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Li T, Liu M, Gu Z, Su X, Liu Y, Lin J, Zhang Y, Shen QT. Structures of the mumps virus polymerase complex via cryo-electron microscopy. Nat Commun 2024; 15:4189. [PMID: 38760379 PMCID: PMC11101452 DOI: 10.1038/s41467-024-48389-9] [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: 06/24/2023] [Accepted: 04/26/2024] [Indexed: 05/19/2024] Open
Abstract
The viral polymerase complex, comprising the large protein (L) and phosphoprotein (P), is crucial for both genome replication and transcription in non-segmented negative-strand RNA viruses (nsNSVs), while structures corresponding to these activities remain obscure. Here, we resolved two L-P complex conformations from the mumps virus (MuV), a typical member of nsNSVs, via cryogenic-electron microscopy. One conformation presents all five domains of L forming a continuous RNA tunnel to the methyltransferase domain (MTase), preferably as a transcription state. The other conformation has the appendage averaged out, which is inaccessible to MTase. In both conformations, parallel P tetramers are revealed around MuV L, which, together with structures of other nsNSVs, demonstrates the diverse origins of the L-binding X domain of P. Our study links varying structures of nsNSV polymerase complexes with genome replication and transcription and points to a sliding model for polymerase complexes to advance along the RNA templates.
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Affiliation(s)
- Tianhao Li
- School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Mingdong Liu
- School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Zhanxi Gu
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xin Su
- School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Yunhui Liu
- School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Qing-Tao Shen
- School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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2
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Fang J, Castillon G, Phan S, McArdle S, Hariharan C, Adams A, Ellisman MH, Deniz AA, Saphire EO. Spatial and functional arrangement of Ebola virus polymerase inside phase-separated viral factories. Nat Commun 2023; 14:4159. [PMID: 37443171 PMCID: PMC10345124 DOI: 10.1038/s41467-023-39821-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Ebola virus (EBOV) infection induces the formation of membrane-less, cytoplasmic compartments termed viral factories, in which multiple viral proteins gather and coordinate viral transcription, replication, and assembly. Key to viral factory function is the recruitment of EBOV polymerase, a multifunctional machine that mediates transcription and replication of the viral RNA genome. We show that intracellularly reconstituted EBOV viral factories are biomolecular condensates, with composition-dependent internal exchange dynamics that likely facilitates viral replication. Within the viral factory, we found the EBOV polymerase clusters into foci. The distance between these foci increases when viral replication is enabled. In addition to the typical droplet-like viral factories, we report the formation of network-like viral factories during EBOV infection. Unlike droplet-like viral factories, network-like factories are inactive for EBOV nucleocapsid assembly. This unique view of EBOV propagation suggests a form-to-function relationship that describes how physical properties and internal structures of biomolecular condensates influence viral biogenesis.
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Affiliation(s)
- Jingru Fang
- La Jolla Institute for Immunology, La Jolla, CA, USA
- Scripps Research, La Jolla, CA, USA
| | - Guillaume Castillon
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sara McArdle
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | | | - Aiyana Adams
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
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3
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Whitehead JD, Grimes JM, Keown JR. Structural and biophysical characterization of the Borna disease virus 1 phosphoprotein. Acta Crystallogr F Struct Biol Commun 2023; 79:51-60. [PMID: 36862093 PMCID: PMC9979977 DOI: 10.1107/s2053230x23000717] [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: 11/30/2022] [Accepted: 01/26/2023] [Indexed: 02/25/2023] Open
Abstract
Bornaviruses are RNA viruses with a mammalian, reptilian, and avian host range. The viruses infect neuronal cells and in rare cases cause a lethal encephalitis. The family Bornaviridae are part of the Mononegavirales order of viruses, which contain a nonsegmented viral genome. Mononegavirales encode a viral phosphoprotein (P) that binds both the viral polymerase (L) and the viral nucleoprotein (N). The P protein acts as a molecular chaperone and is required for the formation of a functional replication/transcription complex. In this study, the structure of the oligomerization domain of the phosphoprotein determined by X-ray crystallography is reported. The structural results are complemented with biophysical characterization using circular dichroism, differential scanning calorimetry and small-angle X-ray scattering. The data reveal the phosphoprotein to assemble into a stable tetramer, with the regions outside the oligomerization domain remaining highly flexible. A helix-breaking motif is observed between the α-helices at the midpoint of the oligomerization domain that appears to be conserved across the Bornaviridae. These data provide information on an important component of the bornavirus replication complex.
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Affiliation(s)
- Jack D. Whitehead
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Jeremy R. Keown
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
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4
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Ebola virus disease: In vivo protection provided by the PAMP restricted TLR3 agonist rintatolimod and its mechanism of action. Antiviral Res 2023; 212:105554. [PMID: 36804324 DOI: 10.1016/j.antiviral.2023.105554] [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: 11/22/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/18/2023]
Abstract
Ebola virus (EBOV) is a highly infectious and lethal pathogen responsible for sporadic self-limiting clusters of Ebola virus disease (EVD) in Central Africa capable of reaching epidemic status. 100% protection from lethal EBOV-Zaire in Balb/c mice was achieved by rintatolimod (Ampligen) at the well tolerated human clinical dose of 6 mg/kg. The data indicate that the mechanism of action is rintatolimod's dual ability to act as both a competitive decoy for the IID domain of VP35 blocking viral dsRNA sequestration and as a pathogen-associated molecular pattern (PAMP) restricted agonist for direct TLR3 activation but lacking RIG-1-like cytosolic helicase agonist properties. These data show promise for rintatolimod as a prophylactic therapy against human Ebola outbreaks.
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5
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Zinzula L, Mereu AM, Orsini M, Seeleitner C, Bracher A, Nagy I, Baumeister W. Ebola and Marburg virus VP35 coiled-coil validated as antiviral target by tripartite split-GFP complementation. iScience 2022; 25:105354. [PMID: 36325051 PMCID: PMC9619376 DOI: 10.1016/j.isci.2022.105354] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/30/2022] Open
Abstract
Ebola virus (EBOV) and Marburg virus (MARV) are highly pathogenic viruses in humans, against which approved antivirals are lacking. During EBOV and MARV infection, coiled-coil mediated oligomerization is essential for the virion protein 35 (VP35) polymerase co-factor function and type I interferon antagonism, making VP35 coiled-coil an elective drug target. We established a tripartite split-green fluorescent protein (GFP) fluorescence complementation (FC) system based on recombinant GFP-tagged EBOV and MARV VP35, which probes VP35 coiled-coil assembly by monitoring fluorescence on E. coli colonies, or in vitro in 96/384-multiwell. Oligomerization-defective VP35 mutants showed that correct coiled-coil knobs-into-holes pairing within VP35 oligomer is pre-requisite for GFP tags and GFP detector to reconstitute fluorescing full-length GFP. The method was validated by screening a small compound library, which identified Myricetin and 4,5,6,7-Tetrabromobenzotriazole as inhibitors of EBOV and MARV VP35 oligomerization-dependent FC with low-micromolar IC50 values. These findings substantiate the VP35 coiled-coil value as antiviral target. Ebola and Marburg virus VP35 oligomerize via trimeric and tetrameric coiled-coil VP35 coiled-coil assembly triggers fluorescence of a tripartite split-GFP system Mutations perturbing VP35 coiled-coil hamper split-GFP complementation Myricetin and TBBT inhibit split-GFP complementation mediated by VP35 coiled-coil
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Affiliation(s)
- Luca Zinzula
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
- Corresponding author
| | - Angela Maria Mereu
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Massimiliano Orsini
- Istituto Zooprofilattico Sperimentale delle Venezie, Department of Risk Analysis and Public Health Surveillance, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Christine Seeleitner
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- The Max-Planck Institute of Biochemistry, Department of Cellular Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - István Nagy
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
- Corresponding author
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6
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Borna Disease Virus 1 Phosphoprotein Forms a Tetramer and Interacts with Host Factors Involved in DNA Double-Strand Break Repair and mRNA Processing. Viruses 2022; 14:v14112358. [PMID: 36366462 PMCID: PMC9692295 DOI: 10.3390/v14112358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 01/31/2023] Open
Abstract
Determining the structural organisation of viral replication complexes and unravelling the impact of infection on cellular homeostasis represent important challenges in virology. This may prove particularly useful when confronted with viruses that pose a significant threat to human health, that appear unique within their family, or for which knowledge is scarce. Among Mononegavirales, bornaviruses (family Bornaviridae) stand out due to their compact genomes and their nuclear localisation for replication. The recent recognition of the zoonotic potential of several orthobornaviruses has sparked a surge of interest in improving our knowledge on this viral family. In this work, we provide a complete analysis of the structural organisation of Borna disease virus 1 (BoDV-1) phosphoprotein (P), an important cofactor for polymerase activity. Using X-ray diffusion and diffraction experiments, we revealed that BoDV-1 P adopts a long coiled-coil α-helical structure split into two parts by an original β-strand twist motif, which is highly conserved across the members of whole Orthobornavirus genus and may regulate viral replication. In parallel, we used BioID to determine the proximal interactome of P in living cells. We confirmed previously known interactors and identified novel proteins linked to several biological processes such as DNA repair or mRNA metabolism. Altogether, our study provides important structure/function cues, which may improve our understanding of BoDV-1 pathogenesis.
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Yuan B, Peng Q, Cheng J, Wang M, Zhong J, Qi J, Gao GF, Shi Y. Structure of the Ebola virus polymerase complex. Nature 2022; 610:394-401. [PMID: 36171293 PMCID: PMC9517992 DOI: 10.1038/s41586-022-05271-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 08/24/2022] [Indexed: 11/24/2022]
Abstract
Filoviruses, including Ebola virus, pose an increasing threat to the public health. Although two therapeutic monoclonal antibodies have been approved to treat the Ebola virus disease1,2, there are no approved broadly reactive drugs to control diverse filovirus infection. Filovirus has a large polymerase (L) protein and the cofactor viral protein 35 (VP35), which constitute the basic functional unit responsible for virus genome RNA synthesis3. Owing to its conservation, the L-VP35 polymerase complex is a promising target for broadly reactive antiviral drugs. Here we determined the structure of Ebola virus L protein in complex with tetrameric VP35 using cryo-electron microscopy (state 1). Structural analysis revealed that Ebola virus L possesses a filovirus-specific insertion element that is essential for RNA synthesis, and that VP35 interacts extensively with the N-terminal region of L by three protomers of the VP35 tetramer. Notably, we captured the complex structure in a second conformation with the unambiguous priming loop and supporting helix away from polymerase active site (state 2). Moreover, we demonstrated that the century-old drug suramin could inhibit the activity of the Ebola virus polymerase in an enzymatic assay. The structure of the L-VP35-suramin complex reveals that suramin can bind at the highly conserved NTP entry channel to prevent substrates from entering the active site. These findings reveal the mechanism of Ebola virus replication and may guide the development of more powerful anti-filovirus drugs.
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Affiliation(s)
- Bin Yuan
- CAS Key Laboratory of Pathogen 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 Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinlong Cheng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Min Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jin Zhong
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Jianxun Qi
- 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.
- Savaid Medical School, University of Chinese Academy of Sciences, 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
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Savaid Medical School, University of Chinese Academy of Sciences, 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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8
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Identification and characterization of coiled-coil motifs across Autographa californica multiple nucleopolyhedrovirus genome. Heliyon 2022; 8:e10588. [PMID: 36132175 PMCID: PMC9483598 DOI: 10.1016/j.heliyon.2022.e10588] [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: 01/25/2022] [Revised: 05/15/2022] [Accepted: 09/05/2022] [Indexed: 12/02/2022] Open
Abstract
Coiled coils (CCs) are protein structural motifs universally found in proteins and mediate a plethora of biological interactions, and thus their reliable annotation is crucial for studies of protein structure and function. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a large double-stranded DNA (dsDNA) virus and encodes 154 proteins. In this study, genome-wide scans of previously uncharacterized CC motifs throughout AcMNPV was conducted using CC prediction software. In total, 24 CC motifs in 19 CC proteins with high confidence were identified. The characteristic of viral CC motifs were analyzed. The CC proteins could be divided into 12 viral structural proteins and 7 non-structural proteins, including viral membrane fusion proteins, enzymes, and transcription factors. Moreover, CC motifs are conserved in the baculoviral orthologs of 14 of the 19 proteins. It is noted that five CC proteins, including Ac51, Ac66, Exon0, Ac13, and GP16, were previously identified to function in the nuclear egress of nucleocapsids, and Ac66 contains multiple CC motifs, the longest of which comprises 252 amino acids, suggesting a role of CC motifs in this process. Taken together, the CC motifs identified in this study are valuable resource for studying protein function and protein interaction networks during virus replication.
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Corona A, Fanunza E, Salata C, Morwitzer MJ, Distinto S, Zinzula L, Sanna C, Frau A, Daino GL, Quartu M, Taglialatela-Scafati O, Rigano D, Reid S, Mirazimi A, Tramontano E. Cynarin blocks Ebola virus replication by counteracting VP35 inhibition of interferon-beta production. Antiviral Res 2022; 198:105251. [DOI: 10.1016/j.antiviral.2022.105251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/16/2021] [Accepted: 01/17/2022] [Indexed: 11/02/2022]
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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: 8] [Impact Index Per Article: 2.7] [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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Rodriguez Galvan J, Donner B, Veseley CH, Reardon P, Forsythe HM, Howe J, Fujimura G, Barbar E. Human Parainfluenza Virus 3 Phosphoprotein Is a Tetramer and Shares Structural and Interaction Features with Ebola Phosphoprotein VP35. Biomolecules 2021; 11:1603. [PMID: 34827601 PMCID: PMC8615749 DOI: 10.3390/biom11111603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
The human parainfluenza virus 3 (HPIV3) poses a risk for pneumonia development in young children and immunocompromised patients. To investigate mechanisms of HPIV3 pathogenesis, we characterized the association state and host protein interactions of HPIV3 phosphoprotein (HPIV3 P), an indispensable viral polymerase cofactor. Sequence analysis and homology modeling predict that HPIV3 P possesses a long, disordered N-terminal tail (PTAIL) a coiled-coil multimerization domain (PMD), similar to the well-characterized paramyxovirus phosphoproteins from measles and Sendai viruses. Using a recombinantly expressed and purified construct of PMD and PTAIL, we show that HPIV3 P in solution is primarily an alpha-helical tetramer that is stable up to 60 °C. Pulldown and isothermal titration calorimetry experiments revealed that HPIV3 P binds the host hub protein LC8, and turbidity experiments demonstrated a new role for LC8 in increasing the solubility of HPIV3 P in the presence of crowding agents such as RNA. For comparison, we show that the multimerization domain of the Zaire Ebola virus phosphoprotein VP35 is also a tetramer and binds LC8 but with significantly higher affinity. Comparative analysis of the domain architecture of various virus phosphoproteins in the order Mononegavirales show multiple predicted and verified LC8 binding motifs, suggesting its prevalence and importance in regulating viral phosphoprotein structures. Our work provides evidence for LC8 binding to phosphoproteins with multiple association states, either tetrameric, as in the HPIV3 and Ebola phosphoproteins shown here, or dimeric as in rabies virus phosphoprotein. Taken together the data suggest that the association states of a virus-specific phosphoprotein and the complex formed by binding of the phosphoprotein to host LC8 are important regulators of viral function.
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Affiliation(s)
- Joaquin Rodriguez Galvan
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Brianna Donner
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Cat Hoang Veseley
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Patrick Reardon
- NMR Facility, Oregon State University, Corvallis, OR 97331, USA;
| | - Heather M. Forsythe
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Jesse Howe
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Gretchen Fujimura
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
| | - Elisar Barbar
- Department of Biochemistry & Biophysics, College of Science, Corvallis, OR 97331, USA; (J.R.G.); (B.D.); (C.H.V.); (H.M.F.); (J.H.); (G.F.)
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12
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Crystal structure of human LC8 bound to a peptide from Ebola virus VP35. J Microbiol 2021; 59:410-416. [PMID: 33630249 DOI: 10.1007/s12275-021-0641-7] [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] [Received: 12/07/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 10/22/2022]
Abstract
Zaire ebolavirus, commonly called Ebola virus (EBOV), is an RNA virus that causes severe hemorrhagic fever with high mortality. Viral protein 35 (VP35) is a virulence factor encoded in the EBOV genome. VP35 inhibits host innate immune responses and functions as a critical cofactor for viral RNA replication. EBOV VP35 contains a short conserved motif that interacts with dynein light chain 8 (LC8), which serves as a regulatory hub protein by associating with various LC8-binding proteins. Herein, we present the crystal structure of human LC8 bound to the peptide comprising residues 67-76 of EBOV VP35. Two VP35 peptides were found to interact with homodimeric LC8 by extending the central β-sheets, constituting a 2:2 complex. Structural analysis demonstrated that the intermolecular binding between LC8 and VP35 is mainly sustained by a network of hydrogen bonds and supported by hydrophobic interactions in which Thr73 and Thr75 of VP35 are involved. These findings were verified by binding measurements using isothermal titration calorimetry. Biochemical analyses also verified that residues 67-76 of EBOV VP35 constitute a core region for interaction with LC8. In addition, corresponding motifs from other members of the genus Ebolavirus commonly bound to LC8 but with different binding affinities. Particularly, VP35 peptides originating from pathogenic species interacted with LC8 with higher affinity than those from noninfectious species, suggesting that the binding of VP35 to LC8 is associated with the pathogenicity of the Ebolavirus species.
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13
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Cardone C, Caseau CM, Pereira N, Sizun C. Pneumoviral Phosphoprotein, a Multidomain Adaptor-Like Protein of Apparent Low Structural Complexity and High Conformational Versatility. Int J Mol Sci 2021; 22:ijms22041537. [PMID: 33546457 PMCID: PMC7913705 DOI: 10.3390/ijms22041537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 01/16/2023] Open
Abstract
Mononegavirales phosphoproteins (P) are essential co-factors of the viral polymerase by serving as a linchpin between the catalytic subunit and the ribonucleoprotein template. They have highly diverged, but their overall architecture is conserved. They are multidomain proteins, which all possess an oligomerization domain that separates N- and C-terminal domains. Large intrinsically disordered regions constitute their hallmark. Here, we exemplify their structural features and interaction potential, based on the Pneumoviridae P proteins. These P proteins are rather small, and their oligomerization domain is the only part with a defined 3D structure, owing to a quaternary arrangement. All other parts are either flexible or form short-lived secondary structure elements that transiently associate with the rest of the protein. Pneumoviridae P proteins interact with several viral and cellular proteins that are essential for viral transcription and replication. The combination of intrinsic disorder and tetrameric organization enables them to structurally adapt to different partners and to act as adaptor-like platforms to bring the latter close in space. Transient structures are stabilized in complex with protein partners. This class of proteins gives an insight into the structural versatility of non-globular intrinsically disordered protein domains.
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14
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Banerjee A, Mitra P. Ebola Virus VP35 Protein: Modeling of the Tetrameric Structure and an Analysis of Its Interaction with Human PKR. J Proteome Res 2020; 19:4533-4542. [PMID: 32871072 PMCID: PMC7640970 DOI: 10.1021/acs.jproteome.0c00473] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Indexed: 01/12/2023]
Abstract
The Viral Protein 35 (VP35), a crucial protein of the Zaire Ebolavirus (EBOV), interacts with a plethora of human proteins to cripple the human immune system. Despite its importance, the entire structure of the tetrameric assembly of EBOV VP35 and the means by which it antagonizes the autophosphorylation of the kinase domain of human protein kinase R (PKRK) is still elusive. We consult existing structural information to model a tetrameric assembly of the VP35 protein where 93% of the protein is modeled using crystal structure templates. We analyze our modeled tetrameric structure to identify interchain bonding networks and use molecular dynamics simulations and normal-mode analysis to unravel the flexibility and deformability of the different regions of the VP35 protein. We establish that the C-terminal of VP35 (VP35C) directly interacts with PKRK to prevent it from autophosphorylation. Further, we identify three plausible VP35C-PKRK complexes with better affinity than the PKRK dimer formed during autophosphorylation and use protein design to establish a new stretch in VP35C that interacts with PKRK. The proposed tetrameric assembly will aid in better understanding of the VP35 protein, and the reported VP35C-PKRK complexes along with their interacting sites will help in the shortlisting of small molecule inhibitors.
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Affiliation(s)
- Anupam Banerjee
- Advanced
Technology Development Centre, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - Pralay Mitra
- Department
of Computer Science and Engineering, Indian
Institute of Technology Kharagpur, West Bengal 721302, India
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15
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Abstract
Mononegavirales, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory syncytial virus (HRSV), and Ebola virus (EBOV). Unfortunately, no effective vaccines and antiviral therapeutics against many Mononegavirales are currently available. Viral polymerases have been attractive and major antiviral therapeutic targets. Therefore, Mononegavirales polymerases have been extensively investigated for their structures and functions. Mononegavirales, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory syncytial virus (HRSV), and Ebola virus (EBOV). Unfortunately, no effective vaccines and antiviral therapeutics against many Mononegavirales are currently available. Viral polymerases have been attractive and major antiviral therapeutic targets. Therefore, Mononegavirales polymerases have been extensively investigated for their structures and functions. Mononegavirales mimic RNA synthesis of their eukaryotic counterparts by utilizing multifunctional RNA polymerases to replicate entire viral genomes and transcribe viral mRNAs from individual viral genes as well as synthesize 5′ methylated cap and 3′ poly(A) tail of the transcribed viral mRNAs. The catalytic subunit large protein (L) and cofactor phosphoprotein (P) constitute the Mononegavirales polymerases. In this review, we discuss the shared and unique features of RNA synthesis, the monomeric multifunctional enzyme L, and the oligomeric multimodular adapter P of Mononegavirales. We outline the structural analyses of the Mononegavirales polymerases since the first structure of the vesicular stomatitis virus (VSV) L protein determined in 2015 and highlight multiple high-resolution cryo-electron microscopy (cryo-EM) structures of the polymerases of Mononegavirales, namely, VSV, RABV, HRSV, human metapneumovirus (HMPV), and human parainfluenza virus (HPIV), that have been reported in recent months (2019 to 2020). We compare the structures of those polymerases grouped by virus family, illustrate the similarities and differences among those polymerases, and reveal the potential RNA synthesis mechanisms and models of highly conserved Mononegavirales. We conclude by the discussion of remaining questions, evolutionary perspectives, and future directions.
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16
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Structural and Functional Characterization of the Phosphoprotein Central Domain of Spring Viremia of Carp Virus. J Virol 2020; 94:JVI.00855-20. [PMID: 32434890 DOI: 10.1128/jvi.00855-20] [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: 05/05/2020] [Accepted: 05/18/2020] [Indexed: 11/20/2022] Open
Abstract
Spring viremia of carp virus (SVCV) is a highly pathogenic Vesiculovirus in the common carp. The phosphoprotein (P protein) of SVCV is a multifunctional protein that acts as a polymerase cofactor and an antagonist of cellular interferon (IFN) response. Here, we report the 1.5-Å-resolution crystal structure of the P protein central domain (PCD) of SVCV (SVCVPCD). The PCD monomer consists of two β sheets, an α helix, and another two β sheets. Two PCD monomers pack together through their hydrophobic surfaces to form a dimer. The mutations of residues on the hydrophobic surfaces of PCD disrupt the dimer formation to different degrees and affect the expression of host IFN consistently. Therefore, the oligomeric state formation of the P protein of SVCV is an important mechanism to negatively regulate host IFN response.IMPORTANCE SVCV can cause spring viremia of carp with up to 90% lethality, and it is the homologous virus of the notorious vesicular stomatitis virus (VSV). There are currently no drugs that effectively cure this disease. P proteins of negative-strand RNA viruses (NSVs) play an essential role in many steps during the replication cycle and an additional role in immunosuppression as a cofactor. All P proteins of NSVs are oligomeric, but the studies on the role of this oligomerization mainly focus on the process of virus transcription or replication, and there are few studies on the role of PCD in immunosuppression. Here, we present the crystal structure of SVCVPCD A new mechanism of immune evasion is clarified by exploring the relationship between SVCVPCD and host IFN response from a structural biology point of view. These findings may provide more accurate target sites for drug design against SVCV and provide new insights into the function of NSVPCD.
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17
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Fanunza E, Frau A, Corona A, Tramontano E. Insights into Ebola Virus VP35 and VP24 Interferon Inhibitory Functions and their Initial Exploitation as Drug Targets. Infect Disord Drug Targets 2020; 19:362-374. [PMID: 30468131 DOI: 10.2174/1871526519666181123145540] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 12/15/2022]
Abstract
Upon viral infection, the interferon (IFN) system triggers potent antiviral mechanisms limiting viral growth and spread. Hence, to sustain their infection, viruses evolved efficient counteracting strategies to evade IFN control. Ebola virus (EBOV), member of the family Filoviridae, is one of the most virulent and deadly pathogen ever faced by humans. The etiological agent of the Ebola Virus Disease (EVD), EBOV can be undoubtedly considered the perfect example of a powerful inhibitor of the host organism immune response activation. Particularly, the efficacious suppression of the IFN cascade contributes to disease progression and severity. Among the EBOVencoded proteins, the Viral Proteins 35 (VP35) and 24 (VP24) are responsible for the EBOV extreme virulence, representing the core of such inhibitory function through which EBOV determines its very effective shield to the cellular immune defenses. VP35 inhibits the activation of the cascade leading to IFN production, while VP24 inhibits the activation of the IFN-stimulated genes. A number of studies demonstrated that both VP35 and VP24 is validated target for drug development. Insights into the structural characteristics of VP35 and VP24 domains revealed crucial pockets exploitable for drug development. Considered the lack of therapy for EVD, restoring the immune activation is a promising approach for drug development. In the present review, we summarize the importance of VP35 and VP24 proteins in counteracting the host IFN cellular response and discuss their potential as druggable viral targets as a promising approach toward attenuation of EBOV virulence.
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Affiliation(s)
- Elisa Fanunza
- Department of Life and Environmental Sciences, University of Cagliari, Sardinia, Italy
| | - Aldo Frau
- Department of Life and Environmental Sciences, University of Cagliari, Sardinia, Italy
| | - Angela Corona
- Department of Life and Environmental Sciences, University of Cagliari, Sardinia, Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Sardinia, Italy.,Genetics and Biomedical Research Institute, National Research Council, Monserrato, Italy
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18
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Vesicular Stomatitis Virus Phosphoprotein Dimerization Domain Is Dispensable for Virus Growth. J Virol 2020; 94:JVI.01789-19. [PMID: 31852780 DOI: 10.1128/jvi.01789-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/06/2019] [Indexed: 02/08/2023] Open
Abstract
The phosphoprotein (P) of the nonsegmented negative-sense RNA viruses is a multimeric modular protein that is essential for RNA transcription and replication. Despite great variability in length and sequence, the architecture of this protein is conserved among the different viral families, with a long N-terminal intrinsically disordered region comprising a nucleoprotein chaperone module, a central multimerization domain (PMD), connected by a disordered linker to a C-terminal nucleocapsid-binding domain. The P protein of vesicular stomatitis virus (VSV) forms dimers, and here we investigate the importance of its dimerization domain, PMD, for viral gene expression and virus growth. A truncated P protein lacking the central dimerization domain (PΔMD) loses its ability to form dimers both in vitro and in a yeast two-hybrid system but conserves its ability to bind N. In a minireplicon system, the truncated monomeric protein performs almost as well as the full-length dimeric protein, while a recombinant virus harboring the same truncation in the P protein has been rescued and follows replication kinetics similar to those seen with the wild-type virus, showing that the dimerization domain of P is dispensable for viral gene expression and virus replication in cell culture. Because RNA viruses have high mutation rates, it is unlikely that a structured domain such as a VSV dimerization domain would persist in the absence of a function(s), but our work indicates that it is not required for the functioning of the RNA polymerase machinery or for the assembly of new viruses.IMPORTANCE The phosphoprotein (P) is an essential and conserved component of all nonsegmented negative-sense RNA viruses, including some major human pathogens (e.g., rabies virus, measles virus, respiratory syncytial virus [RSV], Ebola virus, and Nipah virus). P is a modular protein with intrinsically disordered regions and folded domains that plays specific and similar roles in the replication of the different viruses and, in some cases, hijacks cell components to the advantage of the virus and is involved in immune evasion. All P proteins are multimeric, but the role of this multimerization is still unclear. Here, we demonstrate that the dimerization domain of VSV P is dispensable for the expression of virally encoded proteins and for virus growth in cell culture. This provides new insights into and raises questions about the functioning of the RNA-synthesizing machinery of the nonsegmented negative-sense RNA viruses.
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19
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Mechanisms of Non-segmented Negative Sense RNA Viral Antagonism of Host RIG-I-Like Receptors. J Mol Biol 2019; 431:4281-4289. [PMID: 31202887 DOI: 10.1016/j.jmb.2019.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/29/2019] [Accepted: 06/05/2019] [Indexed: 12/25/2022]
Abstract
The pattern recognition receptors RIG-I-like receptors (RLRs) are critical molecules for cytosolic viral recognition and for subsequent activation of type I interferon production. The interferon signaling pathway plays a key role in viral detection and generating antiviral responses. Among the many pathogens, the non-segmented negative sense RNA viruses target the RLR pathway using a variety of mechanisms. Here, I review the current state of knowledge on the molecular mechanisms that allow non-segmented negative sense RNA virus recognition and antagonism of RLRs.
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20
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Bloyet LM, Schramm A, Lazert C, Raynal B, Hologne M, Walker O, Longhi S, Gerlier D. Regulation of measles virus gene expression by P protein coiled-coil properties. SCIENCE ADVANCES 2019; 5:eaaw3702. [PMID: 31086822 PMCID: PMC6506246 DOI: 10.1126/sciadv.aaw3702] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/01/2019] [Indexed: 05/18/2023]
Abstract
The polymerase of negative-stranded RNA viruses consists of the large protein (L) and the phosphoprotein (P), the latter serving both as a chaperon and a cofactor for L. We mapped within measles virus (MeV) P the regions responsible for binding and stabilizing L and showed that the coiled-coil multimerization domain (MD) of P is required for gene expression. MeV MD is kinked as a result of the presence of a stammer. Both restoration of the heptad regularity and displacement of the stammer strongly decrease or abrogate activity in a minigenome assay. By contrast, P activity is rather tolerant of substitutions within the stammer. Single substitutions at the "a" or "d" hydrophobic anchor positions with residues of variable hydrophobicity revealed that P functionality requires a narrow range of cohesiveness of its MD. Results collectively indicate that, beyond merely ensuring P oligomerization, the MD finely tunes viral gene expression through its cohesiveness.
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Affiliation(s)
- Louis-Marie Bloyet
- CIRI, International Center for Infectiology Research, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - Antoine Schramm
- Aix-Marseille University, CNRS, Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Carine Lazert
- CIRI, International Center for Infectiology Research, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
| | - Bertrand Raynal
- Institut Pasteur, Plateforme de Biophysique Moléculaire, Paris, France
| | - Maggy Hologne
- Institut des Sciences Analytiques (ISA), Univ Lyon, CNRS, UMR5280, Université Claude Bernard Lyon 1, Lyon France
| | - Olivier Walker
- Institut des Sciences Analytiques (ISA), Univ Lyon, CNRS, UMR5280, Université Claude Bernard Lyon 1, Lyon France
| | - Sonia Longhi
- Aix-Marseille University, CNRS, Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Denis Gerlier
- CIRI, International Center for Infectiology Research, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, Lyon, France
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21
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Martell HJ, Masterson SG, McGreig JE, Michaelis M, Wass MN. Is the Bombali virus pathogenic in humans? Bioinformatics 2019; 35:3553-3558. [DOI: 10.1093/bioinformatics/btz267] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 03/14/2019] [Accepted: 04/15/2019] [Indexed: 11/13/2022] Open
Abstract
Abstract
Motivation
The potential of the Bombali virus, a novel Ebolavirus, to cause disease in humans remains unknown. We have previously identified potential determinants of Ebolavirus pathogenicity in humans by analysing the amino acid positions that are differentially conserved (specificity determining positions; SDPs) between human pathogenic Ebolaviruses and the non-pathogenic Reston virus. Here, we include the many Ebolavirus genome sequences that have since become available into our analysis and investigate the amino acid sequence of the Bombali virus proteins at the SDPs that discriminate between human pathogenic and non-human pathogenic Ebolaviruses.
Results
The use of 1408 Ebolavirus genomes (196 in the original analysis) resulted in a set of 166 SDPs (reduced from 180), 146 (88%) of which were retained from the original analysis. This indicates the robustness of our approach and refines the set of SDPs that distinguish human pathogenic Ebolaviruses from Reston virus. At SDPs, Bombali virus shared the majority of amino acids with the human pathogenic Ebolaviruses (63.25%). However, for two SDPs in VP24 (M136L, R139S) that have been proposed to be critical for the lack of Reston virus human pathogenicity because they alter the VP24-karyopherin interaction, the Bombali virus amino acids match those of Reston virus. Thus, Bombali virus may not be pathogenic in humans. Supporting this, no Bombali virus-associated disease outbreaks have been reported, although Bombali virus was isolated from fruit bats cohabitating in close contact with humans, and anti-Ebolavirus antibodies that may indicate contact with Bombali virus have been detected in humans.
Availability and implementation
Data files are available from https://github.com/wasslab/EbolavirusSDPsBioinformatics2019.
Supplementary information
Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Henry J Martell
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Stuart G Masterson
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Jake E McGreig
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Martin Michaelis
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Mark N Wass
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, Kent, UK
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22
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Chanthamontri CK, Jordan DS, Wang W, Wu C, Lin Y, Brett TJ, Gross ML, Leung DW. The Ebola Viral Protein 35 N-Terminus Is a Parallel Tetramer. Biochemistry 2019; 58:657-664. [PMID: 30592210 DOI: 10.1021/acs.biochem.8b01154] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Members of Mononegavirales, the order that includes nonsegmented negative sense RNA viruses (NNSVs), encode a small number of multifunctional proteins. In members of the Filoviridae family, virus protein 35 (VP35) facilitates immune evasion and functions as an obligatory cofactor for viral RNA synthesis. VP35 functions in a manner orthologous to that of phosphoproteins from other NNSVs. Although the critical roles of Ebola viral VP35 (eVP35) in immune evasion and RNA synthesis are well-appreciated, a complete understanding of its organization and its role in carrying out its many functions has yet to be fully realized. In particular, we currently lack information about the role of the oligomerization domain within eVP35. To address this limitation, we report here an investigation of the oligomer structure of eVP35 using hybrid methods that include multiangle light scattering, small-angle X-ray scattering, and cross-linking coupled with mass spectrometry to determine the shape and orientation of the eVP35 oligomer. Our integrative results are consistent with a parallel tetramer in which the N-terminal regions that are required for RNA synthesis are all oriented in the same direction. Furthermore, these results define a framework for targeting the symmetric tetramer for structure-based antiviral discovery.
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Affiliation(s)
- Chamnongsak Ken Chanthamontri
- Department of Chemistry , Washington University in St. Louis , Box 1134, One Brookings Drive , St. Louis , Missouri 63130 , United States
| | - David S Jordan
- Department of Pathology and Immunology , Washington University School of Medicine in St. Louis , St. Louis , Missouri 63110 , United States
| | - Wenjie Wang
- Department of Pathology and Immunology , Washington University School of Medicine in St. Louis , St. Louis , Missouri 63110 , United States
| | - Chao Wu
- Department of Pathology and Immunology , Washington University School of Medicine in St. Louis , St. Louis , Missouri 63110 , United States
| | - Yanchun Lin
- Department of Chemistry , Washington University in St. Louis , Box 1134, One Brookings Drive , St. Louis , Missouri 63130 , United States
| | - Tom J Brett
- Department of Medicine , Washington University School of Medicine in St. Louis , St. Louis , Missouri 63110 , United States
| | - Michael L Gross
- Department of Chemistry , Washington University in St. Louis , Box 1134, One Brookings Drive , St. Louis , Missouri 63130 , United States
| | - Daisy W Leung
- Department of Pathology and Immunology , Washington University School of Medicine in St. Louis , St. Louis , Missouri 63110 , United States
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23
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Di Palma F, Daino GL, Ramaswamy VK, Corona A, Frau A, Fanunza E, Vargiu AV, Tramontano E, Ruggerone P. Relevance of Ebola virus VP35 homo-dimerization on the type I interferon cascade inhibition. Antivir Chem Chemother 2019; 27:2040206619889220. [PMID: 31744306 PMCID: PMC6883671 DOI: 10.1177/2040206619889220] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/13/2019] [Indexed: 01/10/2023] Open
Abstract
Ebola virus high lethality relies on its ability to efficiently bypass the host innate antiviral response, which senses the viral dsRNA through the RIG-I receptor and induces type I interferon α/β production. In the bypassing action, the Ebola virus protein VP35 plays a pivotal role at multiple levels of the RIG-I cascade, masking the viral 5′-triphosphorylated dsRNA from RIG-I, and interacting with other cascade components. The VP35 type I interferon inhibition is exerted by the C-terminal domain, while the N-terminal domain, containing a coiled-coil region, is primarily required for oligomerization. However, mutations at key VP35 residues L90/93/107A (VP35-3m) in the coiled-coil region were reported to affect oligomerization and reduce type I interferon antagonism, indicating a possible but unclear role of homo-oligomerization on VP35 interaction with the RIG-I pathway components. In this work, we investigated the VP35 dimerization thermodynamics and its contribution to type I interferon antagonism by computational and biological methods. Focusing on the coiled-coil region, we combined coarse-grained and all-atom simulations on wild type VP35 and VP35-3m homo-dimerization. According to our results, wild type VP35 coiled-coil is able to self-assemble into dimers, while VP35-3m coiled-coil shows poor propensity to even dimerize. Free-energy calculations confirmed the key role of L90, L93 and L107 in stabilizing the coiled-coil homo-dimeric structure. In vitro type I interferon antagonism studies, using full-length wild type VP35 and VP35-3m, revealed that VP35 homo-dimerization is an essential preliminary step for dsRNA binding, which appears to be the main factor of the VP35 RIG-I cascade inhibition, while it is not essential to block the other steps.
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Affiliation(s)
- Francesco Di Palma
- Department of Physics, University of Cagliari, Cittadella
Universitaria, Monserrato, Italy
| | - Gian Luca Daino
- Department of Life and Environmental Sciences, University of
Cagliari, Cittadella Universitaria, Monserrato, Italy
| | | | - Angela Corona
- Department of Life and Environmental Sciences, University of
Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Aldo Frau
- Department of Life and Environmental Sciences, University of
Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Elisa Fanunza
- Department of Life and Environmental Sciences, University of
Cagliari, Cittadella Universitaria, Monserrato, Italy
| | - Attilio V Vargiu
- Department of Physics, University of Cagliari, Cittadella
Universitaria, Monserrato, Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of
Cagliari, Cittadella Universitaria, Monserrato, Italy
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale
delle Ricerche (CNR), Monserrato, Italy
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Cittadella
Universitaria, Monserrato, Italy
- Istituto Officina dei Materiali (CNR-IOM), UOS Cagliari SLACS,
Monserrato, Italy
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24
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Basler CF, Krogan NJ, Leung DW, Amarasinghe GK. Virus and host interactions critical for filoviral RNA synthesis as therapeutic targets. Antiviral Res 2018; 162:90-100. [PMID: 30550800 DOI: 10.1016/j.antiviral.2018.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/08/2018] [Indexed: 01/24/2023]
Abstract
Filoviruses, which include Ebola virus (EBOV) and Marburg virus, are negative-sense RNA viruses associated with sporadic outbreaks of severe viral hemorrhagic fever characterized by uncontrolled virus replication. The extreme virulence and emerging nature of these zoonotic pathogens make them a significant threat to human health. Replication of the filovirus genome and production of viral RNAs require the function of a complex of four viral proteins, the nucleoprotein (NP), viral protein 35 (VP35), viral protein 30 (VP30) and large protein (L). The latter performs the enzymatic activities required for production of viral RNAs and capping of viral mRNAs. Although it has been recognized that interactions between the virus-encoded components of the EBOV RNA polymerase complex are required for viral RNA synthesis reactions, specific molecular details have, until recently, been lacking. New efforts have combined structural biology and molecular virology to reveal in great detail the molecular basis for critical protein-protein interactions (PPIs) necessary for viral RNA synthesis. These efforts include recent studies that have identified a range of interacting host factors and in some instances demonstrated unique mechanisms by which they act. For a select number of these interactions, combined use of mutagenesis, over-expressing of peptides corresponding to PPI interfaces and identification of small molecules that disrupt PPIs have demonstrated the functional significance of virus-virus and virus-host PPIs and suggest several as potential targets for therapeutic intervention.
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Affiliation(s)
- Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
| | - Nevan J Krogan
- Quantitative Biosciences Institute (QBI), UCSF, San Francisco, CA, USA; Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, CA, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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