1
|
Valusenko-Mehrkens R, Johne R, Falkenhagen A. Engineering human/simian rotavirus VP7 reassortants in the absence of UTR sequence information. Appl Microbiol Biotechnol 2025; 109:52. [PMID: 40014110 PMCID: PMC11868164 DOI: 10.1007/s00253-025-13435-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2024] [Revised: 02/06/2025] [Accepted: 02/16/2025] [Indexed: 02/28/2025]
Abstract
Recently developed plasmid-based reverse genetics systems for rotavirus A (RVA) enable rapid engineering of reassortants carrying human RVA antigens. However, complete genome segment sequences are required for successful generation of such reassortants, and sequencing of the untranslated regions (UTRs) of field strains is often not accomplished. To address this problem, we established a system that permits the generation of reassortants using only the open reading frame (ORF) nucleotide sequence information. Plasmids containing the VP7-ORF nucleotide sequence of six human RVA field strains (genotypes G2, G5, G8, G9, G12 and G29) derived from GenBank and flanked by the UTR sequences of simian RVA strain SA11 were constructed. Using these plasmids, four VP7 (G2, G5, G9 and G12) reassortants in an SA11 backbone were successfully generated. In contrast, the G8 and G29 reassortants were not viable. BLASTp search of the G8 and G29 sequences revealed an unusual amino acid substitution in each sequence, which was not present in related field strains. Site-directed reversion of the corresponding C656T mutation in G8 led to effective rescue of reassortant virus. However, reverting the G84C mutation in G29 did not result in replicating virus. The results suggest that most human RVA VP7 UTRs can be substituted with simian RVA UTRs. However, generation of reassortants might be impeded by potential sequencing errors or intrinsic reassortment limitations. The established system could help to broaden the antigenic repertoire for rapid engineering of potential novel RVA vaccine strains. KEY POINTS: • Generation of diverse rotavirus vaccine strains is impeded by missing UTR sequences. • UTRs from SA11 can be used instead of missing UTR sequences from field strains. • Human RVA reassortants of genotypes G2, G5, G8, G9, G12 were successfully rescued.
Collapse
Affiliation(s)
- Roman Valusenko-Mehrkens
- Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Reimar Johne
- Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Alexander Falkenhagen
- Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany.
| |
Collapse
|
2
|
Latimer-Smith M, Salgado PS, Forsyth I, Makeyev E, Poranen MM, Stuart DI, Grimes JM, El Omari K. Structure of the RNA-dependent RNA polymerase P2 from the cystovirus φ8. Sci Rep 2024; 14:23540. [PMID: 39384884 PMCID: PMC11464883 DOI: 10.1038/s41598-024-75213-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 10/03/2024] [Indexed: 10/11/2024] Open
Abstract
The replication of RNA viruses relies on the activity of RNA-dependent RNA polymerases (RdRps). Despite large variations in their genomic sequences, viral RdRps share a common architecture generally known as a closed right hand. The P2 polymerase of cystovirus φ6 is currently among the best characterized viral RdRps. This polymerase is responsible for carrying out both replication and transcription of the viral double-stranded RNA genome using de novo initiation. Despite the extensive biochemical and structural studies conducted on φ6 P2, further structural information on other cystoviral RdRps is crucial to elucidate the structural and functional diversity of viral RdRps. Here, we have determined the atomic X-ray structure of the RdRp P2 from the φ6-related cystovirus φ8 at 3Å resolution. This structure completes the existing set of structural information on the φ8 polymerase complex and sheds light on the difference and similarities with related cystoviral RdRps.
Collapse
Affiliation(s)
- Merlyn Latimer-Smith
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX110DE, UK
| | - Paula S Salgado
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ismay Forsyth
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX110DE, UK
| | - Eugene Makeyev
- Molecular and Integrative Biosciences Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Centre for Developmental Neurobiology, Kings College London, London, SE1 1UL, UK
| | - Minna M Poranen
- Molecular and Integrative Biosciences Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Dave I Stuart
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX110DE, UK
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Jonathan M Grimes
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Kamel El Omari
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX110DE, UK.
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, OX11 0FA, UK.
| |
Collapse
|
3
|
Almohaimeed HM, Abdulfattah AM, Alsulaimani F, Alshammary A, Almohaini MO, Almehiny KA, Hershan AA, Alkhamiss AS, Alghsham RS, Ghabban H, Soliman MH, Alorabi JA, Abdulmonem WA. Prediction of promiscuous multiepitope-based peptide vaccine against RdRp of rotavirus using immunoinformatics studies. Rev Inst Med Trop Sao Paulo 2024; 66:e55. [PMID: 39258658 PMCID: PMC11385075 DOI: 10.1590/s1678-9946202466055] [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: 05/14/2024] [Accepted: 07/02/2024] [Indexed: 09/12/2024] Open
Abstract
Rotavirus, a dsRNA virus in the Reoviridae family, shows a segmented genome. The VP1 gene encodes the RNA-dependent RNA polymerase (RdRp). This study aims to develop a multiepitope-based vaccine targeting RdRp using immunoinformatic approaches. In this study, 100 available nucleotide sequences of VP1-Rotavirus belonging to different strains across the world were retrieved from NCBI database. The selected sequences were aligned, and a global consensus sequence was developed by using CLC work bench. The study involved immunoinformatic approaches and molecular docking studies to reveal the promiscuous epitopes that can be eventually used as active vaccine candidates for Rotavirus. In total, 27 highly immunogenic, antigenic, and non-allergenic T-cell and B-cell epitopes were predicted for the Multiepitope vaccine (MEV) against rotavirus. It was also observed that MEV can prove to be effective worldwide due to its high population coverage, demonstrating the consistency of this vaccine. Moreover, there is a high docking interaction and immunological response with a binding score of -50.2 kcal/mol, suggesting the vaccine's efficacy. Toll-like receptors (TLRs) also suggest that the vaccine is physiologically and immunologically effective. Collectively, our data point to an effective MEV against rotavirus that can effectively reduce viral infections and improve the health status worldwide.
Collapse
Affiliation(s)
- Hailah M Almohaimeed
- Princess Nourah bint Abdulrahman University, College of Medicine, Department of Basic Science, Riyadh, Saudi Arabia
| | - Ahmed M Abdulfattah
- King Abdulaziz University, Faculty of Applied Medical Sciences, Department of Medical Laboratory Sciences, Jeddah, Saudi Arabia
| | - Fayez Alsulaimani
- King Abdulaziz University, Faculty of Applied Medical Sciences, Department of Medical Laboratory Sciences, Jeddah, Saudi Arabia
| | - Aisha Alshammary
- Alyamamah Hospital, Pediatric Infectious Department, Riyadh, Saudi Arabia
| | | | - Khowlah Abdulrahman Almehiny
- Alyamamah Hospital-Riyadh, Second Health Cluster, Registrars Preventive Medicine and Public Health, Infection Control Department, Riyadh, Saudi Arabia
| | - Almonther Abdullah Hershan
- University of Jeddah, College of Medicine, Department of Medical Microbiology and Parasitology, Jeddah, Saudi Arabia
| | | | - Ruqaih S Alghsham
- Qassim University, College of Medicine, Department of Medical Microbiology and Immunology, Qassim, Saudi Arabia
| | - Hanaa Ghabban
- University of Tabuk, Faculty of Science, Department of Biology, Tabuk, Saudi Arabia
| | - Mona H Soliman
- Cairo University, Faculty of Science, Botany and Microbiology Department, Giza, Egypt
- Taibah University, Faculty of Science, Biology Department, Al-Sharm, Yanbu El-Bahr, Kingdom of Saudi
| | - Jamal A Alorabi
- Taif University, College of Science, Department of Biology, Taif, Saudi Arabia
| | - Waleed Al Abdulmonem
- Qassim University, College of Medicine, Department of Pathology, Buraidah, Saudi Arabia
| |
Collapse
|
4
|
Kordys M, Urbanowicz A. 3D Puzzle at the Nanoscale-How do RNA Viruses Self-Assemble their Capsids into Perfectly Ordered Structures. Macromol Biosci 2024; 24:e2400088. [PMID: 38864315 DOI: 10.1002/mabi.202400088] [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: 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.
Collapse
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
| |
Collapse
|
5
|
Diebold O, Zhou S, Sharp CP, Tesla B, Chook HW, Digard P, Gaunt ER. Towards the Development of a Minigenome Assay for Species A Rotaviruses. Viruses 2024; 16:1396. [PMID: 39339871 PMCID: PMC11437487 DOI: 10.3390/v16091396] [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: 04/24/2024] [Revised: 08/12/2024] [Accepted: 08/26/2024] [Indexed: 09/30/2024] Open
Abstract
RNA virus polymerases carry out multiple functions necessary for successful genome replication and transcription. A key tool for molecular studies of viral RNA-dependent RNA polymerases (RdRps) is a 'minigenome' or 'minireplicon' assay, in which viral RdRps are reconstituted in cells in the absence of full virus infection. Typically, plasmids expressing the viral polymerase protein(s) and other co-factors are co-transfected, along with a plasmid expressing an RNA encoding a fluorescent or luminescent reporter gene flanked by viral untranslated regions containing cis-acting elements required for viral RdRp recognition. This reconstitutes the viral transcription/replication machinery and allows the viral RdRp activity to be measured as a correlate of the reporter protein signal. Here, we report on the development of a 'first-generation' plasmid-based minigenome assay for species A rotavirus using a firefly luciferase reporter gene.
Collapse
Affiliation(s)
- Ola Diebold
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Shu Zhou
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Colin Peter Sharp
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Blanka Tesla
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Hou Wei Chook
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Paul Digard
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Eleanor R Gaunt
- Virology Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| |
Collapse
|
6
|
Maio N, Heffner AL, Rouault TA. Iron‑sulfur clusters in viral proteins: Exploring their elusive nature, roles and new avenues for targeting infections. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119723. [PMID: 38599324 PMCID: PMC11139609 DOI: 10.1016/j.bbamcr.2024.119723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/12/2024]
Abstract
Viruses have evolved complex mechanisms to exploit host factors for replication and assembly. In response, host cells have developed strategies to block viruses, engaging in a continuous co-evolutionary battle. This dynamic interaction often revolves around the competition for essential resources necessary for both host cell and virus replication. Notably, iron, required for the biosynthesis of several cofactors, including iron‑sulfur (FeS) clusters, represents a critical element in the ongoing competition for resources between infectious agents and host. Although several recent studies have identified FeS cofactors at the core of virus replication machineries, our understanding of their specific roles and the cellular processes responsible for their incorporation into viral proteins remains limited. This review aims to consolidate our current knowledge of viral components that have been characterized as FeS proteins and elucidate how viruses harness these versatile cofactors to their benefit. Its objective is also to propose that viruses may depend on incorporation of FeS cofactors more extensively than is currently known. This has the potential to revolutionize our understanding of viral replication, thereby carrying significant implications for the development of strategies to target infections.
Collapse
Affiliation(s)
- Nunziata Maio
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA.
| | - Audrey L Heffner
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Tracey A Rouault
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| |
Collapse
|
7
|
Oraby A, Bilawchuk L, West FG, Marchant DJ. Structure-Based Discovery of Allosteric Inhibitors Targeting a New Druggable Site in the Respiratory Syncytial Virus Polymerase. ACS OMEGA 2024; 9:22213-22229. [PMID: 38799318 PMCID: PMC11112712 DOI: 10.1021/acsomega.4c01207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/08/2024] [Accepted: 04/12/2024] [Indexed: 05/29/2024]
Abstract
Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory infections for which effective treatment options remain limited. Herein, we employed a computational structure-based design strategy aimed at identifying potential targets for a new class of allosteric inhibitors. Our investigation led to the discovery of a previously undisclosed allosteric binding site within the RSV polymerase, the large (L) protein. This discovery was achieved through a combination of virtual screening and molecular dynamics simulations. Subsequently, we identified two inhibitors, 6a and 10b, which both exhibited promising antiviral activity in the low micromolar range. Resistance profiling revealed a distinctive pattern in how RSV evaded treatment with this class of inhibitors. This pattern strongly suggested that this class of small molecules was targeting a new binding site in the RSV L protein, aligning with the computational predictions made in our study. This study paves the way for the development of more potent inhibitors for combating RSV infections by targeting a new druggable pocket within the RdRp which does not overlap with previously known resistance sites.
Collapse
Affiliation(s)
- Ahmed
K. Oraby
- Department
of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department
of Pharmaceutical Organic Chemistry, College of Pharmaceutical Sciences
and Drug Manufacturing, Misr University
for Science and Technology, 6th
of October City P.O. Box 77,Egypt
| | - Leanne Bilawchuk
- Department
of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Frederick G. West
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - David J. Marchant
- Department
of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2R3, Canada
| |
Collapse
|
8
|
Xia X, Sung PY, Martynowycz MW, Gonen T, Roy P, Zhou ZH. RNA genome packaging and capsid assembly of bluetongue virus visualized in host cells. Cell 2024; 187:2236-2249.e17. [PMID: 38614100 PMCID: PMC11182334 DOI: 10.1016/j.cell.2024.03.007] [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: 01/17/2023] [Revised: 10/18/2023] [Accepted: 03/07/2024] [Indexed: 04/15/2024]
Abstract
Unlike those of double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), and ssRNA viruses, the mechanism of genome packaging of dsRNA viruses is poorly understood. Here, we combined the techniques of high-resolution cryoelectron microscopy (cryo-EM), cellular cryoelectron tomography (cryo-ET), and structure-guided mutagenesis to investigate genome packaging and capsid assembly of bluetongue virus (BTV), a member of the Reoviridae family of dsRNA viruses. A total of eleven assembly states of BTV capsid were captured, with resolutions up to 2.8 Å, with most visualized in the host cytoplasm. ATPase VP6 was found underneath the vertices of capsid shell protein VP3 as an RNA-harboring pentamer, facilitating RNA packaging. RNA packaging expands the VP3 shell, which then engages middle- and outer-layer proteins to generate infectious virions. These revealed "duality" characteristics of the BTV assembly mechanism reconcile previous contradictory co-assembly and core-filling models and provide insights into the mysterious RNA packaging and capsid assembly of Reoviridae members and beyond.
Collapse
Affiliation(s)
- Xian Xia
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Po-Yu Sung
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Michael W Martynowycz
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tamir Gonen
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Polly Roy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| |
Collapse
|
9
|
Vetter J, Papa G, Tobler K, Rodriguez JM, Kley M, Myers M, Wiesendanger M, Schraner EM, Luque D, Burrone OR, Fraefel C, Eichwald C. The recruitment of TRiC chaperonin in rotavirus viroplasms correlates with virus replication. mBio 2024; 15:e0049924. [PMID: 38470055 PMCID: PMC11005421 DOI: 10.1128/mbio.00499-24] [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] [Received: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/13/2024] Open
Abstract
Rotavirus (RV) replication takes place in the viroplasms, cytosolic inclusions that allow the synthesis of virus genome segments and their encapsidation in the core shell, followed by the addition of the second layer of the virion. The viroplasms are composed of several viral proteins, including NSP5, which serves as the main building block. Microtubules, lipid droplets, and miRNA-7 are among the host components recruited in viroplasms. We investigated the interaction between RV proteins and host components of the viroplasms by performing a pull-down assay of lysates from RV-infected cells expressing NSP5-BiolD2. Subsequent tandem mass spectrometry identified all eight subunits of the tailless complex polypeptide I ring complex (TRiC), a cellular chaperonin responsible for folding at least 10% of the cytosolic proteins. Our confirmed findings reveal that TRiC is brought into viroplasms and wraps around newly formed double-layered particles. Chemical inhibition of TRiC and silencing of its subunits drastically reduced virus progeny production. Through direct RNA sequencing, we show that TRiC is critical for RV replication by controlling dsRNA genome segment synthesis, particularly negative-sense single-stranded RNA. Importantly, cryo-electron microscopy analysis shows that TRiC inhibition results in defective virus particles lacking genome segments and polymerase complex (VP1/VP3). Moreover, TRiC associates with VP2 and NSP5 but not with VP1. Also, VP2 is shown to be essential for recruiting TRiC in viroplasms and preserving their globular morphology. This study highlights the essential role of TRiC in viroplasm formation and in facilitating virion assembly during the RV life cycle. IMPORTANCE The replication of rotavirus takes place in cytosolic inclusions termed viroplasms. In these inclusions, the distinct 11 double-stranded RNA genome segments are co-packaged to complete a genome in newly generated virus particles. In this study, we show for the first time that the tailless complex polypeptide I ring complex (TRiC), a cellular chaperonin responsible for the folding of at least 10% of the cytosolic proteins, is a component of viroplasms and is required for the synthesis of the viral negative-sense single-stranded RNA. Specifically, TRiC associates with NSP5 and VP2, the cofactor involved in RNA replication. Our study adds a new component to the current model of rotavirus replication, where TRiC is recruited to viroplasms to assist replication.
Collapse
Affiliation(s)
- Janine Vetter
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | - Guido Papa
- Molecular Immunology Lab, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Kurt Tobler
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | - Javier M. Rodriguez
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología/CSIC, Cantoblanco, Madrid, Spain
| | - Manuel Kley
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | - Michael Myers
- Proteomics Lab, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Mahesa Wiesendanger
- Institute of Virology, University of Zurich, Zurich, Switzerland
- Institute of Veterinary Anatomy, University of Zurich, Zurich, Switzerland
| | - Elisabeth M. Schraner
- Institute of Virology, University of Zurich, Zurich, Switzerland
- Institute of Veterinary Anatomy, University of Zurich, Zurich, Switzerland
| | - Daniel Luque
- School of Biomedical Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Electron Microscope Unit, Mark Wainwright Analytical Centre, The University of New South Wales, Sydney, New South Wales, Australia
| | - Oscar R. Burrone
- Molecular Immunology Lab, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Cornel Fraefel
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | | |
Collapse
|
10
|
Dhar D, Mehanovic S, Moss W, Miller CL. Sequences at gene segment termini inclusive of untranslated regions and partial open reading frames play a critical role in mammalian orthoreovirus S gene packaging. PLoS Pathog 2024; 20:e1012037. [PMID: 38394338 PMCID: PMC10917250 DOI: 10.1371/journal.ppat.1012037] [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: 09/13/2023] [Revised: 03/06/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Mammalian orthoreovirus (MRV) is a prototypic member of the Spinareoviridae family and has ten double-stranded RNA segments. One copy of each segment must be faithfully packaged into the mature virion, and prior literature suggests that nucleotides (nts) at the terminal ends of each gene likely facilitate their packaging. However, little is known about the precise packaging sequences required or how the packaging process is coordinated. Using a novel approach, we have determined that 200 nts at each terminus, inclusive of untranslated regions (UTR) and parts of the open reading frame (ORF), are sufficient for packaging S gene segments (S1-S4) individually and together into replicating virus. Further, we mapped the minimal sequences required for packaging the S1 gene segment into a replicating virus to 25 5' nts and 50 3' nts. The S1 UTRs, while not sufficient, were necessary for efficient packaging, as mutations of the 5' or 3' UTRs led to a complete loss of virus recovery. Using a second novel assay, we determined that 50 5' nts and 50 3' nts of S1 are sufficient to package a non-viral gene segment into MRV. The 5' and 3' termini of the S1 gene are predicted to form a panhandle structure and specific mutations within the stem of the predicted panhandle region led to a significant decrease in viral recovery. Additionally, mutation of six nts that are conserved across the three major serotypes of MRV that are predicted to form an unpaired loop in the S1 3' UTR, led to a complete loss of viral recovery. Overall, our data provide strong experimental proof that MRV packaging signals lie at the terminal ends of the S gene segments and offer support that the sequence requirements for efficient packaging of the S1 segment include a predicted panhandle structure and specific sequences within an unpaired loop in the 3' UTR.
Collapse
Affiliation(s)
- Debarpan Dhar
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, Iowa, United States of America
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Samir Mehanovic
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Walter Moss
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Cathy L. Miller
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, Iowa, United States of America
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| |
Collapse
|
11
|
Carossino M, Vissani MA, Barrandeguy ME, Balasuriya UBR, Parreño V. Equine Rotavirus A under the One Health Lens: Potential Impacts on Public Health. Viruses 2024; 16:130. [PMID: 38257830 PMCID: PMC10819593 DOI: 10.3390/v16010130] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 12/29/2023] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
Group A rotaviruses are a well-known cause of viral gastroenteritis in infants and children, as well as in many mammalian species and birds, affecting them at a young age. This group of viruses has a double-stranded, segmented RNA genome with high genetic diversity linked to point mutations, recombination, and, importantly, reassortment. While initial molecular investigations undertaken in the 1900s suggested host range restriction among group A rotaviruses based on the fact that different gene segments were distributed among different animal species, recent molecular surveillance and genome constellation genotyping studies conducted by the Rotavirus Classification Working Group (RCWG) have shown that animal rotaviruses serve as a source of diversification of human rotavirus A, highlighting their zoonotic potential. Rotaviruses occurring in various animal species have been linked with contributing genetic material to human rotaviruses, including horses, with the most recent identification of equine-like G3 rotavirus A infecting children. The goal of this article is to review relevant information related to rotavirus structure/genomic organization, epidemiology (with a focus on human and equine rotavirus A), evolution, inter-species transmission, and the potential zoonotic role of equine and other animal rotaviruses. Diagnostics, surveillance and the current status of human and livestock vaccines against RVA are also reviewed.
Collapse
Affiliation(s)
- Mariano Carossino
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Maria Aldana Vissani
- Escuela de Veterinaria, Facultad de Ciencias Agrarias y Veterinarias, Universidad del Salvador, Pilar, Buenos Aires B1630AHU, Argentina; (M.A.V.); (M.E.B.)
- Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires B1686LQF, Argentina;
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1033AAJ, Argentina
| | - Maria E. Barrandeguy
- Escuela de Veterinaria, Facultad de Ciencias Agrarias y Veterinarias, Universidad del Salvador, Pilar, Buenos Aires B1630AHU, Argentina; (M.A.V.); (M.E.B.)
- Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires B1686LQF, Argentina;
| | - Udeni B. R. Balasuriya
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Viviana Parreño
- Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires B1686LQF, Argentina;
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1033AAJ, Argentina
| |
Collapse
|
12
|
Anderson ML, Sullivan OM, Nichols SL, Kaylor L, Kelly DF, McDonald Esstman S. Rotavirus core shell protein sites that regulate intra-particle polymerase activity. J Virol 2023; 97:e0086023. [PMID: 37830817 PMCID: PMC10617381 DOI: 10.1128/jvi.00860-23] [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: 09/06/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Rotaviruses are important causes of severe gastroenteritis in young children. A characteristic feature of rotaviruses is that they copy ribonucleic acid (RNA) inside of the viral particle. In fact, the viral polymerase (VP1) only functions when it is connected to the viral inner core shell protein (VP2). Here, we employed a biochemical assay to identify which sites of VP2 are critical for regulating VP1 activity. Specifically, we engineered VP2 proteins to contain amino acid changes at structurally defined sites and assayed them for their capacity to support VP1 function in a test tube. Through this work, we were able to identify several VP2 residues that appeared to regulate the activity of the polymerase, positively and negatively. These results are important because they help explain how rotavirus synthesizes its RNA while inside of particles and they identify targets for the future rational design of drugs to prevent rotavirus disease.
Collapse
Affiliation(s)
| | - Owen M. Sullivan
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Sarah L. Nichols
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Liam Kaylor
- Department of Biomedical Engineering, State University, University Park, Pennsylvania, USA
| | - Deborah F. Kelly
- Department of Biomedical Engineering, State University, University Park, Pennsylvania, USA
| | | |
Collapse
|
13
|
Asensio-Cob D, Rodríguez JM, Luque D. Rotavirus Particle Disassembly and Assembly In Vivo and In Vitro. Viruses 2023; 15:1750. [PMID: 37632092 PMCID: PMC10458742 DOI: 10.3390/v15081750] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Rotaviruses (RVs) are non-enveloped multilayered dsRNA viruses that are major etiologic agents of diarrheal disease in humans and in the young in a large number of animal species. The viral particle is composed of three different protein layers that enclose the segmented dsRNA genome and the transcriptional complexes. Each layer defines a unique subparticle that is associated with a different phase of the replication cycle. Thus, while single- and double-layered particles are associated with the intracellular processes of selective packaging, genome replication, and transcription, the viral machinery necessary for entry is located in the third layer. This modular nature of its particle allows rotaviruses to control its replication cycle by the disassembly and assembly of its structural proteins. In this review, we examine the significant advances in structural, molecular, and cellular RV biology that have contributed during the last few years to illuminating the intricate details of the RV particle disassembly and assembly processes.
Collapse
Affiliation(s)
- Dunia Asensio-Cob
- Department of Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G0A4, Canada;
| | - Javier M. Rodríguez
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología/CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Daniel Luque
- Electron Microscopy Unit UCCT/ISCIII, 28220 Majadahonda, Spain
- School of Biomedical Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
- Electron Microscope Unit, Mark Wainwright Analytical Centre, The University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
14
|
Dhar D, Mehanovic S, Moss W, Miller CL. Sequences at gene segment termini inclusive of untranslated regions and partial open reading frames play a critical role in mammalian orthoreovirus S gene packaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542362. [PMID: 37292944 PMCID: PMC10245979 DOI: 10.1101/2023.05.25.542362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mammalian orthoreovirus (MRV) is a prototypic member of the Spinareoviridae family and has ten double-stranded RNA segments. One copy of each segment must be faithfully packaged into the mature virion, and prior literature suggests that nucleotides (nts) at the terminal ends of each gene likely facilitate their packaging. However, little is known about the precise packaging sequences required or how the packaging process is coordinated. Using a novel approach, we have determined that 200 nts at each terminus, inclusive of untranslated regions (UTR) and parts of the open reading frame (ORF), are sufficient for packaging each S gene segment (S1-S4) individually and together into replicating virus. Further, we mapped the minimal sequences required for packaging the S1 gene segment to 25 5' nts and 50 3' nts. The S1 UTRs alone are not sufficient, but are necessary for packaging, as mutations of the 5' or 3' UTRs led to a complete loss of virus recovery. Using a second novel assay, we determined that 50 5'nts and 50 3' nts of S1 are sufficient to package a non-viral gene segment into MRV. The 5' and 3' termini of the S1 gene are predicted to form a panhandle structure and specific mutations within the predicted stem of the panhandle region led to a significant decrease in viral recovery. Additionally, mutation of six nts that are conserved in the three major serotypes of MRV and are predicted to form an unpaired loop in the S1 3'UTR, led to a complete loss of viral recovery. Overall, our data provide strong experimental proof that MRV packaging signals lie at the terminal ends of the S gene segments and offer support that the sequence requirements for efficient packaging of the S1 segment include a predicted panhandle structure and specific sequences within an unpaired loop in the 3' UTR.
Collapse
|
15
|
Zhang Q, Gao Y, Baker ML, Liu S, Jia X, Xu H, He J, Kaelber JT, Weng S, Jiang W. The structure of a 12-segmented dsRNA reovirus: New insights into capsid stabilization and organization. PLoS Pathog 2023; 19:e1011341. [PMID: 37083840 PMCID: PMC10155992 DOI: 10.1371/journal.ppat.1011341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 05/03/2023] [Accepted: 04/02/2023] [Indexed: 04/22/2023] Open
Abstract
Infecting a wide range of hosts, members of Reovirales (formerly Reoviridae) consist of a genome with different numbers of segmented double stranded RNAs (dsRNA) encapsulated by a proteinaceous shell and carry out genome replication and transcription inside the virion. Several cryo-electron microscopy (cryo-EM) structures of reoviruses with 9, 10 or 11 segmented dsRNA genomes have revealed insights into genome arrangement and transcription. However, the structure and genome arrangement of 12-segmented Reovirales members remain poorly understood. Using cryo-EM, we determined the structure of mud crab reovirus (MCRV), a 12-segmented dsRNA virus that is a putative member of Reovirales in the non-turreted Sedoreoviridae family, to near-atomic resolutions with icosahedral symmetry (3.1 Å) and without imposing icosahedral symmetry (3.4 Å). These structures revealed the organization of the major capsid proteins in two layers: an outer T = 13 layer consisting of VP12 trimers and unique VP11 clamps, and an inner T = 1 layer consisting of VP3 dimers. Additionally, ten RNA dependent RNA polymerases (RdRp) were well resolved just below the VP3 layer but were offset from the 5-fold axes and arranged with D5 symmetry, which has not previously been seen in other members of Reovirales. The N-termini of VP3 were shown to adopt four unique conformations; two of which anchor the RdRps, while the other two conformations are likely involved in genome organization and capsid stability. Taken together, these structures provide a new level of understanding for capsid stabilization and genome organization of segmented dsRNA viruses.
Collapse
Affiliation(s)
- Qinfen Zhang
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yuanzhu Gao
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Matthew L Baker
- Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, United States of America
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Shanshan Liu
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xudong Jia
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Haidong Xu
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jianguo He
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jason T Kaelber
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Shaoping Weng
- State key lab for biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen Jiang
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| |
Collapse
|
16
|
Shah PNM, Gilchrist JB, Forsberg BO, Burt A, Howe A, Mosalaganti S, Wan W, Radecke J, Chaban Y, Sutton G, Stuart DI, Boyce M. Characterization of the rotavirus assembly pathway in situ using cryoelectron tomography. Cell Host Microbe 2023; 31:604-615.e4. [PMID: 36996819 PMCID: PMC7615348 DOI: 10.1016/j.chom.2023.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/27/2023] [Accepted: 03/06/2023] [Indexed: 03/30/2023]
Abstract
Rotavirus assembly is a complex process that involves the stepwise acquisition of protein layers in distinct intracellular locations to form the fully assembled particle. Understanding and visualization of the assembly process has been hampered by the inaccessibility of unstable intermediates. We characterize the assembly pathway of group A rotaviruses observed in situ within cryo-preserved infected cells through the use of cryoelectron tomography of cellular lamellae. Our findings demonstrate that the viral polymerase VP1 recruits viral genomes during particle assembly, as revealed by infecting with a conditionally lethal mutant. Additionally, pharmacological inhibition to arrest the transiently enveloped stage uncovered a unique conformation of the VP4 spike. Subtomogram averaging provided atomic models of four intermediate states, including a pre-packaging single-layered intermediate, the double-layered particle, the transiently enveloped double-layered particle, and the fully assembled triple-layered virus particle. In summary, these complementary approaches enable us to elucidate the discrete steps involved in forming an intracellular rotavirus particle.
Collapse
Affiliation(s)
- Pranav N M Shah
- Division of Structural Biology, Nuffield Department of Medicine, University of Oxford, The Wellcome Centre for Human Genetics, Headington, Oxford, UK; CAMS Oxford Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Headington, Oxford, UK.
| | - James B Gilchrist
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, UK
| | - Björn O Forsberg
- Division of Structural Biology, Nuffield Department of Medicine, University of Oxford, The Wellcome Centre for Human Genetics, Headington, Oxford, UK; Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Alister Burt
- Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK
| | - Andrew Howe
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, UK
| | - Shyamal Mosalaganti
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - William Wan
- Vanderbilt University Center for Structural Biology, PMB 407917, 465 21st Ave S, 5140 MRB3, Nashville, TN, USA
| | - Julika Radecke
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, UK
| | - Yuriy Chaban
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, UK
| | - Geoff Sutton
- Division of Structural Biology, Nuffield Department of Medicine, University of Oxford, The Wellcome Centre for Human Genetics, Headington, Oxford, UK
| | - David I Stuart
- Division of Structural Biology, Nuffield Department of Medicine, University of Oxford, The Wellcome Centre for Human Genetics, Headington, Oxford, UK; CAMS Oxford Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Headington, Oxford, UK; Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, UK.
| | - Mark Boyce
- Division of Structural Biology, Nuffield Department of Medicine, University of Oxford, The Wellcome Centre for Human Genetics, Headington, Oxford, UK.
| |
Collapse
|
17
|
Strauss S, Acker J, Papa G, Desirò D, Schueder F, Borodavka A, Jungmann R. Principles of RNA recruitment to viral ribonucleoprotein condensates in a segmented dsRNA virus. eLife 2023; 12:e68670. [PMID: 36700549 PMCID: PMC9925054 DOI: 10.7554/elife.68670] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 01/26/2023] [Indexed: 01/27/2023] Open
Abstract
Rotaviruses transcribe 11 distinct RNAs that must be co-packaged prior to their replication to make an infectious virion. During infection, nontranslating rotavirus transcripts accumulate in cytoplasmic protein-RNA granules known as viroplasms that support segmented genome assembly and replication via a poorly understood mechanism. Here, we analysed the RV transcriptome by combining DNA-barcoded smFISH of rotavirus-infected cells. Rotavirus RNA stoichiometry in viroplasms appears to be distinct from the cytoplasmic transcript distribution, with the largest transcript being the most enriched in viroplasms, suggesting a selective RNA enrichment mechanism. While all 11 types of transcripts accumulate in viroplasms, their stoichiometry significantly varied between individual viroplasms. Accumulation of transcripts requires the presence of 3' untranslated terminal regions and viroplasmic localisation of the viral polymerase VP1, consistent with the observed lack of polyadenylated transcripts in viroplasms. Our observations reveal similarities between viroplasms and other cytoplasmic RNP granules and identify viroplasmic proteins as drivers of viral RNA assembly during viroplasm formation.
Collapse
Affiliation(s)
| | - Julia Acker
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Guido Papa
- Molecular Immunology Laboratory, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Daniel Desirò
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Florian Schueder
- Max Planck Institute of BiochemistryMunichGermany
- Department of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
| | | | - Ralf Jungmann
- Max Planck Institute of BiochemistryMunichGermany
- Department of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
| |
Collapse
|
18
|
Sutto-Ortiz P, Eléouët JF, Ferron F, Decroly E. Biochemistry of the Respiratory Syncytial Virus L Protein Embedding RNA Polymerase and Capping Activities. Viruses 2023; 15:v15020341. [PMID: 36851554 PMCID: PMC9960070 DOI: 10.3390/v15020341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/12/2023] [Accepted: 01/21/2023] [Indexed: 01/27/2023] Open
Abstract
The human respiratory syncytial virus (RSV) is a negative-sense, single-stranded RNA virus. It is the major cause of severe acute lower respiratory tract infection in infants, the elderly population, and immunocompromised individuals. There is still no approved vaccine or antiviral treatment against RSV disease, but new monoclonal prophylactic antibodies are yet to be commercialized, and clinical trials are in progress. Hence, urgent efforts are needed to develop efficient therapeutic treatments. RSV RNA synthesis comprises viral transcription and replication that are catalyzed by the large protein (L) in coordination with the phosphoprotein polymerase cofactor (P), the nucleoprotein (N), and the M2-1 transcription factor. The replication/transcription is orchestrated by the L protein, which contains three conserved enzymatic domains: the RNA-dependent RNA polymerase (RdRp), the polyribonucleotidyl transferase (PRNTase or capping), and the methyltransferase (MTase) domain. These activities are essential for the RSV replicative cycle and are thus considered as attractive targets for the development of therapeutic agents. In this review, we summarize recent findings about RSV L domains structure that highlight how the enzymatic activities of RSV L domains are interconnected, discuss the most relevant and recent antivirals developments that target the replication/transcription complex, and conclude with a perspective on identified knowledge gaps that enable new research directions.
Collapse
Affiliation(s)
| | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires, INRAE, Université Paris Saclay, F78350 Jouy en Josas, France
| | - François Ferron
- Aix Marseille Université, CNRS, AFMB, UMR, 7257 Marseille, France
- European Virus Bioinformatics Center, Leutragraben 1, 07743 Jena, Germany
| | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB, UMR, 7257 Marseille, France
- Correspondence:
| |
Collapse
|
19
|
Anderson ML, McDonald Esstman S. In vitro particle-associated uridyltransferase activity of the rotavirus VP1 polymerase. Virology 2022; 577:24-31. [PMID: 36257129 PMCID: PMC10728782 DOI: 10.1016/j.virol.2022.09.015] [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: 08/29/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
Rotaviruses are 11-segmented, double-stranded RNA (dsRNA) viruses with a unique intra-particle RNA synthesis mechanism. During genome replication, the RNA-dependent RNA polymerase (VP1) performs minus-strand RNA (-ssRNA) synthesis on positive-strand RNA (+ssRNA) templates to create dsRNA segments. Recombinant VP1 catalyzes -ssRNA synthesis using substrate NTPs in vitro, but only when the VP2 core shell protein or virus-like particles made of VP2 and VP6 (2/6-VLPs) are included in the reaction. The dsRNA product can be labeled using [α32P]-UTP and separated from the input +ssRNA template by polyacrylamide gel electrophoresis. Here, we report the generation of [α32P]-labeled rotavirus +ssRNA templates in reactions that lacked non-radiolabeled NTPs but contained catalytically-active VP1, 2/6-VLPs, and [α32P]-UTP. Non-radiolabeled UTP competed with [α32P]-UTP to decrease product levels, whereas CTP and GTP had little effect. Interesting, ATP stimulated [α32P]-labeled product production. These results suggest that rotavirus VP1 transferred [α32P]-UMP onto viral + ssRNA in vitro via a particle-associated uridyltransferase activity.
Collapse
|
20
|
Ding P, Summers MF. Sequestering the 5′‐cap for viral RNA packaging. Bioessays 2022; 44:e2200104. [PMID: 36101513 DOI: 10.1002/bies.202200104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/28/2022] [Accepted: 08/31/2022] [Indexed: 11/11/2022]
Abstract
Many viruses evolved mechanisms for capping the 5'-ends of their plus-strand RNAs as a means of hijacking the eukaryotic messenger RNA (mRNA) splicing/translation machinery. Although capping is critical for replication, the RNAs of these viruses have other essential functions including their requirement to be packaged as either genomes or pre-genomes into progeny viruses. Recent studies indicate that human immunodeficiency virus type-1 (HIV-1) RNAs are segregated between splicing/translation and packaging functions by a mechanism that involves structural sequestration of the 5'-cap. Here, we examined studies reported for other viruses and retrotransposons that require both selective packaging of their RNAs and 5'-RNA capping for host-mediated translation. Our findings suggest that viruses and retrotransposons have evolved multiple mechanisms to control 5'-cap accessibility, consistent with the hypothesis that removal or sequestration of the 5' cap enables packageable RNAs to avoid capture by the cellular RNA processing and translation machinery.
Collapse
Affiliation(s)
- Pengfei Ding
- Department of Chemistry and Biochemistry and Howard Hughes Medical Institute University of Maryland Baltimore County Baltimore Maryland USA
| | - Michael F. Summers
- Department of Chemistry and Biochemistry and Howard Hughes Medical Institute University of Maryland Baltimore County Baltimore Maryland USA
| |
Collapse
|
21
|
Diebold O, Gonzalez V, Venditti L, Sharp C, Blake RA, Tan WS, Stevens J, Caddy S, Digard P, Borodavka A, Gaunt E. Using Species a Rotavirus Reverse Genetics to Engineer Chimeric Viruses Expressing SARS-CoV-2 Spike Epitopes. J Virol 2022; 96:e0048822. [PMID: 35758692 PMCID: PMC9327695 DOI: 10.1128/jvi.00488-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/31/2022] [Indexed: 02/02/2023] Open
Abstract
Species A rotavirus (RVA) vaccines based on live attenuated viruses are used worldwide in humans. The recent establishment of a reverse genetics system for rotoviruses (RVs) has opened the possibility of engineering chimeric viruses expressing heterologous peptides from other viral or microbial species in order to develop polyvalent vaccines. We tested the feasibility of this concept by two approaches. First, we inserted short SARS-CoV-2 spike peptides into the hypervariable region of the simian RV SA11 strain viral protein (VP) 4. Second, we fused the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, or the shorter receptor binding motif (RBM) nested within the RBD, to the C terminus of nonstructural protein (NSP) 3 of the bovine RV RF strain, with or without an intervening Thosea asigna virus 2A (T2A) peptide. Mutating the hypervariable region of SA11 VP4 impeded viral replication, and for these mutants, no cross-reactivity with spike antibodies was detected. To rescue NSP3 mutants, we established a plasmid-based reverse genetics system for the bovine RV RF strain. Except for the RBD mutant that demonstrated a rescue defect, all NSP3 mutants delivered endpoint infectivity titers and exhibited replication kinetics comparable to that of the wild-type virus. In ELISAs, cell lysates of an NSP3 mutant expressing the RBD peptide showed cross-reactivity with a SARS-CoV-2 RBD antibody. 3D bovine gut enteroids were susceptible to infection by all NSP3 mutants, but cross-reactivity with SARS-CoV-2 RBD antibody was only detected for the RBM mutant. The tolerance of large SARS-CoV-2 peptide insertions at the C terminus of NSP3 in the presence of T2A element highlights the potential of this approach for the development of vaccine vectors targeting multiple enteric pathogens simultaneously. IMPORTANCE We explored the use of rotaviruses (RVs) to express heterologous peptides, using SARS-CoV-2 as an example. Small SARS-CoV-2 peptide insertions (<34 amino acids) into the hypervariable region of the viral protein 4 (VP4) of RV SA11 strain resulted in reduced viral titer and replication, demonstrating a limited tolerance for peptide insertions at this site. To test the RV RF strain for its tolerance for peptide insertions, we constructed a reverse genetics system. NSP3 was C-terminally tagged with SARS-CoV-2 spike peptides of up to 193 amino acids in length. With a T2A-separated 193 amino acid tag on NSP3, there was no significant effect on the viral rescue efficiency, endpoint titer, and replication kinetics. Tagged NSP3 elicited cross-reactivity with SARS-CoV-2 spike antibodies in ELISA. We highlight the potential for development of RV vaccine vectors targeting multiple enteric pathogens simultaneously.
Collapse
Affiliation(s)
- Ola Diebold
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Victoria Gonzalez
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Luca Venditti
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Colin Sharp
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Rosemary A. Blake
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Wenfang S. Tan
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Joanne Stevens
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Sarah Caddy
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Paul Digard
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| | - Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Eleanor Gaunt
- Infection and Immunity Division, Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, United Kingdom
| |
Collapse
|
22
|
Lee MD, Creagh JW, Fredericks LR, Crabtree AM, Patel JS, Rowley PA. The Characterization of a Novel Virus Discovered in the Yeast Pichia membranifaciens. Viruses 2022; 14:v14030594. [PMID: 35337001 PMCID: PMC8951182 DOI: 10.3390/v14030594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 02/05/2023] Open
Abstract
Mycoviruses are widely distributed across fungi, including the yeasts of the Saccharomycotina subphylum. This manuscript reports the first double-stranded RNA (dsRNA) virus isolated from Pichia membranifaciens. This novel virus has been named Pichia membranifaciens virus L-A (PmV-L-A) and is a member of the Totiviridae. PmV-L-A is 4579 bp in length, with RNA secondary structures similar to the packaging, replication, and frameshift signals of totiviruses that infect Saccharomycotina yeasts. PmV-L-A was found to be part of a monophyletic group within the I-A totiviruses, implying a shared ancestry between mycoviruses isolated from the Pichiaceae and Saccharomycetaceae yeasts. Energy-minimized AlphaFold2 molecular models of the PmV-L-A Gag protein revealed structural conservation with the Gag protein of Saccharomyces cerevisiae virus L-A (ScV-L-A). The predicted tertiary structure of the PmV-L-A Pol and other homologs provided a possible mechanism for totivirus RNA replication due to structural similarities with the RNA-dependent RNA polymerases of mammalian dsRNA viruses. Insights into the structure, function, and evolution of totiviruses gained from yeasts are essential because of their emerging role in animal disease and their parallels with mammalian viruses.
Collapse
Affiliation(s)
- Mark D. Lee
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Jack W. Creagh
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Lance R. Fredericks
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Angela M. Crabtree
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Jagdish Suresh Patel
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
- Center for Modeling Complex Interactions, University of Idaho, Moscow, ID 83844, USA
| | - Paul A. Rowley
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
- Correspondence:
| |
Collapse
|
23
|
Liu H, Cheng L. Viral Capsid and Polymerase in Reoviridae. Subcell Biochem 2022; 99:525-552. [PMID: 36151388 DOI: 10.1007/978-3-031-00793-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The members of the family Reoviridae (reoviruses) consist of 9-12 discrete double-stranded RNA (dsRNA) segments enclosed by single, double, or triple capsid layers. The outer capsid proteins of reoviruses exhibit the highest diversity in both sequence and structural organization. By contrast, the conserved RNA-dependent RNA polymerase (RdRp) structure in the conserved innermost shell in all reoviruses suggests that they share common transcriptional regulatory mechanisms. After reoviruses are delivered into the cytoplasm of a host cell, their inner capsid particles (ICPs) remain intact and serve as a stable nanoscale machine for RNA transcription and capping performed using enzymes in ICPs. Advances in cryo-electron microscopy have enabled the reconstruction at near-atomic resolution of not only the icosahedral capsid, including capping enzymes, but also the nonicosahedrally distributed complexes of RdRps within the capsid at different transcriptional stages. These near-atomic resolution structures allow us to visualize highly coordinated structural changes in the related enzymes, genomic RNA, and capsid protein during reovirus transcription. In addition, reoviruses encode their own enzymes for nascent RNA capping before RNA releasing from their ICPs.
Collapse
Affiliation(s)
- Hongrong Liu
- Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, School of Physics and Electronics, Hunan Normal University, Changsha, China.
| | - Lingpeng Cheng
- Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, School of Physics and Electronics, Hunan Normal University, Changsha, China.
- School of Life Sciences, Tsinghua University, Beijing, China.
| |
Collapse
|
24
|
Patra U, Mukhopadhyay U, Mukherjee A, Dutta S, Chawla-Sarkar M. Treading a HOSTile path: Mapping the dynamic landscape of host cell-rotavirus interactions to explore novel host-directed curative dimensions. Virulence 2021; 12:1022-1062. [PMID: 33818275 PMCID: PMC8023246 DOI: 10.1080/21505594.2021.1903198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/20/2021] [Accepted: 03/10/2021] [Indexed: 12/27/2022] Open
Abstract
Viruses are intracellular pathogens and are dependent on host cellular resources to carry out their cycles of perpetuation. Obtaining an integrative view of host-virus interaction is of utmost importance to understand the complex and dynamic interplay between viral components and host machineries. Besides its obvious scholarly significance, a comprehensive host-virus interaction profile also provides a platform where from host determinants of pro-viral and antiviral importance can be identified and further be subjected to therapeutic intervention. Therefore, adjunct to conventional methods of prophylactic vaccination and virus-directed antivirals, this host-targeted antiviral approach holds promising therapeutic potential. In this review, we present a comprehensive landscape of host cellular reprogramming in response to infection with rotavirus (RV) which causes profuse watery diarrhea in neonates and infants. In addition, an emphasis is given on how host determinants are either usurped or subverted by RV in course of infection and how therapeutic manipulation of specific host factors can effectively modulate the RV life cycle.
Collapse
Affiliation(s)
- Upayan Patra
- Division of Virology, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, India
| | - Urbi Mukhopadhyay
- Division of Virology, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, India
| | - Arpita Mukherjee
- Division of Virology, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, India
| | - Mamta Chawla-Sarkar
- Division of Virology, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, India
| |
Collapse
|
25
|
Geiger F, Acker J, Papa G, Wang X, Arter WE, Saar KL, Erkamp NA, Qi R, Bravo JPK, Strauss S, Krainer G, Burrone OR, Jungmann R, Knowles TPJ, Engelke H, Borodavka A. Liquid-liquid phase separation underpins the formation of replication factories in rotaviruses. EMBO J 2021; 40:e107711. [PMID: 34524703 PMCID: PMC8561643 DOI: 10.15252/embj.2021107711] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022] Open
Abstract
RNA viruses induce the formation of subcellular organelles that provide microenvironments conducive to their replication. Here we show that replication factories of rotaviruses represent protein-RNA condensates that are formed via liquid-liquid phase separation of the viroplasm-forming proteins NSP5 and rotavirus RNA chaperone NSP2. Upon mixing, these proteins readily form condensates at physiologically relevant low micromolar concentrations achieved in the cytoplasm of virus-infected cells. Early infection stage condensates could be reversibly dissolved by 1,6-hexanediol, as well as propylene glycol that released rotavirus transcripts from these condensates. During the early stages of infection, propylene glycol treatments reduced viral replication and phosphorylation of the condensate-forming protein NSP5. During late infection, these condensates exhibited altered material properties and became resistant to propylene glycol, coinciding with hyperphosphorylation of NSP5. Some aspects of the assembly of cytoplasmic rotavirus replication factories mirror the formation of other ribonucleoprotein granules. Such viral RNA-rich condensates that support replication of multi-segmented genomes represent an attractive target for developing novel therapeutic approaches.
Collapse
Affiliation(s)
- Florian Geiger
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Julia Acker
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | - Guido Papa
- International Center for Genetic Engineering and BiotechnologyTriesteItaly
- Present address:
Medical Research Council Laboratory of Molecular Biology (MRC LMB)CambridgeUK
| | - Xinyu Wang
- Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | - Kadi L Saar
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Nadia A Erkamp
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Runzhang Qi
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Jack PK Bravo
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Present address:
Department of Molecular BiosciencesUniversity of Texas at AustinAustinTXUSA
| | - Sebastian Strauss
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| | - Georg Krainer
- Department of ChemistryUniversity of CambridgeCambridgeUK
| | - Oscar R Burrone
- International Center for Genetic Engineering and BiotechnologyTriesteItaly
| | - Ralf Jungmann
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| | | | - Hanna Engelke
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
- Institute of Pharmaceutical SciencesKarl‐Franzens‐Universität GrazGrazAustria
| | - Alexander Borodavka
- Department of ChemistryLudwig‐Maximilians‐Universität MünchenMunichGermany
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Department of Physics and Center for NanoscienceMax Planck Institute of BiochemistryMunichGermany
| |
Collapse
|
26
|
Abstract
The RNA-dependent RNA polymerase (RdRp) of all known double-stranded RNA viruses is located within the viral particle and is responsible for the transcription and replication of the viral genome. Through an RT-PCR assay, we determined that purified virions, in vitro translated RdRp proteins, and purified recombinant RdRp proteins of partitiviruses also have reverse transcriptase (RT) function. We show that partitivirus RdRps 1) synthesized DNA from homologous and heterologous dsRNA templates; 2) are active using both ssRNA and dsRNA templates; and 3) are active at lower temperatures compared to an optimal reaction temperature of commercial RT enzymes. This finding poses an intriguing question: why do partitiviruses, with dsRNA genomes, have a polymerase with RT functions? In comparison, 3Dpol, the RdRp of poliovirus, did not show any RT activity. Our findings lead us to propose a new evolutionary model for RNA viruses where the RdRp of dsRNA viruses could be the ancestor of RdRps.
Collapse
Affiliation(s)
- Mahtab Peyambari
- Center for Infectious Disease Dynamics, Millennium Science Complex, Pennsylvania State University, University Park, PA, USA
| | | | - Marilyn J Roossinck
- Center for Infectious Disease Dynamics, Millennium Science Complex, Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
27
|
5'-Cap sequestration is an essential determinant of HIV-1 genome packaging. Proc Natl Acad Sci U S A 2021; 118:2112475118. [PMID: 34493679 PMCID: PMC8449379 DOI: 10.1073/pnas.2112475118] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/05/2021] [Indexed: 12/14/2022] Open
Abstract
HIV-1 selectively packages two copies of its 5'-capped RNA genome (gRNA) during virus assembly, a process mediated by the nucleocapsid (NC) domain of the viral Gag polyprotein and encapsidation signals located within the dimeric 5' leader of the viral RNA. Although residues within the leader that promote packaging have been identified, the determinants of authentic packaging fidelity and efficiency remain unknown. Here, we show that a previously characterized 159-nt region of the leader that possesses all elements required for RNA dimerization, high-affinity NC binding, and packaging in a noncompetitive RNA packaging assay (ΨCES) is unexpectedly poorly packaged when assayed in competition with the intact 5' leader. ΨCES lacks a 5'-tandem hairpin element that sequesters the 5' cap, suggesting that cap sequestration may be important for packaging. Consistent with this hypothesis, mutations within the intact leader that expose the cap without disrupting RNA structure or NC binding abrogated RNA packaging, and genetic addition of a 5' ribozyme to ΨCES to enable cotranscriptional shedding of the 5' cap promoted ΨCES-mediated RNA packaging to wild-type levels. Additional mutations that either block dimerization or eliminate subsets of NC binding sites substantially attenuated competitive packaging. Our studies indicate that packaging is achieved by a bipartite mechanism that requires both sequestration of the 5' cap and exposure of NC binding sites that reside fully within the ΨCES region of the dimeric leader. We speculate that cap sequestration prevents irreversible capture by the cellular RNA processing and translation machinery, a mechanism likely employed by other viruses that package 5'-capped RNA genomes.
Collapse
|
28
|
Uprety T, Sreenivasan CC, Hause BM, Li G, Odemuyiwa SO, Locke S, Morgan J, Zeng L, Gilsenan WF, Slovis N, Metcalfe L, Carter CN, Timoney P, Horohov D, Wang D, Erol E, Adam E, Li F. Identification of a Ruminant Origin Group B Rotavirus Associated with Diarrhea Outbreaks in Foals. Viruses 2021; 13:1330. [PMID: 34372536 PMCID: PMC8310321 DOI: 10.3390/v13071330] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 12/16/2022] Open
Abstract
Equine rotavirus group A (ERVA) is one of the most common causes of foal diarrhea. Starting in February 2021, there was an increase in the frequency of severe watery to hemorrhagic diarrhea cases in neonatal foals in Central Kentucky. Diagnostic investigation of fecal samples failed to detect evidence of diarrhea-causing pathogens including ERVA. Based on Illumina-based metagenomic sequencing, we identified a novel equine rotavirus group B (ERVB) in fecal specimens from the affected foals in the absence of any other known enteric pathogens. Interestingly, the protein sequence of all 11 segments had greater than 96% identity with group B rotaviruses previously found in ruminants. Furthermore, phylogenetic analysis demonstrated clustering of the ERVB with group B rotaviruses of caprine and bovine strains from the USA. Subsequent analysis of 33 foal diarrheic samples by RT-qPCR identified 23 rotavirus B-positive cases (69.69%). These observations suggest that the ERVB originated from ruminants and was associated with outbreaks of neonatal foal diarrhea in the 2021 foaling season in Kentucky. Emergence of the ruminant-like group B rotavirus in foals clearly warrants further investigation due to the significant impact of the disease in neonatal foals and its economic impact on the equine industry.
Collapse
Affiliation(s)
- Tirth Uprety
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - Chithra C. Sreenivasan
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - Ben M. Hause
- Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA;
| | - Ganwu Li
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA;
| | - Solomon O. Odemuyiwa
- Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO 65212, USA;
| | - Stephan Locke
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY 40512, USA; (S.L.); (J.M.); (L.Z.); (C.N.C.)
| | - Jocelynn Morgan
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY 40512, USA; (S.L.); (J.M.); (L.Z.); (C.N.C.)
| | - Li Zeng
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY 40512, USA; (S.L.); (J.M.); (L.Z.); (C.N.C.)
| | | | - Nathan Slovis
- Hagyard Equine Medical Institute, Lexington, KY 40511, USA;
| | - Laurie Metcalfe
- Rood and Riddle Equine Hospital, Lexington, KY 40511, USA; (W.F.G.); (L.M.)
| | - Craig N. Carter
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY 40512, USA; (S.L.); (J.M.); (L.Z.); (C.N.C.)
| | - Peter Timoney
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - David Horohov
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - Dan Wang
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - Erdal Erol
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY 40512, USA; (S.L.); (J.M.); (L.Z.); (C.N.C.)
| | - Emma Adam
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| | - Feng Li
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA; (T.U.); (C.C.S.); (P.T.); (D.H.); (D.W.)
| |
Collapse
|
29
|
Nilsson EM, Sullivan OM, Anderson ML, Argobright HM, Shue TM, Fedowitz FR, LaConte LEW, Esstman SM. Reverse genetic engineering of simian rotaviruses with temperature-sensitive lesions in VP1, VP2, and VP6. Virus Res 2021; 302:198488. [PMID: 34146610 DOI: 10.1016/j.virusres.2021.198488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/24/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
Rotaviruses are 11-segmented double-stranded RNA viruses and important causes of acute gastroenteritis in young children. To investigate the functions of specific viral proteins during the rotavirus lifecycle, temperature-sensitive (ts) mutants were previously created using a cultivatable simian strain (SA11) and chemical mutagenesis. These ts SA11 mutants replicate more efficiently at the permissive temperature of 31 °C than at the non-permissive temperature of 39 °C. Prototype strains SA11-tsC, SA11-tsF, and SA11-tsG were mapped to the genes encoding structural proteins VP1, VP2, and VP6, respectively, and putative ts lesions were identified using Sanger sequencing. However, additional background mutations in their genomes had hampered validation of the ts lesions and confounded their use in mechanistic studies. Here, we employed plasmid only-based reverse genetics to engineer recombinant (r) SA11 rotaviruses containing only the putative ts lesions of SA11-tsC (L138P change in VP1), SA11-tsF (A387D change in VP2) or SA11-tsG (S10T, D13H, and A121G changes in VP6). For simplicity, we refer to these newly-engineered, isogenic viruses as rSA11-tsVP1, rSA11-tsVP2, and rSA11-tsVP6. Single-cycle growth assays revealed that these mutants indeed exhibit ts phenotypes with significantly diminished titers (>1.5-logs) at 39 °C versus 31 °C. The rSA11 ts mutants proved genetically stable at the population-level following 3 sequential passages at 39 °C, but individual revertant clones were detected in plaque assays. Heat sensitivity experiments showed that pre-incubation of rSA11-tsVP1 or rSA11-tsVP2, but not rSA11-tsVP6, at 39 °C diminished replication at 31 °C. This result indicates that the ts lesions in VP1 and VP2 affect the incoming virion but those in VP6 affect a later stage of the viral lifecycle. In silico molecular dynamics simulations predicted temperature-dependent, long-range effects of the S10T, D13H, and/or A121G changes on the VP6 structure. Altogether, our results confirm the ts lesions of the original SA11-tsC, SA11-tsF, and SA11-tsG mutants, provide a new set of isogenic strains for investigating aspects of rotavirus replication, and shed light on how the ts lesions might impact VP1, VP2, or VP6 functions.
Collapse
Affiliation(s)
- Emil M Nilsson
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Owen M Sullivan
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | | | | | - Taylor M Shue
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | | | - Leslie E W LaConte
- Fralin Biomedical Research Institute, Roanoke, VA, USA; Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | | |
Collapse
|
30
|
Abstract
Group A rotaviruses (RVAs) are the major cause of severe acute gastroenteritis (AGE) in children under 5 years of age, annually resulting in nearly 130,000 deaths worldwide. Social conditions in developing countries that contribute to decreased oral rehydration and vaccine efficacy and the lack of approved antiviral drugs position RVA as a global health concern. In this minireview, we present an update in the field of antiviral compounds, mainly in relation to the latest findings in RVA virion structure and the viral replication cycle. In turn, we attempt to provide a perspective on the possible treatments for RVA-associated AGE, with special focus on novel approaches, such as those representing broad-spectrum therapeutic options. In this context, the modulation of host factors, lipid droplets, and the viral polymerase, which is highly conserved among AGE-causing viruses, are analyzed as possible drug targets.
Collapse
|
31
|
Cárcamo-Calvo R, Muñoz C, Buesa J, Rodríguez-Díaz J, Gozalbo-Rovira R. The Rotavirus Vaccine Landscape, an Update. Pathogens 2021; 10:520. [PMID: 33925924 PMCID: PMC8145439 DOI: 10.3390/pathogens10050520] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 11/17/2022] Open
Abstract
Rotavirus is the leading cause of severe acute childhood gastroenteritis, responsible for more than 128,500 deaths per year, mainly in low-income countries. Although the mortality rate has dropped significantly since the introduction of the first vaccines around 2006, an estimated 83,158 deaths are still preventable. The two main vaccines currently deployed, Rotarix and RotaTeq, both live oral vaccines, have been shown to be less effective in developing countries. In addition, they have been associated with a slight risk of intussusception, and the need for cold chain maintenance limits the accessibility of these vaccines to certain areas, leaving 65% of children worldwide unvaccinated and therefore unprotected. Against this backdrop, here we review the main vaccines under development and the state of the art on potential alternatives.
Collapse
Affiliation(s)
- Roberto Cárcamo-Calvo
- Department of Microbiology, School of Medicine, University of Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain; (R.C.-C.); (C.M.); (J.B.)
| | - Carlos Muñoz
- Department of Microbiology, School of Medicine, University of Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain; (R.C.-C.); (C.M.); (J.B.)
| | - Javier Buesa
- Department of Microbiology, School of Medicine, University of Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain; (R.C.-C.); (C.M.); (J.B.)
- Instituto de Investigación INCLIVA, Hospital Clínico Universitario de Valencia, 46010 Valencia, Spain
| | - Jesús Rodríguez-Díaz
- Department of Microbiology, School of Medicine, University of Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain; (R.C.-C.); (C.M.); (J.B.)
- Instituto de Investigación INCLIVA, Hospital Clínico Universitario de Valencia, 46010 Valencia, Spain
| | - Roberto Gozalbo-Rovira
- Department of Microbiology, School of Medicine, University of Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain; (R.C.-C.); (C.M.); (J.B.)
- Instituto de Investigación INCLIVA, Hospital Clínico Universitario de Valencia, 46010 Valencia, Spain
| |
Collapse
|
32
|
Smith SC, Gribble J, Diller JR, Wiebe MA, Thoner TW, Denison MR, Ogden KM. Reovirus RNA recombination is sequence directed and generates internally deleted defective genome segments during passage. J Virol 2021; 95:JVI.02181-20. [PMID: 33472930 PMCID: PMC8103698 DOI: 10.1128/jvi.02181-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/14/2021] [Indexed: 12/12/2022] Open
Abstract
For viruses with segmented genomes, genetic diversity is generated by genetic drift, reassortment, and recombination. Recombination produces RNA populations distinct from full-length gene segments and can influence viral population dynamics, persistence, and host immune responses. Viruses in the Reoviridae family, including rotavirus and mammalian orthoreovirus (reovirus), have been reported to package segments containing rearrangements or internal deletions. Rotaviruses with RNA segments containing rearrangements have been isolated from immunocompromised and immunocompetent children and in vitro following serial passage at relatively high multiplicity. Reoviruses that package small, defective RNA segments have established chronic infections in cells and in mice. However, the mechanism and extent of Reoviridae RNA recombination are undefined. Towards filling this gap in knowledge, we determined the titers and RNA segment profiles for reovirus and rotavirus following serial passage in cultured cells. The viruses exhibited occasional titer reductions characteristic of interference. Reovirus strains frequently accumulated segments that retained 5' and 3' terminal sequences and featured large internal deletions, while similarly fragmented segments were rarely detected in rotavirus populations. Using next-generation RNA-sequencing to analyze RNA molecules packaged in purified reovirus particles, we identified distinct recombination sites within individual viral genome segments. Recombination junctions were frequently but not always characterized by short direct sequence repeats upstream and downstream that spanned junction sites. Taken together, these findings suggest that reovirus accumulates defective gene segments featuring internal deletions during passage and undergoes sequence-directed recombination at distinct sites.IMPORTANCE Viruses in the Reoviridae family include important pathogens of humans and other animals and have segmented RNA genomes. Recombination in RNA virus populations can facilitate novel host exploration and increased disease severity. The extent, patterns, and mechanisms of Reoviridae recombination and the functions and effects of recombined RNA products are poorly understood. Here, we provide evidence that mammalian orthoreovirus regularly synthesizes RNA recombination products that retain terminal sequences but contain internal deletions, while rotavirus rarely synthesizes such products. Recombination occurs more frequently at specific sites in the mammalian orthoreovirus genome, and short regions of identical sequence are often detected at junction sites. These findings suggest that mammalian orthoreovirus recombination events are directed in part by RNA sequences. An improved understanding of recombined viral RNA synthesis may enhance our capacity to engineer improved vaccines and virotherapies in the future.
Collapse
Affiliation(s)
- Sydni Caet Smith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
| | - Jennifer Gribble
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
| | - Julia R Diller
- Department of Pediatrics, Vanderbilt University Medical Center
| | - Michelle A Wiebe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
| | - Timothy W Thoner
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
| | - Mark R Denison
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
- Department of Pediatrics, Vanderbilt University Medical Center
| | - Kristen M Ogden
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center
- Department of Pediatrics, Vanderbilt University Medical Center
| |
Collapse
|
33
|
Kanai Y, Kobayashi T. Rotavirus reverse genetics systems: Development and application. Virus Res 2021; 295:198296. [PMID: 33440223 DOI: 10.1016/j.virusres.2021.198296] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 12/14/2022]
Abstract
Rotaviruses (RVs) cause acute gastroenteritis in infants and young children. Since 2006, live-attenuated vaccines have reduced the number of RV-associated deaths; however, RV is still responsible for an estimated 228,047 annual deaths worldwide. RV, a member of the family Reoviridae, has an 11-segmented double-stranded RNA genome contained within a non-enveloped, triple layered virus particle. In 2017, a long-awaited helper virus-free reverse genetics system for RV was established. Since then, numerous studies have reported the generation of recombinant RVs; these studies verify the robustness of reverse genetics systems. This review provides technical insight into current reverse genetics systems for RVs, as well as discussing basic and applied studies that have used these systems.
Collapse
Affiliation(s)
- Yuta Kanai
- Department of Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Takeshi Kobayashi
- Department of Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
34
|
Metagenomic characterisation of additional and novel avian viruses from Australian wild ducks. Sci Rep 2020; 10:22284. [PMID: 33335272 PMCID: PMC7747739 DOI: 10.1038/s41598-020-79413-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Birds, notably wild ducks, are reservoirs of pathogenic and zoonotic viruses such as influenza viruses and coronaviruses. In the current study, we used metagenomics to detect and characterise avian DNA and RNA viruses from wild Pacific black ducks, Chestnut teals and Grey teals collected at different time points from a single location. We characterised a likely new species of duck aviadenovirus and a novel duck gyrovirus. We also report what, to the best of our knowledge, is the first finding of an avian orthoreovirus from Pacific black ducks and a rotavirus F from Chestnut teals. Other viruses characterised from the samples from these wild ducks belong to the virus families Astroviridae, Caliciviridae and Coronaviridae. Some of the viruses may have potential cross-species transmissibility, while others indicated a wide genetic diversity of duck viruses within a genus. The study also showed evidence of potential transmission of viruses along the East Asian-Australasian Flyway; potentially facilitated by migrating shorebirds. The detection and characterisation of several avian viruses not previously described, and causing asymptomatic but potentially also symptomatic infections suggest the need for more virus surveillance studies for pathogenic and potential zoonotic viruses in wildlife reservoirs.
Collapse
|
35
|
Mousavi-Nasab SD, Sabahi F, Kaghazian H, Paryan M, Mirab Samiee S, Ghaderi M, Zali F, Makvandi M. A Real-Time RT-PCR Assay for Genotyping of Rotavirus. IRANIAN BIOMEDICAL JOURNAL 2020; 24:399-404. [PMID: 32660931 PMCID: PMC7601544 DOI: 10.29252/ibj.24.6.394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 12/26/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND Human rotavirus (HRV) is the causative agent of severe gastroenteritis in children and responsible for two million hospitalizations and more than a half-million deaths annually. Sequence characteristics of the gene segments encoding the VP7 and VP4 proteins are used for the genotype classification of rotavirus. A wide variety of molecular methods are available, mainly based on reverse transcription PCR for rapid, specific and sensitive genotyping of rotaviruses. This study describes an alternative real-time PCR assay for genotyping of rotavirus. METHODS The samples of stools studied in this research have been collected from patients referred to Children's Medical Centers, Tehran, Iran. Rotavirus detection and genotyping were performed using the RT-PCR and semi-nested RT-PCR, respectively. Samples were then genotyped with a new real-time PCR. RESULTS The real-time PCR was able to genotype all positive samples with a mean Ct of 28.2. Besides, a concordance rate of 100% was detected between real-time PCR and semi-nested RT-PCR. CONCLUSION In this study, the genotyping of rotavirus with real-time PCR showed that this method can provide several favorable features, including high sensitivity and specificity, and a wide dynamic range for rotavirus genotyping.
Collapse
Affiliation(s)
- Seyed Dawood Mousavi-Nasab
- Department of Research and Development, Production and Research Complex, Pasteur Institute of Iran, Tehran, Iran
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Farzaneh Sabahi
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hooman Kaghazian
- Department of Research and Development, Production and Research Complex, Pasteur Institute of Iran, Tehran, Iran
| | - Mahdi Paryan
- Department of Research and Development, Production and Research Complex, Pasteur Institute of Iran, Tehran, Iran
| | - Siamak Mirab Samiee
- Reference Health Laboratories Research Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Mostafa Ghaderi
- Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran
| | - Fatemeh Zali
- Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Manoochehr Makvandi
- Infectious and Tropical Diseases Research Center, Health research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| |
Collapse
|
36
|
Abid N, Pietrucci D, Salemi M, Chillemi G. New Insights into the Effect of Residue Mutations on the Rotavirus VP1 Function Using Molecular Dynamic Simulations. J Chem Inf Model 2020; 60:5011-5025. [PMID: 32786703 DOI: 10.1021/acs.jcim.0c00475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rotavirus group A remains a major cause of diarrhea in infants and young children worldwide. The permanent emergence of new genotypes puts the potential effectiveness of vaccines under serious questions. Thirteen VP1 structures with mutations mapping to the RNA entry site were analyzed using molecular dynamics simulations, and the results were combined with the experimental findings reported previously. The results revealed structural fluctuations in the protein-protein recognition sites and in the bottleneck of the RNA entry site that may affect the interaction of different proteins and delay the initiation of the viral replication, respectively. Altogether, the structural analysis of VP1 in the region crucial for the initiation of the viral replication, mainly the bottleneck site, may boost efforts to develop antivirals, as they might complement the available vaccines.
Collapse
Affiliation(s)
- Nabil Abid
- Laboratory of Transmissible Diseases and Biological Active Substances LR99ES27, Faculty of Pharmacy, University of Monastir, Rue Ibn Sina, 5000 Monastir, Tunisia.,High Institute of Biotechnology of Sidi Thabet, Department of Biotechnology, University Manouba, BP-66, 2020 Ariana-Tunis, Tunisia
| | - Daniele Pietrucci
- Department of Biology, University of Rome Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Marco Salemi
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Emerging Pathogens Institute, University of Florida, P.O. Box 100009, Gainesville, Florida 32610-3633, United States
| | - Giovanni Chillemi
- Department for Innovation in Biological, Agro-Food and Forest Systems, DIBAF, University of Tuscia, Via S. Camillo de Lellis s.n.c., 01100 Viterbo, Italy.,Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, IBIOM, CNR, Via Giovanni Amendola, 122/O, 70126 Bari, Italy
| |
Collapse
|
37
|
Yang Y, Gaspard G, McMullen N, Duncan R. Polycistronic Genome Segment Evolution and Gain and Loss of FAST Protein Function during Fusogenic Orthoreovirus Speciation. Viruses 2020; 12:v12070702. [PMID: 32610593 PMCID: PMC7412057 DOI: 10.3390/v12070702] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/03/2020] [Accepted: 06/25/2020] [Indexed: 12/29/2022] Open
Abstract
The Reoviridae family is the only non-enveloped virus family with members that use syncytium formation to promote cell–cell virus transmission. Syncytiogenesis is mediated by a fusion-associated small transmembrane (FAST) protein, a novel family of viral membrane fusion proteins. Previous evidence suggested the fusogenic reoviruses arose from an ancestral non-fusogenic virus, with the preponderance of fusogenic species suggesting positive evolutionary pressure to acquire and maintain the fusion phenotype. New phylogenetic analyses that included the atypical waterfowl subgroup of avian reoviruses and recently identified new orthoreovirus species indicate a more complex relationship between reovirus speciation and fusogenic capacity, with numerous predicted internal indels and 5’-terminal extensions driving the evolution of the orthoreovirus’ polycistronic genome segments and their encoded FAST and fiber proteins. These inferred recombination events generated bi- and tricistronic genome segments with diverse gene constellations, they occurred pre- and post-orthoreovirus speciation, and they directly contributed to the evolution of the four extant orthoreovirus FAST proteins by driving both the gain and loss of fusion capability. We further show that two distinct post-speciation genetic events led to the loss of fusion in the waterfowl isolates of avian reovirus, a recombination event that replaced the p10 FAST protein with a heterologous, non-fusogenic protein and point substitutions in a conserved motif that destroyed the p10 assembly into multimeric fusion platforms.
Collapse
Affiliation(s)
- Yiming Yang
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; (Y.Y.); (G.G.); (N.M.)
| | - Gerard Gaspard
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; (Y.Y.); (G.G.); (N.M.)
| | - Nichole McMullen
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; (Y.Y.); (G.G.); (N.M.)
| | - Roy Duncan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; (Y.Y.); (G.G.); (N.M.)
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Correspondence:
| |
Collapse
|
38
|
Kumar D, Singh A, Kumar P, Uversky VN, Rao CD, Giri R. Understanding the penetrance of intrinsic protein disorder in rotavirus proteome. Int J Biol Macromol 2020; 144:892-908. [PMID: 31739058 PMCID: PMC7112477 DOI: 10.1016/j.ijbiomac.2019.09.166] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/09/2019] [Accepted: 09/20/2019] [Indexed: 01/03/2023]
Abstract
Rotavirus is a major cause of severe acute gastroenteritis in the infants and young children. The past decade has evidenced the role of intrinsically disordered proteins/regions (IDPs)/(IDPRs) in viral and other diseases. In general, (IDPs)/(IDPRs) are considered as dynamic conformational ensembles that devoid of a specific 3D structure, being associated with various important biological phenomena. Viruses utilize IDPs/IDPRs to survive in harsh environments, to evade the host immune system, and to highjack and manipulate host cellular proteins. The role of IDPs/IDPRs in Rotavirus biology and pathogenicity are not assessed so far, therefore, we have designed this study to deeply look at the penetrance of intrinsic disorder in rotavirus proteome consisting 12 proteins encoded by 11 segments of viral genome. Also, for all human rotaviral proteins, we have deciphered molecular recognition features (MoRFs), which are disorder based binding sites in proteins. Our study shows the wide spread of intrinsic disorder in several rotavirus proteins, primarily the nonstructural proteins NSP3, NSP4, and NSP5 that are involved in viral replication, translation, viroplasm formation and/or maturation. This study may serve as a primer for understanding the role of IDPs/MoRFs in rotavirus biology, design of alternative therapeutic strategies, and development of disorder-based drugs.
Collapse
Affiliation(s)
- Deepak Kumar
- Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh 175005, India
| | - Ankur Singh
- Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh 175005, India
| | - Prateek Kumar
- Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh 175005, India
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - C Durga Rao
- SRM University, AP - Amaravati, Neerukonda, Mangalagiri Mandal Guntur District, Mangalagiri, Andhra Pradesh 522502, India.
| | - Rajanish Giri
- Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh 175005, India; BioX Center, Indian Institute of Technology Mandi, Himachal Pradesh, India.
| |
Collapse
|
39
|
Horwitz JA, Jenni S, Harrison SC, Whelan SPJ. Structure of a rabies virus polymerase complex from electron cryo-microscopy. Proc Natl Acad Sci U S A 2020; 117:2099-2107. [PMID: 31953264 PMCID: PMC6995008 DOI: 10.1073/pnas.1918809117] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nonsegmented negative-stranded (NNS) RNA viruses, among them the virus that causes rabies (RABV), include many deadly human pathogens. The large polymerase (L) proteins of NNS RNA viruses carry all of the enzymatic functions required for viral messenger RNA (mRNA) transcription and replication: RNA polymerization, mRNA capping, and cap methylation. We describe here a complete structure of RABV L bound with its phosphoprotein cofactor (P), determined by electron cryo-microscopy at 3.3 Å resolution. The complex closely resembles the vesicular stomatitis virus (VSV) L-P, the one other known full-length NNS-RNA L-protein structure, with key local differences (e.g., in L-P interactions). Like the VSV L-P structure, the RABV complex analyzed here represents a preinitiation conformation. Comparison with the likely elongation state, seen in two structures of pneumovirus L-P complexes, suggests differences between priming/initiation and elongation complexes. Analysis of internal cavities within RABV L suggests distinct template and product entry and exit pathways during transcription and replication.
Collapse
Affiliation(s)
- Joshua A Horwitz
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115;
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115
| | - Sean P J Whelan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115;
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| |
Collapse
|
40
|
Suzuki H. Rotavirus Replication: Gaps of Knowledge on Virus Entry and Morphogenesis. TOHOKU J EXP MED 2020; 248:285-296. [PMID: 31447474 DOI: 10.1620/tjem.248.285] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In 1973, rotaviruses A (RVAs) were discovered as major causative agents of acute gastroenteritis in infants and young children worldwide. The infectious RV virion is an icosahedral particle composed of three concentric protein layers surrounding the 11 double-stranded (dsRNA) segments. An in vitro replication system for RVs in permanent cell lines was developed in 1982 and expanded to replication in intestinal organoids in 2015. However, the details of rotavirus (RV) entry into cells and particle maturation mechanisms at the molecular level remain incompletely understood. Slowing down human RVA replication in cell culture on ice allowed morphological visualization of virus particle entry and the assembly of triple-layered particles (virion). Although RVAs are non-enveloped viruses, after virus attachment to the cell membrane, the virus enters the cell by perforating the plasma membrane by a fusion mechanism involving VP5* of the cleaved VP4 protein, as the alternative virus entry route besides the receptor-mediated endocytosis which is generally accepted. After assembling double-layered particles (DLPs) in viroplasm or cytoplasm, they appear to be connected with the endoplasmic reticulum (ER) membrane and become coated with outer capsid proteins (VP4 and VP7) in a coating process. The perforation of the ER membrane is caused by an unknown mechanism following interaction between non-structural protein 4 (NSP4) and the inner capsid protein VP6 of the DLPs. The coating process is closely related to the formation of a hetero-oligomeric complex (NSP4, VP4 and VP7). These lines of evidence suggest the existence of novel mechanisms of RV morphogenesis.
Collapse
|
41
|
Cao D, Gao Y, Roesler C, Rice S, D'Cunha P, Zhuang L, Slack J, Domke M, Antonova A, Romanelli S, Keating S, Forero G, Juneja P, Liang B. Cryo-EM structure of the respiratory syncytial virus RNA polymerase. Nat Commun 2020; 11:368. [PMID: 31953395 PMCID: PMC6969064 DOI: 10.1038/s41467-019-14246-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022] Open
Abstract
The respiratory syncytial virus (RSV) RNA polymerase, constituted of a 250 kDa large (L) protein and tetrameric phosphoprotein (P), catalyzes three distinct enzymatic activities — nucleotide polymerization, cap addition, and cap methylation. How RSV L and P coordinate these activities is poorly understood. Here, we present a 3.67 Å cryo-EM structure of the RSV polymerase (L:P) complex. The structure reveals that the RNA dependent RNA polymerase (RdRp) and capping (Cap) domains of L interact with the oligomerization domain (POD) and C-terminal domain (PCTD) of a tetramer of P. The density of the methyltransferase (MT) domain of L and the N-terminal domain of P (PNTD) is missing. Further analysis and comparison with other RNA polymerases at different stages suggest the structure we obtained is likely to be at an elongation-compatible stage. Together, these data provide enriched insights into the interrelationship, the inhibitors, and the evolutionary implications of the RSV polymerase. Respiratory syncytial virus (RSV) is a pathogenic non-segmented negative-sense RNA virus and active RSV polymerase is composed of a 250 kDa large (L) protein and tetrameric phosphoprotein (P). Here, the authors present the 3.67 Å cryo-EM structure of the RSV polymerase (L:P) complex.
Collapse
Affiliation(s)
- Dongdong Cao
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Yunrong Gao
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Claire Roesler
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Samantha Rice
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Paul D'Cunha
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lisa Zhuang
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Julia Slack
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Mason Domke
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Anna Antonova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Sarah Romanelli
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Shayon Keating
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gabriela Forero
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Puneet Juneja
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Bo Liang
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| |
Collapse
|
42
|
Jenni S, Bloyet LM, Diaz-Avalos R, Liang B, Whelan SPJ, Grigorieff N, Harrison SC. Structure of the Vesicular Stomatitis Virus L Protein in Complex with Its Phosphoprotein Cofactor. Cell Rep 2020; 30:53-60.e5. [PMID: 31914397 PMCID: PMC7049099 DOI: 10.1016/j.celrep.2019.12.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 11/15/2022] Open
Abstract
The large (L) proteins of non-segmented, negative-strand RNA viruses are multifunctional enzymes that produce capped, methylated, and polyadenylated mRNA and replicate the viral genome. A phosphoprotein (P), required for efficient RNA-dependent RNA polymerization from the viral ribonucleoprotein (RNP) template, regulates the function and conformation of the L protein. We report the structure of vesicular stomatitis virus L in complex with its P cofactor determined by electron cryomicroscopy at 3.0 Å resolution, enabling us to visualize bound segments of P. The contacts of three P segments with multiple L domains show how P induces a closed, compact, initiation-competent conformation. Binding of P to L positions its N-terminal domain adjacent to a putative RNA exit channel for efficient encapsidation of newly synthesized genomes with the nucleoprotein and orients its C-terminal domain to interact with an RNP template. The model shows that a conserved tryptophan in the priming loop can support the initiating 5' nucleotide.
Collapse
Affiliation(s)
- Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Louis-Marie Bloyet
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ruben Diaz-Avalos
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Bo Liang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sean P J Whelan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Microbiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nikolaus Grigorieff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
43
|
Structure of RdRps Within a Transcribing dsRNA Virus Provides Insights Into the Mechanisms of RNA Synthesis. J Mol Biol 2020; 432:358-366. [DOI: 10.1016/j.jmb.2019.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/11/2019] [Accepted: 09/16/2019] [Indexed: 12/19/2022]
|
44
|
Reoviridae transcription is more than an open-and-shut case. Nat Struct Mol Biol 2019; 26:991-993. [PMID: 31695186 DOI: 10.1038/s41594-019-0328-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
45
|
In Vitro Double-Stranded RNA Synthesis by Rotavirus Polymerase Mutants with Lesions at Core Shell Contact Sites. J Virol 2019; 93:JVI.01049-19. [PMID: 31341048 DOI: 10.1128/jvi.01049-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 07/17/2019] [Indexed: 12/23/2022] Open
Abstract
The rotavirus polymerase VP1 mediates all stages of viral RNA synthesis within the confines of subviral particles and while associated with the core shell protein VP2. Transcription (positive-strand RNA [+RNA] synthesis) by VP1 occurs within double-layered particles (DLPs), while genome replication (double-stranded RNA [dsRNA] synthesis) by VP1 occurs within assembly intermediates. VP2 is critical for VP1 enzymatic activity; yet, the mechanism by which the core shell protein triggers polymerase function remains poorly understood. Structural analyses of transcriptionally competent DLPs show that VP1 is located beneath the VP2 core shell and sits slightly off-center from each of the icosahedral 5-fold axes. In this position, the polymerase is contacted by the core shell at 5 distinct surface-exposed sites, comprising VP1 residues 264 to 267, 547 to 550, 614 to 620, 968 to 980, and 1022 to 1025. Here, we sought to test the functional significance of these VP2 contact sites on VP1 with regard to polymerase activity. We engineered 19 recombinant VP1 (rVP1) proteins that contained single- or multipoint alanine mutations within each individual contact site and assayed them for the capacity to synthesize dsRNA in vitro in the presence of rVP2. Three rVP1 mutants (E265A/L267A, R614A, and D971A/S978A/I980A) exhibited diminished in vitro dsRNA synthesis. Despite their loss-of-function phenotypes, the mutants did not show major structural changes in silico, and they maintained their overall capacity to bind rVP2 in vitro via their nonmutated contact sites. These results move us toward a mechanistic understanding of rotavirus replication and identify precise VP2-binding sites on the polymerase surface that are critical for its enzymatic activation.IMPORTANCE Rotaviruses are important pathogens that cause severe gastroenteritis in the young of many animals. The viral polymerase VP1 mediates all stages of viral RNA synthesis, and it requires the core shell protein VP2 for its enzymatic activity. Yet, there are several gaps in knowledge about how VP2 engages and activates VP1. Here, we probed the functional significance of 5 distinct VP2 contact sites on VP1 that were revealed through previous structural studies. Specifically, we engineered alanine amino acid substitutions within each of the 5 VP1 regions and assayed the mutant polymerases for the capacity to synthesize RNA in the presence of VP2 in a test tube. Our results identified residues within 3 of the VP2 contact sites that are critical for robust polymerase activity. These results are important because they enhance the understanding of a key step of the rotavirus replication cycle.
Collapse
|
46
|
Gilman MSA, Liu C, Fung A, Behera I, Jordan P, Rigaux P, Ysebaert N, Tcherniuk S, Sourimant J, Eléouët JF, Sutto-Ortiz P, Decroly E, Roymans D, Jin Z, McLellan JS. Structure of the Respiratory Syncytial Virus Polymerase Complex. Cell 2019; 179:193-204.e14. [PMID: 31495574 PMCID: PMC7111336 DOI: 10.1016/j.cell.2019.08.014] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/03/2019] [Accepted: 08/06/2019] [Indexed: 01/29/2023]
Abstract
Numerous interventions are in clinical development for respiratory syncytial virus (RSV) infection, including small molecules that target viral transcription and replication. These processes are catalyzed by a complex comprising the RNA-dependent RNA polymerase (L) and the tetrameric phosphoprotein (P). RSV P recruits multiple proteins to the polymerase complex and, with the exception of its oligomerization domain, is thought to be intrinsically disordered. Despite their critical roles in RSV transcription and replication, structures of L and P have remained elusive. Here, we describe the 3.2-Å cryo-EM structure of RSV L bound to tetrameric P. The structure reveals a striking tentacular arrangement of P, with each of the four monomers adopting a distinct conformation. The structure also rationalizes inhibitor escape mutants and mutations observed in live-attenuated vaccine candidates. These results provide a framework for determining the molecular underpinnings of RSV replication and transcription and should facilitate the design of effective RSV inhibitors.
Collapse
Affiliation(s)
- Morgan S A Gilman
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Cheng Liu
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Amy Fung
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Ishani Behera
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Paul Jordan
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Peter Rigaux
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Nina Ysebaert
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Sergey Tcherniuk
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | - Julien Sourimant
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | | | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Dirk Roymans
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Zhinan Jin
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
| |
Collapse
|
47
|
Cressey TN, Noton SL, Nagendra K, Braun MR, Fearns R. Mechanism for de novo initiation at two sites in the respiratory syncytial virus promoter. Nucleic Acids Res 2019; 46:6785-6796. [PMID: 29873775 PMCID: PMC6061868 DOI: 10.1093/nar/gky480] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/17/2018] [Indexed: 12/18/2022] Open
Abstract
The respiratory syncytial virus (RSV) RNA dependent RNA polymerase (RdRp) initiates two RNA synthesis processes from the viral promoter: genome replication from position 1U and mRNA transcription from position 3C. Here, we examined the mechanism by which a single promoter can direct initiation from two sites. We show that initiation at 1U and 3C occurred independently of each other, and that the same RdRp was capable of precisely selecting the two sites. The RdRp preferred to initiate at 3C, but initiation site selection could be modulated by the relative concentrations of ATP versus GTP. Analysis of template mutations indicated that the RdRp could bind ATP and CTP, or GTP, independently of template nucleotides. The data suggest a model in which innate affinity of the RdRp for particular NTPs, coupled with a repeating element within the promoter, allows precise initiation of replication at 1U or transcription at 3C.
Collapse
Affiliation(s)
- Tessa N Cressey
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Sarah L Noton
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kartikeya Nagendra
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Molly R Braun
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Rachel Fearns
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| |
Collapse
|
48
|
In situ structures of RNA-dependent RNA polymerase inside bluetongue virus before and after uncoating. Proc Natl Acad Sci U S A 2019; 116:16535-16540. [PMID: 31350350 DOI: 10.1073/pnas.1905849116] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bluetongue virus (BTV), a major threat to livestock, is a multilayered, nonturreted member of the Reoviridae, a family of segmented dsRNA viruses characterized by endogenous RNA transcription through an RNA-dependent RNA polymerase (RdRp). To date, the structure of BTV RdRp has been unknown, limiting our mechanistic understanding of BTV transcription and hindering rational drug design effort targeting this essential enzyme. Here, we report the in situ structures of BTV RdRp VP1 in both the triple-layered virion and double-layered core, as determined by cryo-electron microscopy (cryoEM) and subparticle reconstruction. BTV RdRp has 2 unique motifs not found in other viral RdRps: a fingernail, attached to the conserved fingers subdomain, and a bundle of 3 helices: 1 from the palm subdomain and 2 from the N-terminal domain. BTV RdRp VP1 is anchored to the inner surface of the capsid shell via 5 asymmetrically arranged N termini of the inner capsid shell protein VP3A around the 5-fold axis. The structural changes of RdRp VP1 and associated capsid shell proteins between BTV virions and cores suggest that the detachment of the outer capsid proteins VP2 and VP5 during viral entry induces both global movements of the inner capsid shell and local conformational changes of the N-terminal latch helix (residues 34 to 51) of 1 inner capsid shell protein VP3A, priming RdRp VP1 within the capsid for transcription. Understanding this mechanism in BTV also provides general insights into RdRp activation and regulation during viral entry of other multilayered, nonturreted dsRNA viruses.
Collapse
|
49
|
In situ Structure of Rotavirus VP1 RNA-Dependent RNA Polymerase. J Mol Biol 2019; 431:3124-3138. [PMID: 31233764 DOI: 10.1016/j.jmb.2019.06.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/07/2019] [Accepted: 06/14/2019] [Indexed: 02/03/2023]
Abstract
Rotaviruses, like other non-enveloped, double-strand RNA viruses, package an RNA-dependent RNA polymerase (RdRp) with each duplex of their segmented genomes. Rotavirus cell entry results in loss of an outer protein layer and delivery into the cytosol of an intact, inner capsid particle (the "double-layer particle," or DLP). The RdRp, designated VP1, is active inside the DLP; each VP1 achieves many rounds of mRNA transcription from its associated genome segment. Previous work has shown that one VP1 molecule lies close to each 5-fold axis of the icosahedrally symmetric DLP, just beneath the inner surface of its protein shell, embedded in tightly packed RNA. We have determined a high-resolution structure for the rotavirus VP1 RdRp in situ, by local reconstruction of density around individual 5-fold positions. We have analyzed intact virions ("triple-layer particles"), non-transcribing DLPs and transcribing DLPs. Outer layer dissociation enables the DLP to synthesize RNA, in vitro as well as in vivo, but appears not to induce any detectable structural change in the RdRp. Addition of NTPs, Mg2+, and S-adenosylmethionine, which allows active transcription, results in conformational rearrangements, in both VP1 and the DLP capsid shell protein, that allow a transcript to exit the polymerase and the particle. The position of VP1 (among the five symmetrically related alternatives) at one vertex does not correlate with its position at other vertices. This stochastic distribution of site occupancies limits long-range order in the 11-segment, double-strand RNA genome.
Collapse
|
50
|
Ding K, Celma CC, Zhang X, Chang T, Shen W, Atanasov I, Roy P, Zhou ZH. In situ structures of rotavirus polymerase in action and mechanism of mRNA transcription and release. Nat Commun 2019; 10:2216. [PMID: 31101900 PMCID: PMC6525196 DOI: 10.1038/s41467-019-10236-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/25/2019] [Indexed: 01/11/2023] Open
Abstract
Transcribing and replicating a double-stranded genome require protein modules to unwind, transcribe/replicate nucleic acid substrates, and release products. Here we present in situ cryo-electron microscopy structures of rotavirus dsRNA-dependent RNA polymerase (RdRp) in two states pertaining to transcription. In addition to the previously discovered universal "hand-shaped" polymerase core domain shared by DNA polymerases and telomerases, our results show the function of N- and C-terminal domains of RdRp: the former opens the genome duplex to isolate the template strand; the latter splits the emerging template-transcript hybrid, guides genome reannealing to form a transcription bubble, and opens a capsid shell protein (CSP) to release the transcript. These two "helicase" domains also extensively interact with CSP, which has a switchable N-terminal helix that, like cellular transcriptional factors, either inhibits or promotes RdRp activity. The in situ structures of RdRp, CSP, and RNA in action inform mechanisms of not only transcription, but also replication.
Collapse
Affiliation(s)
- Ke Ding
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
| | - Cristina C Celma
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Xing Zhang
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Thomas Chang
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
| | - Wesley Shen
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
| | - Ivo Atanasov
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Polly Roy
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
| | - Z Hong Zhou
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA.
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA.
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA.
| |
Collapse
|