenome assays showed no signs of a general reduction of replicative capacity of the viral polymerase. Therefore, our data suggest that the significant reduction in IAV replication by glycolytic interference occurs mainly due to an impairment of the dynamic regulation of the viral polymerase which conveys the transition of the enzyme's function from transcription to replication.
Collapse
Affiliation(s)
- Jens Kleinehr
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Michael Schöfbänker
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Katharina Daniel
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Franziska Günl
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Fakry Fahmy Mohamed
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
- Department of Virology, Faculty of Veterinary Medicine, Zagazig University, Sharkia, Egypt
| | - Josua Janowski
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Linda Brunotte
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Yvonne Boergeling
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Marie Liebmann
- Department of Neurology with Institute of Translational Neurology, University Hospital Muenster, Muenster, Germany
| | - Matthias Behrens
- Institute of Food Chemistry, Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Andrea Gerdemann
- Institute of Food Chemistry, Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Luisa Klotz
- Department of Neurology with Institute of Translational Neurology, University Hospital Muenster, Muenster, Germany
| | - Melanie Esselen
- Institute of Food Chemistry, Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Stephan Ludwig
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| | - Eike R Hrincius
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, Muenster, Germany
| |
Collapse
|
9
|
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.
Collapse
|
10
|
The ubiquitination landscape of the influenza A virus polymerase. Nat Commun 2023; 14:787. [PMID: 36774438 PMCID: PMC9922279 DOI: 10.1038/s41467-023-36389-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 01/30/2023] [Indexed: 02/13/2023] Open
Abstract
During influenza A virus (IAV) infections, viral proteins are targeted by cellular E3 ligases for modification with ubiquitin. Here, we decipher and functionally explore the ubiquitination landscape of the IAV polymerase proteins during infection of human alveolar epithelial cells by applying mass spectrometry analysis of immuno-purified K-ε-GG (di-glycyl)-remnant-bearing peptides. We have identified 59 modified lysines across the three subunits, PB2, PB1 and PA of the viral polymerase of which 17 distinctively affect mRNA transcription, vRNA replication and the generation of recombinant viruses via non-proteolytic mechanisms. Moreover, further functional and in silico analysis indicate that ubiquitination at K578 in the PB1 thumb domain is mechanistically linked to dynamic structural transitions of the viral polymerase that are required for vRNA replication. Mutations K578A and K578R differentially affect the generation of recombinant viruses by impeding cRNA and vRNA synthesis, NP binding as well as polymerase dimerization. Collectively, our results demonstrate that the ubiquitin-mediated charge neutralization at PB1-K578 disrupts the interaction to an unstructured loop in the PB2 N-terminus that is required to coordinate polymerase dimerization and facilitate vRNA replication. This provides evidence that IAV exploits the cellular ubiquitin system to modulate the activity of the viral polymerase for viral replication.
Collapse
|
11
|
Kouba T, Dubankova A, Drncova P, Donati E, Vidossich P, Speranzini V, Pflug A, Huchting J, Meier C, De Vivo M, Cusack S. Direct observation of backtracking by influenza A and B polymerases upon consecutive incorporation of the nucleoside analog T1106. Cell Rep 2023; 42:111901. [PMID: 36596301 DOI: 10.1016/j.celrep.2022.111901] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 11/11/2022] [Accepted: 12/07/2022] [Indexed: 01/03/2023] Open
Abstract
The antiviral pseudo-base T705 and its de-fluoro analog T1106 mimic adenine or guanine and can be competitively incorporated into nascent RNA by viral RNA-dependent RNA polymerases. Although dispersed, single pseudo-base incorporation is mutagenic, consecutive incorporation causes polymerase stalling and chain termination. Using a template encoding single and then consecutive T1106 incorporation four nucleotides later, we obtained a cryogenic electron microscopy structure of stalled influenza A/H7N9 polymerase. This shows that the entire product-template duplex backtracks by 5 nt, bringing the singly incorporated T1106 to the +1 position, where it forms an unexpected T1106:U wobble base pair. Similar structures show that influenza B polymerase also backtracks after consecutive T1106 incorporation, regardless of whether prior single incorporation has occurred. These results give insight into the unusual mechanism of chain termination by pyrazinecarboxamide base analogs. Consecutive incorporation destabilizes the proximal end of the product-template duplex, promoting irreversible backtracking to a more energetically favorable overall configuration.
Collapse
Affiliation(s)
- Tomas Kouba
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Anna Dubankova
- 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
| | - Elisa Donati
- Molecular Modeling & Drug Discovery Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Pietro Vidossich
- Molecular Modeling & Drug Discovery Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Valentina Speranzini
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Alex Pflug
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Johanna Huchting
- Organic Chemistry, Department of Chemistry, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, Hamburg University, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Marco De Vivo
- Molecular Modeling & Drug Discovery Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Stephen Cusack
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France.
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Dunsing V, Petrich A, Chiantia S. Multicolor fluorescence fluctuation spectroscopy in living cells via spectral detection. eLife 2021; 10:e69687. [PMID: 34494547 PMCID: PMC8545396 DOI: 10.7554/elife.69687] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/07/2021] [Indexed: 01/20/2023] Open
Abstract
Signaling pathways in biological systems rely on specific interactions between multiple biomolecules. Fluorescence fluctuation spectroscopy provides a powerful toolbox to quantify such interactions directly in living cells. Cross-correlation analysis of spectrally separated fluctuations provides information about intermolecular interactions but is usually limited to two fluorophore species. Here, we present scanning fluorescence spectral correlation spectroscopy (SFSCS), a versatile approach that can be implemented on commercial confocal microscopes, allowing the investigation of interactions between multiple protein species at the plasma membrane. We demonstrate that SFSCS enables cross-talk-free cross-correlation, diffusion, and oligomerization analysis of up to four protein species labeled with strongly overlapping fluorophores. As an example, we investigate the interactions of influenza A virus (IAV) matrix protein 2 with two cellular host factors simultaneously. We furthermore apply raster spectral image correlation spectroscopy for the simultaneous analysis of up to four species and determine the stoichiometry of ternary IAV polymerase complexes in the cell nucleus.
Collapse
Affiliation(s)
- Valentin Dunsing
- Universität Potsdam, Institute of Biochemistry and BiologyPotsdamGermany
| | - Annett Petrich
- Universität Potsdam, Institute of Biochemistry and BiologyPotsdamGermany
| | - Salvatore Chiantia
- Universität Potsdam, Institute of Biochemistry and BiologyPotsdamGermany
| |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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.
Collapse
|
17
|
The influenza virus RNA polymerase as an innate immune agonist and antagonist. Cell Mol Life Sci 2021; 78:7237-7256. [PMID: 34677644 PMCID: PMC8532088 DOI: 10.1007/s00018-021-03957-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/16/2021] [Accepted: 09/29/2021] [Indexed: 12/16/2022]
Abstract
Influenza A viruses cause a mild-to-severe respiratory disease that affects millions of people each year. One of the many determinants of disease outcome is the innate immune response to the viral infection. While antiviral responses are essential for viral clearance, excessive innate immune activation promotes lung damage and disease. The influenza A virus RNA polymerase is one of viral proteins that affect innate immune activation during infection, but the mechanisms behind this activity are not well understood. In this review, we discuss how the viral RNA polymerase can both activate and suppress innate immune responses by either producing immunostimulatory RNA species or directly targeting the components of the innate immune signalling pathway, respectively. Furthermore, we provide a comprehensive overview of the polymerase residues, and their mutations, associated with changes in innate immune activation, and discuss their putative effects on polymerase function based on recent advances in our understanding of the influenza A virus RNA polymerase structure.
Collapse
|
18
|
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: 77] [Impact Index Per Article: 19.3] [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.
Collapse
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.
| |
Collapse
|
19
|
Maguire G. Better preventing and mitigating the effects of Covid-19. Future Sci OA 2020; 6:FSO586. [PMID: 32685190 PMCID: PMC7238752 DOI: 10.2144/fsoa-2020-0051] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 04/29/2020] [Indexed: 01/08/2023] Open
Abstract
Currently, there are no proven medical treatments against SARS-CoV-2, the virus responsible for Covid-19. In addition to the all important public health measures needed to prevent the spread of this disease, a number of strategies related to our exposome are recommended herein, to better prevent and mitigate the effects of a SARS-CoV-2 infection through enhancement of our immune system and reduction of inflammation.
Collapse
Affiliation(s)
- Greg Maguire
- BioRegenerative Sciences Inc., NeoGenesis Inc., San Diego, CA 94704, USA
- The California Physiological Society, Berkeley, CA 94704, USA
| |
Collapse
|
20
|
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
|
21
|
Lutz MM, Dunagan MM, Kurebayashi Y, Takimoto T. Key Role of the Influenza A Virus PA Gene Segment in the Emergence of Pandemic Viruses. Viruses 2020; 12:v12040365. [PMID: 32224899 PMCID: PMC7232137 DOI: 10.3390/v12040365] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 03/24/2020] [Indexed: 12/18/2022] Open
Abstract
Influenza A viruses (IAVs) are a significant human pathogen that cause seasonal epidemics and occasional pandemics. Avian waterfowl are the natural reservoir of IAVs, but a wide range of species can serve as hosts. Most IAV strains are adapted to one host species and avian strains of IAV replicate poorly in most mammalian hosts. Importantly, IAV polymerases from avian strains function poorly in mammalian cells but host adaptive mutations can restore activity. The 2009 pandemic H1N1 (H1N1pdm09) virus acquired multiple mutations in the PA gene that activated polymerase activity in mammalian cells, even in the absence of previously identified host adaptive mutations in other polymerase genes. These mutations in PA localize within different regions of the protein suggesting multiple mechanisms exist to activate polymerase activity. Additionally, an immunomodulatory protein, PA-X, is expressed from the PA gene segment. PA-X expression is conserved amongst many IAV strains but activity varies between viruses specific for different hosts, suggesting that PA-X also plays a role in host adaptation. Here, we review the role of PA in the emergence of currently circulating H1N1pdm09 viruses and the most recent studies of host adaptive mutations in the PA gene that modulate polymerase activity and PA-X function.
Collapse
Affiliation(s)
- Michael M. Lutz
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA (M.M.D.); (Y.K.)
| | - Megan M. Dunagan
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA (M.M.D.); (Y.K.)
| | - Yuki Kurebayashi
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA (M.M.D.); (Y.K.)
- Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka-shi 422-8526, Japan
| | - Toru Takimoto
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA (M.M.D.); (Y.K.)
- Correspondence: ; Tel.: +1-585-273-2856
| |
Collapse
|
22
|
Lee CY, An SH, Choi JG, Lee YJ, Kim JH, Kwon HJ. Rank orders of mammalian pathogenicity-related PB2 mutations of avian influenza A viruses. Sci Rep 2020; 10:5359. [PMID: 32210274 PMCID: PMC7093554 DOI: 10.1038/s41598-020-62036-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/05/2020] [Indexed: 11/09/2022] Open
Abstract
The PB2 gene is one of the key determinants for the mammalian adaptation of avian influenza A viruses (IAVs). Although mammalian pathogenicity-related mutations (MPMs) in PB2 genes were identified in different genetic backgrounds of avian IAVs, the relative effects of single or multiple mutations on viral fitness could not be directly compared. Furthermore, their mutational steps during mammalian adaptation had been unclear. In this study, we collectively compared the effects of individual and combined MPMs on viral fitness and determined their rank orders using a prototypic PB2 gene. Early acquired mutations may determine the function and potency of subsequent mutations and be important for recruiting multiple, competent combinations of MPMs. Higher mammalian pathogenicity was acquired with the greater accumulation of MPMs. Thus, the rank orders and the prototypic PB2 gene may be useful for predicting the present and future risks of PB2 genes of avian and mammalian IAVs.
Collapse
Affiliation(s)
- Chung-Young Lee
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea
| | - Se-Hee An
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea
| | - Jun-Gu Choi
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Youn-Jeong Lee
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Jae-Hong Kim
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea
| | - Hyuk-Joon Kwon
- Department of Farm Animal Medicine, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea. .,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea. .,Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, Kangwon-do, Republic of Korea.
| |
Collapse
|