1
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He QY, Zhao HF, Meng L, Geng Z, Gao ZQ, Qi XY, Dong YH, Zhang H. A cardioviral 2C-ATP complex structure reveals the essential role of a conserved arginine in regulation of cardioviral 2C activity. J Virol 2024:e0091124. [PMID: 39240112 DOI: 10.1128/jvi.00911-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 08/02/2024] [Indexed: 09/07/2024] Open
Abstract
2C is a highly conserved picornaviral non-structural protein with ATPase activity and plays a multifunctional role in the viral life cycle as a promising target for anti-picornavirus drug development. While the structure-function of enteroviral 2Cs have been well studied, cardioviral 2Cs remain largely uncharacterized. Here, an endogenous ATP molecule was identified in the crystal structure of 2C from encephalomyocarditis virus (EMCV, Cardiovirus A). The ATP is bound into the ATPase active site with a unique compact conformation. Notably, the γ-phosphate of ATP directly interacts with Arg311 (conserved in cardioviral 2Cs), and its mutation significantly inhibits the ATPase activity. Unexpectedly, this mutation remarkably promotes 2C self-oligomerization and viral replication efficiency. Molecular dynamic simulations showed that the Arg311 side chain is highly dynamic, indicating it may function as a switch between the activation state and the inhibition state of ATPase activity. A hexameric ring model of EMCV 2C full length indicated that the C-terminal helix may get close to the N-terminal amphipathic helices to form a continuous positive region for RNA binding. The RNA-binding studies of EMCV 2C revealed that the RNA length is closely associated with the RNA-binding affinities and indicated that the substrate may wrap around the outer surface of the hexamer. Our studies provide a biochemical framework to guide the characterization of EMCV 2C and the essential role of arginine in cardioviral 2C functions. IMPORTANCE Encephalomyocarditis virus (Cardiovirus A) is the causative agent of the homonymous disease, which may induce myocarditis, encephalitis, and reproductive disorders in various mammals. 2C protein is functionally indispensable and a promising target for drug development involving broad-spectrum picornaviral inhibitors. Here, an endogenous ATP molecule with a unique conformation was discovered by a combination of protein crystallography and high-performance liquid chromatography in the encephalomyocarditis virus (EMCV) 2C structure. Biochemical and structural characterization analysis of EMCV 2C revealed the critical role of conserved Arg311 in ATPase activity and self-oligomerization of EMCV 2C. The viral replication kinetics and infectivity study suggested that the residue negatively regulated the infectivity titer and virus encapsulation efficiency of EMCV and is, therefore, crucial for 2C protein to promote viral replication. Our systemic structure-function analysis provides unique insights into the function and regulation mechanism of cardioviral 2C protein.
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Affiliation(s)
- Qing-Yi He
- School of Life Sciences, University of Science and Technology of China, Hefei, China
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Hai-Fan Zhao
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Liang Meng
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhi Geng
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Zeng-Qiang Gao
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Xin-Yu Qi
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yu-Hui Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Heng Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
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2
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Yin C, Zhao H, Xia X, Pan Z, Li D, Zhang L. Picornavirus 2C proteins: structure-function relationships and interactions with host factors. Front Cell Infect Microbiol 2024; 14:1347615. [PMID: 38465233 PMCID: PMC10921941 DOI: 10.3389/fcimb.2024.1347615] [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: 12/01/2023] [Accepted: 02/07/2024] [Indexed: 03/12/2024] Open
Abstract
Picornaviruses, which are positive-stranded, non-enveloped RNA viruses, are known to infect people and animals with a broad spectrum of diseases. Among the nonstructural proteins in picornaviruses, 2C proteins are highly conserved and exhibit multiple structural domains, including amphipathic α-helices, an ATPase structural domain, and a zinc finger structural domain. This review offers a comprehensive overview of the functional structures of picornaviruses' 2C protein. We summarize the mechanisms by which the 2C protein enhances viral replication. 2C protein interacts with various host factors to form the replication complex, ultimately promoting viral replication. We review the mechanisms through which picornaviruses' 2C proteins interact with the NF-κB, RIG-I, MDA5, NOD2, and IFN pathways, contributing to the evasion of the antiviral innate immune response. Additionally, we provide an overview of broad-spectrum antiviral drugs for treating various enterovirus infections, such as guanidine hydrochloride, fluoxetine, and dibucaine derivatives. These drugs may exert their inhibitory effects on viral infections by targeting interactions with 2C proteins. The review underscores the need for further research to elucidate the precise mechanisms of action of 2C proteins and to identify additional host factors for potential therapeutic intervention. Overall, this review contributes to a deeper understanding of picornaviruses and offers insights into the antiviral strategies against these significant viral pathogens.
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Affiliation(s)
- Chunhui Yin
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Haomiao Zhao
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Xiaoyi Xia
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Zhengyang Pan
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Daoqun Li
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Leiliang Zhang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
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3
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Wang Q, Meng H, Ge D, Shan H, Geri L, Liu F. Structural and nonstructural proteins of Senecavirus A: Recent research advances, and lessons learned from those of other picornaviruses. Virology 2023; 585:155-163. [PMID: 37348144 DOI: 10.1016/j.virol.2023.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Senecavirus A (SVA) is an emerging virus, causing vesicular disease in swine. SVA is a single-stranded, positive-sense RNA virus, which is the only member of the genus Senecavirus in the family Picornaviridae. SVA genome encodes 12 proteins: L, VP4, VP2, VP3, VP1, 2A, 2B, 2C, 3A, 3B, 3C and 3D. The VP1 to VP4 are structural proteins, and the others are nonstructural proteins. The replication of SVA in host cells is a complex process coordinated by an elaborate interplay between the structural and nonstructural proteins. Structural proteins are primarily involved in the invasion and assembly of virions. Nonstructural proteins modulate viral RNA translation and replication, and also take part in antagonizing the antiviral host response and in disrupting some cellular processes to allow virus replication. Here, we systematically reviewed the molecular functions of SVA structural and nonstructural proteins by reference to literatures of SVA itself and other picornaviruses.
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Affiliation(s)
- Qianqian Wang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, China; College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010011, China
| | - Hailan Meng
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, China
| | - Dong Ge
- Qingdao Lijian Bio-tech Co., Ltd., Qingdao, 266114, China
| | - Hu Shan
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, China
| | - Letu Geri
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010011, China.
| | - Fuxiao Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, 266109, China.
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4
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Kejriwal R, Evans T, Calabrese J, Swistak L, Alexandrescu L, Cohen M, Rahman N, Henriksen N, Charan Dash R, Hadden MK, Stonehouse NJ, Rowlands DJ, Kingston NJ, Hartnoll M, Dobson SJ, White SJ. Development of Enterovirus Antiviral Agents That Target the Viral 2C Protein. ChemMedChem 2023; 18:e202200541. [PMID: 36792530 DOI: 10.1002/cmdc.202200541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
The Enterovirus (EV) genus includes several important human and animal pathogens. EV-A71, EV-D68, poliovirus (PV), and coxsackievirus (CV) outbreaks have affected millions worldwide, causing a range of upper respiratory, skin, and neuromuscular diseases, including acute flaccid myelitis, and hand-foot-and-mouth disease. There are no FDA-approved antiviral therapeutics for these enteroviruses. This study describes novel antiviral compounds targeting the conserved non-structural viral protein 2C with low micromolar to nanomolar IC50 values. The selection of resistant mutants resulted in amino acid substitutions in the viral capsid protein, implying these compounds may play a role in inhibiting the interaction of 2C and the capsid protein. The assembly and encapsidation stages of the viral life cycle still need to be fully understood, and the inhibitors reported here could be useful probes in understanding these processes.
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Affiliation(s)
- Rishabh Kejriwal
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Tristan Evans
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Joshua Calabrese
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Lea Swistak
- Institut Pasteur, Université Paris Cité Dynamics of Host-Pathogen Interactions Unit, 75015, Paris, France
| | - Lauren Alexandrescu
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Michelle Cohen
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Nahian Rahman
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Niel Henriksen
- Atomwise Inc., 717 Market St #800, San Francisco, CA 94103, USA
| | - Radha Charan Dash
- Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Unit 3092, Storrs, CT 06029-3092, USA
| | - M Kyle Hadden
- Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Unit 3092, Storrs, CT 06029-3092, USA
| | - Nicola J Stonehouse
- School of Molecular and Cellular Biology Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Rowlands
- School of Molecular and Cellular Biology Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Natalie J Kingston
- School of Molecular and Cellular Biology Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Madeline Hartnoll
- School of Molecular and Cellular Biology Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Samuel J Dobson
- School of Molecular and Cellular Biology Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon J White
- Biology/Physics Building Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
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5
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Liu L, Wang M, Yu R, Li H, Fan J, Yan J, Liu Z, Zhang S. Preparation and verification of a monoclonal antibody against a conserved linear epitope in enterovirus A protein 2C. J Virol Methods 2021; 298:114298. [PMID: 34560110 DOI: 10.1016/j.jviromet.2021.114298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 11/29/2022]
Abstract
Enterovirus A (EV-A) species are the main agents responsible for hand, foot, and mouth disease (HFMD), a serious public health concern. Lack of appropriate reagents prevents the mechanistic study of these virus infections. 2C protein, a non-structural protein of Enterovirus, is crucial for viral replication and antiviral immunity. Here, preparation and testing of a monoclonal antibody by immunizing mice with Coxsackievirus A10 protein 2C (CVA10-2C) was reported. This antibody could identify most EV-A types, both conventional and unconventional groups. We also mapped the antibody epitope SLATGIIARA, which is highly conserved in EV-A species and located in the ATPase domain. Some key amino acids include G140, I141, I142, and R144. In conclusion, we generated a recombinant monoclonal antibody against multiple EVA types and confirmed its performance, which may facilitate the future study of Enterovirus A infection and many potential applications, such as the diagnosis of pathogen or the development of antiviral therapies.
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Affiliation(s)
- Lizhen Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
| | - Min Wang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
| | - Rui Yu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
| | - Hongzheng Li
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China; Department of Microbiology, Weifang Medical University, Weifang 261053, China.
| | - Jun Fan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
| | - Jingjing Yan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
| | - Zhijun Liu
- Department of Microbiology, Weifang Medical University, Weifang 261053, China.
| | - Shuye Zhang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
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6
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Real-Hohn A, Blaas D. Rhinovirus Inhibitors: Including a New Target, the Viral RNA. Viruses 2021; 13:1784. [PMID: 34578365 PMCID: PMC8473194 DOI: 10.3390/v13091784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/21/2021] [Accepted: 09/03/2021] [Indexed: 12/18/2022] Open
Abstract
Rhinoviruses (RVs) are the main cause of recurrent infections with rather mild symptoms characteristic of the common cold. Nevertheless, RVs give rise to enormous numbers of absences from work and school and may become life-threatening in particular settings. Vaccination is jeopardised by the large number of serotypes eliciting only poorly cross-neutralising antibodies. Conversely, antivirals developed over the years failed FDA approval because of a low efficacy and/or side effects. RV species A, B, and C are now included in the fifteen species of the genus Enteroviruses based upon the high similarity of their genome sequences. As a result of their comparably low pathogenicity, RVs have become a handy model for other, more dangerous members of this genus, e.g., poliovirus and enterovirus 71. We provide a short overview of viral proteins that are considered potential drug targets and their corresponding drug candidates. We briefly mention more recently identified cellular enzymes whose inhibition impacts on RVs and comment novel approaches to interfere with infection via aggregation, virus trapping, or preventing viral access to the cell receptor. Finally, we devote a large part of this article to adding the viral RNA genome to the list of potential drug targets by dwelling on its structure, folding, and the still debated way of its exit from the capsid. Finally, we discuss the recent finding that G-quadruplex stabilising compounds impact on RNA egress possibly via obfuscating the unravelling of stable secondary structural elements.
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Affiliation(s)
- Antonio Real-Hohn
- Center for Medical Biochemistry, Vienna Biocenter, Max Perutz Laboratories, Medical University of Vienna, Dr. Bohr Gasse 9/3, A-1030 Vienna, Austria
| | - Dieter Blaas
- Center for Medical Biochemistry, Vienna Biocenter, Max Perutz Laboratories, Medical University of Vienna, Dr. Bohr Gasse 9/3, A-1030 Vienna, Austria
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7
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Chen P, Li Z, Cui S. Picornaviral 2C proteins: A unique ATPase family critical in virus replication. Enzymes 2021; 49:235-264. [PMID: 34696834 DOI: 10.1016/bs.enz.2021.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The 2C proteins of Picornaviridae are unique members of AAA+ protein family. Although picornavirus 2C shares many conserved motifs with Super Family 3 DNA helicases, duplex unwinding activity of many 2C proteins remains undetected, and high-resolution structures of 2C hexamers are unavailable. All characterized 2C proteins exhibit ATPase activity, but the purpose of ATP hydrolysis is not fully understood. 2C is highly conserved among picornaviruses and plays crucial roles in nearly all steps of the virus lifecycle. It is therefore considered as an effective target for broad-spectrum antiviral drug development. Crystallographic investigation of enterovirus 2C proteins provide structural details important for the elucidation of 2C function and development of antiviral drugs. This chapter summarizes not only the findings of enzymatic activities, biochemical and structural characterizations of the 2C proteins, but also their role in virus replication, immune evasion and morphogenesis. The linkage between structure and function of the 2C proteins is discussed in detail. Inhibitors targeting the 2C proteins are also summarized to provide an overview of drug development. Finally, we raise several key questions to be addressed in this field and provide future research perspective on this unique class of ATPases.
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Affiliation(s)
- Pu Chen
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhijian Li
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Sheng Cui
- Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
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8
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Wang SH, Wang K, Zhao K, Hua SC, Du J. The Structure, Function, and Mechanisms of Action of Enterovirus Non-structural Protein 2C. Front Microbiol 2020; 11:615965. [PMID: 33381104 PMCID: PMC7767853 DOI: 10.3389/fmicb.2020.615965] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 11/23/2020] [Indexed: 12/16/2022] Open
Abstract
Enteroviruses are a group of RNA viruses belonging to the family Picornaviridae. They include human enterovirus groups A, B, C, and D as well as non-human enteroviruses. Enterovirus infections can lead to hand, foot, and mouth disease and herpangina, whose clinical manifestations are often mild, although some strains can result in severe neurological complications such as encephalitis, myocarditis, meningitis, and poliomyelitis. To date, research on enterovirus non-structural proteins has mainly focused on the 2A and 3C proteases and 3D polymerase. However, another non-structural protein, 2C, is the most highly conserved protein, and plays a vital role in the enterovirus life cycle. There are relatively few studies on this protein. Previous studies have demonstrated that enterovirus 2C is involved in virus uncoating, host cell membrane rearrangements, RNA replication, encapsidation, morphogenesis, ATPase, helicase, and chaperoning activities. Despite ongoing research, little is known about the pathogenesis of enterovirus 2C proteins in viral replication or in the host innate immune system. In this review, we discuss and summarize the current understanding of the structure, function, and mechanism of the enterovirus 2C proteins, focusing on the key mutations and motifs involved in viral infection, replication, and immune regulation. We also focus on recent progress in research into the role of 2C proteins in regulating the pattern recognition receptors and type I interferon signaling pathway to facilitate viral replication. Given these functions and mechanisms, the potential application of the 2C proteins as a target for anti-viral drug development is also discussed. Future studies will focus on the determination of more crystal structures of enterovirus 2C proteins, which might provide more potential targets for anti-viral drug development against enterovirus infections.
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Affiliation(s)
- Shao-Hua Wang
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, China
| | - Kuan Wang
- Department of Neurotrauma, The First Hospital of Jilin University, Changchun, China
| | - Ke Zhao
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, China
| | - Shu-Cheng Hua
- Department of Internal Medicine, The First Hospital of Jilin University, Changchun, China
| | - Juan Du
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China
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9
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Bauer L, Manganaro R, Zonsics B, Strating JRPM, El Kazzi P, Lorenzo Lopez M, Ulferts R, van Hoey C, Maté MJ, Langer T, Coutard B, Brancale A, van Kuppeveld FJM. Fluoxetine Inhibits Enterovirus Replication by Targeting the Viral 2C Protein in a Stereospecific Manner. ACS Infect Dis 2019; 5:1609-1623. [PMID: 31305993 PMCID: PMC6747591 DOI: 10.1021/acsinfecdis.9b00179] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
![]()
Enteroviruses
(family Picornaviridae) comprise a large group of
human pathogens against which no licensed antiviral therapy exists.
Drug-repurposing screens uncovered the FDA-approved drug fluoxetine
as a replication inhibitor of enterovirus B and D species. Fluoxetine
likely targets the nonstructural viral protein 2C, but detailed mode-of-action
studies are missing because structural information on 2C of fluoxetine-sensitive
enteroviruses is lacking. We here show that broad-spectrum anti-enteroviral
activity of fluoxetine is stereospecific concomitant with binding
to recombinant 2C. (S)-Fluoxetine inhibits with a
5-fold lower 50% effective concentration (EC50) than racemic
fluoxetine. Using a homology model of 2C of the fluoxetine-sensitive
enterovirus coxsackievirus B3 (CVB3) based upon a recently elucidated
structure of a fluoxetine-insensitive enterovirus, we predicted stable
binding of (S)-fluoxetine. Structure-guided mutations
disrupted binding and rendered coxsackievirus B3 (CVB3) resistant
to fluoxetine. The study provides new insights into the anti-enteroviral
mode-of-action of fluoxetine. Importantly, using only (S)-fluoxetine would allow for lower dosing in patients, thereby likely
reducing side effects.
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Affiliation(s)
- Lisa Bauer
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht 3584CL, The Netherlands
| | - Roberto Manganaro
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, United Kingdom
| | - Birgit Zonsics
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, United Kingdom
| | - Jeroen R. P. M. Strating
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht 3584CL, The Netherlands
| | - Priscila El Kazzi
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098 Centre National de la Recherche Scientifique, Université de la Méditerranée and Université de Provence, Aix-Marseille Université, Case 925, 163 Avenue de Luminy, Marseille 3288 CEDEX 9, France
| | - Moira Lorenzo Lopez
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, United Kingdom
| | - Rachel Ulferts
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht 3584CL, The Netherlands
| | - Clara van Hoey
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Althanstraße 14, Vienna A-1090, Austria
| | - Maria J. Maté
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098 Centre National de la Recherche Scientifique, Université de la Méditerranée and Université de Provence, Aix-Marseille Université, Case 925, 163 Avenue de Luminy, Marseille 3288 CEDEX 9, France
| | - Thierry Langer
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Althanstraße 14, Vienna A-1090, Austria
| | - Bruno Coutard
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098 Centre National de la Recherche Scientifique, Université de la Méditerranée and Université de Provence, Aix-Marseille Université, Case 925, 163 Avenue de Luminy, Marseille 3288 CEDEX 9, France
- Unité des Virus Emergents, UVE: Aix-Marseille Univ-IRD 190-Inserm 1207-IHU Méditerranée Infection, 13385 Marseille, CEDEX 5, France
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, United Kingdom
| | - Frank J. M. van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht 3584CL, The Netherlands
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10
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Guan H, Tian J, Zhang C, Qin B, Cui S. Crystal structure of a soluble fragment of poliovirus 2CATPase. PLoS Pathog 2018; 14:e1007304. [PMID: 30231078 PMCID: PMC6166989 DOI: 10.1371/journal.ppat.1007304] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 10/01/2018] [Accepted: 08/28/2018] [Indexed: 11/18/2022] Open
Abstract
Poliovirus (PV) 2CATPase is the most studied 2C protein in the Picornaviridae family. It is involved in RNA replication, encapsidation and uncoating and many inhibitors have been found that target PV 2CATPase. Despite numerous investigations to characterize its functions, a high-resolution structure of PV 2C has not yet been determined. We report here the crystal structure of a soluble fragment of PV 2CATPase to 2.55Å, containing an ATPase domain, a zinc finger and a C-terminal helical domain but missing the N-terminal domain. The ATPase domain shares the common structural features with EV71 2C and other Superfamily 3 helicases. The C-terminal cysteine-rich motif folds into a CCCC type zinc finger in which four cysteine ligands and several auxiliary residues assist in zinc binding. By comparing with the known zinc finger fold groups, we found the zinc finger of 2C proteins belong to a new fold group, which we denote the "Enterovirus 2C-like" group. The C-terminus of PV 2CATPase forms an amphipathic helix that occupies a hydrophobic pocket located on an adjacent PV 2CATPase in the crystal lattice. The C-terminus mediated PV 2C-2C interaction promotes self-oligomerization, most likely hexamerization, which is fundamental to the ATPase activity of 2C. The zinc finger is the most structurally diverse feature in 2C proteins. Available structural and virological data suggest that the zinc finger of 2C might confer the specificity of interaction with other proteins. We built a hexameric ring model of PV 2CATPase and visualized the previously identified functional motifs and drug-resistant sites, thus providing a structure framework for antiviral drug development.
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Affiliation(s)
- Hongxin Guan
- MOH key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Juan Tian
- MOH key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chu Zhang
- MOH key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Bo Qin
- MOH key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Sheng Cui
- MOH key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- * E-mail:
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Oh HS, Banerjee S, Aponte-Diaz D, Sharma SD, Aligo J, Lodeiro MF, Ning G, Sharma R, Arnold JJ, Cameron CE. Multiple poliovirus-induced organelles suggested by comparison of spatiotemporal dynamics of membranous structures and phosphoinositides. PLoS Pathog 2018; 14:e1007036. [PMID: 29702686 PMCID: PMC5942851 DOI: 10.1371/journal.ppat.1007036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 05/09/2018] [Accepted: 04/17/2018] [Indexed: 11/25/2022] Open
Abstract
At the culmination of poliovirus (PV) multiplication, membranes are observed that contain phosphatidylinositol-4-phosphate (PI4P) and appear as vesicular clusters in cross section. Induction and remodeling of PI4P and membranes prior to or concurrent with genome replication has not been well studied. Here, we exploit two PV mutants, termed EG and GG, which exhibit aberrant proteolytic processing of the P3 precursor that substantially delays the onset of genome replication and/or impairs virus assembly, to illuminate the pathway of formation of PV-induced membranous structures. For WT PV, changes to the PI4P pool were observed as early as 30 min post-infection. PI4P remodeling occurred even in the presence of guanidine hydrochloride, a replication inhibitor, and was accompanied by formation of membrane tubules throughout the cytoplasm. Vesicular clusters appeared in the perinuclear region of the cell at 3 h post-infection, a time too slow for these structures to be responsible for genome replication. Delays in the onset of genome replication observed for EG and GG PVs were similar to the delays in virus-induced remodeling of PI4P pools, consistent with PI4P serving as a marker of the genome-replication organelle. GG PV was unable to convert virus-induced tubules into vesicular clusters, perhaps explaining the nearly 5-log reduction in infectious virus produced by this mutant. Our results are consistent with PV inducing temporally distinct membranous structures (organelles) for genome replication (tubules) and virus assembly (vesicular clusters). We suggest that the pace of formation, spatiotemporal dynamics, and the efficiency of the replication-to-assembly-organelle conversion may be set by both the rate of P3 polyprotein processing and the capacity for P3 processing to yield 3AB and/or 3CD proteins. All positive-strand RNA viruses replicate their genomes in association with host cell membranes. PV does not just remodel existing membranes, but induces membranes with unique structure and lipid composition. There has been some suggestion that the functions of the PV-induced structures observed during infection may not be those that perform genome replication. This study uses kinetic analysis and kinetic traps of virus-induced membrane formation/transformation and PI4P induction by WT PV and two PV mutants to provide evidence for the existence of a virus-induced genome-replication organelle temporally and spatially distinct from a virus-assembly organelle. In addition, our studies suggest that formation of both organelles may require participation of viral proteins, 3AB and/or 3CD. Therefore, this study provides a new perspective on the cell biology of PV infection and should inspire a fresh look at picornavirus-induced organelles, their functions and the role of P3 proteins in their formation and interconversion.
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Affiliation(s)
- Hyung S. Oh
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Sravani Banerjee
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - David Aponte-Diaz
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Suresh D. Sharma
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jason Aligo
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Maria F. Lodeiro
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Gang Ning
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Rajni Sharma
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jamie J. Arnold
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Craig E. Cameron
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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12
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Abstract
Reproduction of RNA viruses is typically error-prone due to the infidelity of their replicative machinery and the usual lack of proofreading mechanisms. The error rates may be close to those that kill the virus. Consequently, populations of RNA viruses are represented by heterogeneous sets of genomes with various levels of fitness. This is especially consequential when viruses encounter various bottlenecks and new infections are initiated by a single or few deviating genomes. Nevertheless, RNA viruses are able to maintain their identity by conservation of major functional elements. This conservatism stems from genetic robustness or mutational tolerance, which is largely due to the functional degeneracy of many protein and RNA elements as well as to negative selection. Another relevant mechanism is the capacity to restore fitness after genetic damages, also based on replicative infidelity. Conversely, error-prone replication is a major tool that ensures viral evolvability. The potential for changes in debilitated genomes is much higher in small populations, because in the absence of stronger competitors low-fit genomes have a choice of various trajectories to wander along fitness landscapes. Thus, low-fit populations are inherently unstable, and it may be said that to run ahead it is useful to stumble. In this report, focusing on picornaviruses and also considering data from other RNA viruses, we review the biological relevance and mechanisms of various alterations of viral RNA genomes as well as pathways and mechanisms of rehabilitation after loss of fitness. The relationships among mutational robustness, resilience, and evolvability of viral RNA genomes are discussed.
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Yuan T, Wang H, Li C, Yang D, Zhou G, Yu L. T135I substitution in the nonstructural protein 2C enhances foot-and-mouth disease virus replication. Virus Genes 2017. [PMID: 28634750 DOI: 10.1007/s11262-017-1480-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The foot-and-mouth disease virus (FMDV) nonstructural protein 3A plays an important role in viral replication, virulence, and host range. It has been shown that deletions of 10 or 19-20 amino acids in the C-terminal half of 3A attenuate serotype O and C FMDVs, which replicate poorly in bovine cells but normally in porcine-derived cells, and the C-terminal half of 3A is not essential for serotype Asia1 FMDV replication in BHK-21 cells. In this study, we constructed a 3A deletion FMDV mutant based on a serotype O FMDV, the wild-type virus O/YS/CHA/05, with a 60-amino acid deletion in the 3A protein sequence, between residues 84 and 143. The rescued virus O/YS/CHA/05-Δ3A exhibited slower growth kinetics and formed smaller plaques compared to O/YS/CHA/05 in both BHK-21 and IBRS-2 cells, indicating that the 60-amino acid deletion in the 3A protein impaired FMDV replication. After 14 passages in BHK-21 cells, the replication capacity of the passaged virus O/YS/CHA/05-Δ3A-P14 returned to a level similar to the wild-type virus, suggesting that amino acid substitutions responsible for the enhanced replication capacity occurred in the genome of O/YS/CHA/05-Δ3A-P14. By sequence analysis, two amino acid substitutions, P153L in VP1 and T135I in 2C, were found in the O/YS/CHA/05-Δ3A-P14 genome compared to the O/YS/CHA/05-Δ3A genome. Subsequently, the amino acid substitutions VP1 P153L and 2C T135I were separately introduced into O/YS/CHA/05-Δ3A to rescue mutant viruses for examining their growth kinetics. Results showed that the 2C T135I instead of the VP1 P153L enhanced the virus replication capacity. The 2C T135I substitution also improved the replication of the wild-type virus, indicating that the effect of 2C T135I substitution on FMDV replication is not associated with the 3A deletion. Furthermore, our results showed that the T135I substitution in the nonstructural protein 2C enhanced O/YS/CHA/05 replication through promoting viral RNA synthesis.
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Affiliation(s)
- Tiangang Yuan
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China
| | - Haiwei Wang
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China.
| | - Chen Li
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China
| | - Decheng Yang
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China
| | - Guohui Zhou
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China
| | - Li Yu
- Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, 150069, People's Republic of China.
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Guan H, Tian J, Qin B, Wojdyla JA, Wang B, Zhao Z, Wang M, Cui S. Crystal structure of 2C helicase from enterovirus 71. SCIENCE ADVANCES 2017; 3:e1602573. [PMID: 28508043 PMCID: PMC5409451 DOI: 10.1126/sciadv.1602573] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/24/2017] [Indexed: 06/07/2023]
Abstract
Enterovirus 71 (EV71) is the major pathogen responsible for outbreaks of hand, foot, and mouth disease. EV71 nonstructural protein 2C participates in many critical events throughout the virus life cycle; however, its precise role is not fully understood. Lack of a high-resolution structure made it difficult to elucidate 2C activity and prevented inhibitor development. We report the 2.5 Å-resolution crystal structure of the soluble part of EV71 2C, containing an adenosine triphosphatase (ATPase) domain, a cysteine-rich zinc finger with an unusual fold, and a carboxyl-terminal helical domain. Unlike other AAA+ ATPases, EV71 2C undergoes a carboxyl terminus-mediated self-oligomerization, which is dependent on a specific interaction between the carboxyl-terminal helix of one monomer and a deep pocket formed between the ATPase and the zinc finger domains of the neighboring monomer. The carboxyl terminus-mediated self-oligomerization is fundamental to 2C ATPase activity and EV71 replication. Our findings suggest a strategy for inhibition of enterovirus replication by disruption of the self-oligomerization interface of 2C.
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Affiliation(s)
- Hongxin Guan
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
| | - Juan Tian
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
| | - Bo Qin
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
| | | | - Bei Wang
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
| | - Zhendong Zhao
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
| | - Meitian Wang
- Swiss Light Source at Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Sheng Cui
- Ministry of Health Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 9 Dong Dan San Tiao, Beijing 100730, China
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15
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A Single Amino Acid Substitution in Poliovirus Nonstructural Protein 2CATPase Causes Conditional Defects in Encapsidation and Uncoating. J Virol 2016; 90:6174-6186. [PMID: 27076638 PMCID: PMC4936127 DOI: 10.1128/jvi.02877-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 03/28/2016] [Indexed: 12/11/2022] Open
Abstract
The specificity of encapsidation of C-cluster enteroviruses depends on an interaction between capsid proteins and nonstructural protein 2CATPase. In particular, residue N252 of poliovirus 2CATPase interacts with VP3 of coxsackievirus A20, in the context of a chimeric virus. Poliovirus 2CATPase has important roles both in RNA replication and encapsidation. In this study, we searched for additional sites in 2CATPase, near N252, that are required for encapsidation. Accordingly, segments adjacent to N252 were analyzed by combining triple and single alanine mutations to identify residues required for function. Two triple alanine mutants exhibited defects in RNA replication. The remaining two mutations, located in secondary structures in a predicted three-dimensional model of 2CATPase, caused lethal growth phenotypes. Most single alanine mutants, derived from the lethal variants, were either quasi-infectious and yielded variants with wild-type (wt) or temperature-sensitive (ts) growth phenotypes or had a lethal growth phenotype due to defective RNA replication. The K259A mutation, mapping to an α helix in the predicted structure of 2CATPase, resulted in a cold-sensitive virus. In vivo protein synthesis and virus production were strikingly delayed at 33°C relative to the wt, suggesting a defect in uncoating. Studies with a reporter virus indicated that this mutant is also defective in encapsidation at 33°C. Cell imaging confirmed a much-reduced production of K259A mature virus at 33°C relative to the wt. In conclusion, we have for the first time linked a cold-sensitive encapsidation defect in 2CATPase (K259A) to a subsequent delay in uncoating of the virus particle at 33°C during the next cycle of infection. IMPORTANCE Enterovirus morphogenesis, which involves the encapsidation of newly made virion RNA, is a process still poorly understood. Elucidation of this process is important for future drug development for a large variety of diseases caused by these agents. We have previously shown that the specificity of encapsidation of poliovirus and of C-cluster coxsackieviruses, which are prototypes of enteroviruses, is dependent on an interaction of capsid proteins with the multifunctional nonstructural protein 2CATPase. In this study, we have searched for residues in poliovirus 2CATPase, near a presumed capsid-interacting site, important for encapsidation. An unusual cold-sensitive mutant of 2CATPase possessed a defect in encapsidation at 37°C and subsequently in uncoating during the next cycle of infection at 33°C. These studies not only reveal a new site in 2CATPase that is involved in encapsidation but also identify a link between encapsidation and uncoating.
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16
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Vázquez-Calvo Á, Caridi F, González-Magaldi M, Saiz JC, Sobrino F, Martín-Acebes MA. The Amino Acid Substitution Q65H in the 2C Protein of Swine Vesicular Disease Virus Confers Resistance to Golgi Disrupting Drugs. Front Microbiol 2016; 7:612. [PMID: 27199941 PMCID: PMC4846857 DOI: 10.3389/fmicb.2016.00612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/13/2016] [Indexed: 11/13/2022] Open
Abstract
Swine vesicular disease virus (SVDV) is a porcine pathogen and a member of the species Enterovirus B within the Picornaviridae family. Brefeldin A (BFA) is an inhibitor of guanine nucleotide exchange factors of Arf proteins that induces Golgi complex disassembly and alters the cellular secretory pathway. Since BFA has been shown to inhibit the RNA replication of different enteroviruses, including SVDV, we have analyzed the effect of BFA and of golgicide A (GCA), another Golgi disrupting drug, on SVDV multiplication. BFA and GCA similarly inhibited SVDV production. To investigate the molecular basis of the antiviral effect of BFA, SVDV mutants with increased resistance to BFA were isolated. A single amino acid substitution, Q65H, in the non-structural protein 2C was found to be responsible for increased resistance to BFA. These results provide new insight into the relationship of enteroviruses with the components of the secretory pathway and on the role of SVDV 2C protein in this process.
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Affiliation(s)
- Ángela Vázquez-Calvo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM)Madrid, Spain; Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Madrid, Spain
| | - Flavia Caridi
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM) Madrid, Spain
| | | | - Juan-Carlos Saiz
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Madrid, Spain
| | | | - Miguel A Martín-Acebes
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM)Madrid, Spain; Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Madrid, Spain
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17
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Agudo R, de la Higuera I, Arias A, Grande-Pérez A, Domingo E. Involvement of a joker mutation in a polymerase-independent lethal mutagenesis escape mechanism. Virology 2016; 494:257-66. [PMID: 27136067 PMCID: PMC7111656 DOI: 10.1016/j.virol.2016.04.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 02/05/2023]
Abstract
We previously characterized a foot-and-mouth disease virus (FMDV) with three amino acid replacements in its polymerase (3D) that conferred resistance to the mutagenic nucleoside analogue ribavirin. Here we show that passage of this mutant in the presence of high ribavirin concentrations resulted in selection of viruses with the additional replacement I248T in 2C. This 2C substitution alone (even in the absence of replacements in 3D) increased FMDV fitness mainly in the presence of ribavirin, prevented an incorporation bias in favor of A and U associated with ribavirin mutagenesis, and conferred the ATPase activity of 2C decreased sensitivity to ribavirin-triphosphate. Since in previous studies we described that 2C with I248T was selected under different selective pressures, this replacement qualifies as a joker substitution in FMDV evolution. The results have identified a role of 2C in nucleotide incorporation, and have unveiled a new polymerase-independent mechanism of virus escape to lethal mutagenesis. A replacement in FMDV protein 2C confers reduced sensitivity to the mutagen ribavirin. The effect of the replacement is to prevent a mutational bias evoked by ribavirin. 2C has an effect in nucleotide incorporation by the FMDV polymerase. We describe a new molecular mechanism of escape to ribavirin-mediated extinction.
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Affiliation(s)
- Rubén Agudo
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Ignacio de la Higuera
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Armando Arias
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain
| | - Ana Grande-Pérez
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas, (IHSM-UMA-CSIC) Área de Genética, Campus de Teatinos, 29071 Málaga, Spain
| | - Esteban Domingo
- Centro de Biologia Molecular "Severo Ochoa" (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain.
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18
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van der Linden L, Wolthers KC, van Kuppeveld FJM. Replication and Inhibitors of Enteroviruses and Parechoviruses. Viruses 2015; 7:4529-62. [PMID: 26266417 PMCID: PMC4576193 DOI: 10.3390/v7082832] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 08/03/2015] [Indexed: 01/11/2023] Open
Abstract
The Enterovirus (EV) and Parechovirus genera of the picornavirus family include many important human pathogens, including poliovirus, rhinovirus, EV-A71, EV-D68, and human parechoviruses (HPeV). They cause a wide variety of diseases, ranging from a simple common cold to life-threatening diseases such as encephalitis and myocarditis. At the moment, no antiviral therapy is available against these viruses and it is not feasible to develop vaccines against all EVs and HPeVs due to the great number of serotypes. Therefore, a lot of effort is being invested in the development of antiviral drugs. Both viral proteins and host proteins essential for virus replication can be used as targets for virus inhibitors. As such, a good understanding of the complex process of virus replication is pivotal in the design of antiviral strategies goes hand in hand with a good understanding of the complex process of virus replication. In this review, we will give an overview of the current state of knowledge of EV and HPeV replication and how this can be inhibited by small-molecule inhibitors.
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Affiliation(s)
- Lonneke van der Linden
- Laboratory of Clinical Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam 1105 AZ, The Netherlands.
| | - Katja C Wolthers
- Laboratory of Clinical Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam 1105 AZ, The Netherlands.
| | - Frank J M van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, Utrecht 3584 CL, The Netherlands.
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19
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Abstract
The Picornaviridae represent a large family of small plus-strand RNA viruses that cause a bewildering array of important human and animal diseases. Morphogenesis is the least-understood step in the life cycle of these viruses, and this process is difficult to study because encapsidation is tightly coupled to genome translation and RNA replication. Although the basic steps of assembly have been known for some time, very few details are available about the mechanism and factors that regulate this process. Most of the information available has been derived from studies of enteroviruses, in particular poliovirus, where recent evidence has shown that, surprisingly, the specificity of encapsidation is governed by a viral protein-protein interaction that does not involve an RNA packaging signal. In this review, we make an attempt to summarize what is currently known about the following topics: (i) encapsidation intermediates, (ii) the specificity of encapsidation (iii), viral and cellular factors that are required for encapsidation, (iv) inhibitors of encapsidation, and (v) a model of enterovirus encapsidation. Finally, we compare some features of picornavirus morphogenesis with those of other plus-strand RNA viruses.
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20
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Paul AV, Wimmer E. Initiation of protein-primed picornavirus RNA synthesis. Virus Res 2015; 206:12-26. [PMID: 25592245 DOI: 10.1016/j.virusres.2014.12.028] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/16/2014] [Accepted: 12/24/2014] [Indexed: 12/14/2022]
Abstract
Plus strand RNA viruses use different mechanisms to initiate the synthesis of their RNA chains. The Picornaviridae family constitutes a large group of plus strand RNA viruses that possess a small terminal protein (VPg) covalently linked to the 5'-end of their genomes. The RNA polymerases of these viruses use VPg as primer for both minus and plus strand RNA synthesis. In the first step of the initiation reaction the RNA polymerase links a UMP to the hydroxyl group of a tyrosine in VPg using as template a cis-replicating element (cre) positioned in different regions of the viral genome. In this review we will summarize what is known about the initiation reaction of protein-primed RNA synthesis by the RNA polymerases of the Picornaviridae. As an example we will use the RNA polymerase of poliovirus, the prototype of Picornaviridae. We will also discuss models of how these nucleotidylylated protein primers might be used, together with viral and cellular replication proteins and other cis-replicating RNA elements, during minus and plus strand RNA synthesis.
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Affiliation(s)
- Aniko V Paul
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11790, United States.
| | - Eckard Wimmer
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11790, United States
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21
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Thibaut HJ, van der Linden L, Jiang P, Thys B, Canela MD, Aguado L, Rombaut B, Wimmer E, Paul A, Pérez-Pérez MJ, van Kuppeveld FJM, Neyts J. Binding of glutathione to enterovirus capsids is essential for virion morphogenesis. PLoS Pathog 2014; 10:e1004039. [PMID: 24722756 PMCID: PMC3983060 DOI: 10.1371/journal.ppat.1004039] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 02/17/2014] [Indexed: 11/18/2022] Open
Abstract
Enteroviruses (family of the Picornaviridae) cover a large group of medically important human pathogens for which no antiviral treatment is approved. Although these viruses have been extensively studied, some aspects of the viral life cycle, in particular morphogenesis, are yet poorly understood. We report the discovery of TP219 as a novel inhibitor of the replication of several enteroviruses, including coxsackievirus and poliovirus. We show that TP219 binds directly glutathione (GSH), thereby rapidly depleting intracellular GSH levels and that this interferes with virus morphogenesis without affecting viral RNA replication. The inhibitory effect on assembly was shown not to depend on an altered reducing environment. Using TP219, we show that GSH is an essential stabilizing cofactor during the transition of protomeric particles into pentameric particles. Sequential passaging of coxsackievirus B3 in the presence of low GSH-levels selected for GSH-independent mutants that harbored a surface-exposed methionine in VP1 at the interface between two protomers. In line with this observation, enteroviruses that already contained this surface-exposed methionine, such as EV71, did not rely on GSH for virus morphogenesis. Biochemical and microscopical analysis provided strong evidence for a direct interaction between GSH and wildtype VP1 and a role for this interaction in localizing assembly intermediates to replication sites. Consistently, the interaction between GSH and mutant VP1 was abolished resulting in a relocalization of the assembly intermediates to replication sites independent from GSH. This study thus reveals GSH as a novel stabilizing host factor essential for the production of infectious enterovirus progeny and provides new insights into the poorly understood process of morphogenesis. Enteroviruses contain many significant human pathogens, including poliovirus, enterovirus 71, coxsackieviruses and rhinoviruses. Most enterovirus infections subside mild or asymptomatically, but may also result in severe morbidity and mortality. Here, we report on the mechanism of antiviral action of a small molecule, TP219, as an inhibitor of enterovirus morphogenesis. Morphogenesis represents an important stage at the end of the virus replication cycle and requires multiple steps, of which some are only poorly understood. Better understanding of this process holds much potential to facilitate the development of new therapies to combat enterovirus infections. We demonstrate that TP219 rapidly depletes intracellular glutathione (GSH) by covalently binding free GSH resulting in the inhibition of virus morphogenesis without affecting viral RNA replication. We discovered that GSH directly interacts with viral capsid precursors and mature virions and that this interaction is required for the formation of an assembly intermediate (pentameric particles) and consequently infectious progeny. Remarkably, enteroviruses that were capable of replicating in the absence of GSH contained a surface-exposed methionine at the protomeric interface. We propose that GSH is an essential and stabilizing host factor during morphogenesis and that this stabilization is a prerequisite for a functional encapsidation of progeny viral RNA.
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Affiliation(s)
- Hendrik Jan Thibaut
- Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Lonneke van der Linden
- Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
- Department Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Ping Jiang
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Bert Thys
- Department of Pharmaceutical Biotechnology & Molecular Biology, Vrije Universiteit Brussel, Brussel, Belgium
| | | | - Leire Aguado
- Instituto de Química Médica (IQM-CSIC), Madrid, Spain
| | - Bart Rombaut
- Department of Pharmaceutical Biotechnology & Molecular Biology, Vrije Universiteit Brussel, Brussel, Belgium
| | - Eckard Wimmer
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Aniko Paul
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | | | - Frank J. M. van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Department Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Johan Neyts
- Department of Microbiology and Immunology, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
- * E-mail:
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22
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Wang C, Ma HC, Wimmer E, Jiang P, Paul AV. A C-terminal, cysteine-rich site in poliovirus 2C(ATPase) is required for morphogenesis. J Gen Virol 2014; 95:1255-1265. [PMID: 24558221 DOI: 10.1099/vir.0.062497-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The morphogenesis of viruses belonging to the genus Enterovirus in the family Picornaviridae is still poorly understood despite decades-long investigations. However, we recently provided evidence that 2C(ATPase) gives specificity to poliovirus encapsidation through an interaction with capsid protein VP3. The polypeptide 2C(ATPase) is a highly conserved non-structural protein of enteroviruses with important roles in RNA replication, encapsidation and uncoating. We have identified a site (K279/R280) near the C terminus of the polypeptide that is required for morphogenesis. The aim of the current project was to search for additional functional sites near the C terminus of the 2C(ATPase) polypeptide, with particular interest in those that are required for encapsidation. We selected for analysis a cysteine-rich site of the polypeptide and constructed four mutants in which cysteines or a histidine was changed to an alanine. The RNA transcripts were transfected into HeLa cells yielding two lethal, one temperature-sensitive and one quasi-infectious mutants. All four mutants exhibited normal protein translation in vitro and three of them possessed severe RNA replication defects. The quasi-infectious mutant (C286A) yielded variants with a pseudo-reversion at the original site (A286D), but some also contained one additional mutation: A138V or M293V. The temperature-sensitive mutant (C272A/H273A) exhibited an encapsidation and possibly also an uncoating defect at 37 °C. Variants of this mutant revealed suppressor mutations at three different sites in the 2C(ATPase) polypeptide: A138V, M293V and K295R. We concluded that the cysteine-rich site near the C terminus of 2C(ATPase) is involved in encapsidation, possibly through an interaction with an upstream segment located between boxes A and B of the nucleotide-binding domain.
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Affiliation(s)
- Chunling Wang
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Hsin-Chieh Ma
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Eckard Wimmer
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ping Jiang
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Aniko V Paul
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
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23
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Springer CL, Huntoon HP, Peersen OB. Polyprotein context regulates the activity of poliovirus 2CATPase bound to bilayer nanodiscs. J Virol 2013; 87:5994-6004. [PMID: 23514879 PMCID: PMC3648184 DOI: 10.1128/jvi.03491-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/11/2013] [Indexed: 12/26/2022] Open
Abstract
Positive-strand RNA viruses generally replicate in large membrane-associated complexes. For poliovirus, these replication complexes are anchored to the membrane via the viral 2B, 2C, and 3A proteins. 2C is an AAA+ family ATPase that plays a key role in host cell membrane rearrangement, is a putative helicase, and is implicated in virion assembly and packaging. However, the membrane-binding characteristics of all of these viral proteins have made it difficult to elucidate their exact roles in virus replication. We show here that small lipid bilayers known as nanodiscs can be used to chaperone the in vitro expression of soluble poliovirus 2C, 2BC, and 2BC3AB polyproteins in a membrane-bound form. ATPase assays on these proteins show that the activity of the core 2C domain is stimulated ~0-fold compared to the larger 2BC3AB polyprotein, with most of this stimulation occurring upon removal of 2B. The proteins are active over a wide range of salt concentrations, exhibit slight lipid headgroup dependence, and show significant stimulation by acetate. Our data lead to a model wherein the replication complex can be assembled with a minimally active form of 2C that then becomes fully activated by proteolytic cleavage from the adjacent 2B viroporin domain.
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Affiliation(s)
- Courtney L Springer
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
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24
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Alanine scanning of poliovirus 2CATPase reveals new genetic evidence that capsid protein/2CATPase interactions are essential for morphogenesis. J Virol 2012; 86:9964-75. [PMID: 22761387 DOI: 10.1128/jvi.00914-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polypeptide 2C(ATPase) is one of the most thoroughly studied but least understood proteins in the life cycle of poliovirus. Within the protein, multiple functional domains important for uncoating, host cell membrane alterations, and RNA replication and encapsidation have previously been identified. In this study, charged to alanine-scanning mutagenesis was used to generate conditional-lethal mutations in hitherto-uncharacterized domains of the 2C(ATPase) polypeptide, particularly those involved in morphogenesis. Adjacent or clustered charged amino acids (2 to 4), scattered along the 2C(ATPase) coding sequence, were replaced with alanines. RNA transcripts of mutant poliovirus cDNA clones were transfected into HeLa cells. Subsequently, 10 lethal, 1 severely temperature-sensitive, 2 quasi-infectious, and 3 wild type-like mutants were identified. Using a luciferase-containing reporter virus, we demonstrated RNA replication defects in all lethal and quasi-infectious mutants. Temperature-sensitive mutants were defective in RNA replication only at the restricted temperatures. Furthermore, we characterized a quasi-infectious mutant (K(6)A/K(7)A) that produced a suppressor mutation (G(1)R) and a novel 2B^2C(ATPase) cleavage site (Q^R). Surprisingly, this cleavage site mutation did not interfere with normal processing of the polyprotein. These mutants have led to the identification of several new sites within the 2C(ATPase) polypeptide that are required for RNA replication. In addition, analysis of the suppressor mutants has revealed a new domain near the C terminus of 2C(ATPase) that is involved in encapsidation, possibly achieved through interaction with an amino acid sequence between NTP binding motifs A and B of 2C(ATPase). Most importantly, the identification of suppressor mutations in both 2C(ATPase) and the capsid domains (VP1 and VP3) of poliovirus has confirmed that an interaction between 2C(ATPase) and capsid proteins is involved in viral morphogenesis.
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25
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Thibaut HJ, De Palma AM, Neyts J. Combating enterovirus replication: state-of-the-art on antiviral research. Biochem Pharmacol 2011; 83:185-92. [PMID: 21889497 DOI: 10.1016/j.bcp.2011.08.016] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/17/2011] [Accepted: 08/17/2011] [Indexed: 10/17/2022]
Abstract
Enteroviruses form an important genus within the large family of Picornaviridae. They are small, non-enveloped (+)RNA viruses, many of which are important pathogens in human and veterinary science. Despite their huge medical and socio-economical impact, there is still no approved antiviral therapy at hand for the treatment of these infections. Three capsid-targeting molecules (pleconaril, BTA-798 and V-073) are in clinical development. Pleconaril and BTA-798 are in phase II clinical trials for the treatment of enterovirus-induced sepsis syndrome and rhinovirus-induced aggravation of pre-existing asthma or COPD respectively. V-073 is in preclinical development for the treatment of poliovirus infections in the context of the worldwide polio eradication program. The capsid binding molecules have shown good in vitro potency against a number of enterovirus species, but lack activity against others. Another potential drawback of capsid inhibitors in the clinical setting could be the rapid emergence of drug resistance. It will therefore be important to develop inhibitors that affect other stages in the viral replication cycle. Several viral proteins, such as the viral 3C protease, the putative 2C helicase and the 3D RNA-dependent RNA polymerase may be/are excellent targets for inhibition of viral replication. Also host cell factors that are crucial in viral replication may be considered as potential targets for an antiviral approach. Unraveling these complex virus-host interactions will also provide better insights into the replication of enteroviruses. This review aims to summarize and discuss known inhibitors and potential viral and cellular targets for antiviral therapy against enteroviruses.
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Affiliation(s)
- Hendrik Jan Thibaut
- Rega Institute for Medical Research, KU Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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26
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Zheng Z, Li H, Zhang Z, Meng J, Mao D, Bai B, Lu B, Mao P, Hu Q, Wang H. Enterovirus 71 2C Protein Inhibits TNF-α–Mediated Activation of NF-κB by Suppressing IκB Kinase β Phosphorylation. THE JOURNAL OF IMMUNOLOGY 2011; 187:2202-12. [DOI: 10.4049/jimmunol.1100285] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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27
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Direct interaction between two viral proteins, the nonstructural protein 2C and the capsid protein VP3, is required for enterovirus morphogenesis. PLoS Pathog 2010; 6:e1001066. [PMID: 20865167 PMCID: PMC2928791 DOI: 10.1371/journal.ppat.1001066] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 07/26/2010] [Indexed: 12/27/2022] Open
Abstract
In spite of decades-long studies, the mechanism of morphogenesis of plus-stranded RNA viruses belonging to the genus Enterovirus of Picornaviridae, including poliovirus (PV), is not understood. Numerous attempts to identify an RNA encapsidation signal have failed. Genetic studies, however, have implicated a role of the non-structural protein 2C(ATPase) in the formation of poliovirus particles. Here we report a novel mechanism in which protein-protein interaction is sufficient to explain the specificity in PV encapsidation. Making use of a novel "reporter virus", we show that a quasi-infectious chimera consisting of the capsid precursor of C-cluster coxsackie virus 20 (C-CAV20) and the nonstructural proteins of the closely related PV translated and replicated its genome with wild type kinetics, whereas encapsidation was blocked. On blind passages, encapsidation of the chimera was rescued by a single mutation either in capsid protein VP3 of CAV20 or in 2C(ATPase) of PV. Whereas each of the single-mutation variants expressed severe proliferation phenotypes, engineering both mutations into the chimera yielded a virus encapsidating with wild type kinetics. Biochemical analyses provided strong evidence for a direct interaction between 2C(ATPase) and VP3 of PV and CAV20. Chimeras of other C-CAVs (CAV20/CAV21 or CAV18/CAV20) were blocked in encapsidation (no virus after blind passages) but could be rescued if the capsid and 2C(ATPase) coding regions originated from the same virus. Our novel mechanism explains the specificity of encapsidation without apparent involvement of an RNA signal by considering that (i) genome replication is known to be stringently linked to translation, (ii) morphogenesis is known to be stringently linked to genome replication, (iii) newly synthesized 2C(ATPase) is an essential component of the replication complex, and (iv) 2C(ATPase) has specific affinity to capsid protein(s). These conditions lead to morphogenesis at the site where newly synthesized genomes emerge from the replication complex.
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28
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Cameron CE, Oh HS, Moustafa IM. Expanding knowledge of P3 proteins in the poliovirus lifecycle. Future Microbiol 2010; 5:867-81. [PMID: 20521933 PMCID: PMC2904470 DOI: 10.2217/fmb.10.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Poliovirus is the most extensively studied member of the order Picornavirales, which contains numerous medical, veterinary and agricultural pathogens. The picornavirus genome encodes a single polyprotein that is divided into three regions: P1, P2 and P3. P3 proteins are known to participate more directly in genome replication, for example by containing the viral RNA-dependent RNA polymerase (RdRp or 3Dpol), among several other proteins and enzymes. We will review recent data that provide new insight into the structure, function and mechanism of P3 proteins and their complexes, which are required for initiation of genome replication. Replication of poliovirus genomes occurs within macromolecular complexes, containing viral RNA, viral proteins and host-cell membranes, collectively referred to as replication complexes. P2 proteins clearly contribute to interactions with the host cell that are required for virus multiplication, including formation of replication complexes. We will discuss recent data that suggest a role for P3 proteins in formation of replication complexes. Among the least understood steps of the poliovirus lifecycle is encapsidation of genomic RNA. We will also describe data that suggest a role for P3 proteins in this step.
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Affiliation(s)
- Craig E Cameron
- Department of Biochemistry & Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
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29
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Arias A, Perales C, Escarmís C, Domingo E. Deletion mutants of VPg reveal new cytopathology determinants in a picornavirus. PLoS One 2010; 5:e10735. [PMID: 20505767 PMCID: PMC2873979 DOI: 10.1371/journal.pone.0010735] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 04/30/2010] [Indexed: 11/18/2022] Open
Abstract
Background Success of a viral infection requires that each infected cell delivers a sufficient number of infectious particles to allow new rounds of infection. In picornaviruses, viral replication is initiated by the viral polymerase and a viral-coded protein, termed VPg, that primes RNA synthesis. Foot-and-mouth disease virus (FMDV) is exceptional among picornaviruses in that its genome encodes 3 copies of VPg. Why FMDV encodes three VPgs is unknown. Methodology and Principal Findings We have constructed four mutant FMDVs that encode only one VPg: either VPg1, VPg3, or two chimeric versions containing part of VPg1 and VPg3. All mutants, except that encoding only VPg1, were replication-competent. Unexpectedly, despite being replication-competent, the mutants did not form plaques on BHK-21 cell monolayers. The one-VPg mutant FMDVs released lower amounts of encapsidated viral RNA to the extracellular environment than wild type FMDV, suggesting that deficient plaque formation was associated with insufficient release of infectious progeny. Mutant FMDVs subjected to serial passages in BHK-21 cells regained plaque-forming capacity without modification of the number of copies of VPg. Substitutions in non-structural proteins 2C, 3A and VPg were associated with restoration of plaque formation. Specifically, replacement R55W in 2C was repeatedly found in several mutant viruses that had regained competence in plaque development. The effect of R55W in 2C was to mediate an increase in the extracellular viral RNA release without a detectable increase of total viral RNA that correlated with an enhanced capacity to alter and detach BHK-21 cells from the monolayer, the first stage of cell killing. Conclusions The results link the VPg copies in the FMDV genome with the cytopathology capacity of the virus, and have unveiled yet another function of 2C: modulation of picornavirus cell-to-cell transmission. Implications for picornaviruses pathogenesis are discussed.
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Affiliation(s)
- Armando Arias
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
| | - Celia Perales
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Cristina Escarmís
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
| | - Esteban Domingo
- Departamento de Virología y Microbiología, Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- * E-mail:
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30
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Jauka T, Mutsvunguma L, Boshoff A, Edkins AL, Knox C. Localisation of Theiler's murine encephalomyelitis virus protein 2C to the Golgi apparatus using antibodies generated against a peptide region. J Virol Methods 2010; 168:162-9. [PMID: 20471424 DOI: 10.1016/j.jviromet.2010.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 05/03/2010] [Accepted: 05/06/2010] [Indexed: 11/15/2022]
Abstract
The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31-210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection. Early on, the protein was localised in the perinuclear region with punctate staining in the cytoplasm and at later stages, it was concentrated in one large structure in close proximity to the nucleus and occupying almost 50% of the cell size. Dual-label immunofluorescence using wheat germ agglutinin (WGA) and anti-TMEV 2C antibodies suggested that 2C, and therefore virus replication, is targeted to the Golgi apparatus. At late stages of infection Golgi staining was dispersed, indicating potential reorganisation of membranes. Infection was accompanied by "rounding up" of the cells and a redistribution of actin around the putative replication complex. The results suggest that TMEV behaves similarly to FMDV which also forms replication complexes in the perinuclear region.
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Affiliation(s)
- Tembisa Jauka
- Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, Eastern Cape, South Africa
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31
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A single coxsackievirus B2 capsid residue controls cytolysis and apoptosis in rhabdomyosarcoma cells. J Virol 2010; 84:5868-79. [PMID: 20375176 DOI: 10.1128/jvi.02383-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Coxsackievirus B2 (CVB2), one of six human pathogens of the group B coxsackieviruses within the enterovirus genus of Picornaviridae, causes a wide spectrum of human diseases ranging from mild upper respiratory illnesses to myocarditis and meningitis. The CVB2 prototype strain Ohio-1 (CVB2O) was originally isolated from a patient with summer grippe in the 1950s. Later on, CVB2O was adapted to cytolytic replication in rhabdomyosarcoma (RD) cells. Here, we present analyses of the correlation between the adaptive mutations of this RD variant and the cytolytic infection in RD cells. Using reverse genetics, we identified a single amino acid change within the exposed region of the VP1 protein (glutamine to lysine at position 164) as the determinant for the acquired cytolytic trait. Moreover, this cytolytic virus induced apoptosis, including caspase activation and DNA degradation, in RD cells. These findings contribute to our understanding of the host cell adaptation process of CVB2O and provide a valuable tool for further studies of virus-host interactions.
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Adams P, Kandiah E, Effantin G, Steven AC, Ehrenfeld E. Poliovirus 2C protein forms homo-oligomeric structures required for ATPase activity. J Biol Chem 2009; 284:22012-22021. [PMID: 19520852 DOI: 10.1074/jbc.m109.031807] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The poliovirus protein 2C plays an essential role in viral RNA replication, although its precise biochemical activities or structural requirements have not been elucidated. The protein has several distinctive properties, including ATPase activity and membrane and RNA binding, that are conserved among orthologs of many positive-strand RNA viruses. Sequence alignments have placed these proteins in the SF3 helicase family, a subset of the AAA+ ATPase superfamily. A feature common to AAA+ proteins is the formation of oligomeric rings that are essential for their catalytic functions. Here we show that a recombinant protein, MBP-2C, in which maltose-binding protein was fused to 2C, formed soluble oligomers and that ATPase activity was restricted to oligomer-containing fractions from gel-filtration chromatography. The active fraction was visualized by negative-staining electron microscopy as ring-like particles composed of 5-8 protomers. This conclusion was confirmed by mass measurements obtained by scanning transmission electron microscopy. Mutation of amino acid residues in the 2C nucleotide-binding domain demonstrated that loss of the ability to bind or hydrolyze ATP did not affect oligomerization. Co-expression of active MBP-2C and inactive mutant proteins generated mixed oligomers that exhibited little ATPase activity, suggesting that incorporation of inactive subunits eliminates the function of the entire particle. Finally, deletion of the N-terminal 38 amino acids blocked oligomerization of the fusion protein and eliminated ATPase activity, despite retention of an unaltered nucleotide-binding domain.
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Affiliation(s)
| | | | - Grégory Effantin
- NIAMS, National Institutes of Health, Bethesda, Maryland 20892-8011
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Hepatitis C virus NS2 protein contributes to virus particle assembly via opposing epistatic interactions with the E1-E2 glycoprotein and NS3-NS4A enzyme complexes. J Virol 2009; 83:8379-95. [PMID: 19515772 DOI: 10.1128/jvi.00891-09] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The hepatitis C virus NS2 protein has been recently implicated in virus particle assembly. To further understand the role of NS2 in this process, we conducted a reverse genetic analysis of NS2 in the context of a chimeric genotype 2a infectious cell culture system. Of 32 mutants tested, all were capable of RNA replication and 25 had moderate-to-severe defects in virus assembly. Through forward genetic selection for variants capable of virus spread, we identified second-site mutations in E1, E2, NS2, NS3, and NS4A that suppressed NS2 defects in assembly. Two suppressor mutations, E1 A78T and NS3 Q221L, were further characterized by additional genetic and biochemical experiments. Both mutations were shown to suppress other NS2 defects, often with mutual exclusivity. Thus, several NS2 mutants were enhanced by NS3 Q221L and inhibited by E1 A78T, while others were enhanced by E1 A78T and inhibited by NS3 Q221L. Furthermore, we show that the NS3 Q221L mutation lowers the affinity of native, full-length NS3-NS4A for functional RNA binding. These data reveal a complex network of interactions involving NS2 and other viral structural and nonstructural proteins during virus assembly.
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34
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Chua BH, Phuektes P, Sanders SA, Nicholls PK, McMinn PC. The molecular basis of mouse adaptation by human enterovirus 71. J Gen Virol 2008; 89:1622-1632. [DOI: 10.1099/vir.0.83676-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A mouse-adapted strain of human enterovirus 71 (HEV71) was selected by serial passage of a HEV71 clinical isolate (HEV71-26M) in Chinese hamster ovary (CHO) cells (CHO-26M) and in newborn BALB/c mice (MP-26M). Despite improved growth in CHO cells, CHO-26M did not show increased virulence in newborn BALB/c mice compared with HEV71-26M. By contrast, infection of newborn mice with MP-26M resulted in severe disease of high mortality. Skeletal muscle was the primary site of replication in mice for both viruses. However, MP-26M infection induced severe necrotizing myositis, whereas CHO-26M infection caused only mild inflammation. MP-26M was also isolated from whole blood, heart, liver, spleen and brain of infected mice. CHO-26M harboured a single mutation within the open reading frame (ORF), resulting in an amino acid substitution of K149→I in the VP2 capsid protein; two further ORF mutations that resulted in amino acid substitutions were identified in MP-26M, located within the VP1 capsid protein (G145→E) and the 2C protein (K216→R). Infectious cDNA clone-derived mutant virus populations containing the mutations identified in CHO-26M and MP-26M were generated in order to study the molecular basis of CHO cell and mouse adaptation. The VP2 (K149→I) change was responsible only for improved growth in CHO cells and did not lead to increased virulence in mice. Of the two amino acid substitutions identified in MP-26M, the VP1 (G145→E) mutation alone was sufficient to increase virulence in mice to the level observed in MP-26M-infected mice.
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Affiliation(s)
- Beng Hooi Chua
- Division of Virology, Telethon Institute for Child Health Research, Perth, Australia
| | - Patchara Phuektes
- School of Veterinary and Biomedical Sciences, Murdoch University, Perth, Australia
- Division of Virology, Telethon Institute for Child Health Research, Perth, Australia
| | - Sharon A. Sanders
- Division of Virology, Telethon Institute for Child Health Research, Perth, Australia
| | - Philip K. Nicholls
- School of Veterinary and Biomedical Sciences, Murdoch University, Perth, Australia
| | - Peter C. McMinn
- Discipline of Infectious Diseases and Immunology, The University of Sydney, Australia
- Division of Virology, Telethon Institute for Child Health Research, Perth, Australia
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35
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De Palma AM, Heggermont W, Lanke K, Coutard B, Bergmann M, Monforte AM, Canard B, De Clercq E, Chimirri A, Pürstinger G, Rohayem J, van Kuppeveld F, Neyts J. The thiazolobenzimidazole TBZE-029 inhibits enterovirus replication by targeting a short region immediately downstream from motif C in the nonstructural protein 2C. J Virol 2008; 82:4720-30. [PMID: 18337578 PMCID: PMC2346740 DOI: 10.1128/jvi.01338-07] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 03/03/2008] [Indexed: 11/20/2022] Open
Abstract
TBZE-029 {1-(2,6-difluorophenyl)-6-trifluoromethyl-1H,3H-thiazolo[3,4-a]benzimidazole} is a novel selective inhibitor of the replication of several enteroviruses. We show that TBZE-029 exerts its antiviral activity through inhibition of viral RNA replication, without affecting polyprotein processing. To identify the viral target of TBZE-029, drug-resistant coxsackievirus B3 (CVB3) was selected. Genotyping of resistant clones led to the identification of three amino acid mutations in nonstructural protein 2C, clustered at amino acid positions 224, 227, and 229, immediately downstream of NTPase/helicase motif C. The mutations were reintroduced, either alone or combined, into an infectious full-length CVB3 clone. In particular the mutations at positions 227 and 229 proved essential for the altered sensitivity of CVB3 to TBZE-029. Resistant virus exhibited cross-resistance to the earlier-reported antienterovirus agents targeting 2C, namely, guanidine hydrochloride, HBB [2-(alpha-hydroxybenzyl)-benzimidazole], and MRL-1237 {1-(4-fluorophenyl)-2-[(4-imino-1,4-dihydropyridin-1-yl)methyl]benzimidazole hydrochloride}. The ATPase activity of 2C, however, remained unaltered in the presence of TBZE-029.
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Affiliation(s)
- Armando M De Palma
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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36
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Lee HS, Ahn J, Jee Y, Seo IS, Jeon EJ, Jeon ES, Joo CH, Kim YK, Lee H. Universal and mutation-resistant anti-enteroviral activity: potency of small interfering RNA complementary to the conserved cis-acting replication element within the enterovirus coding region. J Gen Virol 2007; 88:2003-2012. [PMID: 17554034 DOI: 10.1099/vir.0.82633-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The promising potential of RNA interference-based antiviral therapies has been well established. However, the antiviral efficacy is largely limited by genomic diversity and genetic instability of various viruses, including human enterovirus B (HEB). In this work, the first evidence supporting the anti-HEB activity of the small interfering RNA (siRNA) targeting the highly conserved cis-acting replication element (CRE) within virus coding region 2C is presented. HeLa cells pre-treated with siRNA complementary to the conserved sequence of the loop region of CRE(2C) were effectively rescued from the cytopathic effects of HEBs. Downregulation of virus replication and attenuation of cytotoxicity were consistently observed in various reference strains and clinical isolates. Cells treated with this siRNA were resistant to the emergence of viable escape mutants and showed sustained antiviral ability. Collectively, the data suggest that the siRNA based on the disordered structure within the highly conserved cis-acting coding region has potential as a universal, persistent anti-HEB agent. The same strategy can be successfully applied to the development of siRNA with consistent antiviral effects in other virus groups possessing similar RNA elements.
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Affiliation(s)
- Hui Sun Lee
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jeonghyun Ahn
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Youngmee Jee
- Division of Enteric and Hepatitis Viruses, Department of Virology, National Institute of Health, Korea Center for Disease Control and Prevention, Seoul, Korea
| | - Il Sun Seo
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun Jung Jeon
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun-Seok Jeon
- Cardiac and Vascular Center, Samsung Medical Center, Seoul, Korea
- Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chul Hyun Joo
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Yoo Kyum Kim
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Heuiran Lee
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul, Korea
- Department of Microbiology, University of Ulsan College of Medicine, Seoul, Korea
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37
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Teterina NL, Levenson E, Rinaudo MS, Egger D, Bienz K, Gorbalenya AE, Ehrenfeld E. Evidence for functional protein interactions required for poliovirus RNA replication. J Virol 2007; 80:5327-37. [PMID: 16699013 PMCID: PMC1472133 DOI: 10.1128/jvi.02684-05] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Poliovirus protein 2C contains a predicted N-terminal amphipathic helix that mediates association of the protein with the membranes of the viral RNA replication complex. A chimeric virus that contains sequences encoding the 18-residue core from the orthologous amphipathic helix from human rhinovirus type 14 (HRV14) was constructed. The chimeric virus exhibited defects in viral RNA replication and produced minute plaques on HeLa cell monolayers. Large plaque variants that contained mutations within the 2C-encoding region were generated upon subsequent passage. However, the majority of viruses that emerged with improved growth properties contained no changes in the region encoding 2C. Sequence analysis and reconstruction of genomes with individual mutations revealed changes in 3A or 2B sequences that compensated for the HRV14 amphipathic helix in the polio 2C-containing proteins, implying functional interactions among these proteins during the replication process. Direct binding between these viral proteins was confirmed by mammalian cell two-hybrid analysis.
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Affiliation(s)
- Natalya L Teterina
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases/NIH, Bldg. 50, 50 South Drive, Bethesda, MD 20892-8011, USA
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38
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Banerjee R, Weidman MK, Echeverri A, Kundu P, Dasgupta A. Regulation of poliovirus 3C protease by the 2C polypeptide. J Virol 2004; 78:9243-56. [PMID: 15308719 PMCID: PMC506913 DOI: 10.1128/jvi.78.17.9243-9256.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2004] [Accepted: 05/04/2004] [Indexed: 11/20/2022] Open
Abstract
Poliovirus-encoded nonstructural polypeptide 2C is a multifunctional protein that plays an important role in viral RNA replication. 2C interacts with both intracellular membranes and virus-specific RNAs and has ATPase and GTPase activities. Extensive computer analysis of the 2C sequence revealed that in addition to the known ATPase-, GTPase-, membrane-, and RNA-binding domains it also contains several "serpin" (serine protease inhibitor) motifs. We provide experimental evidence suggesting that 2C is indeed capable of regulating virus-encoded proteases. The purified 2C protein inhibits 3C(pro)-catalyzed cleavage of cellular transcription factors at Q-G sites in vitro. It also inhibits cleavage of a viral precursor by the other viral protease, 2A(pro). However, at least three cellular proteases appear not to be inhibited by 2C in vitro. The 2C-associated protease inhibitory activity can be depleted by anti-2C antibody. A physical interaction between 2C and His-tagged 3C(pro) can be demonstrated in vitro by coimmunoprecipitation of 2C with anti-His antibody. Deletion analysis suggests that the 2C central and C-terminal domains that include several serpin motifs are important for 3C(pro)-inhibitory activity. To examine the 2C protease inhibitory activity in vivo, stable HeLa cell lines were made that express 2C in an inducible fashion. Infection of 2C-expressing cells with poliovirus led to incomplete (or inefficient) processing of viral precursor polypeptides compared to control cell lines containing the vector alone. These results suggest that 2C can negatively regulate the viral protease 3C(pro). The possible role of the 2C protease inhibitory activity in viral RNA replication is discussed.
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Affiliation(s)
- Rajeev Banerjee
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA School of Medicine, University of California, Los Angeles, Los Angeles, California 90095-1747, USA
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39
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Teterina NL, Rinaudo MS, Ehrenfeld E. Strand-specific RNA synthesis defects in a poliovirus with a mutation in protein 3A. J Virol 2004; 77:12679-91. [PMID: 14610190 PMCID: PMC262582 DOI: 10.1128/jvi.77.23.12679-12691.2003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Substitution of a methionine residue at position 79 in poliovirus protein 3A with valine or threonine caused defective viral RNA synthesis, manifested as delayed onset and reduced yield of viral RNA, in HeLa cells transfected with a luciferase-containing replicon. Viruses containing these same mutations produced small or minute plaques that generated revertants upon further passage, with either wild-type 3A sequences or additional nearby compensating mutations. Translation and polyprotein processing were not affected by the mutations, and 3AB proteins containing the altered amino acids at position 79 showed no detectable loss of membrane-binding activity. Analysis of individual steps of viral RNA synthesis in HeLa cell extracts that support translation and replication of viral RNA showed that VPg uridylylation and negative-strand RNA synthesis occurred normally from mutant viral RNA; however, positive-strand RNA synthesis was specifically reduced. The data suggest that a function of viral protein 3A is required for positive-strand RNA synthesis but not for production of negative strands.
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Affiliation(s)
- Natalya L Teterina
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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40
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Abstract
The parechoviruses differ in many biological properties from other picornaviruses, and their replication strategy is largely unknown. In order to identify the viral RNA replication complex in human parechovirus type 1 (HPEV-1)-infected cells, we located viral protein and RNA in correlation to virus-induced membrane alterations. Structural changes in the infected cells included a disintegrated Golgi apparatus and disorganized, dilated endoplasmic reticulum (ER) which had lost its ribosomes. Viral plus-strand RNA, located by electron microscopic (EM) in situ hybridization, and the viral protein 2C, located by EM immunocytochemistry were found on clusters of small vesicles. Nascent viral RNA, visualized by 5-bromo-UTP incorporation, localized to compartments which were immunocytochemically found to contain the viral protein 2C and the trans-Golgi marker 1,4-galactosyltransferase. Protein 2C was immunodetected additionally on altered ER membranes which displayed a complex network-like structure devoid of cytoskeletal elements and with no apparent involvement in viral RNA replication. This protein also exhibited membrane binding properties in an in vitro assay. Our data suggest that the HPEV-1 replication complex is built up from vesicles carrying a Golgi marker and forming a structure different from that of replication complexes induced by other picornaviruses.
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Affiliation(s)
- Camilla Krogerus
- Haartman Institute, Department of Virology, University of Helsinki, FIN-00014 Helsinki, Finland.
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41
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Abstract
Rhinovirus type 16 was found to replicate in mouse L cells that express the viral receptor, human intercellular adhesion molecule 1 (ICAM-1). However, infection of these cells at a low multiplicity of infection leads to no discernible cytopathic effect, and low virus titers are produced. A variant virus, 16/L, was isolated after alternate passage of rhinovirus 16 between HeLa and ICAM-1 L cells. Infection of mouse cells with 16/L leads to higher virus titers, increased production of RNA, and total cytopathic effect. Three amino acid changes were identified in the P2 region of virus 16/L, and the adaptation phenotype mapped to two changes in protein 2C. The characterization of a rhinovirus host range mutant will facilitate the investigation of cellular proteins required for efficient viral growth and the development of a murine model for rhinovirus infection.
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Affiliation(s)
- Julie R Harris
- Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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42
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Shimizu H, Agoh M, Agoh Y, Yoshida H, Yoshii K, Yoneyama T, Hagiwara A, Miyamura T. Mutations in the 2C region of poliovirus responsible for altered sensitivity to benzimidazole derivatives. J Virol 2000; 74:4146-54. [PMID: 10756027 PMCID: PMC111929 DOI: 10.1128/jvi.74.9.4146-4154.2000] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/1999] [Accepted: 02/09/2000] [Indexed: 11/20/2022] Open
Abstract
MRL-1237, [1-(4-fluorophenyl)-2-(4-imino-1,4-dihydropyridin-1-yl) methylbenzimidazole hydrochloride], is a potent and selective inhibitor of the replication of enteroviruses. To reveal the target molecule of MRL-1237 in viral replication, we selected spontaneous MRL-1237-resistant poliovirus mutants. Of 15 MRL-1237-resistant mutants obtained, 14 were cross-resistant to guanidine hydrochloride (mrgr), while 1 was susceptible (mrgs). Sequence analysis of the 2C region revealed that the 14 mrgr mutants contained a single nucleotide substitution that altered an amino acid residue from Phe-164 to Tyr. The mrgs mutant, on the other hand, contained a substitution of Ile-120 to Val. Through the construction of a cDNA-derived mutant, we confirmed that the single mutation at Phe-164 was really responsible for the reduced susceptibility to MRL-1237. MRL-1237 inhibited poliovirus-specific RNA synthesis in HeLa cells infected with a wild strain but not with an F164Y mutant. We furthermore examined the effect of mutations of the 2C region on the drug sensitivity of cDNA-derived guanidine-resistant and -dependent mutants. Two guanidine-resistant mutants were cross-resistant to MRL-1237 but remained susceptible to another benzimidazole, enviroxime. Either MRL-1237 or guanidine stimulated the viral replication of two guanidine-dependent mutants, but enviroxime did not. These results indicate that MRL-1237, like guanidine, targets the 2C protein of poliovirus for its antiviral effect.
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Affiliation(s)
- H Shimizu
- Department of Virology II, National Institute of Infectious Diseases, Musashimurayama-shi, Tokyo 208-0011, Japan
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43
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Klein M, Hadaschik D, Zimmermann H, Eggers HJ, Nelsen-Salz B. The picornavirus replication inhibitors HBB and guanidine in the echovirus-9 system: the significance of viral protein 2C. J Gen Virol 2000; 81:895-901. [PMID: 10725414 DOI: 10.1099/0022-1317-81-4-895] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HBB [2-(alpha-hydroxybenzyl)-benzimidazole] and guanidine are potent inhibitors of picornavirus replication. Among other evidence, limited cross-resistance and a synergistic effect of both inhibitors suggest similar but not identical mechanisms of antiviral action. Echovirus-9 variants resistant to each of these drugs were characterized and sequenced. Complete resistance to HBB or guanidine was shown to be due to single but different point mutations in the non-structural protein 2C. Protein 2C was expressed as GST fusion and His-tagged proteins for the wild-type and various mutants. Although three mutations were located in or near conserved NTP binding motifs, NTPase activity was not altered in the presence of HBB or guanidine.
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Affiliation(s)
- M Klein
- Institut für Virologie der Universität zu Köln, Fürst-Pückler-Str. 56, 50935 Köln, Germany
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44
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Pfister T, Jones KW, Wimmer E. A cysteine-rich motif in poliovirus protein 2C(ATPase) is involved in RNA replication and binds zinc in vitro. J Virol 2000; 74:334-43. [PMID: 10590122 PMCID: PMC111544 DOI: 10.1128/jvi.74.1.334-343.2000] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein 2C(ATPase) of picornaviruses is involved in the rearrangement of host cell organelles, viral RNA replication, and encapsidation. However, the biochemical and molecular mechanisms by which 2C(ATPase) engages in these processes are not known. To characterize functional domains of 2C(ATPase), we have focused on a cysteine-rich motif near the carboxy terminus of poliovirus 2C(ATPase). This region, which is well conserved among enteroviruses and rhinoviruses displaying an amino acid arrangement resembling zinc finger motifs, was studied by genetic and biochemical analyses. A mutation that replaced the first cysteine residue of the motif with a serine was lethal. A mutant virus which lacked the second of four potential coordination sites for zinc was temperature sensitive. At the restrictive temperature, RNA replication was inhibited whereas translation and polyprotein processing, assayed in vitro and in vivo, appeared to be normal. An intragenomic second-site revertant which reinserted the missing coordination site for zinc and recovered RNA replication at the restrictive temperature was isolated. The cysteine-rich motif was sufficient to bind zinc in vitro, as assessed in the presence of 4-(2-pyridylazo)resorcinol by a colorimetric assay. Zinc binding, however, was not required for hydrolysis of ATP. 2C(ATPase) as well as its precursors 2BC and P2 were found to exist in a reduced form in poliovirus-infected cells.
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Affiliation(s)
- T Pfister
- Department of Molecular Genetics and Microbiology, State University of New York at Stony Brook, Stony Brook, New York 11794-5222, USA
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45
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Abstract
A new genus of the family Picornaviridae, Parechovirus, has recently been recognised on the basis of distinctive biological and molecular properties. In particular: parechoviruses exhibit characteristic effects on the host cell; cleavage of the capsid protein VP0, required for maturation of the virus particle in most other picornaviruses, does not occur; there is a unique extension, which is highly basic in character, to the N-terminus of the capsid protein VP3; and the 2A protein, in common with those of only two other known picornaviruses, is a homologue of a family of cellular proteins involved in the control of cell proliferation. The type member of the Parechovirus genus is a frequent human pathogen, formerly known as echovirus 22, which has been renamed human parechovirus 1. The genus also includes the closely related virus, human parechovirus 2 (formerly echovirus 23). Human parechoviruses generally cause mild, gastrointestinal or respiratory illness, but more serious consequences of infection, such as myocarditis and encephalitis have been reported. Most infections occur in young children. Ljungan virus, a newly identified virus of rodents, shares a number of molecular features with the human parechoviruses, raising important questions about the evolution of parechoviruses and their introduction into the human population.
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Affiliation(s)
- G Stanway
- Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
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46
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Klein M, Eggers HJ, Nelsen-Salz B. Echovirus 9 strain barty non-structural protein 2C has NTPase activity. Virus Res 1999; 65:155-60. [PMID: 10581388 DOI: 10.1016/s0168-1702(99)00110-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Non-structural protein 2C is known to play a fundamental role in the replication of picornaviruses. Sequence analyses revealed that 2C belongs to a rapidly expanding group of proteins containing a consensus sequence for nucleotide binding (NTB). We report that echovirus 9 polypeptide 2C displays NTPase activity in vitro. In our experiments, several P2 genes were expressed in Escherichia coli as fusion proteins linked to glutathione S-transferase (GST) prior to purification close to homogeneity. In contrast to GST-2B, both GST-2C and GST-2BC showed ATPase as well as GTPase activity indicating that the site for NTB binding and splitting is located in 2C.
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Affiliation(s)
- M Klein
- Institut für Virologie der Universität zu Köln, Fürst-Pückler-Str. 56, 50935, Cologne, Germany
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47
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Hadaschik D, Klein M, Zimmermann H, Eggers HJ, Nelsen-Salz B. Dependence of echovirus 9 on the enterovirus RNA replication inhibitor 2-(alpha-Hydroxybenzyl)-benzimidazole maps to nonstructural protein 2C. J Virol 1999; 73:10536-9. [PMID: 10559374 PMCID: PMC113111 DOI: 10.1128/jvi.73.12.10536-10539.1999] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HBB [2-(alpha-hydroxybenzyl)-benzimidazole] selectively inhibits RNA synthesis of most enteroviruses. However, isolation of HBB-dependent variants is possible. Sequence analysis and characterization of recombinant viruses revealed that HBB dependence maps to the nonstructural protein 2C. A single point mutation at position C(4782)U is sufficient to establish the HBB-dependent phenotype in our echovirus 9 model.
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Affiliation(s)
- D Hadaschik
- Institut für Virologie der Universität zu Köln, 50935 Cologne, Germany
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48
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Pfister T, Wimmer E. Characterization of the nucleoside triphosphatase activity of poliovirus protein 2C reveals a mechanism by which guanidine inhibits poliovirus replication. J Biol Chem 1999; 274:6992-7001. [PMID: 10066753 DOI: 10.1074/jbc.274.11.6992] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The highly conserved non-structural protein 2C of picornaviruses is involved in viral genome replication and encapsidation and in the rearrangement of intracellular structures. 2C binds RNA, has nucleoside triphosphatase activity, and shares three motifs with superfamily III helicases. Motifs "A" and "B" are involved in nucleotide triphosphate (NTP) binding and hydrolysis, whereas a function for motif "C" has not yet been demonstrated. Poliovirus RNA replication is inhibited by millimolar concentrations of guanidine hydrochloride (GdnHCl). Resistance and dependence to GdnHCl map to 2C. To characterize the nucleoside triphosphatase activity of 2C, we purified poliovirus recombinant 2C fused to glutathione S-transferase (GST-2C) from Escherichia coli. GST-2C hydrolyzed ATP with a Km of 0.7 mM. Other NTPs, including GTP, competed with ATP for binding to 2C but were poor substrates for hydrolysis. Mutation of conserved residues in motif A and B abolished ATPase activity, as did mutation of the conserved asparagine residue in motif C, an observation indicating the involvement of this motif in ATP hydrolysis. GdnHCl at millimolar concentrations inhibited ATP hydrolysis. Mutations in 2C that confer poliovirus resistant to or dependent on GdnHCl increased the tolerance to GdnHCl up to 100-fold.
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Affiliation(s)
- T Pfister
- Department of Molecular Genetics and Microbiology, State University of New York at Stony Brook, Stony Brook, New York 11794-5222, USA
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49
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van Dinten LC, Rensen S, Gorbalenya AE, Snijder EJ. Proteolytic processing of the open reading frame 1b-encoded part of arterivirus replicase is mediated by nsp4 serine protease and Is essential for virus replication. J Virol 1999; 73:2027-37. [PMID: 9971783 PMCID: PMC104445 DOI: 10.1128/jvi.73.3.2027-2037.1999] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/1998] [Accepted: 12/10/1998] [Indexed: 11/20/2022] Open
Abstract
The open reading frame (ORF) 1b-encoded part of the equine arteritis virus (EAV) replicase is expressed by ribosomal frameshifting during genome translation, which results in the production of an ORF1ab fusion protein (345 kDa). Four ORF1b-encoded processing products, nsp9 (p80), nsp10 (p50), nsp11 (p26), and nsp12 (p12), have previously been identified in EAV-infected cells (L. C. van Dinten, A. L. M. Wassenaar, A. E. Gorbalenya, W. J. M. Spaan, and E. J. Snijder, J. Virol. 70:6625-6633, 1996). In the present study, the generation of these four nonstructural proteins was shown to be mediated by the nsp4 serine protease, which is the main viral protease (E. J. Snijder, A. L. M. Wassenaar, L. C. van Dinten, W. J. M. Spaan, and A. E. Gorbalenya, J. Biol. Chem. 271:4864-4871, 1996). Mutagenesis of candidate cleavage sites revealed that Glu-2370/Ser, Gln-2837/Ser, and Glu-3056/Gly are the probable nsp9/10, nsp10/11, and nsp11/12 junctions, respectively. Mutations which abolished ORF1b protein processing were introduced into a recently developed infectious cDNA clone (L. C. van Dinten, J. A. den Boon, A. L. M. Wassenaar, W. J. M. Spaan, and E. J. Snijder, Proc. Natl. Acad. Sci. USA 94:991-997, 1997). An analysis of these mutants showed that the selective blockage of ORF1b processing affected different stages of EAV reproduction. In particular, the mutant with the nsp10/11 cleavage site mutation Gln-2837-->Pro displayed an unusual phenotype, since it was still capable of RNA synthesis but was incapable of producing infectious virus.
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Affiliation(s)
- L C van Dinten
- Department of Virology, Leiden University Medical Center, Leiden, The Netherlands
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Nugent CI, Johnson KL, Sarnow P, Kirkegaard K. Functional coupling between replication and packaging of poliovirus replicon RNA. J Virol 1999; 73:427-35. [PMID: 9847348 PMCID: PMC103849 DOI: 10.1128/jvi.73.1.427-435.1999] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Poliovirus RNA genomes that contained deletions in the capsid-coding regions were synthesized in monkey kidney cells that constitutively expressed T7 RNA polymerase. These replication-competent subgenomic RNAs, or replicons (G. Kaplan and V. R. Racaniello, J. Virol. 62:1687-1696, 1988), were encapsidated in trans by superinfecting polioviruses. When superinfecting poliovirus resistant to the antiviral compound guanidine was used, the RNA replication of the replicon RNAs could be inhibited independently of the RNA replication of the guanidine-resistant helper virus. Inhibiting the replication of the replicon RNA also profoundly inhibited its trans-encapsidation, even though the capsid proteins present in the cells could efficiently encapsidate the helper virus. The observed coupling between RNA replication and RNA packaging could account for the specificity of poliovirus RNA packaging in infected cells and the observed effects of mutations in the coding regions of nonstructural proteins on virion morphogenesis. It is suggested that this coupling results from direct interactions between the RNA replication machinery and the capsid proteins. The coupling of RNA packaging to RNA replication and of RNA replication to translation (J. E. Novak and K. Kirkegaard, Genes Dev. 8:1726-1737, 1994) could serve as mechanisms for late proofreading of poliovirus RNA, allowing only those RNA genomes capable of translating a full complement of functional RNA replication proteins to be propagated.
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Affiliation(s)
- C I Nugent
- Department of Molecular, Cellular and Developmental Biology and Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado 80309, USA
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