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Alanzi AR, Alajmi MF, Al-Dosari MS, Parvez MK, Alqahtani MJ. In silico exploration of deep-sea fungal metabolites as inhibitor of Ebola and Marburg VP35 and VP40. PLoS One 2024; 19:e0307579. [PMID: 39052567 DOI: 10.1371/journal.pone.0307579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
VP30 and VP40 proteins of Ebola and Marburg viruses have been recognized as potential targets for antiviral drug development due to their essential roles in the viral lifecycle. Targeting these proteins could disrupt key stages of the viral replication process, inhibiting the viruses' ability to propagate and cause disease. The current study aims to perform molecular docking and virtual screening on deep-sea fungal metabolites targeting Marburg virus VP40 Dimer, matrix protein VP40 from Ebola virus Sudan, Ebola VP35 Interferon Inhibitory Domain, and VP35 from Marburg virus. The top ten compounds for each protein target were chosen using the glide score. All the compounds obtained indicate a positive binding interaction. Furthermore, AdmetSAR was utilized to investigate the pharmacokinetics of the inhibitors chosen. Gliotoxin was used as a ligand with Marburg virus VP40 Dimer, Austinol with matrix protein VP40 from Ebola virus Sudan, Ozazino-cyclo-(2,3-dihydroxyl-trp-tyr) with Ebola VP35 Interferon Inhibitory Domain, and Dehydroaustinol with VP35 from Marburg virus. MD modeling and MMPBSA studies were used to provide a better understanding of binding behaviors. Pre-clinical experiments can assist validate our in-silico studies and assess whether the molecule can be employed as an anti-viral drug.
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Affiliation(s)
- Abdullah R Alanzi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed F Alajmi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed S Al-Dosari
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad K Parvez
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Moneerah J Alqahtani
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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2
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Inhibiting the transcription and replication of Ebola viruses by disrupting the nucleoprotein and VP30 protein interaction with small molecules. Acta Pharmacol Sin 2023:10.1038/s41401-023-01055-0. [PMID: 36759643 PMCID: PMC9909651 DOI: 10.1038/s41401-023-01055-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 01/10/2023] [Indexed: 02/11/2023] Open
Abstract
Ebola virus (EBOV) causes hemorrhagic fever in humans with high morbidity and fatality. Although over 45 years have passed since the first EBOV outbreak, small molecule drugs are not yet available. Ebola viral protein VP30 is a unique RNA synthesis cofactor, and the VP30/NP interaction plays a critical role in initiating the transcription and propagation of EBOV. Here, we designed a high-throughput screening technique based on a competitive binding assay to bind VP30 between an NP-derived peptide and a chemical compound. By screening a library of 8004 compounds, we obtained two lead compounds, Embelin and Kobe2602. The binding of these compounds to the VP30-NP interface was validated by dose-dependent competitive binding assay, surface plasmon resonance, and thermal shift assay. Moreover, the compounds were confirmed to inhibit the transcription and replication of the Ebola genome by a minigenome assay. Similar results were obtained for their two respective analogs (8-gingerol and Kobe0065). Interestingly, these two structurally different molecules exhibit synergistic binding to the VP30/NP interface. The antiviral efficacy (EC50) increased from 1 μM by Kobe0065 alone to 351 nM when Kobe0065 and Embelin were combined in a 4:1 ratio. The synergistic anti-EBOV effect provides a strong incentive for further developing these lead compounds in future studies.
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3
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Edwards MR, Vogel OA, Mori H, Davey RA, Basler CF. Marburg Virus VP30 Is Required for Transcription Initiation at the Glycoprotein Gene. mBio 2022; 13:e0224322. [PMID: 35997284 PMCID: PMC9601197 DOI: 10.1128/mbio.02243-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 12/04/2022] Open
Abstract
Marburg virus (MARV) is an enveloped, negative-sense RNA virus from the filovirus family that causes outbreaks of severe, frequently fatal illness in humans. Of the seven MARV proteins, the VP30 protein stands out because it is essential for viral growth but lacks a definitive function. Here, we used model MARV genome RNAs for one or two reporter genes and the MARV VP40, glycoprotein (GP), and VP24 genes to demonstrate that VP30 is dispensable for the transcription of some genes but critical for transcription reinitiation at the GP gene. This results in the loss of the expression of GP and downstream genes and the impaired production of infectious particles when VP30 is absent. Bicistronic minigenome assays demonstrate that the VP40 gene end/GP gene start junction specifically confers VP30 dependence. A region at the GP gene start site predicted to form a stem-loop contributes to VP30 dependence because the replacement of the GP stem-loop with corresponding sequences from the MARV VP35 gene relieves VP30 dependence. Finally, a Cys3-His zinc binding motif characteristic of filovirus VP30 proteins was demonstrated to be critical for reinitiation at GP. These findings address a long-standing gap in our understanding of MARV biology by defining a critical role for VP30 in MARV transcription. IMPORTANCE Marburg virus and Ebola virus encode VP30 proteins. While the role of VP30 in Ebola virus transcription has been well studied, the role of VP30 in the Marburg virus life cycle is not well understood. The work here demonstrates that different gene start sites within the Marburg viral genome have variable levels of dependence on Marburg virus VP30, with its expression being critical for transcription reinitiation at the GP gene start site. These findings address a long-standing question regarding Marburg virus VP30 function and further our understanding of how Marburg virus gene expression is regulated.
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Affiliation(s)
- Megan R. Edwards
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | - Olivia A. Vogel
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hiroyuki Mori
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - Robert A. Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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4
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Doan PTK, Low WY, Ren Y, Tearle R, Hemmatzadeh F. Newcastle disease virus genotype VII gene expression in experimentally infected birds. Sci Rep 2022; 12:5249. [PMID: 35347193 PMCID: PMC8960812 DOI: 10.1038/s41598-022-09257-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/07/2022] [Indexed: 11/23/2022] Open
Abstract
Newcastle disease virus genotype VII (NDV-GVII) is a highly contagious pathogen responsible for pandemics that have caused devastating economic losses in the poultry industry. Several features in the transcription of NDV mRNA, including differentially expressed genes across the viral genome, are shared with that for other single, non-segmented, negative-strand viruses. Previous studies measuring viral gene expression using northern blotting indicated that the NDV transcription produced non-equimolar levels of viral mRNAs. However, deep high-throughput sequencing of virus-infected tissues can provide a better insight into the patterns of viral transcription. In this report, the transcription pattern of virulent NDV-GVII was analysed using RNA-seq and qRT-PCR. This study revealed the transcriptional profiling of these highly pathogenic NDV-GVII genes: NP:P:M:F:HN:L, in which there was a slight attenuation at the NP:P and HN:L gene boundaries. Our result also provides a fully comprehensive qPCR protocol for measuring viral transcript abundance that may be more convenient for laboratories where accessing RNA-seq is not feasible.
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Affiliation(s)
- Phuong Thi Kim Doan
- School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia. .,Faculty of Animal and Veterinary Sciences, Tay Nguyen University, Dak Lak, Vietnam.
| | - Wai Yee Low
- Davies Research Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia
| | - Yan Ren
- Davies Research Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia
| | - Rick Tearle
- Davies Research Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia
| | - Farhid Hemmatzadeh
- School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia.,Davies Research Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, Australia
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5
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Liu CH, Hu YT, Wong SH, Lin LT. Therapeutic Strategies against Ebola Virus Infection. Viruses 2022; 14:v14030579. [PMID: 35336986 PMCID: PMC8954160 DOI: 10.3390/v14030579] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 12/10/2022] Open
Abstract
Since the 2014–2016 epidemic, Ebola virus (EBOV) has spread to several countries and has become a major threat to global health. EBOV is a risk group 4 pathogen, which imposes significant obstacles for the development of countermeasures against the virus. Efforts have been made to develop anti-EBOV immunization and therapeutics, with three vaccines and two antibody-based therapeutics approved in recent years. Nonetheless, the high fatality of Ebola virus disease highlights the need to continuously develop antiviral strategies for the future management of EBOV outbreaks in conjunction with vaccination programs. This review aims to highlight potential EBOV therapeutics and their target(s) of inhibition, serving as a summary of the literature to inform readers of the novel candidates available in the continued search for EBOV antivirals.
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Affiliation(s)
- Ching-Hsuan Liu
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Yee-Tung Hu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Shu Hui Wong
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Liang-Tzung Lin
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Correspondence:
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6
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Structural and Functional Aspects of Ebola Virus Proteins. Pathogens 2021; 10:pathogens10101330. [PMID: 34684279 PMCID: PMC8538763 DOI: 10.3390/pathogens10101330] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 01/14/2023] Open
Abstract
Ebola virus (EBOV), member of genus Ebolavirus, family Filoviridae, have a non-segmented, single-stranded RNA that contains seven genes: (a) nucleoprotein (NP), (b) viral protein 35 (VP35), (c) VP40, (d) glycoprotein (GP), (e) VP30, (f) VP24, and (g) RNA polymerase (L). All genes encode for one protein each except GP, producing three pre-proteins due to the transcriptional editing. These pre-proteins are translated into four products, namely: (a) soluble secreted glycoprotein (sGP), (b) Δ-peptide, (c) full-length transmembrane spike glycoprotein (GP), and (d) soluble small secreted glycoprotein (ssGP). Further, shed GP is released from infected cells due to cleavage of GP by tumor necrosis factor α-converting enzyme (TACE). This review presents a detailed discussion on various functional aspects of all EBOV proteins and their residues. An introduction to ebolaviruses and their life cycle is also provided for clarity of the available analysis. We believe that this review will help understand the roles played by different EBOV proteins in the pathogenesis of the disease. It will help in targeting significant protein residues for therapeutic and multi-protein/peptide vaccine development.
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7
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Batra J, Mori H, Small GI, Anantpadma M, Shtanko O, Mishra N, Zhang M, Liu D, Williams CG, Biedenkopf N, Becker S, Gross ML, Leung DW, Davey RA, Amarasinghe GK, Krogan NJ, Basler CF. Non-canonical proline-tyrosine interactions with multiple host proteins regulate Ebola virus infection. EMBO J 2021; 40:e105658. [PMID: 34260076 DOI: 10.15252/embj.2020105658] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/23/2021] [Accepted: 07/09/2021] [Indexed: 01/08/2023] Open
Abstract
The Ebola virus VP30 protein interacts with the viral nucleoprotein and with host protein RBBP6 via PPxPxY motifs that adopt non-canonical orientations, as compared to other proline-rich motifs. An affinity tag-purification mass spectrometry approach identified additional PPxPxY-containing host proteins hnRNP L, hnRNPUL1, and PEG10, as VP30 interactors. hnRNP L and PEG10, like RBBP6, inhibit viral RNA synthesis and EBOV infection, whereas hnRNPUL1 enhances. RBBP6 and hnRNP L modulate VP30 phosphorylation, increase viral transcription, and exert additive effects on viral RNA synthesis. PEG10 has more modest inhibitory effects on EBOV replication. hnRNPUL1 positively affects viral RNA synthesis but in a VP30-independent manner. Binding studies demonstrate variable capacity of the PPxPxY motifs from these proteins to bind VP30, define PxPPPPxY as an optimal binding motif, and identify the fifth proline and the tyrosine as most critical for interaction. Competition binding and hydrogen-deuterium exchange mass spectrometry studies demonstrate that each protein binds a similar interface on VP30. VP30 therefore presents a novel proline recognition domain that is targeted by multiple host proteins to modulate viral transcription.
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Affiliation(s)
- Jyoti Batra
- J. David Gladstone Institutes, San Francisco, CA, USA.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.,Quantitative Biosciences Institute, University of California, San Francisco, CA, USA
| | - Hiroyuki Mori
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Gabriel I Small
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Manu Anantpadma
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Olena Shtanko
- Host-Pathogen Interactions, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Nawneet Mishra
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Mengru Zhang
- Department of Chemistry, Washington University School of Medicine, St. Louis, MO, USA
| | - Dandan Liu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Caroline G Williams
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Nadine Biedenkopf
- Institute of Virology, Philipps University of Marburg, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps University of Marburg, Marburg, Germany
| | - Michael L Gross
- Department of Chemistry, Washington University School of Medicine, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,John T. Milliken Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Robert A Davey
- Department of Microbiology, NEIDL, Boston University School of Medicine, Boston, MA, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Nevan J Krogan
- J. David Gladstone Institutes, San Francisco, CA, USA.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.,Quantitative Biosciences Institute, University of California, San Francisco, CA, USA
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
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8
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Whitfield ZJ, Prasad AN, Ronk AJ, Kuzmin IV, Ilinykh PA, Andino R, Bukreyev A. Species-Specific Evolution of Ebola Virus during Replication in Human and Bat Cells. Cell Rep 2020; 32:108028. [PMID: 32814037 PMCID: PMC7434439 DOI: 10.1016/j.celrep.2020.108028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 05/12/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022] Open
Abstract
Ebola virus (EBOV) causes a severe, often fatal disease in humans and nonhuman primates. Within the past decade, EBOV has caused two large and difficult-to-control outbreaks, one of which recently ended in the Democratic Republic of the Congo. Bats are the likely reservoir of EBOV, but little is known of their relationship with the virus. We perform serial passages of EBOV in human and bat cells and use circular sequencing to compare the short-term evolution of the virus. Virus populations passaged in bat cells have sequence markers indicative of host RNA editing enzyme activity, including evidence for ADAR editing of the EBOV glycoprotein. Multiple regions in the EBOV genome appear to have undergone adaptive evolution when passaged in bat and human cells. Individual mutated viruses are rescued and characterized. Our results provide insight into the host species-specific evolution of EBOV and highlight the adaptive flexibility of the virus.
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Affiliation(s)
- Zachary J Whitfield
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Abhishek N Prasad
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Adam J Ronk
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Ivan V Kuzmin
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Philipp A Ilinykh
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Department Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA; Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA.
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9
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Monteiro AFM, de Oliveira Viana J, Muratov E, Scotti MT, Scotti L. In Silico Studies against Viral Sexually Transmitted Diseases. Curr Protein Pept Sci 2020; 20:1135-1150. [PMID: 30854957 DOI: 10.2174/1389203720666190311142747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 01/02/2023]
Abstract
Sexually Transmitted Diseases (STDs) refer to a variety of clinical syndromes and infections caused by pathogens that can be acquired and transmitted through sexual activity. Among STDs widely reported in the literature, viral sexual diseases have been increasing in a number of cases globally. This emphasizes the need for prevention and treatment. Among the methods widely used in drug planning are Computer-Aided Drug Design (CADD) studies and molecular docking which have the objective of investigating molecular interactions between two molecules to better understand the three -dimensional structural characteristics of the compounds. This review will discuss molecular docking studies applied to viral STDs, such as Ebola virus, Herpes virus and HIV, and reveal promising new drug candidates with high levels of specificity to their respective targets.
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Affiliation(s)
- Alex F M Monteiro
- Program of Natural and Synthetic Bioactive Products (PgPNSB), Health Sciences Center, Federal University of Paraíba, Joao Pessoa-PB, Brazil
| | - Jessika de Oliveira Viana
- Program of Natural and Synthetic Bioactive Products (PgPNSB), Health Sciences Center, Federal University of Paraíba, Joao Pessoa-PB, Brazil
| | - Engene Muratov
- Laboratory for Molecular Modeling, Division of Medicinal Chemistry and Natural Products, Eshelman School of Pharmacy, University of North Carolina, Beard Hall 301, CB#7568, Chapel Hill, NC, 27599, United States
| | - Marcus T Scotti
- Program of Natural and Synthetic Bioactive Products (PgPNSB), Health Sciences Center, Federal University of Paraíba, Joao Pessoa-PB, Brazil
| | - Luciana Scotti
- Program of Natural and Synthetic Bioactive Products (PgPNSB), Health Sciences Center, Federal University of Paraíba, Joao Pessoa-PB, Brazil.,Teaching and Research Management - University Hospital, Federal University of Paraíba, Campus I, 58051-900, João Pessoa-PB, Brazil
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10
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Abstract
The largest Ebola virus (EBOV) epidemic in West Africa ever caused more than 28,000 cases and 11,000 deaths, and the current EBOV epidemic in the Democratic Republic of the Congo continues, with more than 3,000 cases to date. Therefore, it is essential to develop antivirals against EBOV. Recently, an inhibitor of the cellular phosphatase PP2A-mediated dephosphorylation of the EBOV transcription factor VP30 has been shown to suppress the spread of Ebola virus. Here, we identified the protein kinase SRPK1 as a VP30-specific kinase that phosphorylates serine 29, the same residue that is dephosphorylated by PP2A. SRPK1-mediated phosphorylation of serine 29 enabled primary viral transcription. Mutation of the SRPK1 recognition motif in VP30 resulted in significant growth inhibition of EBOV. Similarly, elevation of the phosphorylation status of serine 29 by overexpression of SRPK1 inhibited EBOV growth, highlighting the importance of reversible phosphorylation of VP30 as a potential therapeutic target. Ebola virus (EBOV) causes a severe and often fatal disease for which no approved vaccines or antivirals are currently available. EBOV VP30 has been described as a viral phosphoprotein, and nonphosphorylated VP30 is essential and sufficient to support secondary transcription in an EBOV-specific minigenome system; however, phosphorylatable serine residues near the N terminus of VP30 are required to support primary viral transcription as well as the reinitiation of VP30-mediated transcription at internal EBOV genes. While the dephosphorylation of VP30 by the cellular phosphatase PP2A was found to be mediated by nucleoprotein, the VP30-specific kinases and the role of phosphorylation remain unknown. Here, we report that serine-arginine protein kinase 1 (SRPK1) and SRPK2 phosphorylate serine 29 of VP30, which is located in an N-terminal R26xxS29 motif. Interaction with VP30 via the R26xxS29 motif recruits SRPK1 into EBOV-induced inclusion bodies, the sites of viral RNA synthesis, and an inhibitor of SRPK1/SRPK2 downregulates primary viral transcription. When the SRPK1 recognition motif of VP30 was mutated in a recombinant EBOV, virus replication was severely impaired. It is presumed that the interplay between SRPK1 and PP2A in the EBOV inclusions provides a comprehensive regulatory circuit to ensure the activity of VP30 in EBOV transcription. Thus, the identification of SRPK1 is an important mosaic stone that completes our picture of the players involved in Ebola virus transcription regulation.
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11
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Chen J, He Z, Yuan Y, Huang F, Luo B, Zhang J, Pan T, Zhang H, Zhang J. Host factor SMYD3 is recruited by Ebola virus nucleoprotein to facilitate viral mRNA transcription. Emerg Microbes Infect 2020; 8:1347-1360. [PMID: 31516086 PMCID: PMC6758638 DOI: 10.1080/22221751.2019.1662736] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The polymerase complex of Ebola virus (EBOV) is the functional unit for transcription and replication of viral genome. Nucleoprotein (NP) is a multifunctional protein with high RNA binding affinity and recruits other viral proteins to form functional polymerase complex. In our study, we investigated host proteins associated with EBOV polymerase complex using NP as bait in a transcription and replication competent minigenome system by mass spectrometry analysis and identified SET and MYND domain-containing protein 3 (SMYD3) as a novel host protein which was required for the replication of EBOV. SMYD3 specifically interacted with NP and was recruited to EBOV inclusion bodies through NP. The depletion of SMYD3 dramatically suppressed EBOV mRNA production. A mimic of non-phosphorylated VP30, which is a transcription activator, could partially rescue the viral mRNA production downregulated by the depletion of SMYD3. In addition, SMYD3 promoted NP-VP30 interaction in a dose-dependent manner. These results revealed that SMYD3 was a novel host factor recruited by NP to supporting EBOV mRNA transcription through increasing the binding of VP30 to NP. Thus, our study provided a new understanding of mechanism underlying the transcription of EBOV genome, and a novel anti-EBOV drug design strategy by targeting SMYD3.
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Affiliation(s)
- Jingliang Chen
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Zhangping He
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Yaochang Yuan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Feng Huang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China.,Department of Respiration, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Baohong Luo
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Jianhua Zhang
- CAS Key Laboratory for Pathogenic Microbiology, Institute of Microbiology, Chinese Academy of Sciences , Beijing , People's Republic of China
| | - Ting Pan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Hui Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
| | - Junsong Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University , Guangzhou , People's Republic of China
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12
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Venkatesan A, Ravichandran L, Dass JFP. Computational Drug Design against Ebola Virus Targeting Viral Matrix Protein VP30. BORNEO JOURNAL OF PHARMACY 2019. [DOI: 10.33084/bjop.v2i2.836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Ebola viral disease (EVD) is a deadly infectious hemorrhagic viral fever caused by the Ebola virus with a high mortality rate. Until date, there is no effective drug or vaccination available to combat this condition. This study focuses on designing an effective antiviral drug for Ebola viral disease targeting viral protein 30 (VP30) of Ebola virus, highly required for transcription initiation. The lead molecules were screened for Lipinski rule of five, ADMET study following which molecular docking and bioactivity prediction was carried out. The compounds with the least binding energy were analyzed using interaction software. The results revealed that 6-Hydroxyluteolin and (-)-Arctigenin represent active lead compounds that inhibit the activity of VP30 protein and exhibits efficient pharmacokinetics. Both these compounds are plant-derived flavonoids and possess no known adverse effects on human health. In addition, they bind strongly to the predicted binding site centered on Lys180, suggesting that these two lead molecules can be imperative in designing a potential drug for EVD.
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13
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Hume AJ, Mühlberger E. Distinct Genome Replication and Transcription Strategies within the Growing Filovirus Family. J Mol Biol 2019; 431:4290-4320. [PMID: 31260690 PMCID: PMC6879820 DOI: 10.1016/j.jmb.2019.06.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/31/2019] [Accepted: 06/24/2019] [Indexed: 11/18/2022]
Abstract
Research on filoviruses has historically focused on the highly pathogenic ebola- and marburgviruses. Indeed, until recently, these were the only two genera in the filovirus family. Recent advances in sequencing technologies have facilitated the discovery of not only a new ebolavirus, but also three new filovirus genera and a sixth proposed genus. While two of these new genera are similar to the ebola- and marburgviruses, the other two, discovered in saltwater fishes, are considerably more diverse. Nonetheless, these viruses retain a number of key features of the other filoviruses. Here, we review the key characteristics of filovirus replication and transcription, highlighting similarities and differences between the viruses. In particular, we focus on key regulatory elements in the genomes, replication and transcription strategies, and the conservation of protein domains and functions among the viruses. In addition, using computational analyses, we were able to identify potential homology and functions for some of the genes of the novel filoviruses with previously unknown functions. Although none of the newly discovered filoviruses have yet been isolated, initial studies of some of these viruses using minigenome systems have yielded insights into their mechanisms of replication and transcription. In general, the Cuevavirus and proposed Dianlovirus genera appear to follow the transcription and replication strategies employed by the ebola- and marburgviruses, respectively. While our knowledge of the fish filoviruses is currently limited to sequence analysis, the lack of certain conserved motifs and even entire genes necessitates that they have evolved distinct mechanisms of replication and transcription.
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Affiliation(s)
- Adam J Hume
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA; National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA; National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA.
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14
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Abstract
This chapter reviews our current knowledge about the spatiotemporal assembly of filoviral particles. We will follow particles from nucleocapsid entry into the cytoplasm until the nucleocapsids are enveloped at the plasma membrane. We will also highlight the currently open scientific questions surrounding filovirus assembly.
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15
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Abstract
Marburgviruses are closely related to ebolaviruses and cause a devastating disease in humans. In 2012, we published a comprehensive review of the first 45 years of research on marburgviruses and the disease they cause, ranging from molecular biology to ecology. Spurred in part by the deadly Ebola virus outbreak in West Africa in 2013-2016, research on all filoviruses has intensified. Not meant as an introduction to marburgviruses, this article instead provides a synopsis of recent progress in marburgvirus research with a particular focus on molecular biology, advances in animal modeling, and the use of Egyptian fruit bats in infection experiments.
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Affiliation(s)
- Judith Olejnik
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, 02118, USA.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, 02118, USA
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, 02118, USA.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, 02118, USA
| | - Adam J Hume
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, 02118, USA.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, 02118, USA
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16
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Involvement of Surfactant Protein D in Ebola Virus Infection Enhancement via Glycoprotein Interaction. Viruses 2018; 11:v11010015. [PMID: 30587835 PMCID: PMC6356362 DOI: 10.3390/v11010015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 01/05/2023] Open
Abstract
Since the largest 2014⁻2016 Ebola virus disease outbreak in West Africa, understanding of Ebola virus infection has improved, notably the involvement of innate immune mediators. Amongst them, collectins are important players in the antiviral innate immune defense. A screening of Ebola glycoprotein (GP)-collectins interactions revealed the specific interaction of human surfactant protein D (hSP-D), a lectin expressed in lung and liver, two compartments where Ebola was found in vivo. Further analyses have demonstrated an involvement of hSP-D in the enhancement of virus infection in several in vitro models. Similar effects were observed for porcine SP-D (pSP-D). In addition, both hSP-D and pSP-D interacted with Reston virus (RESTV) GP and enhanced pseudoviral infection in pulmonary cells. Thus, our study reveals a novel partner of Ebola GP that may participate to enhance viral spread.
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17
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Phosphorylated VP30 of Marburg Virus Is a Repressor of Transcription. J Virol 2018; 92:JVI.00426-18. [PMID: 30135121 DOI: 10.1128/jvi.00426-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/06/2018] [Indexed: 12/29/2022] Open
Abstract
The filoviruses Marburg virus (MARV) and Ebola virus (EBOV) cause hemorrhagic fever in humans and nonhuman primates, with high case fatality rates. MARV VP30 is known to be phosphorylated and to interact with nucleoprotein (NP), but its role in regulation of viral transcription is disputed. Here, we analyzed phosphorylation of VP30 by mass spectrometry, which resulted in identification of multiple phosphorylated amino acids. Modeling the full-length three-dimensional structure of VP30 and mapping the identified phosphorylation sites showed that all sites lie in disordered regions, mostly in the N-terminal domain of the protein. Minigenome analysis of the identified phosphorylation sites demonstrated that phosphorylation of a cluster of amino acids at positions 46 through 53 inhibits transcription. To test the effect of VP30 phosphorylation on its interaction with other MARV proteins, coimmunoprecipitation analyses were performed. They demonstrated the involvement of VP30 phosphorylation in interaction with two other proteins of the MARV ribonucleoprotein complex, NP and VP35. To identify the role of protein phosphatase 1 (PP1) in the identified effects, a small molecule, 1E7-03, targeting a noncatalytic site of the enzyme that previously was shown to increase EBOV VP30 phosphorylation was used. Treatment of cells with 1E7-03 increased phosphorylation of VP30 at a cluster of phosphorylated amino acids from Ser-46 to Thr-53, reduced transcription of MARV minigenome, enhanced binding to NP and VP35, and dramatically reduced replication of infectious MARV particles. Thus, MARV VP30 phosphorylation can be targeted for development of future antivirals such as PP1-targeting compounds. IMPORTANCE The largest outbreak of MARV occurred in Angola in 2004 to 2005 and had a 90% case fatality rate. There are no approved treatments available for MARV. Development of antivirals as therapeutics requires a fundamental understanding of the viral life cycle. Because of the close similarity of MARV to another member of Filoviridae family, EBOV, it was assumed that the two viruses have similar mechanisms of regulation of transcription and replication. Here, characterization of the role of VP30 and its phosphorylation sites in transcription of the MARV genome demonstrated differences from those of EBOV. The identified phosphorylation sites appeared to inhibit transcription and appeared to be involved in interaction with both NP and VP35 ribonucleoproteins. A small molecule targeting PP1 inhibited transcription of the MARV genome, effectively suppressing replication of the viral particles. These data demonstrate the possibility developing antivirals based on compounds targeting PP1.
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18
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Abstract
In this chapter, we describe the minigenome system for Ebola virus (EBOV), which reconstitutes EBOV polymerase activity in cells and can be used to model viral genome replication and transcription. This protocol comprises all steps including cell culture, plasmid preparation, transfection, and luciferase reporter assay readout.
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Kruse T, Biedenkopf N, Hertz EPT, Dietzel E, Stalmann G, López-Méndez B, Davey NE, Nilsson J, Becker S. The Ebola Virus Nucleoprotein Recruits the Host PP2A-B56 Phosphatase to Activate Transcriptional Support Activity of VP30. Mol Cell 2017; 69:136-145.e6. [PMID: 29290611 DOI: 10.1016/j.molcel.2017.11.034] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/01/2017] [Accepted: 11/27/2017] [Indexed: 10/18/2022]
Abstract
Transcription of the Ebola virus genome depends on the viral transcription factor VP30 in its unphosphorylated form, but the underlying molecular mechanism of VP30 dephosphorylation is unknown. Here we show that the Ebola virus nucleoprotein (NP) recruits the host PP2A-B56 protein phosphatase through a B56-binding LxxIxE motif and that this motif is essential for VP30 dephosphorylation and viral transcription. The LxxIxE motif and the binding site of VP30 in NP are in close proximity, and both binding sites are required for the dephosphorylation of VP30. We generate a specific inhibitor of PP2A-B56 and show that it suppresses Ebola virus transcription and infection. This work dissects the molecular mechanism of VP30 dephosphorylation by PP2A-B56, and it pinpoints this phosphatase as a potential target for therapeutic intervention.
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Affiliation(s)
- Thomas Kruse
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Nadine Biedenkopf
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Giessen-Marburg-Langen, Marburg, Germany
| | - Emil Peter Thrane Hertz
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Erik Dietzel
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Giessen-Marburg-Langen, Marburg, Germany
| | - Gertrud Stalmann
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Giessen-Marburg-Langen, Marburg, Germany
| | - Blanca López-Méndez
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Norman E Davey
- Conway Institute of Biomolecular and Biomedical Sciences, University College Dublin, Dublin 4, Ireland
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Stephan Becker
- Institute of Virology, Philipps Universität Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Giessen-Marburg-Langen, Marburg, Germany.
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20
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Tartour K, Nguyen XN, Appourchaux R, Assil S, Barateau V, Bloyet LM, Burlaud Gaillard J, Confort MP, Escudero-Perez B, Gruffat H, Hong SS, Moroso M, Reynard O, Reynard S, Decembre E, Ftaich N, Rossi A, Wu N, Arnaud F, Baize S, Dreux M, Gerlier D, Paranhos-Baccala G, Volchkov V, Roingeard P, Cimarelli A. Interference with the production of infectious viral particles and bimodal inhibition of replication are broadly conserved antiviral properties of IFITMs. PLoS Pathog 2017; 13:e1006610. [PMID: 28957419 PMCID: PMC5619827 DOI: 10.1371/journal.ppat.1006610] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/28/2017] [Indexed: 12/31/2022] Open
Abstract
IFITMs are broad antiviral factors that block incoming virions in endosomal vesicles, protecting target cells from infection. In the case of HIV-1, we and others reported the existence of an additional antiviral mechanism through which IFITMs lead to the production of virions of reduced infectivity. However, whether this second mechanism of inhibition is unique to HIV or extends to other viruses is currently unknown. To address this question, we have analyzed the susceptibility of a broad spectrum of viruses to the negative imprinting of the virion particles infectivity by IFITMs. The results we have gathered indicate that this second antiviral property of IFITMs extends well beyond HIV and we were able to identify viruses susceptible to the three IFITMs altogether (HIV-1, SIV, MLV, MPMV, VSV, MeV, EBOV, WNV), as well as viruses that displayed a member-specific susceptibility (EBV, DUGV), or were resistant to all IFITMs (HCV, RVFV, MOPV, AAV). The swapping of genetic elements between resistant and susceptible viruses allowed us to point to specificities in the viral mode of assembly, rather than glycoproteins as dominant factors of susceptibility. However, we also show that, contrarily to X4-, R5-tropic HIV-1 envelopes confer resistance against IFITM3, suggesting that viral receptors add an additional layer of complexity in the IFITMs-HIV interplay. Lastly, we show that the overall antiviral effects ascribed to IFITMs during spreading infections, are the result of a bimodal inhibition in which IFITMs act both by protecting target cells from incoming viruses and in driving the production of virions of reduced infectivity. Overall, our study reports for the first time that the negative imprinting of the virion particles infectivity is a conserved antiviral property of IFITMs and establishes IFITMs as a paradigm of restriction factor capable of interfering with two distinct phases of a virus life cycle. IFITMs are interferon-regulated proteins that inhibit a broad range of viruses. Until recently, IFITMs had been described to arrest incoming viral particles in target cells, by inducing their retention in endosomal vesicles. More recently in the case of HIV-1, ours and other laboratories have highlighted the existence of an additional antiviral mechanism with which IFITMs could act in virus-producing cells, leading to the production of virion particles of reduced infectivity. In the present study, we assessed whether the negative imprinting of the virion particles infectivity was a conserved antiviral property of IFITMs by examining a panel of fourteen different DNA or RNA viruses. Our results indicate that a wide spectrum of viruses is susceptible to this antiviral mechanism of inhibition, although some are able to resist it. Swapping of elements between susceptible and resistant viruses strongly suggests that specificities in the mode of virion assembly and not the viral glycoprotein are the dominant factor in the susceptibility of a given virus to this inhibition. However, we also show that HIV-1 strains that engage the CCR5 co-receptor display a notable resistance towards IFITM3, indicating that at least in the case of HIV-1, co-receptor usage is likely to add an additional layer of complexity in the relationship established between IFITMs and the virus, that may or may not extend to other viral families as well. In the context of spreading infections, the results of this study highlight that the overall antiviral effect of IFITMs is mechanistically caused by a previously unappreciated dual mode of action in which they act both in target cells and in virus-producing cells, by respectively forcing endosome trapping of incoming viruses and by commandeering the formation of new virion particles of reduced infectivity. Overall, the results presented here indicate that the negative imprinting of viral particles is a largely conserved antiviral feature of IFITMs and point to IFITMs as a novel paradigm of innate defense proteins capable of interfering with viral replication at two distinct steps of a virus life cycle.
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Affiliation(s)
- Kevin Tartour
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Xuan-Nhi Nguyen
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Romain Appourchaux
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Sonia Assil
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Véronique Barateau
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Louis-Marie Bloyet
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Julien Burlaud Gaillard
- Plateforme IBiSA de Microscopie Electronique, Université F. Rabelais et CHRU de Tours, Tours, France
- INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France
| | - Marie-Pierre Confort
- IVPC UMR754, INRA, Univ Lyon, Université Claude Bernard Lyon1, EPHE, Lyon, France
| | - Beatriz Escudero-Perez
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Henri Gruffat
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Saw See Hong
- IVPC UMR754, INRA, Univ Lyon, Université Claude Bernard Lyon1, EPHE, Lyon, France
| | - Marie Moroso
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- Fondation Mérieux, Lyon, France
| | - Olivier Reynard
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Stéphanie Reynard
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- Institut Pasteur, Lyon, France
| | - Elodie Decembre
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Najate Ftaich
- IVPC UMR754, INRA, Univ Lyon, Université Claude Bernard Lyon1, EPHE, Lyon, France
| | - Axel Rossi
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Nannan Wu
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- Institute of BioMedical Science (IBMS), East China Normal University (ECNU), Shanghai, China
| | - Frédérick Arnaud
- IVPC UMR754, INRA, Univ Lyon, Université Claude Bernard Lyon1, EPHE, Lyon, France
| | - Sylvain Baize
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- Institut Pasteur, Lyon, France
| | - Marlène Dreux
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Denis Gerlier
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Glaucia Paranhos-Baccala
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- Fondation Mérieux, Lyon, France
| | - Viktor Volchkov
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
| | - Philippe Roingeard
- Plateforme IBiSA de Microscopie Electronique, Université F. Rabelais et CHRU de Tours, Tours, France
- INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France
| | - Andrea Cimarelli
- CIRI, Centre International de Recherche en Infectiologie, Lyon, France
- INSERM, U1111, Lyon, France
- Université Claude Bernard Lyon1, Lyon, France
- CNRS, UMR5308, Lyon, France
- Ecole Normale Supérieure de Lyon, Lyon, France
- Univ Lyon, Lyon, France, Lyon, France
- * E-mail:
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21
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Lier C, Becker S, Biedenkopf N. Dynamic phosphorylation of Ebola virus VP30 in NP-induced inclusion bodies. Virology 2017; 512:39-47. [PMID: 28915404 DOI: 10.1016/j.virol.2017.09.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/18/2017] [Accepted: 09/07/2017] [Indexed: 12/22/2022]
Abstract
Zaire Ebolavirus (EBOV) causes a severe feverish disease with high case fatality rates. Transcription of EBOV is dependent on the activity of the nucleocapsid protein VP30 which represents an essential viral transcription factor. Activity of VP30 is regulated via phosphorylation at six N-terminal serine residues. Recent data demonstrated that dynamic phosphorylation and dephosphorylation of serine residue 29 is essential for transcriptional support activity of VP30. To analyze the spatio/temporal dynamics of VP30 phosphorylation, we generated a peptide antibody recognizing specifically VP30 phosphorylated at serine 29. Using this antibody we could demonstrate that (i) the majority of VP30 molecules in EBOV-infected cells is dephosphorylated at the crucial position serine 29, (ii) both, VP30 phosphorylation and dephosphorylation take place in viral inclusion bodies that are induced by the nucleoprotein NP and (iii) NP influences the phosphorylation state of VP30.
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Affiliation(s)
- Clemens Lier
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany.
| | - Nadine Biedenkopf
- Institute of Virology, Philipps-University Marburg, Marburg, Germany; German Center of Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Marburg, Germany.
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22
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Xu W, Luthra P, Wu C, Batra J, Leung DW, Basler CF, Amarasinghe GK. Ebola virus VP30 and nucleoprotein interactions modulate viral RNA synthesis. Nat Commun 2017; 8:15576. [PMID: 28593988 PMCID: PMC5472179 DOI: 10.1038/ncomms15576] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 04/11/2017] [Indexed: 12/20/2022] Open
Abstract
Ebola virus (EBOV) is an enveloped negative-sense RNA virus that causes sporadic outbreaks with high case fatality rates. Ebola viral protein 30 (eVP30) plays a critical role in EBOV transcription initiation at the nucleoprotein (eNP) gene, with additional roles in the replication cycle such as viral assembly. However, the mechanistic basis for how eVP30 functions during the virus replication cycle is currently unclear. Here we define a key interaction between eVP30 and a peptide derived from eNP that is important to facilitate interactions leading to the recognition of the RNA template. We present crystal structures of the eVP30 C-terminus in complex with this eNP peptide. Functional analyses of the eVP30–eNP interface identify residues that are critical for viral RNA synthesis. Altogether, these results support a model where the eVP30–eNP interaction plays a critical role in transcription initiation and provides a novel target for the development of antiviral therapy. Ebola virus (EBOV) VP30 is a multifunctional protein that plays a role in transcription, but molecular details remain unknown. Here, using X-ray crystallography and minigenome assays, Xu et al. define the interaction between VP30 and a portion of NP that is critical for optimal EBOV RNA synthesis.
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Affiliation(s)
- Wei Xu
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63105, USA
| | - Priya Luthra
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia 30303, USA
| | - Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63105, USA
| | - Jyoti Batra
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia 30303, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63105, USA
| | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia 30303, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63105, USA
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23
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A comparison of host gene expression signatures associated with infection in vitro by the Makona and Ecran (Mayinga) variants of Ebola virus. Sci Rep 2017; 7:43144. [PMID: 28240256 PMCID: PMC5327407 DOI: 10.1038/srep43144] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/18/2017] [Indexed: 11/08/2022] Open
Abstract
The Ebola virus (EBOV) variant Makona (which emerged in 2013) was the causative agent of the largest outbreak of Ebola Virus Disease recorded. Differences in virus-host interactions between viral variants have potential consequences for transmission, disease severity and mortality. A detailed profile of the cellular changes induced by the Makona variant compared with other Ebola virus variants was lacking. In this study, A549 cells, a human cell line with a robust innate response, were infected with the Makona variant or with the Ecran variant originating from the 1976 outbreak in Central Africa. The abundance of viral and cellular mRNA transcripts was profiled using RNASeq and differential gene expression analysis performed. Differences in effects of each virus on the expression of interferon-stimulated genes were also investigated in A549 NPro cells where the type 1 interferon response had been attenuated. Cellular transcriptomic changes were compared with those induced by human respiratory syncytial virus (HRSV), a virus with a similar genome organisation and replication strategy to EBOV. Pathway and gene ontology analysis revealed differential expression of functionally important genes; including genes involved in the inflammatory response, cell proliferation, leukocyte extravasation and cholesterol biosynthesis. Whilst there was overlap with HRSV, there was unique commonality to the EBOV variants.
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Filovirus proteins for antiviral drug discovery: Structure/function bases of the replication cycle. Antiviral Res 2017; 141:48-61. [PMID: 28192094 DOI: 10.1016/j.antiviral.2017.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/12/2017] [Accepted: 02/07/2017] [Indexed: 12/26/2022]
Abstract
Filoviruses are important pathogens that cause severe and often fatal hemorrhagic fever in humans, for which no approved vaccines and antiviral treatments are yet available. In an earlier article (Martin et al., Antiviral Research, 2016), we reviewed the role of the filovirus surface glycoprotein in replication and as a target for drugs and vaccines. In this review, we focus on recent findings on the filovirus replication machinery and how they could be used for the identification of new therapeutic targets and the development of new antiviral compounds. First, we summarize the recent structural and functional advances on the molecules involved in filovirus replication/transcription cycle, particularly the NP, VP30, VP35 proteins, and the "large" protein L, which harbors the RNA-dependent RNA polymerase (RdRp) and mRNA capping activities. These proteins are essential for viral mRNA synthesis and genome replication, and consequently they constitute attractive targets for drug design. We then describe how these insights into filovirus replication mechanisms and the structure/function characterization of the involved proteins have led to the development of new and innovative antiviral strategies that may help reduce the filovirus disease case fatality rate through post-exposure or prophylactic treatments.
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25
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Hoenen T, Brandt J, Caì Y, Kuhn JH, Finch C. Reverse Genetics of Filoviruses. Curr Top Microbiol Immunol 2017; 411:421-445. [PMID: 28918537 DOI: 10.1007/82_2017_55] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Reverse genetics systems are used for the generation of recombinant viruses. For filoviruses, this technology has been available for more than 15 years and has been used to investigate questions regarding the molecular biology, pathogenicity, and host adaptation determinants of these viruses. Further, reporter-expressing, recombinant viruses are increasingly used as tools for screening for and characterization of candidate medical countermeasures. Thus, reverse genetics systems represent powerful research tools. Here we provide an overview of available reverse genetics systems for the generation of recombinant filoviruses, potential applications, and the achievements that have been made using these systems.
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Affiliation(s)
- Thomas Hoenen
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
| | - Janine Brandt
- Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA.
| | - Courtney Finch
- Integrated Research Facility at Fort Detrick (IRF-Frederick), Division of Clinical Research (DCR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), B-8200 Research Plaza, Fort Detrick, Frederick, MD, 21702, USA
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26
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Kirchdoerfer RN, Wasserman H, Amarasinghe GK, Saphire EO. Filovirus Structural Biology: The Molecules in the Machine. Curr Top Microbiol Immunol 2017; 411:381-417. [PMID: 28795188 DOI: 10.1007/82_2017_16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In this chapter, we describe what is known thus far about the structures and functions of the handful of proteins encoded by filovirus genomes. Amongst the fascinating findings of the last decade is the plurality of functions and structures that these polypeptides can adopt. Many of the encoded proteins can play multiple, distinct roles in the virus life cycle, although the mechanisms by which these functions are determined and controlled remain mostly veiled. Further, some filovirus proteins are multistructural: adopting different oligomeric assemblies and sometimes, different tertiary structures to achieve their separate, and equally essential functions. Structures, and the functions they dictate, are described for components of the nucleocapsid, the matrix, and the surface and secreted glycoproteins.
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Affiliation(s)
- Robert N Kirchdoerfer
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Hal Wasserman
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Erica Ollmann Saphire
- Department of Immunology and Microbiology, The Scripps Research Institute, The Skaggs Institute for Chemical Biology, La Jolla, CA, 92037, USA.
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27
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The Ebola Virus VP30-NP Interaction Is a Regulator of Viral RNA Synthesis. PLoS Pathog 2016; 12:e1005937. [PMID: 27755595 PMCID: PMC5068707 DOI: 10.1371/journal.ppat.1005937] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/14/2016] [Indexed: 12/20/2022] Open
Abstract
Filoviruses are capable of causing deadly hemorrhagic fevers. All nonsegmented negative-sense RNA-virus nucleocapsids are composed of a nucleoprotein (NP), a phosphoprotein (VP35) and a polymerase (L). However, the VP30 RNA-synthesis co-factor is unique to the filoviruses. The assembly, structure, and function of the filovirus RNA replication complex remain unclear. Here, we have characterized the interactions of Ebola, Sudan and Marburg virus VP30 with NP using in vitro biochemistry, structural biology and cell-based mini-replicon assays. We have found that the VP30 C-terminal domain interacts with a short peptide in the C-terminal region of NP. Further, we have solved crystal structures of the VP30-NP complex for both Ebola and Marburg viruses. These structures reveal that a conserved, proline-rich NP peptide binds a shallow hydrophobic cleft on the VP30 C-terminal domain. Structure-guided Ebola virus VP30 mutants have altered affinities for the NP peptide. Correlation of these VP30-NP affinities with the activity for each of these mutants in a cell-based mini-replicon assay suggests that the VP30-NP interaction plays both essential and inhibitory roles in Ebola virus RNA synthesis. Filoviruses use a system of proteins and RNA to regulate viral RNA genome transcription and replication. Here, we have determined crystal structures and the biological functions of the protein complex formed by the filovirus transcriptional activator, VP30, and the core component of the nucleocapsid machinery, NP. The complex of these two essential players represses Ebola virus RNA synthesis and may have played a role in the evolution of filoviruses to tune viral RNA synthesis activity to a level ideal for infection. This interaction is conserved across the filoviruses and may provide an opportunity for therapeutic development.
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28
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RNA Binding of Ebola Virus VP30 Is Essential for Activating Viral Transcription. J Virol 2016; 90:7481-7496. [PMID: 27279615 DOI: 10.1128/jvi.00271-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/31/2016] [Indexed: 01/17/2023] Open
Abstract
UNLABELLED The template for Ebola virus (EBOV) transcription and replication is the helical viral nucleocapsid composed of the viral negative-sense (-) RNA genome, which is complexed by the nucleoprotein (NP), VP35, polymerase L, VP24, and VP30. While viral replication is exerted by polymerase L and its cofactor VP35, EBOV mRNA synthesis is regulated by the viral nucleocapsid protein VP30, an essential EBOV-specific transcription factor. VP30 is a homohexameric phosphoprotein containing a nonconventional zinc finger. The transcriptional support activity of VP30 is strongly influenced by its phosphorylation state. We studied here how RNA binding contributed to VP30's function in transcriptional activation. Using a novel mobility shift assay and the 3'-terminal 154 nucleotides of the EBOV genome as a standard RNA substrate, we detected that RNA binding of VP30 was severely impaired by VP30 mutations that (i) destroy the protein's capability to form homohexamers, (ii) disrupt the integrity of its zinc finger domain, (iii) mimic its fully phosphorylated state, or (iv) alter the putative RNA binding region. RNA binding of the mutant VP30 proteins correlated strongly with their transcriptional support activity. Furthermore, we showed that the interaction between VP30 and the polymerase cofactor VP35 is RNA dependent, while formation of VP30 homohexamers and VP35 homotetramers is not. Our data indicate that RNA binding of VP30 is essential for its transcriptional support activity and stabilizes complexes of VP35/L polymerase with the (-) RNA template to favor productive transcriptional initiation in the presence of termination-active RNA secondary structures. IMPORTANCE Ebola virus causes severe fevers with unusually high case fatality rates. The recent outbreak of Ebola virus in West Africa claimed more than 11,000 lives and threatened to destabilize a whole region because of its dramatic effects on the public health systems. It is currently not completely understood how Ebola virus manages to balance viral transcription and replication in the infected cells. This study shows that transcriptional support activity of the Ebola virus transcription factor VP30 is highly correlated with its ability to bind viral RNA. The interaction between VP30 and VP35, the Ebola virus polymerase cofactor, is dependent on the presence of RNA as well. Our data contribute to the understanding of the dynamic interplay between nucleocapsid proteins and the viral RNA template in order to promote viral RNA synthesis.
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29
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Phosphorylation of Human Metapneumovirus M2-1 Protein Upregulates Viral Replication and Pathogenesis. J Virol 2016; 90:7323-7338. [PMID: 27252537 DOI: 10.1128/jvi.00755-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/25/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a major causative agent of upper- and lower-respiratory-tract infections in infants, the elderly, and immunocompromised individuals worldwide. Like all pneumoviruses, hMPV encodes the zinc binding protein M2-1, which plays important regulatory roles in RNA synthesis. The M2-1 protein is phosphorylated, but the specific role(s) of the phosphorylation in viral replication and pathogenesis remains unknown. In this study, we found that hMPV M2-1 is phosphorylated at amino acid residues S57 and S60. Subsequent mutagenesis found that phosphorylation is not essential for zinc binding activity and oligomerization, whereas inhibition of zinc binding activity abolished the phosphorylation and oligomerization of the M2-1 protein. Using a reverse genetics system, recombinant hMPVs (rhMPVs) lacking either one or both phosphorylation sites in the M2-1 protein were recovered. These recombinant viruses had a significant decrease in both genomic RNA replication and mRNA transcription. In addition, these recombinant viruses were highly attenuated in cell culture and cotton rats. Importantly, rhMPVs lacking phosphorylation in the M2-1 protein triggered high levels of neutralizing antibody and provided complete protection against challenge with wild-type hMPV. Collectively, these data demonstrated that phosphorylation of the M2-1 protein upregulates hMPV RNA synthesis, replication, and pathogenesis in vivo IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Currently, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that phosphorylation of M2-1 is essential for virus replication and pathogenesis in vivo Recombinant hMPVs lacking phosphorylation in M2-1 exhibited limited replication in the upper and lower respiratory tract and triggered strong protective immunity in cotton rats. This work highlights the important role of M2-1 phosphorylation in viral replication and that inhibition of M2-1 phosphorylation may serve as a novel approach to develop live attenuated vaccines as well as antiviral drugs for pneumoviruses.
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30
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Albariño CG, Guerrero LW, Chakrabarti AK, Kainulainen MH, Whitmer SLM, Welch SR, Nichol ST. Virus fitness differences observed between two naturally occurring isolates of Ebola virus Makona variant using a reverse genetics approach. Virology 2016; 496:237-243. [PMID: 27366976 DOI: 10.1016/j.virol.2016.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 11/30/2022]
Abstract
During the large outbreak of Ebola virus disease that occurred in Western Africa from late 2013 to early 2016, several hundred Ebola virus (EBOV) genomes have been sequenced and the virus genetic drift analyzed. In a previous report, we described an efficient reverse genetics system designed to generate recombinant EBOV based on a Makona variant isolate obtained in 2014. Using this system, we characterized the replication and fitness of 2 isolates of the Makona variant. These virus isolates are nearly identical at the genetic level, but have single amino acid differences in the VP30 and L proteins. The potential effects of these differences were tested using minigenomes and recombinant viruses. The results obtained with this approach are consistent with the role of VP30 and L as components of the EBOV RNA replication machinery. Moreover, the 2 isolates exhibited clear fitness differences in competitive growth assays.
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Affiliation(s)
- César G Albariño
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA.
| | | | - Ayan K Chakrabarti
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | | | - Shannon L M Whitmer
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | - Stephen R Welch
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
| | - Stuart T Nichol
- Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA, USA
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31
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Schlereth J, Grünweller A, Biedenkopf N, Becker S, Hartmann RK. RNA binding specificity of Ebola virus transcription factor VP30. RNA Biol 2016; 13:783-98. [PMID: 27315567 DOI: 10.1080/15476286.2016.1194160] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.
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Affiliation(s)
- Julia Schlereth
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Arnold Grünweller
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Nadine Biedenkopf
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Stephan Becker
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Roland K Hartmann
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
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32
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Dynamic Phosphorylation of VP30 Is Essential for Ebola Virus Life Cycle. J Virol 2016; 90:4914-4925. [PMID: 26937028 DOI: 10.1128/jvi.03257-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 02/21/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Ebola virus is the causative agent of a severe fever with high fatality rates in humans and nonhuman primates. The regulation of Ebola virus transcription and replication currently is not well understood. An important factor regulating viral transcription is VP30, an Ebola virus-specific transcription factor associated with the viral nucleocapsid. Previous studies revealed that the phosphorylation status of VP30 impacts viral transcription. Together with NP, L, and the polymerase cofactor VP35, nonphosphorylated VP30 supports viral transcription. Upon VP30 phosphorylation, viral transcription ceases. Phosphorylation weakens the interaction between VP30 and the polymerase cofactor VP35 and/or the viral RNA. VP30 thereby is excluded from the viral transcription complex, simultaneously leading to increased viral replication which is supported by NP, L, and VP35 alone. Here, we use an infectious virus-like particle assay and recombinant viruses to show that the dynamic phosphorylation of VP30 is critical for the cotransport of VP30 with nucleocapsids to the sites of viral RNA synthesis, where VP30 is required to initiate primary viral transcription. We further demonstrate that a single serine residue at amino acid position 29 was sufficient to render VP30 active in primary transcription and to generate a recombinant virus with characteristics comparable to those of wild-type virus. In contrast, the rescue of a recombinant virus with a single serine at position 30 in VP30 was unsuccessful. Our results indicate critical roles for phosphorylated and dephosphorylated VP30 during the viral life cycle. IMPORTANCE The current Ebola virus outbreak in West Africa has caused more than 28,000 cases and 11,000 fatalities. Very little is known regarding the molecular mechanisms of how the Ebola virus transcribes and replicates its genome. Previous investigations showed that the transcriptional support activity of VP30 is activated upon VP30 dephosphorylation. The current study reveals that the situation is more complex and that primary transcription as well as the rescue of recombinant Ebola virus also requires the transient phosphorylation of VP30. VP30 encodes six N-proximal serine residues that serve as phosphorylation acceptor sites. The present study shows that the dynamic phosphorylation of serine at position 29 alone is sufficient to activate primary viral transcription. Our results indicate a series of phosphorylation/dephosphorylation events that trigger binding to and release from the nucleocapsid and transcription complex to be essential for the full activity of VP30.
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33
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Baer A, Shafagati N, Benedict A, Ammosova T, Ivanov A, Hakami RM, Terasaki K, Makino S, Nekhai S, Kehn-Hall K. Protein Phosphatase-1 regulates Rift Valley fever virus replication. Antiviral Res 2016; 127:79-89. [PMID: 26801627 DOI: 10.1016/j.antiviral.2016.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/21/2015] [Accepted: 01/14/2016] [Indexed: 12/21/2022]
Abstract
Rift Valley fever virus (RVFV), genus Phlebovirus family Bunyaviridae, is an arthropod-borne virus endemic throughout sub-Saharan Africa. Recent outbreaks have resulted in cyclic epidemics with an increasing geographic footprint, devastating both livestock and human populations. Despite being recognized as an emerging threat, relatively little is known about the virulence mechanisms and host interactions of RVFV. To date there are no FDA approved therapeutics or vaccines for RVF and there is an urgent need for their development. The Ser/Thr protein phosphatase 1 (PP1) has previously been shown to play a significant role in the replication of several viruses. Here we demonstrate for the first time that PP1 plays a prominent role in RVFV replication early on during the viral life cycle. Both siRNA knockdown of PP1α and a novel PP1-targeting small molecule compound 1E7-03, resulted in decreased viral titers across several cell lines. Deregulation of PP1 was found to inhibit viral RNA production, potentially through the disruption of viral RNA transcript/protein interactions, and indicates a potential link between PP1α and the viral L polymerase and nucleoprotein. These results indicate that PP1 activity is important for RVFV replication early on during the viral life cycle and may prove an attractive therapeutic target.
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Affiliation(s)
- Alan Baer
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Nazly Shafagati
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Ashwini Benedict
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Andrey Ivanov
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Ramin M Hakami
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, D.C., USA
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA.
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34
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Reynard O, Nguyen XN, Alazard-Dany N, Barateau V, Cimarelli A, Volchkov VE. Identification of a New Ribonucleoside Inhibitor of Ebola Virus Replication. Viruses 2015; 7:6233-40. [PMID: 26633464 PMCID: PMC4690858 DOI: 10.3390/v7122934] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/16/2015] [Accepted: 11/16/2015] [Indexed: 11/17/2022] Open
Abstract
The current outbreak of Ebola virus (EBOV) in West Africa has claimed the lives of more than 15,000 people and highlights an urgent need for therapeutics capable of preventing virus replication. In this study we screened known nucleoside analogues for their ability to interfere with EBOV replication. Among them, the cytidine analogue β-d-N4-hydroxycytidine (NHC) demonstrated potent inhibitory activities against EBOV replication and spread at non-cytotoxic concentrations. Thus, NHC constitutes an interesting candidate for the development of a suitable drug treatment against EBOV.
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Affiliation(s)
- Olivier Reynard
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Xuan-Nhi Nguyen
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Nathalie Alazard-Dany
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Véronique Barateau
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Andrea Cimarelli
- Host Pathogen interaction during lentiviral infection, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
| | - Viktor E Volchkov
- Molecular Basis of Viral Pathogenicity, CIRI, INSERM, U1111-CNRS UMR5308, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
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35
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Abstract
Ebolavirus is the pathogen for Ebola Hemorrhagic Fever (EHF). This disease exhibits a high fatality rate and has recently reached a historically epidemic proportion in West Africa. Out of the 5 known Ebolavirus species, only Reston ebolavirus has lost human pathogenicity, while retaining the ability to cause EHF in long-tailed macaque. Significant efforts have been spent to determine the three-dimensional (3D) structures of Ebolavirus proteins, to study their interaction with host proteins, and to identify the functional motifs in these viral proteins. Here, in light of these experimental results, we apply computational analysis to predict the 3D structures and functional sites for Ebolavirus protein domains with unknown structure, including a zinc-finger domain of VP30, the RNA-dependent RNA polymerase catalytic domain and a methyltransferase domain of protein L. In addition, we compare sequences of proteins that interact with Ebolavirus proteins from RESTV-resistant primates with those from RESTV-susceptible monkeys. The host proteins that interact with GP and VP35 show an elevated level of sequence divergence between the RESTV-resistant and RESTV-susceptible species, suggesting that they may be responsible for host specificity. Meanwhile, we detect variable positions in protein sequences that are likely associated with the loss of human pathogenicity in RESTV, map them onto the 3D structures and compare their positions to known functional sites. VP35 and VP30 are significantly enriched in these potential pathogenicity determinants and the clustering of such positions on the surfaces of VP35 and GP suggests possible uncharacterized interaction sites with host proteins that contribute to the virulence of Ebolavirus.
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Affiliation(s)
- Qian Cong
- a Departments of Biophysics and Biochemistry ; University of Texas Southwestern Medical Center at Dallas ; Dallas , TX USA
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36
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Kirchdoerfer RN, Abelson DM, Li S, Wood MR, Saphire EO. Assembly of the Ebola Virus Nucleoprotein from a Chaperoned VP35 Complex. Cell Rep 2015; 12:140-149. [PMID: 26119732 PMCID: PMC4500542 DOI: 10.1016/j.celrep.2015.06.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/01/2015] [Accepted: 05/29/2015] [Indexed: 12/25/2022] Open
Abstract
Ebolavirus NP oligomerizes into helical filaments found at the core of the virion, encapsidates the viral RNA genome, and serves as a scaffold for additional viral proteins within the viral nucleocapsid. We identified a portion of the phosphoprotein homolog VP35 that binds with high affinity to nascent NP and regulates NP assembly and viral genome binding. Removal of the VP35 peptide leads to NP self-assembly via its N-terminal oligomerization arm. NP oligomerization likely causes a conformational change between the NP N- and C-terminal domains, facilitating RNA binding. These functional data are complemented by crystal structures of the NP°-VP35 complex at 2.4 Å resolution. The interactions between NP and VP35 illuminated by these structures are conserved among filoviruses and provide key targets for therapeutic intervention.
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Affiliation(s)
- Robert N Kirchdoerfer
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Dafna M Abelson
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sheng Li
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Malcolm R Wood
- Core Microscopy Facility, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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37
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Kugelman JR, Wiley MR, Mate S, Ladner JT, Beitzel B, Fakoli L, Taweh F, Prieto K, Diclaro JW, Minogue T, Schoepp RJ, Schaecher KE, Pettitt J, Bateman S, Fair J, Kuhn JH, Hensley L, Park DJ, Sabeti PC, Sanchez-Lockhart M, Bolay FK, Palacios G. Monitoring of Ebola Virus Makona Evolution through Establishment of Advanced Genomic Capability in Liberia. Emerg Infect Dis 2015; 21:1135-43. [PMID: 26079255 PMCID: PMC4816332 DOI: 10.3201/eid2107.150522] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
To support Liberia's response to the ongoing Ebola virus (EBOV) disease epidemic in Western Africa, we established in-country advanced genomic capabilities to monitor EBOV evolution. Twenty-five EBOV genomes were sequenced at the Liberian Institute for Biomedical Research, which provided an in-depth view of EBOV diversity in Liberia during September 2014-February 2015. These sequences were consistent with a single virus introduction to Liberia; however, shared ancestry with isolates from Mali indicated at least 1 additional instance of movement into or out of Liberia. The pace of change is generally consistent with previous estimates of mutation rate. We observed 23 nonsynonymous mutations and 1 nonsense mutation. Six of these changes are within known binding sites for sequence-based EBOV medical countermeasures; however, the diagnostic and therapeutic impact of EBOV evolution within Liberia appears to be low.
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Schudt G, Dolnik O, Kolesnikova L, Biedenkopf N, Herwig A, Becker S. Transport of Ebolavirus Nucleocapsids Is Dependent on Actin Polymerization: Live-Cell Imaging Analysis of Ebolavirus-Infected Cells. J Infect Dis 2015; 212 Suppl 2:S160-6. [PMID: 26038396 DOI: 10.1093/infdis/jiv083] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Transport of ebolavirus (EBOV) nucleocapsids from perinuclear viral inclusions, where they are formed, to the site of budding at the plasma membrane represents an obligatory step of virus assembly. Until now, no live-cell studies on EBOV nucleocapsid transport have been performed, and participation of host cellular factors in this process, as well as the trajectories and speed of nucleocapsid transport, remain unknown. METHODS Live-cell imaging of EBOV-infected cells treated with different inhibitors of cellular cytoskeleton was used for the identification of cellular proteins involved in the nucleocapsid transport. EBOV nucleocapsids were visualized by expression of green fluorescent protein (GFP)-labeled nucleocapsid viral protein 30 (VP30) in EBOV-infected cells. RESULTS Incorporation of the fusion protein VP30-GFP into EBOV nucleocapsids was confirmed by Western blot and indirect immunofluorescence analyses. Importantly, VP30-GFP fluorescence was readily detectable in the densely packed nucleocapsids inside perinuclear viral inclusions and in the dispersed rod-like nucleocapsids located outside of viral inclusions. Live-cell imaging of EBOV-infected cells revealed exit of single nucleocapsids from the viral inclusions and their intricate transport within the cytoplasm before budding at the plasma membrane. Nucleocapsid transport was arrested upon depolymerization of actin filaments (F-actin) and inhibition of the actin-nucleating Arp2/3 complex, and it was not altered upon depolymerization of microtubules or inhibition of N-WASP. Actin comet tails were often detected at the rear end of nucleocapsids. Marginally located nucleocapsids entered filopodia, moved inside, and budded from the tip of these thin cellular protrusions. CONCLUSIONS Live-cell imaging of EBOV-infected cells revealed actin-dependent long-distance transport of EBOV nucleocapsids before budding at the cell surface. These findings provide useful insights into EBOV assembly and have potential application in the development of antivirals.
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Affiliation(s)
- Gordian Schudt
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | - Olga Dolnik
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | | | | | - Astrid Herwig
- Institut für Virologie, Philipps-Universität Marburg, Germany
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Germany
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Zinc binding activity of human metapneumovirus M2-1 protein is indispensable for viral replication and pathogenesis in vivo. J Virol 2015; 89:6391-405. [PMID: 25855728 DOI: 10.1128/jvi.03488-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/30/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a member of the Pneumovirinae subfamily in the Paramyxoviridae family that causes respiratory tract infections in humans. Unlike members of the Paramyxovirinae subfamily, the polymerase complex of pneumoviruses requires an additional cofactor, the M2-1 protein, which functions as a transcriptional antitermination factor. The M2-1 protein was found to incorporate zinc ions, although the specific role(s) of the zinc binding activity in viral replication and pathogenesis remains unknown. In this study, we found that the third cysteine (C21) and the last histidine (H25) in the zinc binding motif (CCCH) of hMPV M2-1 were essential for zinc binding activity, whereas the first two cysteines (C7 and C15) play only minor or redundant roles in zinc binding. In addition, the zinc binding motif is essential for the oligomerization of M2-1. Subsequently, recombinant hMPVs (rhMPVs) carrying mutations in the zinc binding motif were recovered. Interestingly, rhMPV-C21S and -H25L mutants, which lacked zinc binding activity, had delayed replication in cell culture and were highly attenuated in cotton rats. In contrast, rhMPV-C7S and -C15S strains, which retained 60% of the zinc binding activity, replicated as efficiently as rhMPV in cotton rats. Importantly, rhMPVs that lacked zinc binding activity triggered high levels of neutralizing antibody and provided complete protection against challenge with rhMPV. Taken together, these results demonstrate that zinc binding activity is indispensable for viral replication and pathogenesis in vivo. These results also suggest that inhibition of zinc binding activity may serve as a novel approach to rationally attenuate hMPV and perhaps other pneumoviruses for vaccine purposes. IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Despite major efforts, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that the zinc binding activity of M2-1 is essential for virus replication and pathogenesis in vivo. Recombinant hMPVs that lacked zinc binding activity were not only defective in replication in the upper and lower respiratory tract but also triggered a strong protective immunity in cotton rats. Thus, inhibition of M2-1 zinc binding activity can lead to the development of novel, live attenuated vaccines, as well as antiviral drugs for pneumoviruses.
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Abstract
The current Ebola virus disease (EVD) outbreak in West Africa is the largest with over 5100 deaths in four West African countries as of 14 November 2014. EVD has high case-fatality rates but no licensed treatment or vaccine is yet available. Several vaccine candidates that protected nonhuman primates are not yet available for clinical use. Slow development of vaccine-stimulated immunity, sporadic nature and fast progression of EVD underlines the need for the development of effective postexposure therapeutic drugs. WHO encouraged the use of untested drugs for EVD to curb the fast-spreading outbreak. Here, we summarize therapeutics for EVD including monoclonal antibody-based therapy and inhibitors of viral replication including our recently developed small-molecule inhibitors of VP30 dephosphorylation.
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Affiliation(s)
- Marina Jerebtsova
- Department of Microbiology, Howard University, Washington, DC 20059, USA
| | - Sergei Nekhai
- Department of Microbiology, Howard University, Washington, DC 20059, USA ; Center for Sickle Cell Disease, Howard University, Washington, DC 20059, USA ; Department of Medicine, Howard University, Washington, DC 20059, USA ; Department of Pharmacology, Howard University, Washington, DC 20059, USA
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Kajihara M, Takada A. Host Cell Factors Involved in Filovirus Infection. CURRENT TROPICAL MEDICINE REPORTS 2015. [DOI: 10.1007/s40475-015-0039-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Lai KY, Ng WYG, Cheng FF. Human Ebola virus infection in West Africa: a review of available therapeutic agents that target different steps of the life cycle of Ebola virus. Infect Dis Poverty 2014; 3:43. [PMID: 25699183 PMCID: PMC4334593 DOI: 10.1186/2049-9957-3-43] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022] Open
Abstract
The recent outbreak of the human Zaire ebolavirus (EBOV) epidemic is spiraling out of control in West Africa. Human EBOV hemorrhagic fever has a case fatality rate of up to 90%. The EBOV is classified as a biosafety level 4 pathogen and is considered a category A agent of bioterrorism by Centers for Disease Control and Prevention, with no approved therapies and vaccines available for its treatment apart from supportive care. Although several promising therapeutic agents and vaccines against EBOV are undergoing the Phase I human trial, the current epidemic might be outpacing the speed at which drugs and vaccines can be produced. Like all viruses, the EBOV largely relies on host cell factors and physiological processes for its entry, replication, and egress. We have reviewed currently available therapeutic agents that have been shown to be effective in suppressing the proliferation of the EBOV in cell cultures or animal studies. Most of the therapeutic agents in this review are directed against non-mutable targets of the host, which is independent of viral mutation. These medications are approved by the Food and Drug Administration (FDA) for the treatment of other diseases. They are available and stockpileable for immediate use. They may also have a complementary role to those therapeutic agents under development that are directed against the mutable targets of the EBOV.
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Affiliation(s)
- Kang Yiu Lai
- />Department of Intensive Care, Queen Elizabeth Hospital, HKSAR, B6, 30 Gascoigne Rd, Kowloon, Hong Kong SAR China
| | - Wing Yiu George Ng
- />Department of Intensive Care, Queen Elizabeth Hospital, HKSAR, B6, 30 Gascoigne Rd, Kowloon, Hong Kong SAR China
| | - Fan Fanny Cheng
- />Department of Medicine, Queen Elizabeth Hospital, HKSAR, Kowloon, Hong Kong SARChina
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Ilinykh PA, Tigabu B, Ivanov A, Ammosova T, Obukhov Y, Garron T, Kumari N, Kovalskyy D, Platonov MO, Naumchik VS, Freiberg AN, Nekhai S, Bukreyev A. Role of protein phosphatase 1 in dephosphorylation of Ebola virus VP30 protein and its targeting for the inhibition of viral transcription. J Biol Chem 2014; 289:22723-22738. [PMID: 24936058 DOI: 10.1074/jbc.m114.575050] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The filovirus Ebola (EBOV) causes the most severe hemorrhagic fever known. The EBOV RNA-dependent polymerase complex includes a filovirus-specific VP30, which is critical for the transcriptional but not replication activity of EBOV polymerase; to support transcription, VP30 must be in a dephosphorylated form. Here we show that EBOV VP30 is phosphorylated not only at the N-terminal serine clusters identified previously but also at the threonine residues at positions 143 and 146. We also show that host cell protein phosphatase 1 (PP1) controls VP30 dephosphorylation because expression of a PP1-binding peptide cdNIPP1 increased VP30 phosphorylation. Moreover, targeting PP1 mRNA by shRNA resulted in the overexpression of SIPP1, a cytoplasm-shuttling regulatory subunit of PP1, and increased EBOV transcription, suggesting that cytoplasmic accumulation of PP1 induces EBOV transcription. Furthermore, we developed a small molecule compound, 1E7-03, that targeted a non-catalytic site of PP1 and increased VP30 dephosphorylation. The compound inhibited the transcription but increased replication of the viral genome and completely suppressed replication of EBOV in cultured cells. Finally, mutations of Thr(143) and Thr(146) of VP30 significantly inhibited EBOV transcription and strongly induced VP30 phosphorylation in the N-terminal Ser residues 29-46, suggesting a novel mechanism of regulation of VP30 phosphorylation. Our findings suggest that targeting PP1 with small molecules is a feasible approach to achieve dysregulation of the EBOV polymerase activity. This novel approach may be used for the development of antivirals against EBOV and other filovirus species.
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Affiliation(s)
- Philipp A Ilinykh
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Bersabeh Tigabu
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Andrey Ivanov
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Tatiana Ammosova
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059; Departments of Medicine and Howard University, Washington, D. C. 20059
| | - Yuri Obukhov
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Tania Garron
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555,; Departments of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas 77555
| | - Namita Kumari
- Center for Sickle Cell Disease and Howard University, Washington, D. C. 20059
| | - Dmytro Kovalskyy
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Maxim O Platonov
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Vasiliy S Naumchik
- Kiev National Taras Shevchenko University, Kiev 01601, Ukraine, and; Enamine Ltd., Kiev 01103, Ukraine
| | - Alexander N Freiberg
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555
| | - Sergei Nekhai
- Galveston National Laboratory, Galveston, Texas 77555,; Departments of Medicine and Howard University, Washington, D. C. 20059; Departments of Microbiology, Howard University, Washington, D. C. 20059,.
| | - Alexander Bukreyev
- Departments of Pathology and University of Texas Medical Branch at Galveston, Galveston, Texas 77555; Galveston National Laboratory, Galveston, Texas 77555,; Departments of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas 77555,.
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Kuhn JH, Bào Y, Bavari S, Becker S, Bradfute S, Brauburger K, Brister JR, Bukreyev AA, Caì Y, Chandran K, Davey RA, Dolnik O, Dye JM, Enterlein S, Gonzalez JP, Formenty P, Freiberg AN, Hensley LE, Hoenen T, Honko AN, Ignatyev GM, Jahrling PB, Johnson KM, Klenk HD, Kobinger G, Lackemeyer MG, Leroy EM, Lever MS, Mühlberger E, Netesov SV, Olinger GG, Palacios G, Patterson JL, Paweska JT, Pitt L, Radoshitzky SR, Ryabchikova EI, Saphire EO, Shestopalov AM, Smither SJ, Sullivan NJ, Swanepoel R, Takada A, Towner JS, van der Groen G, Volchkov VE, Volchkova VA, Wahl-Jensen V, Warren TK, Warfield KL, Weidmann M, Nichol ST. Virus nomenclature below the species level: a standardized nomenclature for filovirus strains and variants rescued from cDNA. Arch Virol 2014; 159:1229-37. [PMID: 24190508 PMCID: PMC4010566 DOI: 10.1007/s00705-013-1877-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 09/30/2013] [Indexed: 12/12/2022]
Abstract
Specific alterations (mutations, deletions, insertions) of virus genomes are crucial for the functional characterization of their regulatory elements and their expression products, as well as a prerequisite for the creation of attenuated viruses that could serve as vaccine candidates. Virus genome tailoring can be performed either by using traditionally cloned genomes as starting materials, followed by site-directed mutagenesis, or by de novo synthesis of modified virus genomes or parts thereof. A systematic nomenclature for such recombinant viruses is necessary to set them apart from wild-type and laboratory-adapted viruses, and to improve communication and collaborations among researchers who may want to use recombinant viruses or create novel viruses based on them. A large group of filovirus experts has recently proposed nomenclatures for natural and laboratory animal-adapted filoviruses that aim to simplify the retrieval of sequence data from electronic databases. Here, this work is extended to include nomenclature for filoviruses obtained in the laboratory via reverse genetics systems. The previously developed template for natural filovirus genetic variant naming, (/)///-, is retained, but we propose to adapt the type of information added to each field for cDNA clone-derived filoviruses. For instance, the full-length designation of an Ebola virus Kikwit variant rescued from a plasmid developed at the US Centers for Disease Control and Prevention could be akin to "Ebola virus H.sapiens-rec/COD/1995/Kikwit-abc1" (with the suffix "rec" identifying the recombinant nature of the virus and "abc1" being a placeholder for any meaningful isolate designator). Such a full-length designation should be used in databases and the methods section of publications. Shortened designations (such as "EBOV H.sap/COD/95/Kik-abc1") and abbreviations (such as "EBOV/Kik-abc1") could be used in the remainder of the text, depending on how critical it is to convey information contained in the full-length name. "EBOV" would suffice if only one EBOV strain/variant/isolate is addressed.
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Affiliation(s)
- Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Yīmíng Bào
- Information Engineering Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Sina Bavari
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Stephan Becker
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | | | - Kristina Brauburger
- Department of Microbiology and National Emerging Infectious Diseases Laboratory, Boston University School of Medicine, Boston, Massachusetts, USA
| | - J. Rodney Brister
- Information Engineering Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Alexander A. Bukreyev
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yíngyún Caì
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Robert A. Davey
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Olga Dolnik
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - John M. Dye
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Sven Enterlein
- Integrated BioTherapeutics, Inc., Gaithersburg, Maryland, USA
| | - Jean-Paul Gonzalez
- Health Department, Institut de Recherche pour le Développement, Marseille, France
- Metabiota, Inc., San Francisco, California, USA
| | | | - Alexander N. Freiberg
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Lisa E. Hensley
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Thomas Hoenen
- Laboratory for Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Anna N. Honko
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Georgy M. Ignatyev
- Federal State Unitary Company “Microgen Scientific Industrial Company for Immunobiological Medicines”, Ministry of Health of the Russian Federation, Moscow, Russia
| | - Peter B. Jahrling
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | | | - Hans-Dieter Klenk
- Institut für Virologie, Philipps-Universität Marburg, Marburg, Germany
| | - Gary Kobinger
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Matthew G. Lackemeyer
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Eric M. Leroy
- Centre International de Recherches Médicales de Franceville, Franceville, Gabon
| | - Mark S. Lever
- Biomedical Sciences Department, Dstl, Porton Down, Salisbury, Wiltshire, UK
| | - Elke Mühlberger
- Department of Microbiology and National Emerging Infectious Diseases Laboratory, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Sergey V. Netesov
- Novosibirsk State University, Novosibirsk, Novosibirsk Region, Russia
| | - Gene G. Olinger
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Jean L. Patterson
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Janusz T. Paweska
- Center for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham-Johannesburg, Gauteng, South Africa
| | - Louise Pitt
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Sheli R. Radoshitzky
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | - Elena I. Ryabchikova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Novosibirsk Region, Russia
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Aleksandr M. Shestopalov
- Novosibirsk State University, Novosibirsk, Novosibirsk Region, Russia
- State Research Center of Virology and Biotechnology “Vector”, Koltsovo, Novosibirsk Region, Russia
| | - Sophie J. Smither
- Biomedical Sciences Department, Dstl, Porton Down, Salisbury, Wiltshire, UK
| | - Nancy J. Sullivan
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert Swanepoel
- Zoonoses Research Unit, University of Pretoria, Pretoria, South Africa
| | - Ayato Takada
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Jonathan S. Towner
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Viktor E. Volchkov
- Laboratoire des Filovirus, Inserm U758, Université de Lyon, UCB-Lyon-1, Ecole-Normale-Supérieure de Lyon, Lyon, France
| | - Valentina A. Volchkova
- Laboratoire des Filovirus, Inserm U758, Université de Lyon, UCB-Lyon-1, Ecole-Normale-Supérieure de Lyon, Lyon, France
| | - Victoria Wahl-Jensen
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland, USA
| | - Travis K. Warren
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA
| | | | - Manfred Weidmann
- Universitätsmedizin Göttingen, Abteilung Virologie, Göttingen, Germany
| | - Stuart T. Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Clifton MC, Kirchdoerfer RN, Atkins K, Abendroth J, Raymond A, Grice R, Barnes S, Moen S, Lorimer D, Edwards TE, Myler PJ, Saphire EO. Structure of the Reston ebolavirus VP30 C-terminal domain. Acta Crystallogr F Struct Biol Commun 2014; 70:457-60. [PMID: 24699737 PMCID: PMC3976061 DOI: 10.1107/s2053230x14003811] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 02/18/2014] [Indexed: 11/11/2022] Open
Abstract
The ebolaviruses can cause severe hemorrhagic fever. Essential to the ebolavirus life cycle is the protein VP30, which serves as a transcriptional cofactor. Here, the crystal structure of the C-terminal, NP-binding domain of VP30 from Reston ebolavirus is presented. Reston VP30 and Ebola VP30 both form homodimers, but the dimeric interfaces are rotated relative to each other, suggesting subtle inherent differences or flexibility in the dimeric interface.
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Affiliation(s)
- Matthew C. Clifton
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, Preston Court, Bedford, MA 01730, USA
| | - Robert N. Kirchdoerfer
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, IMM-21, La Jolla, CA 92037, USA
| | - Kateri Atkins
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Jan Abendroth
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Amy Raymond
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Rena Grice
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Steve Barnes
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Spencer Moen
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Don Lorimer
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Thomas E. Edwards
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Emerald Bio, 7869 NE Day Road West, Bainbridge Isle, WA 98110, USA
| | - Peter J. Myler
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Erica Ollmann Saphire
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, IMM-21, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, IMM-21, La Jolla, CA 92037, USA
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Tanner SJ, Ariza A, Richard CA, Kyle HF, Dods RL, Blondot ML, Wu W, Trincão J, Trinh CH, Hiscox JA, Carroll MW, Silman NJ, Eléouët JF, Edwards TA, Barr JN. Crystal structure of the essential transcription antiterminator M2-1 protein of human respiratory syncytial virus and implications of its phosphorylation. Proc Natl Acad Sci U S A 2014; 111:1580-5. [PMID: 24434552 PMCID: PMC3910626 DOI: 10.1073/pnas.1317262111] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The M2-1 protein of the important pathogen human respiratory syncytial virus is a zinc-binding transcription antiterminator that is essential for viral gene expression. We present the crystal structure of full-length M2-1 protein in its native tetrameric form at a resolution of 2.5 Å. The structure reveals that M2-1 forms a disk-like assembly with tetramerization driven by a long helix forming a four-helix bundle at its center, further stabilized by contact between the zinc-binding domain and adjacent protomers. The tetramerization helix is linked to a core domain responsible for RNA binding activity by a flexible region on which lie two functionally critical serine residues that are phosphorylated during infection. The crystal structure of a phosphomimetic M2-1 variant revealed altered charge density surrounding this flexible region although its position was unaffected. Structure-guided mutagenesis identified residues that contributed to RNA binding and antitermination activity, revealing a strong correlation between these two activities, and further defining the role of phosphorylation in M2-1 antitermination activity. The data we present here identify surfaces critical for M2-1 function that may be targeted by antiviral compounds.
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Affiliation(s)
- Sian J. Tanner
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Public Health England, Porton Down SP4 0JG, United Kingdom
| | - Antonio Ariza
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Charles-Adrien Richard
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Hannah F. Kyle
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rachel L. Dods
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Marie-Lise Blondot
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Weining Wu
- Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, United Kingdom; and
| | - José Trincão
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0FA, United Kingdom
| | - Chi H. Trinh
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Julian A. Hiscox
- Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, United Kingdom; and
| | | | | | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Thomas A. Edwards
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John N. Barr
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
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Falzarano D, Groseth A, Hoenen T. Development and application of reporter-expressing mononegaviruses: current challenges and perspectives. Antiviral Res 2014; 103:78-87. [PMID: 24462694 DOI: 10.1016/j.antiviral.2014.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 01/06/2014] [Accepted: 01/12/2014] [Indexed: 12/19/2022]
Abstract
Reverse genetics allows the generation of recombinant viruses entirely from cDNA. One application of this technology is the creation of reporter-expressing viruses, which greatly increase the detail and ease with which these viruses can be studied. However, there are a number of challenges when working with reporter-expressing viruses. Both the reporter protein itself as well as the genetic manipulations within the viral genome required for expression of this reporter can result in altered biological properties of the recombinant virus, and lead to attenuation in vitro and/or in vivo. Further, instability of reporter expression and purging of the genetic information encoding for the reporter from the viral genome can be an issue. Finally, a practical challenge for in vivo studies lies in the attenuation of light signals when traversing tissues. Novel expression strategies and the continued development of brighter, red and far-red shifted reporters and the increased use of bioluminescent reporters for in vivo applications promise to overcome some of these limitations in future. However, a "one size fits all" approach to the design of reporter-expressing viruses has thus far not been possible. Rather, a reporter suited to the intended application must be selected and an appropriate expression strategy and location for the reporter in the viral genome chosen. Still, attenuating effects of the reporter on viral fitness are difficult to predict and have to be carefully assessed with respect to the intended application. Despite these limitations the generation of suitable reporter-expressing viruses will become more common as technology and our understanding of the intricacies of viral gene expression and regulation improves, allowing deeper insight into virus biology both in living cells and in animals.
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Affiliation(s)
- Darryl Falzarano
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Allison Groseth
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Thomas Hoenen
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.
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48
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Trunschke M, Conrad D, Enterlein S, Olejnik J, Brauburger K, Mühlberger E. The L-VP35 and L-L interaction domains reside in the amino terminus of the Ebola virus L protein and are potential targets for antivirals. Virology 2013; 441:135-45. [PMID: 23582637 DOI: 10.1016/j.virol.2013.03.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 02/18/2013] [Accepted: 03/14/2013] [Indexed: 11/25/2022]
Abstract
The Ebola virus (EBOV) RNA-dependent RNA polymerase (RdRp) complex consists of the catalytic subunit of the polymerase, L, and its cofactor VP35. Using immunofluorescence analysis and coimmunoprecipitation assays, we mapped the VP35 binding site on L. A core binding domain spanning amino acids 280-370 of L was sufficient to mediate weak interaction with VP35, while the entire N-terminus up to amino acid 380 was required for strong VP35-L binding. Interestingly, the VP35 binding site overlaps with an N-terminal L homo-oligomerization domain in a non-competitive manner. N-terminal L deletion mutants containing the VP35 binding site were able to efficiently block EBOV replication and transcription in a minigenome system suggesting the VP35 binding site on L as a potential target for the development of antivirals.
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Affiliation(s)
- Martina Trunschke
- Department of Virology, Philipps University of Marburg, Hans-Meerwein-Strβe 2, 35043 Marburg, Germany
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49
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Biedenkopf N, Hartlieb B, Hoenen T, Becker S. Phosphorylation of Ebola virus VP30 influences the composition of the viral nucleocapsid complex: impact on viral transcription and replication. J Biol Chem 2013; 288:11165-74. [PMID: 23493393 DOI: 10.1074/jbc.m113.461285] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ebola virus is a non-segmented negative-sense RNA virus causing severe hemorrhagic fever with high fatality rates in humans and nonhuman primates. For transcription of the viral genome four viral proteins are essential: the nucleoprotein NP, the polymerase L, the polymerase cofactor VP35, and VP30. VP30 represents an essential Ebola virus-specific transcription factor whose activity is regulated via its phosphorylation state. In contrast to viral transcription, VP30 is not required for viral replication. Using a minigenome assay, we show that phosphorylation of VP30 inhibits viral transcription while viral replication is increased. Concurrently, phosphorylation of VP30 reciprocally regulates a newly described interaction of VP30 with VP35, and strengthens the interaction with NP. Our results indicate a critical role of VP30 phosphorylation for viral transcription and replication, suggesting a mechanism by which VP30 phosphorylation modulates the composition of the viral polymerase complex presumably forming a transcriptase in the presence of non-phosphorylated VP30 or a replicase in the presence of phosphorylated VP30.
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Affiliation(s)
- Nadine Biedenkopf
- Institut für Virologie, Philipps-Universität Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany
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Nanbo A, Watanabe S, Halfmann P, Kawaoka Y. The spatio-temporal distribution dynamics of Ebola virus proteins and RNA in infected cells. Sci Rep 2013; 3:1206. [PMID: 23383374 PMCID: PMC3563031 DOI: 10.1038/srep01206] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 10/31/2012] [Indexed: 12/16/2022] Open
Abstract
Here, we used a biologically contained Ebola virus system to characterize the spatio-temporal distribution of Ebola virus proteins and RNA during virus replication. We found that viral nucleoprotein (NP), the polymerase cofactor VP35, the major matrix protein VP40, the transcription activator VP30, and the minor matrix protein VP24 were distributed in cytoplasmic inclusions. These inclusions enlarged near the nucleus, became smaller pieces, and subsequently localized near the plasma membrane. GP was distributed in the cytoplasm and transported to the plasma membrane independent of the other viral proteins. We also found that viral RNA synthesis occurred within the inclusions. Newly synthesized negative-sense RNA was distributed inside the inclusions, whereas positive-sense RNA was distributed both inside and outside. These findings provide useful insights into Ebola virus replication.
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Affiliation(s)
- Asuka Nanbo
- Influenza Research Institute, Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI 53711, USA.
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