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Watanabe R, Zyla D, Parekh D, Hong C, Jones Y, Schendel SL, Wan W, Castillon G, Saphire EO. Intracellular Ebola virus nucleocapsid assembly revealed by in situ cryo-electron tomography. Cell 2024:S0092-8674(24)00973-5. [PMID: 39293445 DOI: 10.1016/j.cell.2024.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/04/2024] [Accepted: 08/21/2024] [Indexed: 09/20/2024]
Abstract
Filoviruses, including the Ebola and Marburg viruses, cause hemorrhagic fevers with up to 90% lethality. The viral nucleocapsid is assembled by polymerization of the nucleoprotein (NP) along the viral genome, together with the viral proteins VP24 and VP35. We employed cryo-electron tomography of cells transfected with viral proteins and infected with model Ebola virus to illuminate assembly intermediates, as well as a 9 Å map of the complete intracellular assembly. This structure reveals a previously unresolved third and outer layer of NP complexed with VP35. The intrinsically disordered region, together with the C-terminal domain of this outer layer of NP, provides the constant width between intracellular nucleocapsid bundles and likely functions as a flexible tether to the viral matrix protein in the virion. A comparison of intracellular nucleocapsids with prior in-virion nucleocapsid structures reveals that the nucleocapsid further condenses vertically in the virion. The interfaces responsible for nucleocapsid assembly are highly conserved and offer targets for broadly effective antivirals.
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Affiliation(s)
- Reika Watanabe
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Dawid Zyla
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Diptiben Parekh
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Connor Hong
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Ying Jones
- Electron Microscopy Core, University of California, San Diego, La Jolla, CA 92037, USA
| | - Sharon L Schendel
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - William Wan
- Vanderbilt University Center for Structural Biology, Nashville, TN 37235, USA
| | - Guillaume Castillon
- Electron Microscopy Core, University of California, San Diego, La Jolla, CA 92037, USA
| | - Erica Ollmann Saphire
- Center for Vaccine Innovation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA; Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.
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2
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Kleiner VA, Fearns R. How does the polymerase of non-segmented negative strand RNA viruses commit to transcription or genome replication? J Virol 2024; 98:e0033224. [PMID: 39078194 PMCID: PMC11334523 DOI: 10.1128/jvi.00332-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024] Open
Abstract
The Mononegavirales, or non-segmented negative-sense RNA viruses (nsNSVs), includes significant human pathogens, such as respiratory syncytial virus, parainfluenza virus, measles virus, Ebola virus, and rabies virus. Although these viruses differ widely in their pathogenic properties, they are united by each having a genome consisting of a single strand of negative-sense RNA. Consistent with their shared genome structure, the nsNSVs have evolved similar ways to transcribe their genome into mRNAs and replicate it to produce new genomes. Importantly, both mRNA transcription and genome replication are performed by a single virus-encoded polymerase. A fundamental and intriguing question is: how does the nsNSV polymerase commit to being either an mRNA transcriptase or a replicase? The polymerase must become committed to one process or the other either before it interacts with the genome template or in its initial interactions with the promoter sequence at the 3´ end of the genomic RNA. This review examines the biochemical, molecular biology, and structural biology data regarding the first steps of transcription and RNA replication that have been gathered over several decades for different families of nsNSVs. These findings are discussed in relation to possible models that could explain how an nsNSV polymerase initiates and commits to either transcription or genome replication.
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Affiliation(s)
- Victoria A. Kleiner
- Department of Virology, Immunology & Microbiology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, USA
| | - Rachel Fearns
- Department of Virology, Immunology & Microbiology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, USA
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3
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Kordys M, Urbanowicz A. 3D Puzzle at the Nanoscale-How do RNA Viruses Self-Assemble their Capsids into Perfectly Ordered Structures. Macromol Biosci 2024:e2400088. [PMID: 38864315 DOI: 10.1002/mabi.202400088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 06/03/2024] [Indexed: 06/13/2024]
Abstract
The phenomenon of RNA virus self-organization, first observed in the mid-20th century in tobacco mosaic virus, is the subject of extensive research. Efforts to comprehend this process intensify due to its potential for producing vaccines or antiviral compounds as well as nanocarriers and nanotemplates. However, direct observation of the self-assembly is hindered by its prevalence within infected host cells. One of the approaches involves in vitro and in silico research using model viruses featuring a ssRNA(+) genome enclosed within a capsid made up of a single type protein. While various pathways are proposed based on these studies, their relevance in vivo remains uncertain. On the other hand, the development of advanced microscopic methods provide insights into the events within living cells, where following viral infection, specialized compartments form to facilitate the creation of nascent virions. Intriguingly, a growing body of evidence indicates that the primary function of packaging signals in viral RNA is to effectively initiate the virion self-assembly. This is in contrast to earlier opinions suggesting a role in marking RNA for encapsidation. Another noteworthy observation is that many viruses undergo self-assembly within membraneless liquid organelles, which are specifically induced by viral proteins.
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Affiliation(s)
- Martyna Kordys
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego Str. 12/14, Poznan, 61-704, Poland
| | - Anna Urbanowicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego Str. 12/14, Poznan, 61-704, Poland
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4
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Hayat M, Gao T, Cao Y, Rafiq M, Zhuo L, Li YZ. Identification of Prospective Ebola Virus VP35 and VP40 Protein Inhibitors from Myxobacterial Natural Products. Biomolecules 2024; 14:660. [PMID: 38927063 PMCID: PMC11201620 DOI: 10.3390/biom14060660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/01/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
The Ebola virus (EBOV) is a lethal pathogen causing hemorrhagic fever syndrome which remains a global health challenge. In the EBOV, two multifunctional proteins, VP35 and VP40, have significant roles in replication, virion assembly, and budding from the cell and have been identified as druggable targets. In this study, we employed in silico methods comprising molecular docking, molecular dynamic simulations, and pharmacological properties to identify prospective drugs for inhibiting VP35 and VP40 proteins from the myxobacterial bioactive natural product repertoire. Cystobactamid 934-2, Cystobactamid 919-1, and Cittilin A bound firmly to VP35. Meanwhile, 2-Hydroxysorangiadenosine, Enhypyrazinone B, and Sorangiadenosine showed strong binding to the matrix protein VP40. Molecular dynamic simulations revealed that, among these compounds, Cystobactamid 919-1 and 2-Hydroxysorangiadenosine had stable interactions with their respective targets. Similarly, molecular mechanics Poisson-Boltzmann surface area (MMPBSA) calculations indicated close-fitting receptor binding with VP35 or VP40. These two compounds also exhibited good pharmacological properties. In conclusion, we identified Cystobactamid 919-1 and 2-Hydroxysorangiadenosine as potential ligands for EBOV that target VP35 and VP40 proteins. These findings signify an essential step in vitro and in vivo to validate their potential for EBOV inhibition.
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Affiliation(s)
- Muhammad Hayat
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.H.); (T.G.); (Y.C.); (Y.-Z.L.)
| | - Tian Gao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.H.); (T.G.); (Y.C.); (Y.-Z.L.)
| | - Ying Cao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.H.); (T.G.); (Y.C.); (Y.-Z.L.)
| | - Muhammad Rafiq
- Department of Microbiology, Faculty of Life Sciences and Informatics, Balochistan University of IT, Engineering and Management Sciences, Quetta 87100, Pakistan
| | - Li Zhuo
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.H.); (T.G.); (Y.C.); (Y.-Z.L.)
- Shenzhen Research Institute, Shandong University, Shenzhen 518057, China
- Suzhou Research Institute, Shandong University, Suzhou 215123, China
| | - Yue-Zhong Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.H.); (T.G.); (Y.C.); (Y.-Z.L.)
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5
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Bodmer BS, Hoenen T, Wendt L. Molecular insights into the Ebola virus life cycle. Nat Microbiol 2024; 9:1417-1426. [PMID: 38783022 DOI: 10.1038/s41564-024-01703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
Ebola virus and other orthoebolaviruses cause severe haemorrhagic fevers in humans, with very high case fatality rates. Their non-segmented single-stranded RNA genome encodes only seven structural proteins and a small number of non-structural proteins to facilitate the virus life cycle. The basics of this life cycle are well established, but recent advances have substantially increased our understanding of its molecular details, including the viral and host factors involved. Here we provide a comprehensive overview of our current knowledge of the molecular details of the orthoebolavirus life cycle, with a special focus on proviral host factors. We discuss the multistep entry process, viral RNA synthesis in specialized phase-separated intracellular compartments called inclusion bodies, the expression of viral proteins and ultimately the assembly of new virus particles and their release at the cell surface. In doing so, we integrate recent studies into the increasingly detailed model that has developed for these fundamental aspects of orthoebolavirus biology.
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Affiliation(s)
- Bianca S Bodmer
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
| | - Lisa Wendt
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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6
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Carlson RJ, Patten JJ, Stefanakis G, Soong BY, Radhakrishnan A, Singh A, Thakur N, Amarasinghe GK, Hacohen N, Basler CF, Leung D, Uhler C, Davey RA, Blainey PC. Single-cell image-based genetic screens systematically identify regulators of Ebola virus subcellular infection dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.06.588168. [PMID: 38617272 PMCID: PMC11014611 DOI: 10.1101/2024.04.06.588168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Ebola virus (EBOV) is a high-consequence filovirus that gives rise to frequent epidemics with high case fatality rates and few therapeutic options. Here, we applied image-based screening of a genome-wide CRISPR library to systematically identify host cell regulators of Ebola virus infection in 39,085,093 million single cells. Measuring viral RNA and protein levels together with their localization in cells identified over 998 related host factors and provided detailed information about the role of each gene across the virus replication cycle. We trained a deep learning model on single-cell images to associate each host factor with predicted replication steps, and confirmed the predicted relationship for select host factors. Among the findings, we showed that the mitochondrial complex III subunit UQCRB is a post-entry regulator of Ebola virus RNA replication, and demonstrated that UQCRB inhibition with a small molecule reduced overall Ebola virus infection with an IC50 of 5 μM. Using a random forest model, we also identified perturbations that reduced infection by disrupting the equilibrium between viral RNA and protein. One such protein, STRAP, is a spliceosome-associated factor that was found to be closely associated with VP35, a viral protein required for RNA processing. Loss of STRAP expression resulted in a reduction in full-length viral genome production and subsequent production of non-infectious virus particles. Overall, the data produced in this genome-wide high-content single-cell screen and secondary screens in additional cell lines and related filoviruses (MARV and SUDV) revealed new insights about the role of host factors in virus replication and potential new targets for therapeutic intervention.
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Affiliation(s)
- Rebecca J Carlson
- Massachusetts Institute of Technology, Department of Health Sciences and Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - J J Patten
- Department of Virology, Immunology, and Microbiology, Boston University School of Medicine, Boston, MA, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - George Stefanakis
- Laboratory for Information & Decision Systems, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Brian Y Soong
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Adityanarayanan Radhakrishnan
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Harvard School of Engineering and Applied Sciences, Cambridge, MA, USA
| | - Avtar Singh
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Naveen Thakur
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Gaya K Amarasinghe
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Nir Hacohen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Massachusetts General Hospital, Cancer Center, Boston, MA, USA
| | - Christopher F Basler
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Daisy Leung
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Caroline Uhler
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Laboratory for Information & Decision Systems, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert A Davey
- Department of Virology, Immunology, and Microbiology, Boston University School of Medicine, Boston, MA, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Paul C Blainey
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Massachusetts Institute of Technology, Department of Biological Engineering, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA, USA
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7
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Fang J, Zhou ZJ, Yuan S, Qiu Y, Ge XY. Lineage classification and selective site identification of Orthoebolavirus zairense. Microbes Infect 2024:105304. [PMID: 38278475 DOI: 10.1016/j.micinf.2024.105304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 01/28/2024]
Abstract
As the high pathogenic species of Filoviridae virus family, Orthoebolavirus zairense (EBOV) shows frequent outbreaks in human in recently years since its first emerging in 1976 in Democratic Republic of the Congo (COD), bringing ongoing risks and burden on public health safety. Here, the phylogenetic relationship among major outbreaks was analyzed. The results showed that EBOV isolates could be divided into four lineages according to spatial and temporal epidemics. Then, the positive selection sites (PSSs) were detected on all proteins of the EBOV, exhibiting lineage characteristic. Particularly, sites in GP and VP24 were identified to be significantly under positive selection, and partial of which were maintained in the latest isolates in 2021. GP and L were found to have high variability between lineages. Substitutions including F443L and F443S in GP, as well as F1610L and I1951V in L could be characteristic of the two large outbreaks in COD (2018) and West Africa (2014), respectively. Further, substitutions of significant PSSs in VP24 and L proteins were visualized for analysis of structural changes, which may affect EBOV pathogenesis. In summary, our results gains insights in genetic characteristic and adaptive evolution of EBOV, which could facilitate gene functional research against EBOV.
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Affiliation(s)
- Jie Fang
- Hunan Provincial Key Laboratory of Medical Virology, Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, 27 Tianma Rd., Changsha, Hunan, 410012, China
| | - Zhi-Jian Zhou
- Hunan Provincial Key Laboratory of Medical Virology, Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, 27 Tianma Rd., Changsha, Hunan, 410012, China
| | - Shuofeng Yuan
- Department of Microbiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ye Qiu
- Hunan Provincial Key Laboratory of Medical Virology, Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, 27 Tianma Rd., Changsha, Hunan, 410012, China
| | - Xing-Yi Ge
- Hunan Provincial Key Laboratory of Medical Virology, Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, 27 Tianma Rd., Changsha, Hunan, 410012, China.
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8
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Ferrero DS, Tomás Gilabert O, Verdaguer N. Structural insights on the nucleoprotein C-terminal domain of Měnglà virus. Microbiol Spectr 2023; 11:e0237323. [PMID: 37888996 PMCID: PMC10714759 DOI: 10.1128/spectrum.02373-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE Filoviruses are the causative agents of severe and often fatal hemorrhagic disease in humans. Měnglà virus (MLAV) is a recently reported filovirus, isolated from fruit bats that is capable to replicate in human cells, representing a potential risk for human health. An in-depth structural and functional knowledge of MLAV proteins is an essential step for antiviral research on this virus that can also be extended to other emerging filoviruses. In this study, we determined the first crystal structures of the C-terminal domain (CTD) of the MLAV nucleoprotein (NP), showing important similarities to the equivalent domain in MARV. The structural data also show that the NP CTD has the ability to form large helical oligomers that may participate in the control of cytoplasmic inclusion body formation during viral replication.
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Affiliation(s)
| | | | - Nuria Verdaguer
- Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
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9
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Bodmer BS, Vallbracht M, Ushakov DS, Wendt L, Chlanda P, Hoenen T. Ebola virus inclusion bodies are liquid organelles whose formation is facilitated by nucleoprotein oligomerization. Emerg Microbes Infect 2023; 12:2223727. [PMID: 37306660 PMCID: PMC10288931 DOI: 10.1080/22221751.2023.2223727] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 05/16/2023] [Accepted: 06/06/2023] [Indexed: 06/13/2023]
Abstract
Viral RNA synthesis of several non-segmented, negative-sense RNA viruses (NNSVs) takes place in inclusion bodies (IBs) that show properties of liquid organelles, which are formed by liquid-liquid phase separation of scaffold proteins. It is believed that this is driven by intrinsically disordered regions (IDRs) and/or multiple copies of interaction domains, which for NNSVs are usually located in their nucleo - and phosphoproteins. In contrast to other NNSVs, the Ebola virus (EBOV) nucleoprotein NP alone is sufficient to form IBs without the need for a phosphoprotein, and to facilitate the recruitment of other viral proteins into these structures. While it has been proposed that also EBOV IBs are liquid organelles, this has so far not been formally demonstrated. Here we used a combination of live cell microscopy, fluorescence recovery after photobleaching assays, and mutagenesis approaches together with reverse genetics-based generation of recombinant viruses to study the formation of EBOV IBs. Our results demonstrate that EBOV IBs are indeed liquid organelles, and that oligomerization but not IDRs of the EBOV nucleoprotein plays a key role in their formation. Additionally, VP35 (often considered the phosphoprotein-equivalent of EBOV) is not essential for IB formation, but alters their liquid behaviour. These findings define the molecular mechanism for the formation of EBOV IBs, which play a central role in the life cycle of this deadly virus.
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Affiliation(s)
- Bianca S. Bodmer
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Melina Vallbracht
- Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Dmitry S. Ushakov
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Lisa Wendt
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Petr Chlanda
- Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Hoenen
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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10
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Wu C, Wagner ND, Moyle AB, Feng A, Sharma N, Stubbs SH, Donahue C, Davey RA, Gross ML, Leung DW, Amarasinghe GK. Disruption of Ebola NP 0VP35 Inclusion Body-like Structures reduce Viral Infection. J Mol Biol 2023; 435:168241. [PMID: 37598728 PMCID: PMC11312838 DOI: 10.1016/j.jmb.2023.168241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 08/04/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023]
Abstract
Viral inclusion bodies (IBs) are potential sites of viral replication and assembly. How viral IBs form remains poorly defined. Here we describe a combined biophysical and cellular approach to identify the components necessary for IB formation during Ebola virus (EBOV) infection. We find that the eNP0VP35 complex containing Ebola nucleoprotein (eNP) and viral protein 35 (eVP35), the functional equivalents of nucleoprotein (N) and phosphoprotein (P) in non-segmented negative strand viruses (NNSVs), phase separates to form inclusion bodies. Phase separation of eNP0VP35 is reversible and modulated by ionic strength. The multivalency of eVP35, and not eNP, is also critical for phase separation. Furthermore, overexpression of an eVP35 peptide disrupts eNP0VP35 complex formation, leading to reduced frequency of IB formation and limited viral infection. Together, our results show that upon EBOV infection, the eNP0VP35 complex forms the minimum unit to drive IB formation and viral replication.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA; Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Annie Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nitin Sharma
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sarah H Stubbs
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Callie Donahue
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Robert A Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
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11
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Collados Rodríguez M, Maillard P, Journeaux A, Komarova AV, Najburg V, David RYS, Helynck O, Guo M, Zhong J, Baize S, Tangy F, Jacob Y, Munier-Lehmann H, Meurs EF. Novel Antiviral Molecules against Ebola Virus Infection. Int J Mol Sci 2023; 24:14791. [PMID: 37834238 PMCID: PMC10573436 DOI: 10.3390/ijms241914791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Infection with Ebola virus (EBOV) is responsible for hemorrhagic fever in humans with a high mortality rate. Combined efforts of prevention and therapeutic intervention are required to tackle highly variable RNA viruses, whose infections often lead to outbreaks. Here, we have screened the 2P2I3D chemical library using a nanoluciferase-based protein complementation assay (NPCA) and isolated two compounds that disrupt the interaction of the EBOV protein fragment VP35IID with the N-terminus of the dsRNA-binding proteins PKR and PACT, involved in IFN response and/or intrinsic immunity, respectively. The two compounds inhibited EBOV infection in cell culture as well as infection by measles virus (MV) independently of IFN induction. Consequently, we propose that the compounds are antiviral by restoring intrinsic immunity driven by PACT. Given that PACT is highly conserved across mammals, our data support further testing of the compounds in other species, as well as against other negative-sense RNA viruses.
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Affiliation(s)
- Mila Collados Rodríguez
- School of Infection & Immunity (SII), College of Medical, Veterinary and Life Sciences (MVLS), Sir Michael Stoker Building, MRC-University of Glasgow Centre for Virus Research (CVR), Glasgow G61 1QH, UK
- Unité Hépacivirus et Immunité Innée, CNRS, UMR 3569, Département de Virologie, Institut Pasteur, 75015 Paris, France; (P.M.); (E.F.M.)
| | - Patrick Maillard
- Unité Hépacivirus et Immunité Innée, CNRS, UMR 3569, Département de Virologie, Institut Pasteur, 75015 Paris, France; (P.M.); (E.F.M.)
| | - Alexandra Journeaux
- Unit of Biology of Emerging Viral Infections, Institut Pasteur, 69007 Lyon, France; (A.J.); (S.B.)
| | - Anastassia V. Komarova
- Interactomics, RNA and Immunity Laboratory, Institut Pasteur, 75015 Paris, France;
- Unité de Génomique Virale et Vaccination, Institut Pasteur, 75015 Paris, France; (V.N.); (R.-Y.S.D.); (F.T.)
- Université Paris Cité, 75013 Paris, France;
| | - Valérie Najburg
- Unité de Génomique Virale et Vaccination, Institut Pasteur, 75015 Paris, France; (V.N.); (R.-Y.S.D.); (F.T.)
- Université Paris Cité, 75013 Paris, France;
| | - Raul-Yusef Sanchez David
- Unité de Génomique Virale et Vaccination, Institut Pasteur, 75015 Paris, France; (V.N.); (R.-Y.S.D.); (F.T.)
- Blizard Institute—Faculty of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Olivier Helynck
- Unité de Chimie et Biocatalyse, CNRS, UMR 3523, Institut Pasteur, Université de Paris, 75015 Paris, France; (O.H.); (H.M.-L.)
| | - Mingzhe Guo
- CAS Key Laboratory of Molecular Virology and Immunology, Unit of Viral Hepatitis, Shanghai Institute of Immunity and Infection, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Shanghai 200023, China; (M.G.); (J.Z.)
| | - Jin Zhong
- CAS Key Laboratory of Molecular Virology and Immunology, Unit of Viral Hepatitis, Shanghai Institute of Immunity and Infection, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Shanghai 200023, China; (M.G.); (J.Z.)
| | - Sylvain Baize
- Unit of Biology of Emerging Viral Infections, Institut Pasteur, 69007 Lyon, France; (A.J.); (S.B.)
| | - Frédéric Tangy
- Unité de Génomique Virale et Vaccination, Institut Pasteur, 75015 Paris, France; (V.N.); (R.-Y.S.D.); (F.T.)
- Université Paris Cité, 75013 Paris, France;
| | - Yves Jacob
- Université Paris Cité, 75013 Paris, France;
- Unité Génétique Moléculaire des Virus à ARN, CNRS, UMR 3569, Département de Virologie, Institut Pasteur, 75015 Paris, France
| | - Hélène Munier-Lehmann
- Unité de Chimie et Biocatalyse, CNRS, UMR 3523, Institut Pasteur, Université de Paris, 75015 Paris, France; (O.H.); (H.M.-L.)
| | - Eliane F. Meurs
- Unité Hépacivirus et Immunité Innée, CNRS, UMR 3569, Département de Virologie, Institut Pasteur, 75015 Paris, France; (P.M.); (E.F.M.)
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12
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Fang J, Castillon G, Phan S, McArdle S, Hariharan C, Adams A, Ellisman MH, Deniz AA, Saphire EO. Spatial and functional arrangement of Ebola virus polymerase inside phase-separated viral factories. Nat Commun 2023; 14:4159. [PMID: 37443171 PMCID: PMC10345124 DOI: 10.1038/s41467-023-39821-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Ebola virus (EBOV) infection induces the formation of membrane-less, cytoplasmic compartments termed viral factories, in which multiple viral proteins gather and coordinate viral transcription, replication, and assembly. Key to viral factory function is the recruitment of EBOV polymerase, a multifunctional machine that mediates transcription and replication of the viral RNA genome. We show that intracellularly reconstituted EBOV viral factories are biomolecular condensates, with composition-dependent internal exchange dynamics that likely facilitates viral replication. Within the viral factory, we found the EBOV polymerase clusters into foci. The distance between these foci increases when viral replication is enabled. In addition to the typical droplet-like viral factories, we report the formation of network-like viral factories during EBOV infection. Unlike droplet-like viral factories, network-like factories are inactive for EBOV nucleocapsid assembly. This unique view of EBOV propagation suggests a form-to-function relationship that describes how physical properties and internal structures of biomolecular condensates influence viral biogenesis.
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Affiliation(s)
- Jingru Fang
- La Jolla Institute for Immunology, La Jolla, CA, USA
- Scripps Research, La Jolla, CA, USA
| | - Guillaume Castillon
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sara McArdle
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | | | - Aiyana Adams
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
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13
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Ahmad A, Tigabu B, Ivanov A, Jerebtsova M, Ammosova T, Ramanathan P, Kumari N, Brantner CA, Pietzsch CA, Abdullah G, Popratiloff A, Widen S, Bukreyev A, Nekhai S. Ebola Virus NP Binding to Host Protein Phosphatase-1 Regulates Capsid Formation. RESEARCH SQUARE 2023:rs.3.rs-2963943. [PMID: 37333330 PMCID: PMC10274954 DOI: 10.21203/rs.3.rs-2963943/v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The Ebola virus (EBOV) transcriptional regulation involves host protein phosphatases PP1 and PP2A, which dephosphorylate the transcriptional cofactor of EBOV polymerase VP30. The 1E7-03 compound, which targets PP1, induces VP30 phosphorylation and inhibits EBOV infection. This study aimed to investigate the role of PP1 in EBOV replication. When EBOV-infected cells were continuously treated with 1E7-03, the NP E619K mutation was selected. This mutation moderately reduced EBOV minigenome transcription, which was restored by the treatment with 1E7-03. Formation of EBOV capsids, when NP was co-expressed with VP24 and VP35, was impaired with NPE 619K. Treatment with 1E7-03 restored capsid formation by NP E619K mutation, but inhibited capsids formed by WT NP. The dimerization of NP E619K, tested in a split NanoBiT assay, was significantly decreased (~ 15-fold) compared to WT NP. NP E619K bound more efficiently to PP1 (~ 3-fold) but not B56 subunit of PP2A or VP30. Cross-linking and co-immunoprecipitation experiments showed fewer monomers and dimers for NP E619K which were increased with 1E7-03 treatment. NP E619K showed increased co-localization with PP1α compared to WT NP. Mutations of potential PP1 binding sites and NP deletions disrupted its interaction with PP1. Collectively, our findings suggest that PP1 binding to the NP regulates NP dimerization and capsid formation, and that NP E619K mutation, which has the enhanced PP1 binding, disrupts these processes. Our results point to a new role for PP1 in EBOV replication in which NP binding to PP1 may facilitate viral transcription by delaying capsid formation and EBOV replication.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Steve Widen
- UTMB: The University of Texas Medical Branch at Galveston
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14
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Wang Y, Ling X, Zhang C, Zou J, Luo B, Luo Y, Jia X, Jia G, Zhang M, Hu J, Liu T, Wang Y, Lu K, Li D, Ma J, Liu C, Su Z. Modular characterization of SARS-CoV-2 nucleocapsid protein domain functions in nucleocapsid-like assembly. MOLECULAR BIOMEDICINE 2023; 4:16. [PMID: 37211575 DOI: 10.1186/s43556-023-00129-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/09/2023] [Indexed: 05/23/2023] Open
Abstract
SARS-CoV-2 and its variants, with the Omicron subvariant XBB currently prevailing the global infections, continue to pose threats on public health worldwide. This non-segmented positive-stranded RNA virus encodes the multi-functional nucleocapsid protein (N) that plays key roles in viral infection, replication, genome packaging and budding. N protein consists of two structural domains, NTD and CTD, and three intrinsically disordered regions (IDRs) including the NIDR, the serine/arginine rich motif (SRIDR), and the CIDR. Previous studies revealed functions of N protein in RNA binding, oligomerization, and liquid-liquid phase separation (LLPS), however, characterizations of individual domains and their dissected contributions to N protein functions remain incomplete. In particular, little is known about N protein assembly that may play essential roles in viral replication and genome packing. Here, we present a modular approach to dissect functional roles of individual domains in SARS-CoV-2 N protein that reveals inhibitory or augmented modulations of protein assembly and LLPS in the presence of viral RNAs. Intriguingly, full-length N protein (NFL) assembles into ring-like architecture whereas the truncated SRIDR-CTD-CIDR (N182-419) promotes filamentous assembly. Moreover, LLPS droplets of NFL and N182-419 are significantly enlarged in the presence of viral RNAs, and we observed filamentous structures in the N182-419 droplets using correlative light and electron microscopy (CLEM), suggesting that the formation of LLPS droplets may promote higher-order assembly of N protein for transcription, replication and packaging. Together this study expands our understanding of the multiple functions of N protein in SARS-CoV-2.
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Affiliation(s)
- Yan Wang
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Xiaobin Ling
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Chong Zhang
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Jian Zou
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Bingnan Luo
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Yongbo Luo
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Xinyu Jia
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Guowen Jia
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Minghua Zhang
- College of Polymer Science and Engineering, Sichuan University, Chengdu, 610065, Sichuan, China
| | - Junchao Hu
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Ting Liu
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Yuanfeiyi Wang
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Kefeng Lu
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, 200438, China.
| | - Cong Liu
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.
- State Key Laboratory of Bio-Organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, National Clinical Research Center for Geriatrics and Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, 610044, Sichuan, China.
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15
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Hu S, Fujita-Fujiharu Y, Sugita Y, Wendt L, Muramoto Y, Nakano M, Hoenen T, Noda T. Cryoelectron microscopic structure of the nucleoprotein-RNA complex of the European filovirus, Lloviu virus. PNAS NEXUS 2023; 2:pgad120. [PMID: 37124400 PMCID: PMC10139700 DOI: 10.1093/pnasnexus/pgad120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/17/2023] [Accepted: 03/27/2023] [Indexed: 05/02/2023]
Abstract
Lloviu virus (LLOV) is a novel filovirus detected in Schreiber's bats in Europe. The isolation of the infectious LLOV from bats has raised public health concerns. However, the virological and molecular characteristics of LLOV remain largely unknown. The nucleoprotein (NP) of LLOV encapsidates the viral genomic RNA to form a helical NP-RNA complex, which acts as a scaffold for nucleocapsid formation and de novo viral RNA synthesis. In this study, using single-particle cryoelectron microscopy, we determined two structures of the LLOV NP-RNA helical complex, comprising a full-length and a C-terminally truncated NP. The two helical structures were identical, demonstrating that the N-terminal region determines the helical arrangement of the NP. The LLOV NP-RNA protomers displayed a structure similar to that in the Ebola and Marburg virus, but the spatial arrangements in the helix differed. Structure-based mutational analysis identified amino acids involved in the helical assembly and viral RNA synthesis. These structures advance our understanding of the filovirus nucleocapsid formation and provide a structural basis for the development of antifiloviral therapeutics.
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Affiliation(s)
- Shangfan Hu
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Yoko Fujita-Fujiharu
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Yukihiko Sugita
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Hakubi Center for Advanced Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Lisa Wendt
- Laboratory for Integrative Cell and Infection Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Insel Riems, Greifswald 17493, Germany
| | - Yukiko Muramoto
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Masahiro Nakano
- Laboratory of Ultrastructural Virology, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Thomas Hoenen
- Laboratory for Integrative Cell and Infection Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Insel Riems, Greifswald 17493, Germany
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16
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Whitehead JD, Grimes JM, Keown JR. Structural and biophysical characterization of the Borna disease virus 1 phosphoprotein. Acta Crystallogr F Struct Biol Commun 2023; 79:51-60. [PMID: 36862093 PMCID: PMC9979977 DOI: 10.1107/s2053230x23000717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/26/2023] [Indexed: 02/25/2023] Open
Abstract
Bornaviruses are RNA viruses with a mammalian, reptilian, and avian host range. The viruses infect neuronal cells and in rare cases cause a lethal encephalitis. The family Bornaviridae are part of the Mononegavirales order of viruses, which contain a nonsegmented viral genome. Mononegavirales encode a viral phosphoprotein (P) that binds both the viral polymerase (L) and the viral nucleoprotein (N). The P protein acts as a molecular chaperone and is required for the formation of a functional replication/transcription complex. In this study, the structure of the oligomerization domain of the phosphoprotein determined by X-ray crystallography is reported. The structural results are complemented with biophysical characterization using circular dichroism, differential scanning calorimetry and small-angle X-ray scattering. The data reveal the phosphoprotein to assemble into a stable tetramer, with the regions outside the oligomerization domain remaining highly flexible. A helix-breaking motif is observed between the α-helices at the midpoint of the oligomerization domain that appears to be conserved across the Bornaviridae. These data provide information on an important component of the bornavirus replication complex.
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Affiliation(s)
- Jack D. Whitehead
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Jeremy R. Keown
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
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17
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Gérard FCA, Bourhis JM, Mas C, Branchard A, Vu DD, Varhoshkova S, Leyrat C, Jamin M. Structure and Dynamics of the Unassembled Nucleoprotein of Rabies Virus in Complex with Its Phosphoprotein Chaperone Module. Viruses 2022; 14:v14122813. [PMID: 36560817 PMCID: PMC9786881 DOI: 10.3390/v14122813] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
As for all non-segmented negative RNA viruses, rabies virus has its genome packaged in a linear assembly of nucleoprotein (N), named nucleocapsid. The formation of new nucleocapsids during virus replication in cells requires the production of soluble N protein in complex with its phosphoprotein (P) chaperone. In this study, we reconstituted a soluble heterodimeric complex between an armless N protein of rabies virus (RABV), lacking its N-terminal subdomain (NNT-ARM), and a peptide encompassing the N0 chaperon module of the P protein. We showed that the chaperone module undergoes a disordered-order transition when it assembles with N0 and measured an affinity in the low nanomolar range using a competition assay. We solved the crystal structure of the complex at a resolution of 2.3 Å, unveiling the details of the conserved interfaces. MD simulations showed that both the chaperon module of P and RNA-mediated polymerization reduced the ability of the RNA binding cavity to open and close. Finally, by reconstituting a complex with full-length P protein, we demonstrated that each P dimer could independently chaperon two N0 molecules.
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Affiliation(s)
- Francine C. A. Gérard
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Jean-Marie Bourhis
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Caroline Mas
- Integrated Structural Biology Grenoble (ISBG), Université Grenoble Alpes, CNRS, CEA, EMBL, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Anaïs Branchard
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Duc Duy Vu
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Sylvia Varhoshkova
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Cédric Leyrat
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
- Correspondence: (C.L.); (M.J.)
| | - Marc Jamin
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
- Correspondence: (C.L.); (M.J.)
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18
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Madhu P, Davey NE, Ivarsson Y. How viral proteins bind short linear motifs and intrinsically disordered domains. Essays Biochem 2022; 66:EBC20220047. [PMID: 36504386 DOI: 10.1042/ebc20220047] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 02/11/2024]
Abstract
Viruses are the obligate intracellular parasites that exploit the host cellular machinery to replicate their genome. During the viral life cycle viruses manipulate the host cell through interactions with host proteins. Many of these protein-protein interactions are mediated through the recognition of host globular domains by short linear motifs (SLiMs), or longer intrinsically disordered domains (IDD), in the disordered regions of viral proteins. However, viruses also employ their own globular domains for binding to SLiMs and IDDs present in host proteins or virus proteins. In this review, we focus on the different strategies adopted by viruses to utilize proteins or protein domains for binding to the disordered regions of human or/and viral ligands. With a set of examples, we describe viral domains that bind human SLiMs. We also provide examples of viral proteins that bind to SLiMs, or IDDs, of viral proteins as a part of complex assembly and regulation of protein functions. The protein-protein interactions are often crucial for viral replication, and may thus offer possibilities for innovative inhibitor design.
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Affiliation(s)
- Priyanka Madhu
- Department of Chemistry, BMC, Uppsala University, Uppsala, Sweden
| | - Norman E Davey
- Division of Cancer Biology, The Institute of Cancer Research, London, U.K
| | - Ylva Ivarsson
- Department of Chemistry, BMC, Uppsala University, Uppsala, Sweden
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19
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Zinzula L, Mereu AM, Orsini M, Seeleitner C, Bracher A, Nagy I, Baumeister W. Ebola and Marburg virus VP35 coiled-coil validated as antiviral target by tripartite split-GFP complementation. iScience 2022; 25:105354. [PMID: 36325051 PMCID: PMC9619376 DOI: 10.1016/j.isci.2022.105354] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/30/2022] Open
Abstract
Ebola virus (EBOV) and Marburg virus (MARV) are highly pathogenic viruses in humans, against which approved antivirals are lacking. During EBOV and MARV infection, coiled-coil mediated oligomerization is essential for the virion protein 35 (VP35) polymerase co-factor function and type I interferon antagonism, making VP35 coiled-coil an elective drug target. We established a tripartite split-green fluorescent protein (GFP) fluorescence complementation (FC) system based on recombinant GFP-tagged EBOV and MARV VP35, which probes VP35 coiled-coil assembly by monitoring fluorescence on E. coli colonies, or in vitro in 96/384-multiwell. Oligomerization-defective VP35 mutants showed that correct coiled-coil knobs-into-holes pairing within VP35 oligomer is pre-requisite for GFP tags and GFP detector to reconstitute fluorescing full-length GFP. The method was validated by screening a small compound library, which identified Myricetin and 4,5,6,7-Tetrabromobenzotriazole as inhibitors of EBOV and MARV VP35 oligomerization-dependent FC with low-micromolar IC50 values. These findings substantiate the VP35 coiled-coil value as antiviral target. Ebola and Marburg virus VP35 oligomerize via trimeric and tetrameric coiled-coil VP35 coiled-coil assembly triggers fluorescence of a tripartite split-GFP system Mutations perturbing VP35 coiled-coil hamper split-GFP complementation Myricetin and TBBT inhibit split-GFP complementation mediated by VP35 coiled-coil
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Affiliation(s)
- Luca Zinzula
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
- Corresponding author
| | - Angela Maria Mereu
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Massimiliano Orsini
- Istituto Zooprofilattico Sperimentale delle Venezie, Department of Risk Analysis and Public Health Surveillance, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Christine Seeleitner
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- The Max-Planck Institute of Biochemistry, Department of Cellular Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - István Nagy
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- The Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
- Corresponding author
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20
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Borna Disease Virus 1 Phosphoprotein Forms a Tetramer and Interacts with Host Factors Involved in DNA Double-Strand Break Repair and mRNA Processing. Viruses 2022; 14:v14112358. [PMID: 36366462 PMCID: PMC9692295 DOI: 10.3390/v14112358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 01/31/2023] Open
Abstract
Determining the structural organisation of viral replication complexes and unravelling the impact of infection on cellular homeostasis represent important challenges in virology. This may prove particularly useful when confronted with viruses that pose a significant threat to human health, that appear unique within their family, or for which knowledge is scarce. Among Mononegavirales, bornaviruses (family Bornaviridae) stand out due to their compact genomes and their nuclear localisation for replication. The recent recognition of the zoonotic potential of several orthobornaviruses has sparked a surge of interest in improving our knowledge on this viral family. In this work, we provide a complete analysis of the structural organisation of Borna disease virus 1 (BoDV-1) phosphoprotein (P), an important cofactor for polymerase activity. Using X-ray diffusion and diffraction experiments, we revealed that BoDV-1 P adopts a long coiled-coil α-helical structure split into two parts by an original β-strand twist motif, which is highly conserved across the members of whole Orthobornavirus genus and may regulate viral replication. In parallel, we used BioID to determine the proximal interactome of P in living cells. We confirmed previously known interactors and identified novel proteins linked to several biological processes such as DNA repair or mRNA metabolism. Altogether, our study provides important structure/function cues, which may improve our understanding of BoDV-1 pathogenesis.
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21
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Yuan B, Peng Q, Cheng J, Wang M, Zhong J, Qi J, Gao GF, Shi Y. Structure of the Ebola virus polymerase complex. Nature 2022; 610:394-401. [PMID: 36171293 PMCID: PMC9517992 DOI: 10.1038/s41586-022-05271-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 08/24/2022] [Indexed: 11/24/2022]
Abstract
Filoviruses, including Ebola virus, pose an increasing threat to the public health. Although two therapeutic monoclonal antibodies have been approved to treat the Ebola virus disease1,2, there are no approved broadly reactive drugs to control diverse filovirus infection. Filovirus has a large polymerase (L) protein and the cofactor viral protein 35 (VP35), which constitute the basic functional unit responsible for virus genome RNA synthesis3. Owing to its conservation, the L-VP35 polymerase complex is a promising target for broadly reactive antiviral drugs. Here we determined the structure of Ebola virus L protein in complex with tetrameric VP35 using cryo-electron microscopy (state 1). Structural analysis revealed that Ebola virus L possesses a filovirus-specific insertion element that is essential for RNA synthesis, and that VP35 interacts extensively with the N-terminal region of L by three protomers of the VP35 tetramer. Notably, we captured the complex structure in a second conformation with the unambiguous priming loop and supporting helix away from polymerase active site (state 2). Moreover, we demonstrated that the century-old drug suramin could inhibit the activity of the Ebola virus polymerase in an enzymatic assay. The structure of the L-VP35-suramin complex reveals that suramin can bind at the highly conserved NTP entry channel to prevent substrates from entering the active site. These findings reveal the mechanism of Ebola virus replication and may guide the development of more powerful anti-filovirus drugs.
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Affiliation(s)
- Bin Yuan
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Peng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinlong Cheng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Min Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jin Zhong
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - George F Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- Center for Influenza Research and Early-Warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China.
| | - Yi Shi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
- Center for Influenza Research and Early-Warning (CASCIRE), CAS-TWAS Center of Excellence for Emerging Infectious Disease (CEEID), Chinese Academy of Sciences, Beijing, China.
- Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China.
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22
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Wu C, Holehouse AS, Leung DW, Amarasinghe GK, Dutch RE. Liquid Phase Partitioning in Virus Replication: Observations and Opportunities. Annu Rev Virol 2022; 9:285-306. [PMID: 35709511 PMCID: PMC11331907 DOI: 10.1146/annurev-virology-093020-013659] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viruses frequently carry out replication in specialized compartments within cells. The effect of these structures on virus replication is poorly understood. Recent research supports phase separation as a foundational principle for organization of cellular components with the potential to influence viral replication. In this review, phase separation is described in the context of formation of viral replication centers, with an emphasis on the nonsegmented negative-strand RNA viruses. Consideration is given to the interplay between phase separation and the critical processes of viral transcription and genome replication, and the role of these regions in pathogen-host interactions is discussed. Finally, critical questions that must be addressed to fully understand how phase separation influences viral replication and the viral life cycle are presented, along with information about new approaches that could be used to make important breakthroughs in this emerging field.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Science and Engineering Living Systems, Washington University, St. Louis, Missouri, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA;
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Evidence for Viral mRNA Export from Ebola Virus Inclusion Bodies by the Nuclear RNA Export Factor NXF1. J Virol 2022; 96:e0090022. [PMID: 36040180 PMCID: PMC9517727 DOI: 10.1128/jvi.00900-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many negative-sense RNA viruses, including the highly pathogenic Ebola virus (EBOV), use cytoplasmic inclusion bodies (IBs) for viral RNA synthesis. However, it remains unclear how viral mRNAs are exported from these IBs for subsequent translation. We recently demonstrated that the nuclear RNA export factor 1 (NXF1) is involved in a late step in viral protein expression, i.e., downstream of viral mRNA transcription, and proposed it to be involved in this mRNA export process. We now provide further evidence for this function by showing that NXF1 is not required for translation of viral mRNAs, thus pinpointing its function to a step between mRNA transcription and translation. We further show that RNA binding of both NXF1 and EBOV NP is necessary for export of NXF1 from IBs, supporting a model in which NP hands viral mRNA over to NXF1 for export. Mapping of NP-NXF1 interactions allowed refinement of this model, revealing two separate interaction sites, one of them directly involving the RNA binding cleft of NP, even though these interactions are RNA-independent. Immunofluorescence analyses demonstrated that individual NXF1 domains are sufficient for its recruitment into IBs, and complementation assays helped to define NXF1 domains important for its function in the EBOV life cycle. Finally, we show that NXF1 is also required for protein expression of other viruses that replicate in cytoplasmic IBs, including Lloviu and Junín virus. These data suggest a role for NXF1 in viral mRNA export from IBs for various viruses, making it a potential target for broadly active antivirals. IMPORTANCE Filoviruses such as the Ebola virus (EBOV) cause severe hemorrhagic fevers with high case fatality rates and limited treatment options. The identification of virus-host cell interactions shared among several viruses would represent promising targets for the development of broadly active antivirals. In this study, we reveal the mechanistic details of how EBOV usurps the nuclear RNA export factor 1 (NXF1) to export viral mRNAs from viral inclusion bodies (IBs). We further show that NXF1 is not only required for the EBOV life cycle but also necessary for other viruses known to replicate in cytoplasmic IBs, including the filovirus Lloviu virus and the highly pathogenic arenavirus Junín virus. This suggests NXF1 as a promising target for the development of broadly active antivirals.
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24
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Abstract
Filovirus-infected cells are characterized by typical cytoplasmic inclusion bodies (IBs) located in the perinuclear region. The formation of these IBs is induced mainly by the accumulation of the filoviral nucleoprotein NP, which recruits the other nucleocapsid proteins, the polymerase co-factor VP35, the polymerase L, the transcription factor VP30 and VP24 via direct or indirect protein-protein interactions. Replication of the negative-strand RNA genomes by the viral polymerase L and VP35 occurs in the IBs, resulting in the synthesis of positive-strand genomes, which are encapsidated by NP, thus forming ribonucleoprotein complexes (antigenomic RNPs). These newly formed antigenomic RNPs in turn serve as templates for the synthesis of negative-strand RNA genomes that are also encapsidated by NP (genomic RNPs). Still in the IBs, genomic RNPs mature into tightly packed transport-competent nucleocapsids (NCs) by the recruitment of the viral protein VP24. NCs are tightly coiled left-handed helices whose structure is mainly determined by the multimerization of NP at its N-terminus, and these helices form the inner layer of the NCs. The RNA genome is fixed by 2 lobes of the NP N-terminus and is thus guided by individual NP molecules along the turns of the helix. Direct interaction of the NP C-terminus with the VP35 and VP24 molecules forms the outer layer of the NCs. Once formed, NCs that are located at the border of the IBs recruit actin polymerization machinery to one of their ends to drive their transport to budding sites for their envelopment and final release. Here, we review the current knowledge on the structure, assembly, and transport of filovirus NCs.
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Affiliation(s)
- Olga Dolnik
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
| | - Stephan Becker
- Institute of Virology, Philipps-University Marburg, Marburg, Germany
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25
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Wang F, Sheppard CM, Mistry B, Staller E, Barclay WS, Grimes JM, Fodor E, Fan H. The C-terminal LCAR of host ANP32 proteins interacts with the influenza A virus nucleoprotein to promote the replication of the viral RNA genome. Nucleic Acids Res 2022; 50:5713-5725. [PMID: 35639917 PMCID: PMC9177957 DOI: 10.1093/nar/gkac410] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 04/11/2022] [Accepted: 05/09/2022] [Indexed: 12/12/2022] Open
Abstract
The segmented negative-sense RNA genome of influenza A virus is assembled into ribonucleoprotein complexes (RNP) with viral RNA-dependent RNA polymerase and nucleoprotein (NP). It is in the context of these RNPs that the polymerase transcribes and replicates viral RNA (vRNA). Host acidic nuclear phosphoprotein 32 (ANP32) family proteins play an essential role in vRNA replication by mediating the dimerization of the viral polymerase via their N-terminal leucine-rich repeat (LRR) domain. However, whether the C-terminal low-complexity acidic region (LCAR) plays a role in RNA synthesis remains unknown. Here, we report that the LCAR is required for viral genome replication during infection. Specifically, we show that the LCAR directly interacts with NP and this interaction is mutually exclusive with RNA. Furthermore, we show that the replication of a short vRNA-like template that can be replicated in the absence of NP is less sensitive to LCAR truncations compared with the replication of full-length vRNA segments which is NP-dependent. We propose a model in which the LCAR interacts with NP to promote NP recruitment to nascent RNA during influenza virus replication, ensuring the co-replicative assembly of RNA into RNPs.
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Affiliation(s)
- Fangzheng Wang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Carol M Sheppard
- Department of Infectious Disease, Faculty of Medicine, Imperial College, London, UK
| | - Bhakti Mistry
- Department of Infectious Disease, Faculty of Medicine, Imperial College, London, UK
| | - Ecco Staller
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.,Department of Infectious Disease, Faculty of Medicine, Imperial College, London, UK
| | - Wendy S Barclay
- Department of Infectious Disease, Faculty of Medicine, Imperial College, London, UK
| | - Jonathan M Grimes
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Oxford, UK.,Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, UK
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Haitian Fan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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26
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Alizadeh M, Amini-Khoei H, Tahmasebian S, Ghatrehsamani M, Ghatreh Samani K, Edalatpanah Y, Rostampur S, Salehi M, Ghasemi-Dehnoo M, Azadegan-Dehkordi F, Sanami S, Bagheri N. Designing a novel multi‑epitope vaccine against Ebola virus using reverse vaccinology approach. Sci Rep 2022; 12:7757. [PMID: 35545650 PMCID: PMC9094136 DOI: 10.1038/s41598-022-11851-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/19/2022] [Indexed: 12/18/2022] Open
Abstract
Ebola virus (EBOV) is a dangerous zoonotic infectious disease. To date, more than 25 EBOV outbreaks have been documented, the majority of which have occurred in Central Africa. The rVSVG-ZEBOV-GP vaccine (ERVEBO), a live attenuated vaccine, has been approved by the US Food and Drug Administration (FDA) to combat EBOV. Because of the several drawbacks of live attenuated vaccines, multi-epitope vaccines probably appear to be safer than live attenuated vaccines. In this work, we employed immunoinformatics tools to design a multi-epitope vaccine against EBOV. We collected sequences of VP35, VP24, VP30, VP40, GP, and NP proteins from the NCBI database. T-cell and linear B-cell epitopes from target proteins were identified and tested for antigenicity, toxicity, allergenicity, and conservancy. The selected epitopes were then linked together in the vaccine's primary structure using appropriate linkers, and the 50S ribosomal L7/L12 (Locus RL7 MYCTU) sequence was added as an adjuvant to the vaccine construct's N-terminal. The physicochemical, antigenicity, and allergenicity parameters of the vaccine were all found to be satisfactory. The 3D model of the vaccine was predicted, refined, and validated. The vaccine construct had a stable and strong interaction with toll-like receptor 4 (TLR4) based on molecular docking and molecular dynamic simulation (MD) analysis. The results of codon optimization and in silico cloning revealed that the proposed vaccine was highly expressed in Escherichia coli (E. coli). The findings of this study are promising; however, experimental validations should be carried out to confirm these findings.
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Affiliation(s)
- Morteza Alizadeh
- Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Hossein Amini-Khoei
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Shahram Tahmasebian
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mahdi Ghatrehsamani
- Department of Microbiology and Immunology, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Keihan Ghatreh Samani
- Clinical Biochemistry Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Yadolah Edalatpanah
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Susan Rostampur
- Department of Molecular Medicine, School of Advanced Medical Science and Technology, Shiraz University of Medical Science, Shiraz, Iran
| | - Majid Salehi
- Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Maryam Ghasemi-Dehnoo
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Fatemeh Azadegan-Dehkordi
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Samira Sanami
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran.
| | - Nader Bagheri
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran.
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27
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Galão RP, Wilson H, Schierhorn KL, Debeljak F, Bodmer BS, Goldhill D, Hoenen T, Wilson SJ, Swanson CM, Neil SJD. TRIM25 and ZAP target the Ebola virus ribonucleoprotein complex to mediate interferon-induced restriction. PLoS Pathog 2022; 18:e1010530. [PMID: 35533151 PMCID: PMC9119685 DOI: 10.1371/journal.ppat.1010530] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 05/19/2022] [Accepted: 04/18/2022] [Indexed: 12/14/2022] Open
Abstract
Ebola virus (EBOV) causes highly pathogenic disease in primates. Through screening a library of human interferon-stimulated genes (ISGs), we identified TRIM25 as a potent inhibitor of EBOV transcription-and-replication-competent virus-like particle (trVLP) propagation. TRIM25 overexpression inhibited the accumulation of viral genomic and messenger RNAs independently of the RNA sensor RIG-I or secondary proinflammatory gene expression. Deletion of TRIM25 strongly attenuated the sensitivity of trVLPs to inhibition by type-I interferon. The antiviral activity of TRIM25 required ZAP and the effect of type-I interferon was modulated by the CpG dinucleotide content of the viral genome. We find that TRIM25 interacts with the EBOV vRNP, resulting in its autoubiquitination and ubiquitination of the viral nucleoprotein (NP). TRIM25 is recruited to incoming vRNPs shortly after cell entry and leads to dissociation of NP from the vRNA. We propose that TRIM25 targets the EBOV vRNP, exposing CpG-rich viral RNA species to restriction by ZAP.
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Affiliation(s)
- Rui Pedro Galão
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
| | - Harry Wilson
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
| | - Kristina L. Schierhorn
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
| | - Franka Debeljak
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
| | - Bianca S. Bodmer
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Daniel Goldhill
- Section of Virology, Department of Medicine, Imperial College London, London, United Kingdom
| | - Thomas Hoenen
- Institute for Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Sam J. Wilson
- MRC Centre for Virus Research, University of Glasgow, United Kingdom
| | - Chad M. Swanson
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
| | - Stuart J. D. Neil
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King’s College London, United Kingdom
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28
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van Tol S, Kalveram B, Ilinykh PA, Ronk A, Huang K, Aguilera-Aguirre L, Bharaj P, Hage A, Atkins C, Giraldo MI, Wakamiya M, Gonzalez-Orozco M, Warren AN, Bukreyev A, Freiberg AN, Rajsbaum R. Ubiquitination of Ebola virus VP35 at lysine 309 regulates viral transcription and assembly. PLoS Pathog 2022; 18:e1010532. [PMID: 35533195 PMCID: PMC9119628 DOI: 10.1371/journal.ppat.1010532] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 05/19/2022] [Accepted: 04/18/2022] [Indexed: 11/18/2022] Open
Abstract
Ebola virus (EBOV) VP35 is a polyfunctional protein involved in viral genome packaging, viral polymerase function, and host immune antagonism. The mechanisms regulating VP35's engagement in different functions are not well-understood. We previously showed that the host E3 ubiquitin ligase TRIM6 ubiquitinates VP35 at lysine 309 (K309) to facilitate virus replication. However, how K309 ubiquitination regulates the function of VP35 as the viral polymerase co-factor and the precise stage(s) of the EBOV replication cycle that require VP35 ubiquitination are not known. Here, we generated recombinant EBOVs encoding glycine (G) or arginine (R) mutations at VP35/K309 (rEBOV-VP35/K309G/-R) and show that both mutations prohibit VP35/K309 ubiquitination. The K309R mutant retains dsRNA binding and efficient type-I Interferon (IFN-I) antagonism due to the basic residue conservation. The rEBOV-VP35/K309G mutant loses the ability to efficiently antagonize the IFN-I response, while the rEBOV-VP35/K309R mutant's suppression is enhanced. The replication of both mutants was significantly attenuated in both IFN-competent and -deficient cells due to impaired interactions with the viral polymerase. The lack of ubiquitination on VP35/K309 or TRIM6 deficiency disrupts viral transcription with increasing severity along the transcriptional gradient. This disruption of the transcriptional gradient results in unbalanced viral protein production, including reduced synthesis of the viral transcription factor VP30. In addition, lack of ubiquitination on K309 results in enhanced interactions with the viral nucleoprotein and premature nucleocapsid packaging, leading to dysregulation of virus assembly. Overall, we identified a novel role of VP35 ubiquitination in coordinating viral transcription and assembly.
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Affiliation(s)
- Sarah van Tol
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Birte Kalveram
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Philipp A. Ilinykh
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Adam Ronk
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kai Huang
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Leopoldo Aguilera-Aguirre
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Preeti Bharaj
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Adam Hage
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Colm Atkins
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Maria I. Giraldo
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Maki Wakamiya
- Transgenic Mouse Core Facility, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Maria Gonzalez-Orozco
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Abbey N. Warren
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Alexander Bukreyev
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Ricardo Rajsbaum
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
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29
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Fang J, Pietzsch C, Tsaprailis G, Crynen G, Cho KF, Ting AY, Bukreyev A, de la Torre JC, Saphire EO. Functional interactomes of the Ebola virus polymerase identified by proximity proteomics in the context of viral replication. Cell Rep 2022; 38:110544. [PMID: 35320713 PMCID: PMC10496643 DOI: 10.1016/j.celrep.2022.110544] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/26/2021] [Accepted: 03/01/2022] [Indexed: 11/21/2022] Open
Abstract
Ebola virus (EBOV) critically depends on the viral polymerase to replicate and transcribe the viral RNA genome in the cytoplasm of host cells, where cellular factors can antagonize or facilitate the virus life cycle. Here we leverage proximity proteomics and conduct a small interfering RNA (siRNA) screen to define the functional interactome of EBOV polymerase. As a proof of principle, we validate two cellular mRNA decay factors from 35 identified host factors: eukaryotic peptide chain release factor subunit 3a (eRF3a/GSPT1) and up-frameshift protein 1 (UPF1). Our data suggest that EBOV can subvert restrictions of cellular mRNA decay and repurpose GSPT1 and UPF1 to promote viral replication. Treating EBOV-infected human hepatocytes with a drug candidate that targets GSPT1 for degradation significantly reduces viral RNA load and particle production. Our work demonstrates the utility of proximity proteomics to capture the functional host interactome of the EBOV polymerase and to illuminate host-dependent regulation of viral RNA synthesis.
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Affiliation(s)
- Jingru Fang
- La Jolla Institute for Immunology, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Colette Pietzsch
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77555, USA
| | | | - Gogce Crynen
- Bioinformatics and Statistics Core, Scripps Research, Jupiter, FL 33458, USA
| | - Kelvin Frank Cho
- Cancer Biology Program, Stanford University, Stanford, CA 94305, USA
| | - Alice Y Ting
- Department of Genetics, Department of Biology, and Department of Chemistry, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Alexander Bukreyev
- Department of Pathology and Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA.
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Wang Y, Binning JM, Pintilie GD, Chiu W, Amarasinghe GK, Leung DW, Su Z. Cryo-EM analysis of Ebola virus nucleocapsid-like assembly. STAR Protoc 2022; 3:101030. [PMID: 34977676 PMCID: PMC8689349 DOI: 10.1016/j.xpro.2021.101030] [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] [Indexed: 02/05/2023] Open
Abstract
This protocol describes the reconstitution of the filamentous Ebola virus nucleocapsid-like assembly in vitro. This is followed by solving the cryo-EM structure using helical reconstruction, and flexible fitting of the existing model into the 5.8 Å cryo-EM map. The protocol can be applied to other filamentous viral protein assemblies, particularly those with high flexibility and moderate resolution maps, which present technical challenges to model building. For complete details on the use and execution of this profile, please refer to Su et al. (2018). Preparation of Ebola nucleocapsid-like assembly for cryo-EM Cryo-EM helical reconstruction of flexible filamentous protein assembly Flexible fitting of protein model into cryo-EM density at moderate resolution
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Affiliation(s)
- Yan Wang
- The State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610044, China
| | - Jennifer M. Binning
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Grigore D. Pintilie
- Department of Bioengineering and Department of Microbiology and Immunology, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
- Division of Cryo-EM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Department of Bioengineering and Department of Microbiology and Immunology, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
- Division of Cryo-EM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Corresponding author
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Corresponding author
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610044, China
- Corresponding author
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Fujita-Fujiharu Y, Sugita Y, Takamatsu Y, Houri K, Igarashi M, Muramoto Y, Nakano M, Tsunoda Y, Taniguchi I, Becker S, Noda T. Structural insight into Marburg virus nucleoprotein-RNA complex formation. Nat Commun 2022; 13:1191. [PMID: 35246537 PMCID: PMC8897395 DOI: 10.1038/s41467-022-28802-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 02/10/2022] [Indexed: 11/15/2022] Open
Abstract
The nucleoprotein (NP) of Marburg virus (MARV), a close relative of Ebola virus (EBOV), encapsidates the single-stranded, negative-sense viral genomic RNA (vRNA) to form the helical NP-RNA complex. The NP-RNA complex constitutes the core structure for the assembly of the nucleocapsid that is responsible for viral RNA synthesis. Although appropriate interactions among NPs and RNA are required for the formation of nucleocapsid, the structural basis of the helical assembly remains largely elusive. Here, we show the structure of the MARV NP-RNA complex determined using cryo-electron microscopy at a resolution of 3.1 Å. The structures of the asymmetric unit, a complex of an NP and six RNA nucleotides, was very similar to that of EBOV, suggesting that both viruses share common mechanisms for the nucleocapsid formation. Structure-based mutational analysis of both MARV and EBOV NPs identified key residues for helical assembly and subsequent viral RNA synthesis. Importantly, most of the residues identified were conserved in both viruses. These findings provide a structural basis for understanding the nucleocapsid formation and contribute to the development of novel antivirals against MARV and EBOV.
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Affiliation(s)
- Yoko Fujita-Fujiharu
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Yukihiko Sugita
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Hakubi Center for Advanced Research, Kyoto University, Kyoto, 606-8501, Japan
| | - Yuki Takamatsu
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Department of Virology I, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama-city, Tokyo, 208-0011, Japan
| | - Kazuya Houri
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Manabu Igarashi
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, 001-0020, Japan
| | - Yukiko Muramoto
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Masahiro Nakano
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Yugo Tsunoda
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Ichiro Taniguchi
- Laboratory of RNA system, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Stephan Becker
- Institute of Virology, University of Marburg, 35043, Marburg, Germany
- German Center for Infection Research (DZIF), Marburg-Gießen-Langen Site, University of Marburg, 35043, Marburg, Germany
| | - Takeshi Noda
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
- Laboratory of Ultrastructural Virology, Graduate School of Biostudies, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
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Dong X, Wang X, Xie M, Wu W, Chen Z. Structural Basis of Human Parainfluenza Virus 3 Unassembled Nucleoprotein in Complex with Its Viral Chaperone. J Virol 2022; 96:e0164821. [PMID: 34730394 PMCID: PMC8791282 DOI: 10.1128/jvi.01648-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/30/2021] [Indexed: 11/20/2022] Open
Abstract
Human parainfluenza virus 3 (HPIV3) belongs to the Paramyxoviridae, causing annual worldwide epidemics of respiratory diseases, especially in newborns and infants. The core components consist of just three viral proteins: nucleoprotein (N), phosphoprotein (P), and RNA polymerase (L), playing essential roles in replication and transcription of HPIV3 as well as other paramyxoviruses. Viral genome encapsidated by N is as a template and recognized by RNA-dependent RNA polymerase complex composed of L and P. The offspring RNA also needs to assemble with N to form nucleocapsids. The N is one of the most abundant viral proteins in infected cells and chaperoned in the RNA-free form (N0) by P before encapsidation. In this study, we presented the structure of unassembled HPIV3 N0 in complex with the N-terminal portion of the P, revealing the molecular details of the N0 and the conserved N0-P interaction. Combined with biological experiments, we showed that the P binds to the C-terminal domain of N0 mainly by hydrophobic interaction and maintains the unassembled conformation of N by interfering with the formation of N-RNA oligomers, which might be a target for drug development. Based on the complex structure, we developed a method to obtain the monomeric N0. Furthermore, we designed a P-derived fusion peptide with 10-fold higher affinity, which hijacked the N and interfered with the binding of the N to RNA significantly. Finally, we proposed a model of conformational transition of N from the unassembled state to the assembled state, which helped to further understand viral replication. IMPORTANCE Human parainfluenza virus 3 (HPIV3) causes annual epidemics of respiratory diseases, especially in newborns and infants. For the replication of HPIV3 and other paramyxoviruses, only three viral proteins are required: phosphoprotein (P), RNA polymerase (L), and nucleoprotein (N). Here, we report the crystal structure of the complex of N and its chaperone P. We describe in detail how P acts as a chaperone to maintain the unassembled conformation of N. Our analysis indicated that the interaction between P and N is conserved and mediated by hydrophobicity, which can be used as a target for drug development. We obtained a high-affinity P-derived peptide inhibitor, specifically targeted N, and greatly interfered with the binding of the N to RNA, thereby inhibiting viral encapsidation and replication. In summary, our results provide new insights into the paramyxovirus genome replication and nucleocapsid assembly and lay the basis for drug development.
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Affiliation(s)
- Xiaofei Dong
- State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xue Wang
- State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Mengjia Xie
- State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology and Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing, China
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Corona A, Fanunza E, Salata C, Morwitzer MJ, Distinto S, Zinzula L, Sanna C, Frau A, Daino GL, Quartu M, Taglialatela-Scafati O, Rigano D, Reid S, Mirazimi A, Tramontano E. Cynarin blocks Ebola virus replication by counteracting VP35 inhibition of interferon-beta production. Antiviral Res 2022; 198:105251. [DOI: 10.1016/j.antiviral.2022.105251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/16/2021] [Accepted: 01/17/2022] [Indexed: 11/02/2022]
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The Nucleocapsid of Paramyxoviruses: Structure and Function of an Encapsidated Template. Viruses 2021; 13:v13122465. [PMID: 34960734 PMCID: PMC8708338 DOI: 10.3390/v13122465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 01/28/2023] Open
Abstract
Viruses of the Paramyxoviridae family share a common and complex molecular machinery for transcribing and replicating their genomes. Their non-segmented, negative-strand RNA genome is encased in a tight homopolymer of viral nucleoproteins (N). This ribonucleoprotein complex, termed a nucleocapsid, is the template of the viral polymerase complex made of the large protein (L) and its co-factor, the phosphoprotein (P). This review summarizes the current knowledge on several aspects of paramyxovirus transcription and replication, including structural and functional data on (1) the architecture of the nucleocapsid (structure of the nucleoprotein, interprotomer contacts, interaction with RNA, and organization of the disordered C-terminal tail of N), (2) the encapsidation of the genomic RNAs (structure of the nucleoprotein in complex with its chaperon P and kinetics of RNA encapsidation in vitro), and (3) the use of the nucleocapsid as a template for the polymerase complex (release of the encased RNA and interaction network allowing the progress of the polymerase complex). Finally, this review presents models of paramyxovirus transcription and replication.
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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: 27] [Impact Index Per Article: 9.0] [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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Vasudevan K, Thirumal Kumar D, Udhaya Kumar S, Saleem A, Nagasundaram N, Siva R, Tayubi IA, George Priya Doss C, Zayed H. A computational overview on phylogenetic characterization, pathogenic mutations, and drug targets for Ebola virus disease. Curr Opin Pharmacol 2021; 61:28-35. [PMID: 34563987 DOI: 10.1016/j.coph.2021.08.015] [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: 04/18/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 11/18/2022]
Abstract
The World Health Organization declared Ebola virus disease (EVD) as the major outbreak in the 20th century. EVD was first identified in 1976 in South Sudan and the Democratic Republic of the Congo. EVD was transmitted from infected fruit bats to humans via contact with infected animal body fluids. The Ebola virus (EBOV) has a genome size of ∼18,959 bp. It encodes seven distinct proteins: nucleoprotein (NP), glycoprotein (GP), viral proteins VP24, VP30, VP35, matrix protein VP40, and polymerase L is considered a prime target for potential antiviral strategies. The current US FDA-approved anti-EVD vaccine, ERVERBO, and the other equally effective anti-EBOV combinations of three fully human monoclonal antibodies such as REGN-EB3, primarily target the envelope glycoprotein. This work elaborates on the EBOV's phylogenetic structure and the crucial mutations associated with viral pathogenicity.
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Affiliation(s)
- Karthick Vasudevan
- School of Applied Sciences, Reva University, Bengaluru, Karnataka, India.
| | - D Thirumal Kumar
- Meenakshi Academy of Higher Education and Research, Chennai, Tamil Nadu, India.
| | - S Udhaya Kumar
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Aisha Saleem
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - N Nagasundaram
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - R Siva
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Iftikhar Aslam Tayubi
- Faculty of Computing and Information Technology, King Abdulaziz University, Rabigh, 21911, Saudi Arabia
| | - C George Priya Doss
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Hatem Zayed
- Department of Biomedical Sciences, College of Health and Sciences, QU Health, Qatar University, Doha, Qatar.
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Levine CB, Mire CE, Geisbert TW. Comparison of Zaire and Bundibugyo Ebolavirus Polymerase Complexes and Susceptibility to Antivirals through a Newly Developed Bundibugyo Minigenome System. J Virol 2021; 95:e0064321. [PMID: 34379503 PMCID: PMC8475504 DOI: 10.1128/jvi.00643-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/28/2021] [Indexed: 11/20/2022] Open
Abstract
Members of the genus Ebolavirus cause lethal disease in humans, with Zaire ebolavirus (EBOV) being the most pathogenic (up to 90% morality) and Bundibugyo ebolavirus (BDBV) the least pathogenic (∼37% mortality). Historically, there has been a lack of research on BDBV, and there is no means to study BDBV outside of a high-containment laboratory. Here, we describe a minigenome replication system to study BDBV transcription and compare the efficacy of small-molecule inhibitors between EBOV and BDBV. Using this system, we examined the ability of the polymerase complex proteins from EBOV and BDBV to interact and form a functional unit as well as the impact of the genomic untranslated ends, known to contain important signals for transcription (3'-untranslated region) and replication (5'-untranslated region). Various levels of compatibility were observed between proteins of the polymerase complex from each ebolavirus, resulting in differences in genome transcription efficiency. Most pronounced was the effect of the nucleoprotein and the 3'-untranslated region. These data suggest that there are intrinsic specificities in the polymerase complex and untranslated signaling regions that could offer insight regarding observed pathogenic differences. Further adding to the differences in the polymerase complexes, posttransfection/infection treatment with the compound remdesivir (GS-5734) showed a greater inhibitory effect against BDBV than EBOV. The delayed growth kinetics of BDBV and the greater susceptibility to polymerase inhibitors indicate that disruption of the polymerase complex is a viable target for therapeutics. IMPORTANCE Ebolavirus disease is a viral infection and is fatal in 25 to 90% of cases, depending on the viral species and the amount of supportive care available. Two species have caused outbreaks in the Democratic Republic of the Congo, Zaire ebolavirus (EBOV) and Bundibugyo ebolavirus (BDBV). Pathogenesis and clinical outcome differ between these two species, but there is still limited information regarding the viral mechanism for these differences. Previous studies suggested that BDBV replicates slower than EBOV, but it is unknown if this is due to differences in the polymerase complex and its role in transcription and replication. This study details the construction of a minigenome replication system that can be used in a biosafety level 2 laboratory. This system will be important for studying the polymerase complex of BDBV and comparing it with other filoviruses and can be used as a tool for screening inhibitors of viral growth.
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Affiliation(s)
- Corri B. Levine
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Chad E. Mire
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Thomas W. Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
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Salladini E, Gondelaud F, Nilsson JF, Pesce G, Bignon C, Murrali MG, Fabre R, Pierattelli R, Kajava AV, Horvat B, Gerlier D, Mathieu C, Longhi S. Identification of a Region in the Common Amino-terminal Domain of Hendra Virus P, V, and W Proteins Responsible for Phase Transition and Amyloid Formation. Biomolecules 2021; 11:1324. [PMID: 34572537 PMCID: PMC8471210 DOI: 10.3390/biom11091324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 12/14/2022] Open
Abstract
Henipaviruses are BSL-4 zoonotic pathogens responsible in humans for severe encephalitis. Their V protein is a key player in the evasion of the host innate immune response. We previously showed that the Henipavirus V proteins consist of a long intrinsically disordered N-terminal domain (NTD) and a β-enriched C-terminal domain (CTD). These terminals are critical for V binding to DDB1, which is a cellular protein that is a component of the ubiquitin ligase E3 complex, as well as binding to MDA5 and LGP2, which are two host sensors of viral RNA. Here, we serendipitously discovered that the Hendra virus V protein undergoes a liquid-to-hydrogel phase transition and identified the V region responsible for this phenomenon. This region, referred to as PNT3 and encompassing residues 200-310, was further investigated using a combination of biophysical and structural approaches. Congo red binding assays, together with negative-staining transmisison electron microscopy (TEM) studies, show that PNT3 forms amyloid-like fibrils. Fibrillation abilities are dramatically reduced in a rationally designed PNT3 variant in which a stretch of three contiguous tyrosines, falling within an amyloidogenic motif, were replaced by three alanines. Worthy to note, Congo red staining experiments provided hints that these amyloid-like fibrils form not only in vitro but also in cellula after transfection or infection. The present results set the stage for further investigations aimed at assessing the functional role of phase separation and fibrillation by the Henipavirus V proteins.
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Affiliation(s)
- Edoardo Salladini
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Frank Gondelaud
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Juliet F. Nilsson
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Giulia Pesce
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Christophe Bignon
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Maria Grazia Murrali
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Roxane Fabre
- Centre d’Immunologie de Marseille-Luminy (CIML), CNRS, Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille University, CEDEX 9, 13288 Marseille, France;
| | - Roberta Pierattelli
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Andrey V. Kajava
- Centre de Recherche en Biologie Cellulaire de Montpellier, UMR 5237, CNRS, Université Montpellier, 34293 Montpellier, France;
| | - Branka Horvat
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Denis Gerlier
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Cyrille Mathieu
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Sonia Longhi
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
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Banerjee G, Shokeen K, Chakraborty N, Agarwal S, Mitra A, Kumar S, Banerjee P. Modulation of immune response in Ebola virus disease. Curr Opin Pharmacol 2021; 60:158-167. [PMID: 34425392 DOI: 10.1016/j.coph.2021.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 06/29/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
Ebola virus disease targets and destroys immune cells, including macrophages and dendritic cells, leading to impairment of host response. After infection, a combination of strategies including alteration and evasion of immune response culminating in a strong inflammatory response can lead to multi-organ failure and death in most infected patients. This review discusses immune response dynamics, mainly focusing on how Ebola manipulates innate and adaptive immune responses and strategizes to thwart host immune responses. We also discuss the challenges and prospects of developing therapeutics and vaccines against Ebola.
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Affiliation(s)
- Goutam Banerjee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Kamal Shokeen
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Nilanjan Chakraborty
- Department of Microbiology, Adamas University, Kolkata, West Bengal, 700126, India
| | - Saumya Agarwal
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Arindam Mitra
- Department of Microbiology, Adamas University, Kolkata, West Bengal, 700126, India.
| | - Sachin Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
| | - Pratik Banerjee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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Zinzula L, Beck F, Klumpe S, Bohn S, Pfeifer G, Bollschweiler D, Nagy I, Plitzko JM, Baumeister W. Cryo-EM structure of the cetacean morbillivirus nucleoprotein-RNA complex. J Struct Biol 2021; 213:107750. [PMID: 34089875 DOI: 10.1016/j.jsb.2021.107750] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/17/2021] [Accepted: 05/31/2021] [Indexed: 11/30/2022]
Abstract
Cetacean morbillivirus (CeMV) is an emerging and highly infectious paramyxovirus that causes outbreaks in cetaceans and occasionally in pinnipeds, representing a major threat to biodiversity and conservation of endangered marine mammal populations in both hemispheres. As for all non-segmented, negative-sense, single-stranded RNA (ssRNA) viruses, the morbilliviral genome is enwrapped by thousands of nucleoprotein (N) protomers. Each bound to six ribonucleotides, N protomers assemble to form a helical ribonucleoprotein (RNP) complex that serves as scaffold for nucleocapsid formation and as template for viral replication and transcription. While the molecular details on RNP complexes elucidated in human measles virus (MeV) served as paradigm model for these processes in all members of the Morbillivirus genus, no structural information has been obtained from other morbilliviruses, nor has any CeMV structure been solved so far. We report the structure of the CeMV RNP complex, reconstituted in vitro upon binding of recombinant CeMV N to poly-adenine ssRNA hexamers and solved to 4.0 Å resolution by cryo-electron microscopy. In spite of the amino acid sequence similarity and consequently similar folding of the N protomer, the CeMV RNP complex exhibits different helical parameters as compared to previously reported MeV orthologs. The CeMV structure reveals exclusive interactions leading to more extensive protomer-RNA and protomer-protomer interfaces. We identified twelve residues, among those varying between CeMV strains, as putatively important for the stabilization of the RNP complex, which highlights the need to study the potential of CeMV N mutations that modulate nucleocapsid assembly to also affect viral phenotype and host adaptation.
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Affiliation(s)
- Luca Zinzula
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Florian Beck
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Sven Klumpe
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Stefan Bohn
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Günter Pfeifer
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Daniel Bollschweiler
- Max-Planck Institute of Biochemistry, Cryo-EM Facility, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - István Nagy
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Jürgen M Plitzko
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Am Klopferspitz 18, 82152 Martinsried, Germany.
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Xu C, Katyal N, Nesterova T, Perilla JR. Molecular determinants of Ebola nucleocapsid stability from molecular dynamics simulations. J Chem Phys 2021; 153:155102. [PMID: 33092380 DOI: 10.1063/5.0021491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ebola virus (EBOV) is a human pathogen with the ability to cause hemorrhagic fever and bleeding diathesis in hosts. The life cycle of EBOV depends on its nucleocapsid. The Ebola nucleocapsid consists of a helical assembly of nucleoproteins (NPs) encapsidating single-stranded viral RNA (ssRNA). Knowledge of the molecular determinants of Ebola nucleocapsid stability is essential for the development of therapeutics against EBOV. However, large degrees of freedom associated with the Ebola nucleocapsid helical assembly pose a computational challenge, thereby limiting the previous simulation studies to the level of monomers. In the present work, we have performed all atom molecular dynamics (MD) simulations of the helical assembly of EBOV nucleoproteins in the absence and presence of ssRNA. We found that ssRNA is essential for maintaining structural integrity of the nucleocapsid. Other molecular determinants observed to stabilize the nucleocapsid include NP-RNA and NP-NP interactions and ion distributions. Additionally, the structural and dynamical behavior of the nucleocapsid monomer depends on its position in the helical assembly. NP monomers present on the longitudinal edges of the helical tube are more exposed, flexible, and have weaker NP-NP interactions than those residing in the center. This work provides key structural features stabilizing the nucleocapsid that may serve as therapeutic targets.
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Affiliation(s)
- Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Nidhi Katyal
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Tanya Nesterova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Juan R Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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Fearns R. Negative‐strand RNA Viruses. Virology 2021. [DOI: 10.1002/9781119818526.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Crystal structure of human LC8 bound to a peptide from Ebola virus VP35. J Microbiol 2021; 59:410-416. [PMID: 33630249 DOI: 10.1007/s12275-021-0641-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 10/22/2022]
Abstract
Zaire ebolavirus, commonly called Ebola virus (EBOV), is an RNA virus that causes severe hemorrhagic fever with high mortality. Viral protein 35 (VP35) is a virulence factor encoded in the EBOV genome. VP35 inhibits host innate immune responses and functions as a critical cofactor for viral RNA replication. EBOV VP35 contains a short conserved motif that interacts with dynein light chain 8 (LC8), which serves as a regulatory hub protein by associating with various LC8-binding proteins. Herein, we present the crystal structure of human LC8 bound to the peptide comprising residues 67-76 of EBOV VP35. Two VP35 peptides were found to interact with homodimeric LC8 by extending the central β-sheets, constituting a 2:2 complex. Structural analysis demonstrated that the intermolecular binding between LC8 and VP35 is mainly sustained by a network of hydrogen bonds and supported by hydrophobic interactions in which Thr73 and Thr75 of VP35 are involved. These findings were verified by binding measurements using isothermal titration calorimetry. Biochemical analyses also verified that residues 67-76 of EBOV VP35 constitute a core region for interaction with LC8. In addition, corresponding motifs from other members of the genus Ebolavirus commonly bound to LC8 but with different binding affinities. Particularly, VP35 peptides originating from pathogenic species interacted with LC8 with higher affinity than those from noninfectious species, suggesting that the binding of VP35 to LC8 is associated with the pathogenicity of the Ebolavirus species.
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Keiser PT, Anantpadma M, Staples H, Carrion R, Davey RA. Automation of Infectious Focus Assay for Determination of Filovirus Titers and Direct Comparison to Plaque and TCID 50 Assays. Microorganisms 2021; 9:microorganisms9010156. [PMID: 33445537 PMCID: PMC7826780 DOI: 10.3390/microorganisms9010156] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/09/2021] [Accepted: 01/10/2021] [Indexed: 11/16/2022] Open
Abstract
Ongoing efforts to develop effective therapies against filoviruses rely, to different extents, on quantifying the amount of viable virus in samples by plaque, TCID50, and focus assays. Unfortunately, these techniques have inherent variance, and laboratory-specific preferences make direct comparison of data difficult. Additionally, human errors such as operator errors and subjective bias can further compound the differences in outcomes. To overcome these biases, we developed a computer-based automated image-processing method for a focus assay based on the open-source CellProfiler software platform, which enables high-throughput screening of many treatment samples at one time. We compared virus titers calculated using this platform to plaque and TCID50 assays using common stocks of virus for 3 major Filovirus species, Zaire ebolavirus, Sudan ebolavirus, and Marburg marburgvirus with each assay performed by multiple operators on multiple days. We show that plaque assays give comparable findings that differ by less than 3-fold. Focus-forming unit (FFU) and TCID50 assays differ by 10-fold or less from the plaque assays due a higher (FFU) and lower (TCID50) sensitivity. However, reproducibility and accuracy of each assay differs significantly with Neutral Red Agarose Overlay plaque assays and TCID50 with the lowest reproducibility due to subjective analysis and operator error. Both crystal violet methylcellulose overlay plaque assay and focus assays perform best for accuracy and the focus assay performs best for speed and throughput.
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Affiliation(s)
- Patrick T. Keiser
- Department of Microbiology, National Emerging Infectious Disease Laboratories, Boston University, Boston, MA 02215, USA; (P.T.K.); (M.A.)
- Disease Intervention & Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (H.S.); (R.C.)
| | - Manu Anantpadma
- Department of Microbiology, National Emerging Infectious Disease Laboratories, Boston University, Boston, MA 02215, USA; (P.T.K.); (M.A.)
- Disease Intervention & Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (H.S.); (R.C.)
| | - Hilary Staples
- Disease Intervention & Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (H.S.); (R.C.)
| | - Ricardo Carrion
- Disease Intervention & Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (H.S.); (R.C.)
| | - Robert A. Davey
- Department of Microbiology, National Emerging Infectious Disease Laboratories, Boston University, Boston, MA 02215, USA; (P.T.K.); (M.A.)
- Disease Intervention & Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (H.S.); (R.C.)
- Correspondence: ; Tel.: +1-617-358-9166
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Wu L, Jin D, Wang D, Jing X, Gong P, Qin Y, Chen M. The two-stage interaction of Ebola virus VP40 with nucleoprotein results in a switch from viral RNA synthesis to virion assembly/budding. Protein Cell 2020; 13:120-140. [PMID: 33141416 PMCID: PMC8783937 DOI: 10.1007/s13238-020-00764-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 07/06/2020] [Indexed: 11/28/2022] Open
Abstract
Ebola virus (EBOV) is an enveloped negative-sense RNA virus and a member of the filovirus family. Nucleoprotein (NP) expression alone leads to the formation of inclusion bodies (IBs), which are critical for viral RNA synthesis. The matrix protein, VP40, not only plays a critical role in virus assembly/budding, but also can regulate transcription and replication of the viral genome. However, the molecular mechanism by which VP40 regulates viral RNA synthesis and virion assembly/budding is unknown. Here, we show that within IBs the N-terminus of NP recruits VP40 and is required for VLP-containing NP release. Furthermore, we find four point mutations (L692A, P697A, P698A and W699A) within the C-terminal hydrophobic core of NP result in a stronger VP40-NP interaction within IBs, sequestering VP40 within IBs, reducing VP40-VLP egress, abolishing the incorporation of NC-like structures into VP40-VLP, and inhibiting viral RNA synthesis, suggesting that the interaction of N-terminus of NP with VP40 induces a conformational change in the C-terminus of NP. Consequently, the C-terminal hydrophobic core of NP is exposed and binds VP40, thereby inhibiting RNA synthesis and initiating virion assembly/budding.
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Affiliation(s)
- Linjuan Wu
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Dongning Jin
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Dan Wang
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xuping Jing
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Peng Gong
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Yali Qin
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Mingzhou Chen
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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Abstract
Mononegavirales, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory syncytial virus (HRSV), and Ebola virus (EBOV). Unfortunately, no effective vaccines and antiviral therapeutics against many Mononegavirales are currently available. Viral polymerases have been attractive and major antiviral therapeutic targets. Therefore, Mononegavirales polymerases have been extensively investigated for their structures and functions. Mononegavirales, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory syncytial virus (HRSV), and Ebola virus (EBOV). Unfortunately, no effective vaccines and antiviral therapeutics against many Mononegavirales are currently available. Viral polymerases have been attractive and major antiviral therapeutic targets. Therefore, Mononegavirales polymerases have been extensively investigated for their structures and functions. Mononegavirales mimic RNA synthesis of their eukaryotic counterparts by utilizing multifunctional RNA polymerases to replicate entire viral genomes and transcribe viral mRNAs from individual viral genes as well as synthesize 5′ methylated cap and 3′ poly(A) tail of the transcribed viral mRNAs. The catalytic subunit large protein (L) and cofactor phosphoprotein (P) constitute the Mononegavirales polymerases. In this review, we discuss the shared and unique features of RNA synthesis, the monomeric multifunctional enzyme L, and the oligomeric multimodular adapter P of Mononegavirales. We outline the structural analyses of the Mononegavirales polymerases since the first structure of the vesicular stomatitis virus (VSV) L protein determined in 2015 and highlight multiple high-resolution cryo-electron microscopy (cryo-EM) structures of the polymerases of Mononegavirales, namely, VSV, RABV, HRSV, human metapneumovirus (HMPV), and human parainfluenza virus (HPIV), that have been reported in recent months (2019 to 2020). We compare the structures of those polymerases grouped by virus family, illustrate the similarities and differences among those polymerases, and reveal the potential RNA synthesis mechanisms and models of highly conserved Mononegavirales. We conclude by the discussion of remaining questions, evolutionary perspectives, and future directions.
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Targeting the Respiratory Syncytial Virus N 0-P Complex with Constrained α-Helical Peptides in Cells and Mice. Antimicrob Agents Chemother 2020; 64:AAC.00717-20. [PMID: 32660994 PMCID: PMC7508628 DOI: 10.1128/aac.00717-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023] Open
Abstract
Respiratory syncytial virus (RSV) is the main cause of severe respiratory infection in young children worldwide, and no therapies have been approved for the treatment of RSV infection. Data from recent clinical trials of fusion or L polymerase inhibitors for the treatment of RSV-infected patients revealed the emergence of escape mutants, highlighting the need for the discovery of inhibitors with novel mechanisms of action. Here we describe stapled peptides derived from the N terminus of the phosphoprotein (P) that act as replication inhibitors. Respiratory syncytial virus (RSV) is the main cause of severe respiratory infection in young children worldwide, and no therapies have been approved for the treatment of RSV infection. Data from recent clinical trials of fusion or L polymerase inhibitors for the treatment of RSV-infected patients revealed the emergence of escape mutants, highlighting the need for the discovery of inhibitors with novel mechanisms of action. Here we describe stapled peptides derived from the N terminus of the phosphoprotein (P) that act as replication inhibitors. We demonstrate that these peptides inhibit RSV replication in vitro and in vivo by preventing the formation of the N0-P complex. The present strategy provides a novel means of targeting RSV replication with constrained macrocyclic peptides or small molecules and is broadly applicable to other viruses of the Mononegavirales order.
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Fragment screening targeting Ebola virus nucleoprotein C-terminal domain identifies lead candidates. Antiviral Res 2020; 180:104822. [PMID: 32446802 PMCID: PMC7894038 DOI: 10.1016/j.antiviral.2020.104822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/08/2020] [Accepted: 05/15/2020] [Indexed: 01/24/2023]
Abstract
The Ebola Virus is a causative agent of viral hemorrhagic fever outbreaks and a potential global health risk. The outbreak in West Africa (2013-2016) led to 11,000+ deaths and 30,000+ Ebola infected individuals. The current outbreak in the Democratic Republic of Congo (DRC) with 3000+ confirmed cases and 2000+ deaths attributed to Ebola virus infections provides a reminder that innovative countermeasures are still needed. Ebola virus encodes 7 open reading frames (ORFs). Of these, the nucleocapsid protein (eNP) encoded by the first ORF plays many significant roles, including a role in viral RNA synthesis. Here we describe efforts to target the C-terminal domain of eNP (eNP-CTD) that contains highly conserved residues 641-739 as a pan-Ebola antiviral target. Interactions of eNP-CTD with Ebola Viral Protein 30 (eVP30) and Viral Protein 40 (eVP40) have been shown to be crucial for viral RNA synthesis, virion formation, and virion transport. We used nuclear magnetic response (NMR)-based methods to screened the eNP-CTD against a fragment library. Perturbations of 1D 1H NMR spectra identified of 48 of the 439 compounds screened as potential eNP CTD interactors. Subsequent analysis of these compounds to measure chemical shift perturbations in 2D 1H,15N NMR spectra of 15N-labeled protein identified six with low millimolar affinities. All six perturbed an area consisting mainly of residues at or near the extreme C-terminus that we named "Site 1" while three other sites were perturbed by other compounds. Our findings here demonstrate the potential utility of eNP as a target, several fragment hits, and provide an experimental pipeline to validate viral-viral interactions as potential panfiloviral inhibitor targets.
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Miyake T, Farley CM, Neubauer BE, Beddow TP, Hoenen T, Engel DA. Ebola Virus Inclusion Body Formation and RNA Synthesis Are Controlled by a Novel Domain of Nucleoprotein Interacting with VP35. J Virol 2020; 94:e02100-19. [PMID: 32493824 PMCID: PMC7394894 DOI: 10.1128/jvi.02100-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/24/2020] [Indexed: 12/15/2022] Open
Abstract
Ebola virus (EBOV) inclusion bodies (IBs) are cytoplasmic sites of nucleocapsid formation and RNA replication, housing key steps in the virus life cycle that warrant further investigation. During infection, IBs display dynamic properties regarding their size and location. The contents of IBs also must transition prior to further viral maturation, assembly, and release, implying additional steps in IB function. Interestingly, the expression of the viral nucleoprotein (NP) alone is sufficient for the generation of IBs, indicating that it plays an important role in IB formation during infection. In addition to NP, other components of the nucleocapsid localize to IBs, including VP35, VP24, VP30, and the RNA polymerase L. We previously defined and solved the crystal structure of the C-terminal domain of NP (NP-Ct), but its role in virus replication remained unclear. Here, we show that NP-Ct is necessary for IB formation when NP is expressed alone. Interestingly, we find that NP-Ct is also required for the production of infectious virus-like particles (VLPs), and that defective VLPs with NP-Ct deletions are significantly reduced in viral RNA content. Furthermore, coexpression of the nucleocapsid component VP35 overcomes deletion of NP-Ct in triggering IB formation, demonstrating a functional interaction between the two proteins. Of all the EBOV proteins, only VP35 is able to overcome the defect in IB formation caused by the deletion of NP-Ct. This effect is mediated by a novel protein-protein interaction between VP35 and NP that controls both regulation of IB formation and RNA replication itself and that is mediated by a newly identified functional domain of NP, the central domain.IMPORTANCE Inclusion bodies (IBs) are cytoplasmic sites of RNA synthesis for a variety of negative-sense RNA viruses, including Ebola virus. In addition to housing important steps in the viral life cycle, IBs protect new viral RNA from innate immune attack and contain specific host proteins whose function is under study. A key viral factor in Ebola virus IB formation is the nucleoprotein, NP, which also is important in RNA encapsidation and synthesis. In this study, we have identified two domains of NP that control inclusion body formation. One of these, the central domain (CD), interacts with viral protein VP35 to control both inclusion body formation and RNA synthesis. The other is the NP C-terminal domain (NP-Ct), whose function has not previously been reported. These findings contribute to a model in which NP and its interactions with VP35 link the establishment of IBs to the synthesis of viral RNA.
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Affiliation(s)
- Tsuyoshi Miyake
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Charlotte M Farley
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Benjamin E Neubauer
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas P Beddow
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Daniel A Engel
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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50
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Structural and Functional Characterization of the Phosphoprotein Central Domain of Spring Viremia of Carp Virus. J Virol 2020; 94:JVI.00855-20. [PMID: 32434890 DOI: 10.1128/jvi.00855-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 05/18/2020] [Indexed: 11/20/2022] Open
Abstract
Spring viremia of carp virus (SVCV) is a highly pathogenic Vesiculovirus in the common carp. The phosphoprotein (P protein) of SVCV is a multifunctional protein that acts as a polymerase cofactor and an antagonist of cellular interferon (IFN) response. Here, we report the 1.5-Å-resolution crystal structure of the P protein central domain (PCD) of SVCV (SVCVPCD). The PCD monomer consists of two β sheets, an α helix, and another two β sheets. Two PCD monomers pack together through their hydrophobic surfaces to form a dimer. The mutations of residues on the hydrophobic surfaces of PCD disrupt the dimer formation to different degrees and affect the expression of host IFN consistently. Therefore, the oligomeric state formation of the P protein of SVCV is an important mechanism to negatively regulate host IFN response.IMPORTANCE SVCV can cause spring viremia of carp with up to 90% lethality, and it is the homologous virus of the notorious vesicular stomatitis virus (VSV). There are currently no drugs that effectively cure this disease. P proteins of negative-strand RNA viruses (NSVs) play an essential role in many steps during the replication cycle and an additional role in immunosuppression as a cofactor. All P proteins of NSVs are oligomeric, but the studies on the role of this oligomerization mainly focus on the process of virus transcription or replication, and there are few studies on the role of PCD in immunosuppression. Here, we present the crystal structure of SVCVPCD A new mechanism of immune evasion is clarified by exploring the relationship between SVCVPCD and host IFN response from a structural biology point of view. These findings may provide more accurate target sites for drug design against SVCV and provide new insights into the function of NSVPCD.
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