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Phosphorylation of Human Metapneumovirus M2-1 Protein Upregulates Viral Replication and Pathogenesis. J Virol 2016; 90:7323-7338. [PMID: 27252537 DOI: 10.1128/jvi.00755-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/25/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a major causative agent of upper- and lower-respiratory-tract infections in infants, the elderly, and immunocompromised individuals worldwide. Like all pneumoviruses, hMPV encodes the zinc binding protein M2-1, which plays important regulatory roles in RNA synthesis. The M2-1 protein is phosphorylated, but the specific role(s) of the phosphorylation in viral replication and pathogenesis remains unknown. In this study, we found that hMPV M2-1 is phosphorylated at amino acid residues S57 and S60. Subsequent mutagenesis found that phosphorylation is not essential for zinc binding activity and oligomerization, whereas inhibition of zinc binding activity abolished the phosphorylation and oligomerization of the M2-1 protein. Using a reverse genetics system, recombinant hMPVs (rhMPVs) lacking either one or both phosphorylation sites in the M2-1 protein were recovered. These recombinant viruses had a significant decrease in both genomic RNA replication and mRNA transcription. In addition, these recombinant viruses were highly attenuated in cell culture and cotton rats. Importantly, rhMPVs lacking phosphorylation in the M2-1 protein triggered high levels of neutralizing antibody and provided complete protection against challenge with wild-type hMPV. Collectively, these data demonstrated that phosphorylation of the M2-1 protein upregulates hMPV RNA synthesis, replication, and pathogenesis in vivo IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Currently, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that phosphorylation of M2-1 is essential for virus replication and pathogenesis in vivo Recombinant hMPVs lacking phosphorylation in M2-1 exhibited limited replication in the upper and lower respiratory tract and triggered strong protective immunity in cotton rats. This work highlights the important role of M2-1 phosphorylation in viral replication and that inhibition of M2-1 phosphorylation may serve as a novel approach to develop live attenuated vaccines as well as antiviral drugs for pneumoviruses.
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Schlereth J, Grünweller A, Biedenkopf N, Becker S, Hartmann RK. RNA binding specificity of Ebola virus transcription factor VP30. RNA Biol 2016; 13:783-98. [PMID: 27315567 DOI: 10.1080/15476286.2016.1194160] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.
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Affiliation(s)
- Julia Schlereth
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Arnold Grünweller
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
| | - Nadine Biedenkopf
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Stephan Becker
- b Institut für Virologie, Philipps-Universität Marburg , Marburg , Germany
| | - Roland K Hartmann
- a Institut für Pharmazeutische Chemie, Philipps-Universität Marburg , Marburg , Germany
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Bailly B, Richard CA, Sharma G, Wang L, Johansen L, Cao J, Pendharkar V, Sharma DC, Galloux M, Wang Y, Cui R, Zou G, Guillon P, von Itzstein M, Eléouët JF, Altmeyer R. Targeting human respiratory syncytial virus transcription anti-termination factor M2-1 to inhibit in vivo viral replication. Sci Rep 2016; 6:25806. [PMID: 27194388 PMCID: PMC4872165 DOI: 10.1038/srep25806] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/22/2016] [Indexed: 01/05/2023] Open
Abstract
Human respiratory syncytial virus (hRSV) is a leading cause of acute lower respiratory tract infection in infants, elderly and immunocompromised individuals. To date, no specific antiviral drug is available to treat or prevent this disease. Here, we report that the Smoothened receptor (Smo) antagonist cyclopamine acts as a potent and selective inhibitor of in vitro and in vivo hRSV replication. Cyclopamine inhibits hRSV through a novel, Smo-independent mechanism. It specifically impairs the function of the hRSV RNA-dependent RNA polymerase complex notably by reducing expression levels of the viral anti-termination factor M2-1. The relevance of these findings is corroborated by the demonstration that a single R151K mutation in M2-1 is sufficient to confer virus resistance to cyclopamine in vitro and that cyclopamine is able to reduce virus titers in a mouse model of hRSV infection. The results of our study open a novel avenue for the development of future therapies against hRSV infection.
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Affiliation(s)
- B Bailly
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China.,Institute for Glycomics, Griffith University, Gold Coast Campus, Gold Coast, QLD 4222, Australia.,Shandong University-Helmholtz Institute of Biotechnology, Qingdao, 266101, P.R. China
| | - C-A Richard
- INRA, Unité de Virologie et Immunologie Moléculaires (UR892), Jouy-en-Josas, 78352, France
| | - G Sharma
- CombinatoRx-Singapore, 138667, Singapore
| | - L Wang
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China
| | | | - J Cao
- Shandong University-Helmholtz Institute of Biotechnology, Qingdao, 266101, P.R. China.,Qingdao Municipal Center for Disease Control &Prevention, Qingdao, 266033, P.R. China
| | | | - D-C Sharma
- CombinatoRx-Singapore, 138667, Singapore
| | - M Galloux
- INRA, Unité de Virologie et Immunologie Moléculaires (UR892), Jouy-en-Josas, 78352, France
| | - Y Wang
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China
| | - R Cui
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China
| | - G Zou
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China
| | - P Guillon
- Institute for Glycomics, Griffith University, Gold Coast Campus, Gold Coast, QLD 4222, Australia
| | - M von Itzstein
- Institute for Glycomics, Griffith University, Gold Coast Campus, Gold Coast, QLD 4222, Australia
| | - J-F Eléouët
- INRA, Unité de Virologie et Immunologie Moléculaires (UR892), Jouy-en-Josas, 78352, France
| | - R Altmeyer
- Institut Pasteur of Shanghai - Chinese Academy of Sciences, Unit of anti-infective research, Shanghai, 200031, P.R. China.,Institute for Glycomics, Griffith University, Gold Coast Campus, Gold Coast, QLD 4222, Australia.,Shandong University-Helmholtz Institute of Biotechnology, Qingdao, 266101, P.R. China.,CombinatoRx-Singapore, 138667, Singapore.,CombinatoRx, Cambridge, MA 02142, USA.,Qingdao Municipal Center for Disease Control &Prevention, Qingdao, 266033, P.R. China
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Cox R, Plemper RK. Structure-guided design of small-molecule therapeutics against RSV disease. Expert Opin Drug Discov 2016; 11:543-556. [PMID: 27046051 PMCID: PMC5074927 DOI: 10.1517/17460441.2016.1174212] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION In the United States, respiratory syncytial virus (RSV) is responsible for the majority of infant hospitalizations resulting from viral infections, as well as a leading source of pneumonia and bronchiolitis in young children and the elderly. In the absence of vaccine prophylaxis or an effective antiviral for improved disease management, the development of novel anti-RSV therapeutics is critical. Several advanced drug development campaigns of the past decade have focused on blocking viral infection. These efforts have returned a chemically distinct panel of small-molecule RSV entry inhibitors, but binding sites and molecular mechanism of action appeared to share a common mechanism, resulting in comprehensive cross-resistance and calling for alternative druggable targets such as viral RNA-dependent RNA-polymerase complex. Areas Covered: In this review, the authors discuss the current status of the mechanism of action of RSV entry inhibitors. They also provide the recent structural insight into the organization of the polymerase complex that have revealed novel drug targets sites, and outline a path towards the discovery of next-generation RSV therapeutics. Expert opinion: Considering the tremendous progress experienced in our structural understanding of RSV biology in recent years and encouraging early results of a nucleoside analog inhibitor in clinical trials, there is high prospect that new generations of much needed effective anti-RSV therapeutics will become available for clinical use in the foreseeable future.
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Affiliation(s)
- Robert Cox
- Institute for Biomedical Sciences, Georgia State University, 100 Piedmont Av, Atlanta, Georgia 30303-3222 USA
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, 100 Piedmont Av, Atlanta, Georgia 30303-3222 USA
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55
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Zinc binding activity of human metapneumovirus M2-1 protein is indispensable for viral replication and pathogenesis in vivo. J Virol 2015; 89:6391-405. [PMID: 25855728 DOI: 10.1128/jvi.03488-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/30/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human metapneumovirus (hMPV) is a member of the Pneumovirinae subfamily in the Paramyxoviridae family that causes respiratory tract infections in humans. Unlike members of the Paramyxovirinae subfamily, the polymerase complex of pneumoviruses requires an additional cofactor, the M2-1 protein, which functions as a transcriptional antitermination factor. The M2-1 protein was found to incorporate zinc ions, although the specific role(s) of the zinc binding activity in viral replication and pathogenesis remains unknown. In this study, we found that the third cysteine (C21) and the last histidine (H25) in the zinc binding motif (CCCH) of hMPV M2-1 were essential for zinc binding activity, whereas the first two cysteines (C7 and C15) play only minor or redundant roles in zinc binding. In addition, the zinc binding motif is essential for the oligomerization of M2-1. Subsequently, recombinant hMPVs (rhMPVs) carrying mutations in the zinc binding motif were recovered. Interestingly, rhMPV-C21S and -H25L mutants, which lacked zinc binding activity, had delayed replication in cell culture and were highly attenuated in cotton rats. In contrast, rhMPV-C7S and -C15S strains, which retained 60% of the zinc binding activity, replicated as efficiently as rhMPV in cotton rats. Importantly, rhMPVs that lacked zinc binding activity triggered high levels of neutralizing antibody and provided complete protection against challenge with rhMPV. Taken together, these results demonstrate that zinc binding activity is indispensable for viral replication and pathogenesis in vivo. These results also suggest that inhibition of zinc binding activity may serve as a novel approach to rationally attenuate hMPV and perhaps other pneumoviruses for vaccine purposes. IMPORTANCE The pneumoviruses include many important human and animal pathogens, such as human respiratory syncytial virus (hRSV), hMPV, bovine RSV, and avian metapneumovirus (aMPV). Among these viruses, hRSV and hMPV are the leading causes of acute respiratory tract infection in infants and children. Despite major efforts, there is no antiviral or vaccine to combat these diseases. All known pneumoviruses encode a zinc binding protein, M2-1, which is a transcriptional antitermination factor. In this work, we found that the zinc binding activity of M2-1 is essential for virus replication and pathogenesis in vivo. Recombinant hMPVs that lacked zinc binding activity were not only defective in replication in the upper and lower respiratory tract but also triggered a strong protective immunity in cotton rats. Thus, inhibition of M2-1 zinc binding activity can lead to the development of novel, live attenuated vaccines, as well as antiviral drugs for pneumoviruses.
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56
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Fine mapping and characterization of the L-polymerase-binding domain of the respiratory syncytial virus phosphoprotein. J Virol 2015; 89:4421-33. [PMID: 25653447 DOI: 10.1128/jvi.03619-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED The minimum requirement for an active RNA-dependent RNA polymerase of respiratory syncytial virus (RSV) is a complex made of two viral proteins, the polymerase large protein (L) and the phosphoprotein (P). Here we have investigated the domain on P that is responsible for this critical P-L interaction. By use of recombinant proteins and serial deletions, an L binding site was mapped in the C-terminal region of P, just upstream of the N-RNA binding site. The role of this molecular recognition element of about 30 amino acid residues in the L-P interaction and RNA polymerase activity was evaluated in cellula using an RSV minigenome system and site-directed mutagenesis. The results highlighted the critical role of hydrophobic residues located in this region. IMPORTANCE Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness in infants. Since no vaccine and no good antivirals against RSV are available, it is essential to better understand how the viral machinery functions in order to develop new antiviral strategies. Like all negative-strand RNA viruses, RSV codes for its own machinery to replicate and transcribe its genome. The core of this machinery is composed of two proteins, the phosphoprotein (P) and the large protein (L). Here, using recombinant proteins, we have mapped and characterized the P domain responsible for this L-P interaction and the formation of an active L-P complex. These findings extend our understanding of the mechanism of action of RSV RNA polymerase and allow us to define a new target for the development of drugs against RSV.
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57
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Shapiro AB, Gao N, O'Connell N, Hu J, Thresher J, Gu RF, Overman R, Hardern IM, Sproat GG. Quantitative investigation of the affinity of human respiratory syncytial virus phosphoprotein C-terminus binding to nucleocapsid protein. Virol J 2014; 11:191. [PMID: 25407889 PMCID: PMC4239318 DOI: 10.1186/s12985-014-0191-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 10/26/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There are no approved small molecule drug therapies for human respiratory syncytial virus (hRSV), a cause of morbidity and mortality in at-risk newborns, the immunocompromised, and the elderly. We have investigated as a potential novel hRSV drug target the protein-protein interaction between the C-terminus of the viral phosphoprotein (P) and the viral nucleocapsid protein (N), components of the ribonucleoprotein complex that contains, replicates, and transcribes the viral RNA genome. Earlier work by others established that the 9 C-terminal residues of P are necessary and sufficient for binding to N. METHODS We used a fluorescence anisotropy assay, surface plasmon resonance and 2-D NMR to quantify the affinities of peptides based on the C terminus of P for RNA-free, monomeric N-terminal-truncated N(13-391). We calculated the contributions to the free energies of binding of P to N(13-391) attributable to the C-terminal 11 residues, phosphorylation of the C-terminal 2 serine residues, the C-terminal Asp-Phe, and the phenyl ring of the C-terminal Phe. RESULTS Binding studies confirmed the crucial role of the phosphorylated C-terminal peptide D(pS)DNDL(pS)LEDF for binding of P to RNA-free, monomeric N(13-391), contributing over 90% of the binding free energy at low ionic strength. The phenyl ring of the C-terminal Phe residue contributed an estimated -2.7 kcal/mole of the free energy of binding, the C-terminal Asp-Phe residues contributed -3.8 kcal/mole, the sequence DSDNDLSLE contributed -3.1 kcal/mole, and phosphorylation of the 2 Ser residues contributed -1.8 kcal/mole. Due to the high negative charge of the C-terminal peptide, the affinity of the P C-terminus for N(13-391) decreased as the ionic strength increased. CONCLUSIONS The results support the idea that the interaction of the C-terminal residues of P with N constitutes a protein-protein interaction hotspot that may be a suitable target for small-molecule drugs that inhibit viral genome replication and transcription.
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Affiliation(s)
- Adam B Shapiro
- Biology Department, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA, USA.
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58
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Radzimanowski J, Effantin G, Weissenhorn W. Conformational plasticity of the Ebola virus matrix protein. Protein Sci 2014; 23:1519-27. [PMID: 25159197 DOI: 10.1002/pro.2541] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/01/2014] [Accepted: 08/04/2014] [Indexed: 12/14/2022]
Abstract
Filoviruses are the causative agents of a severe and often fatal hemorrhagic fever with repeated outbreaks in Africa. They are negative sense single stranded enveloped viruses that can cross species barriers from its natural host bats to primates including humans. The small size of the genome poses limits to viral adaption, which may be partially overcome by conformational plasticity. Here we review the different conformational states of the Ebola virus (EBOV) matrix protein VP40 that range from monomers, to dimers, hexamers, and RNA-bound octamers. This conformational plasticity that is required for the viral life cycle poses a unique opportunity for development of VP40 specific drugs. Furthermore, we compare the structure to homologous matrix protein structures from Paramyxoviruses and Bornaviruses and we predict that they do not only share the fold but also the conformational flexibility of EBOV VP40.
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Affiliation(s)
- Jens Radzimanowski
- University Grenoble Alpes, UVHCI, F-38000, Grenoble, France; CNRS, UVHCI, F-38000, Grenoble, France
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Abstract
Human metapneumovirus is a major cause of respiratory tract infections worldwide. Previous reports have shown that the viral attachment glycoprotein (G) modulates innate and adaptive immune responses, leading to incomplete immunity and promoting reinfection. Using bioinformatics analyses, static light scattering, and small-angle X-ray scattering, we show that the extracellular region of G behaves as a heavily glycosylated, intrinsically disordered polymer. We discuss potential implications of these findings for the modulation of immune responses by G.
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60
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Leyrat C, Renner M, Harlos K, Huiskonen JT, Grimes JM. Drastic changes in conformational dynamics of the antiterminator M2-1 regulate transcription efficiency in Pneumovirinae. eLife 2014; 3:e02674. [PMID: 24842877 PMCID: PMC4051120 DOI: 10.7554/elife.02674] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/15/2014] [Indexed: 12/24/2022] Open
Abstract
The M2-1 protein of human metapneumovirus (HMPV) is a zinc-binding transcription antiterminator which is highly conserved among pneumoviruses. We report the structure of tetrameric HMPV M2-1. Each protomer features a N-terminal zinc finger domain and an α-helical tetramerization motif forming a rigid unit, followed by a flexible linker and an α-helical core domain. The tetramer is asymmetric, three of the protomers exhibiting a closed conformation, and one an open conformation. Molecular dynamics simulations and SAXS demonstrate a dynamic equilibrium between open and closed conformations in solution. Structures of adenosine monophosphate- and DNA- bound M2-1 establish the role of the zinc finger domain in base-specific recognition of RNA. Binding to 'gene end' RNA sequences stabilized the closed conformation of M2-1 leading to a drastic shift in the conformational landscape of M2-1. We propose a model for recognition of gene end signals and discuss the implications of these findings for transcriptional regulation in pneumoviruses.DOI: http://dx.doi.org/10.7554/eLife.02674.001.
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Affiliation(s)
- Cedric Leyrat
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Max Renner
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Juha T Huiskonen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Jonathan M Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom Diamond Light Source Ltd, Didcot, United Kingdom
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Application of minigenome technology in virology research of the Paramyxoviridae family. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2014; 48:123-9. [PMID: 24767419 DOI: 10.1016/j.jmii.2014.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/12/2014] [Accepted: 02/19/2014] [Indexed: 11/23/2022]
Abstract
Minigenomes (MGs) are complementary DNAs of the synthetic analogs of genomic RNA. MGs are widely used to study the life cycle of the Paramyxoviridae family of viruses. MG-based studies have provided valuable insights into the mechanisms of viral replication and transcription in this family, including the roles of viral proteins, the location and boundaries of the cis-acting elements, the functional domains of trans-acting proteins, techniques for the measurement of neutralizing antibody, virus-host interactions, and the structure and function of viral RNA. This article provides a brief overview of the principle and application of MG technology in studies involving members of the Paramyxoviridae family. The advantages, potential limitations, and future scope of MG technology are also discussed.
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Tanner SJ, Ariza A, Richard CA, Kyle HF, Dods RL, Blondot ML, Wu W, Trincão J, Trinh CH, Hiscox JA, Carroll MW, Silman NJ, Eléouët JF, Edwards TA, Barr JN. Crystal structure of the essential transcription antiterminator M2-1 protein of human respiratory syncytial virus and implications of its phosphorylation. Proc Natl Acad Sci U S A 2014; 111:1580-5. [PMID: 24434552 PMCID: PMC3910626 DOI: 10.1073/pnas.1317262111] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The M2-1 protein of the important pathogen human respiratory syncytial virus is a zinc-binding transcription antiterminator that is essential for viral gene expression. We present the crystal structure of full-length M2-1 protein in its native tetrameric form at a resolution of 2.5 Å. The structure reveals that M2-1 forms a disk-like assembly with tetramerization driven by a long helix forming a four-helix bundle at its center, further stabilized by contact between the zinc-binding domain and adjacent protomers. The tetramerization helix is linked to a core domain responsible for RNA binding activity by a flexible region on which lie two functionally critical serine residues that are phosphorylated during infection. The crystal structure of a phosphomimetic M2-1 variant revealed altered charge density surrounding this flexible region although its position was unaffected. Structure-guided mutagenesis identified residues that contributed to RNA binding and antitermination activity, revealing a strong correlation between these two activities, and further defining the role of phosphorylation in M2-1 antitermination activity. The data we present here identify surfaces critical for M2-1 function that may be targeted by antiviral compounds.
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Affiliation(s)
- Sian J. Tanner
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Public Health England, Porton Down SP4 0JG, United Kingdom
| | - Antonio Ariza
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Charles-Adrien Richard
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Hannah F. Kyle
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rachel L. Dods
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Marie-Lise Blondot
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Weining Wu
- Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, United Kingdom; and
| | - José Trincão
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0FA, United Kingdom
| | - Chi H. Trinh
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Julian A. Hiscox
- Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, United Kingdom; and
| | | | | | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires (UR892), Institut National de la Recherche Agronomique, F-78352 Jouy-en-Josas, France
| | - Thomas A. Edwards
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John N. Barr
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
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Esperante SA, Noval MG, Altieri TA, de Oliveira GAP, Silva JL, de Prat-Gay G. Fine modulation of the respiratory syncytial virus M2-1 protein quaternary structure by reversible zinc removal from its Cys(3)-His(1) motif. Biochemistry 2013; 52:6779-89. [PMID: 23984912 DOI: 10.1021/bi401029q] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human respiratory syncytial virus (hRSV) is a worldwide distributed pathogen that causes respiratory disease mostly in infants and the elderly. The M2-1 protein of hRSV functions as a transcription antiterminator and partakes in virus particle budding. It is present only in Pneumovirinae, namely, Pneumovirus (RSV) and Metapneumovirus, making it an interesting target for specific antivirals. hRSV M2-1 is a tight tetramer bearing a Cys3-His1 zinc-binding motif, present in Ebola VP30 protein and some eukaryotic proteins, whose integrity was shown to be essential for protein function but without a biochemical mechanistic basis. We showed that removal of the zinc atom causes dissociation to a monomeric apo-M2-1 species. Surprisingly, the secondary structure and stability of the apo-monomer is indistinguishable from that of the M2-1 tetramer. Dissociation reported by a highly sensitive tryptophan residue is much increased at pH 5.0 compared to pH 7.0, suggesting a histidine protonation cooperating in zinc removal. The monomeric apo form binds RNA at least as well as the tetramer, and this interaction is outcompeted by the phosphoprotein P, the RNA polymerase cofactor. The role of zinc goes beyond stabilization of local structure, finely tuning dissociation to a fully folded and binding competent monomer. Removal of zinc is equivalent to the disruption of the motif by mutation, only that the former is potentially reversible in the cellular context. Thus, this process could be triggered by a natural chelator such as glutathione or thioneins, where reversibility strongly suggests a modulatory role in the participation of M2-1 in the assembly of the polymerase complex or in virion budding.
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Affiliation(s)
- Sebastián A Esperante
- Protein Structure-Function and Engineering Laboratory, Fundación Instituto Leloir and IIBA-Conicet , Patricias Argentinas 435, (1405) Buenos Aires, Argentina
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Gotesman M, Soliman H, El-Matbouli M. Antibody screening identifies 78 putative host proteins involved in Cyprinid herpesvirus 3 infection or propagation in common carp, Cyprinus carpio L. JOURNAL OF FISH DISEASES 2013; 36:721-33. [PMID: 23347276 PMCID: PMC3961710 DOI: 10.1111/jfd.12073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/16/2012] [Accepted: 11/17/2012] [Indexed: 05/15/2023]
Abstract
Cyprinid herpesvirus 3 (CyHV-3) is the aetiological agent of a serious and notifiable disease afflicting common and koi carp, Cyprinus carpio L., termed koi herpesvirus disease (KHVD). Significant progress has been achieved in the last 15 years, since the initial reports surfaced from Germany, USA and Israel of the CyHV-3 virus, in terms of pathology and detection. However, relatively few studies have been carried out in understanding viral replication and propagation. Antibody-based affinity has been used for detection of CyHV-3 in enzyme-linked immunosorbent assay and PCR-based techniques, and immunohistological assays have been used to describe a CyHV-3 membrane protein, termed ORF81. In this study, monoclonal antibodies linked to N-hydroxysuccinimide (NHS)-activated spin columns were used to purify CyHV-3 and host proteins from tissue samples originating in either CyHV-3 symptomatic or asymptomatic fish. The samples were next analysed either by polyacrylamide gel electrophoresis (PAGE) and subsequently by electrospray ionization coupled to mass spectrometry (ESI-MS) or by ESI-MS analysis directly after purification. A total of 78 host proteins and five CyHV-3 proteins were identified in the two analyses. These data can be used to develop novel control methods for CyHV-3, based on pathways or proteins identified in this study.
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Affiliation(s)
- M Gotesman
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria
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Characterization of the chandipura virus leader RNA–phosphoprotein interaction using single tryptophan mutants and its detection in viral infected cells. Biochimie 2013; 95:180-94. [DOI: 10.1016/j.biochi.2012.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 09/11/2012] [Indexed: 11/15/2022]
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Respiratory syncytial virus: virology, reverse genetics, and pathogenesis of disease. Curr Top Microbiol Immunol 2013; 372:3-38. [PMID: 24362682 DOI: 10.1007/978-3-642-38919-1_1] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human respiratory syncytial virus (RSV) is an enveloped, nonsegmented negative-strand RNA virus of family Paramyxoviridae. RSV is the most complex member of the family in terms of the number of genes and proteins. It is also relatively divergent and distinct from the prototype members of the family. In the past 30 years, we have seen a tremendous increase in our understanding of the molecular biology of RSV based on a succession of advances involving molecular cloning, reverse genetics, and detailed studies of protein function and structure. Much remains to be learned. RSV disease is complex and variable, and the host and viral factors that determine tropism and disease are poorly understood. RSV is notable for a historic vaccine failure in the 1960s involving a formalin-inactivated vaccine that primed for enhanced disease in RSV naïve recipients. Live vaccine candidates have been shown to be free of this complication. However, development of subunit or other protein-based vaccines for pediatric use is hampered by the possibility of enhanced disease and the difficulty of reliably demonstrating its absence in preclinical studies.
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