51
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Rantalainen K, Berndsen ZT, Antanasijevic A, Schiffner T, Zhang X, Lee WH, Torres JL, Zhang L, Irimia A, Copps J, Zhou KH, Kwon YD, Law WH, Schramm CA, Verardi R, Krebs SJ, Kwong PD, Doria-Rose NA, Wilson IA, Zwick MB, Yates JR, Schief WR, Ward AB. HIV-1 Envelope and MPER Antibody Structures in Lipid Assemblies. Cell Rep 2020; 31:107583. [PMID: 32348769 PMCID: PMC7196886 DOI: 10.1016/j.celrep.2020.107583] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/05/2020] [Accepted: 04/07/2020] [Indexed: 11/25/2022] Open
Abstract
Structural and functional studies of HIV envelope glycoprotein (Env) as a transmembrane protein have long been complicated by challenges associated with inherent flexibility of the molecule and the membrane-embedded hydrophobic regions. Here, we present approaches for incorporating full-length, wild-type HIV-1 Env, as well as C-terminally truncated and stabilized versions, into lipid assemblies, providing a modular platform for Env structural studies by single particle electron microscopy. We reconstitute a full-length Env clone into a nanodisc, complex it with a membrane-proximal external region (MPER) targeting antibody 10E8, and structurally define the full quaternary epitope of 10E8 consisting of lipid, MPER, and ectodomain contacts. By aligning this and other Env-MPER antibody complex reconstructions with the lipid bilayer, we observe evidence of Env tilting as part of the neutralization mechanism for MPER-targeting antibodies. We also adapt the platform toward vaccine design purposes by introducing stabilizing mutations that allow purification of unliganded Env with a peptidisc scaffold.
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Affiliation(s)
- Kimmo Rantalainen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Zachary T Berndsen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Aleksandar Antanasijevic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Torben Schiffner
- Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xi Zhang
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jonathan L Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lei Zhang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Adriana Irimia
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffrey Copps
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenneth H Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Young D Kwon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - William H Law
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Chaim A Schramm
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Shelly J Krebs
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicole A Doria-Rose
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Michael B Zwick
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - William R Schief
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02129, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA; International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Center for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA.
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52
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He W, Auclert LZ, Zhai X, Wong G, Zhang C, Zhu H, Xing G, Wang S, He W, Li K, Wang L, Han GZ, Veit M, Zhou J, Su S. Interspecies Transmission, Genetic Diversity, and Evolutionary Dynamics of Pseudorabies Virus. J Infect Dis 2020; 219:1705-1715. [PMID: 30590733 DOI: 10.1093/infdis/jiy731] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 12/22/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Pseudorabies virus (PRV) causes Aujeszky's disease in pigs and can be transmitted to other mammals, including humans. In the current study, we systematically studied the interspecies transmission and evolutionary history of PRV. METHODS We performed comprehensive analysis on the phylodynamics, selection, and structural biology to summarize the phylogenetic and adaptive evolution of PRV based on all available full-length and major glycoprotein sequences. RESULTS PRV can be divided into 2 main clades with frequent interclade and intraclade recombination. Clade 2.2 (variant PRV) is currently the most prevalent genotype worldwide, and most commonly involved in cross-species transmission events (including humans). We also found that the population size of clade 2.2 has increased since 2011, and the effective reproduction number was >1 from 2011 to 2016, indicating that PRV may be still circulating in swine herds and is still a risk in relation with cross-species transmission in China. Of note, we identified amino acid sites in some important glycoproteins gB, gC, gD, and gE that may be associated with PRV adaptation to new hosts and immune escape to vaccines. CONCLUSIONS Our study provides important genetic insight into the interspecies transmission and evolution of PRV within and between different hosts that warrant additional surveillance.
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Affiliation(s)
- Wanting He
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | | | - Xiaofeng Zhai
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | - Gary Wong
- College of Life Sciences, Nanjing Normal University, Hangzhou.,CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,MRC-University of Glasgow Centre for Virus Research, United Kingdom
| | - Cheng Zhang
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | - Henan Zhu
- Département de Microbiologie-Infectiologie et d'Immunologie, Université Laval, Québec, Canada
| | - Gang Xing
- Key laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou
| | - Shilei Wang
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | - Wei He
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | - Kemang Li
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
| | - Liang Wang
- MRC-University of Glasgow Centre for Virus Research, United Kingdom
| | - Guan-Zhu Han
- Institut Pasteur of Shanghai, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Michael Veit
- Institute for Virology, Center for Infection Medicine, Veterinary Faculty, Free University Berlin, Germany
| | - Jiyong Zhou
- Key laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou
| | - Shuo Su
- MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, Jiangsu Engineering Laboratory of Animal Immunology, Institute of Immunology, College of Veterinary Medicine, Nanjing Agricultural University
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53
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Komala Sari T, Gianopulos KA, Nicola AV. Glycoprotein C of Herpes Simplex Virus 1 Shields Glycoprotein B from Antibody Neutralization. J Virol 2020; 94:e01852-19. [PMID: 31826995 PMCID: PMC7022361 DOI: 10.1128/jvi.01852-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/04/2019] [Indexed: 12/19/2022] Open
Abstract
Viruses have evolved strategies to avoid neutralization by the host antibody response. Herpes simplex virus (HSV) glycoprotein C (gC) functions in viral entry and binds to complement component C3b, inhibiting complement-mediated immunity. We investigated whether gC protects HSV from antibody neutralization. HSV-1 that lacks gC was more sensitive to complement-independent neutralization by a panel of gB monoclonal antibodies than a wild-type gC rescuant virus. The presence of gC decreased neutralization by 2- to 16-fold. The gB in the native envelope of HSV-1 had reduced reactivity with antibodies in comparison to gB from the gC-null virus, suggesting that gC hampers the recognition of gB epitopes in the viral particle. The protein composition of the gC-null virus, including the surface glycoproteins essential for entry, was equivalent to that of the wild type, suggesting that gC is directly responsible for the reduced antibody recognition and neutralization. The neutralizing activity of antibodies to gD and gH antibodies was also increased in HSV lacking gC. Together, the data suggest that HSV-1 gC protects the viral envelope glycoproteins essential for entry, including gB, by shielding them from neutralization as a potential mechanism of immune evasion.IMPORTANCE HSV-1 causes lifelong infection in the human population and can be fatal in neonatal and immunocompromised individuals. There is no vaccine or cure, in part due to the ability of HSV to escape the host immune response by various mechanisms. The HSV particle contains at least 15 envelope proteins, four of which are required for entry and replication. This work suggests a novel role for gC in shielding the HSV entry glycoproteins. gC may function to help HSV escape neutralization by antibodies.
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Affiliation(s)
- Tri Komala Sari
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Katrina A Gianopulos
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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54
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Cooper RS, Heldwein EE. Expression, Purification, and Crystallization of Full-Length HSV-1 gB for Structure Determination. Methods Mol Biol 2020; 2060:395-407. [PMID: 31617193 PMCID: PMC10167678 DOI: 10.1007/978-1-4939-9814-2_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
HSV glycoproteins play important roles in the viral life cycle, particularly viral cell entry. Here we describe the protocol for expression, purification, and crystallization of full-length HSV-1 glycoprotein B. The protocol provides a framework for incorporating transmembrane domain-stabilizing amphipols into the crystallization setup and can be adapted to isolate other complete HSV glycoproteins.
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Affiliation(s)
- Rebecca S Cooper
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Ekaterina E Heldwein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
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55
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Lai Y, Kuo Y, Chiang Y. Identifying Protein Conformational Dynamics Using Spin‐label ESR. Chem Asian J 2019; 14:3981-3991. [DOI: 10.1002/asia.201900855] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/02/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Yei‐Chen Lai
- Department of Chemistry National Tsing Hua University Hsinchu 30013 Taiwan
- Department of Chemistry&Biochemistry University of California Santa Barbara CA 93106-9510 USA
| | - Yun‐Hsuan Kuo
- Department of Chemistry National Tsing Hua University Hsinchu 30013 Taiwan
| | - Yun‐Wei Chiang
- Department of Chemistry National Tsing Hua University Hsinchu 30013 Taiwan
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56
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Vallbracht M, Backovic M, Klupp BG, Rey FA, Mettenleiter TC. Common characteristics and unique features: A comparison of the fusion machinery of the alphaherpesviruses Pseudorabies virus and Herpes simplex virus. Adv Virus Res 2019; 104:225-281. [PMID: 31439150 DOI: 10.1016/bs.aivir.2019.05.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Membrane fusion is a fundamental biological process that allows different cellular compartments delimited by a lipid membrane to release or exchange their respective contents. Similarly, enveloped viruses such as alphaherpesviruses exploit membrane fusion to enter and infect their host cells. For infectious entry the prototypic human Herpes simplex viruses 1 and 2 (HSV-1 and -2, collectively termed HSVs) and the porcine Pseudorabies virus (PrV) utilize four different essential envelope glycoproteins (g): the bona fide fusion protein gB and the regulatory heterodimeric gH/gL complex that constitute the "core fusion machinery" conserved in all members of the Herpesviridae; and the subfamily specific receptor binding protein gD. These four components mediate attachment and fusion of the virion envelope with the host cell plasma membrane through a tightly regulated sequential activation process. Although PrV and the HSVs are closely related and employ the same set of glycoproteins for entry, they show remarkable differences in the requirements for fusion. Whereas the HSVs strictly require all four components for membrane fusion, PrV can mediate cell-cell fusion without gD. Moreover, in contrast to the HSVs, PrV provides a unique opportunity for reversion analyses of gL-negative mutants by serial cell culture passaging, due to a limited cell-cell spread capacity of gL-negative PrV not observed in the HSVs. This allows a more direct analysis of the function of gH/gL during membrane fusion. Unraveling the molecular mechanism of herpesvirus fusion has been a goal of fundamental research for years, and yet important mechanistic details remain to be uncovered. Nevertheless, the elucidation of the crystal structures of all key players involved in PrV and HSV membrane fusion, coupled with a wealth of functional data, has shed some light on this complex puzzle. In this review, we summarize and discuss the contemporary knowledge on the molecular mechanism of entry and membrane fusion utilized by the alphaherpesvirus PrV, and highlight similarities but also remarkable differences in the requirements for fusion between PrV and the HSVs.
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Affiliation(s)
- Melina Vallbracht
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany.
| | - Marija Backovic
- Institut Pasteur, Unité de Virologie Structurale, UMR3569 (CNRS), Paris, France
| | - Barbara G Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Felix A Rey
- Institut Pasteur, Unité de Virologie Structurale, UMR3569 (CNRS), Paris, France
| | - Thomas C Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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57
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Fu Q, Piai A, Chen W, Xia K, Chou JJ. Structure determination protocol for transmembrane domain oligomers. Nat Protoc 2019; 14:2483-2520. [PMID: 31270510 DOI: 10.1038/s41596-019-0188-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 04/30/2019] [Indexed: 01/08/2023]
Abstract
The transmembrane (TM) anchors of cell surface proteins have been one of the 'blind spots' in structural biology because they are generally very hydrophobic, sometimes dynamic, and thus difficult targets for structural characterization. A plethora of examples show these membrane anchors are not merely anchors but can multimerize specifically to activate signaling receptors on the cell surface or to stabilize envelope proteins in viruses. Through a series of studies of the TM domains (TMDs) of immune receptors and viral membrane proteins, we have established a robust protocol for determining atomic-resolution structures of TM oligomers by NMR in bicelles that closely mimic a lipid bilayer. Our protocol overcomes hurdles typically encountered by structural biology techniques such as X-ray crystallography and cryo-electron microscopy (cryo-EM) when studying small TMDs. Here, we provide the details of the protocol, covering five major technical aspects: (i) a general method for producing isotopically labeled TM or membrane-proximal (MP) protein fragments that involves expression of the protein (which is fused to TrpLE) into inclusion bodies and releasing the target protein by cyanogen bromide (CNBr) cleavage; (ii) determination of the oligomeric state of TMDs in bicelles; (iii) detection of intermolecular contacts using nuclear Overhauser effect (NOE) experiments; (iv) structure determination; and (v) paramagnetic probe titration (PPT) to characterize the membrane partition of the TM oligomers. This protocol is broadly applicable for filling structural gaps of many type I/II membrane proteins. The procedures may take 3-6 months to complete, depending on the complexity and stability of the protein sample.
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Affiliation(s)
- Qingshan Fu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Alessandro Piai
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Wen Chen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Ke Xia
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - James J Chou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
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58
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Meirovitch E, Freed JH. Local ordering and dynamics in anisotropic media by magnetic resonance: from liquid crystals to proteins. LIQUID CRYSTALS 2019; 47:1926-1954. [PMID: 32435078 PMCID: PMC7239324 DOI: 10.1080/02678292.2019.1622158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 06/11/2023]
Abstract
Magnetic resonance methods have been used extensively for over 50 years to elucidate molecular structure and dynamics of liquid crystals (LCs), providing information quite unique in its rigour and extent. The ESR- or NMR-active probe is often a solute molecule reporting on characteristics associated with the surrounding (LC) medium, which exerts the spatial restrictions on the probe. The theoretical approaches developed for LCs are applicable to anisotropic media in general. Of particular interest is the interior space of a globular protein labelled, e.g. with a nitroxide moiety or a 15N-1H bond. The ESR or NMR label plays the role of the probe and the internal protein surroundings the role of the anisotropic medium. A general feature of the restricted motions is the local ordering, i.e. the nature, magnitude and symmetry of the spatial restraints exerted at the site of the moving probe. This property is the main theme of the present review article. We outline its treatment in our work from both the theoretical and the experimental points of view, highlighting the new physical insights gained. Our illustrations include studies on thermotropic (nematic and smectic) and lyotropic liquid crystals formed by phospholipids, in addition to studies of proteins.
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Affiliation(s)
- Eva Meirovitch
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Jack H Freed
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
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Abstract
In this chapter, we present an overview on betaherpesvirus entry, with a focus on human cytomegalovirus, human herpesvirus 6A and human herpesvirus 6B. Human cytomegalovirus (HCMV) is a complex human pathogen with a genome of 235kb encoding more than 200 genes. It infects a broad range of cell types by switching its viral ligand on the virion, using the trimer gH/gL/gO for infection of fibroblasts and the pentamer gH/gL/UL128/UL130/UL131 for infection of other cells such as epithelial and endothelial cells, leading to membrane fusion mediated by the fusion protein gB. Adding to this scenario, however, accumulating data reveal the actual complexity in the viral entry process of HCMV with an intricate interplay among viral and host factors. Key novel findings include the identification of entry receptors platelet-derived growth factor-α receptor (PDGFRα) and Netropilin-2 (Nrp2) for trimer and pentamer, respectively, the determination of atomic structures of the fusion protein gB and the pentamer, and the in situ visualization of the state and arrangement of functional glycoproteins on virion. This is covered in the first part of this review. The second part focusses on HHV-6 which is a T lymphotropic virus categorized as two distinct virus species, HHV-6A and HHV-6B based on differences in epidemiological, biological, and immunological aspects, although homology of their entire genome sequences is nearly 90%. HHV-6B is a causative agent of exanthema subitum (ES), but the role of HHV-6A is unknown. HHV-6B reactivation occasionally causes encephalitis in patients with hematopoietic stem cell transplant. The HHV-6 specific envelope glycoprotein complex, gH/gL/gQ1/gQ2 is a viral ligand for the entry receptor. Recently, each virus has been found to recognize a different cellular receptor, CD46 for HHV 6A amd CD134 for HHV 6B. These findings show that distinct receptor recognition differing between both viruses could explain their different pathogenesis.
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Affiliation(s)
- Mitsuhiro Nishimura
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yasuko Mori
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
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60
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Li CC, Hung CL, Yeh PS, Li CE, Chiang YW. Doubly spin-labeled nanodiscs to improve structural determination of membrane proteins by ESR. RSC Adv 2019; 9:9014-9021. [PMID: 35517660 PMCID: PMC9062051 DOI: 10.1039/c9ra00896a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 03/14/2019] [Indexed: 11/30/2022] Open
Abstract
Pulsed dipolar spectroscopy (PDS) is a powerful tool to explore conformational changes of membrane proteins (MPs). However, the MPs suffer from relatively weak dipolar signals due to their complex nature in membrane environments, which consequently reduces the interspin distance resolution obtainable by PDS. Here we report the use of nanodiscs (NDs) to improve the distance resolution. Two genetically engineered membrane scaffold protein mutants are introduced, each of which is shown to form double-labeled ND efficiently and with high homogeneity. The resultant interspin distance distribution is featured by a small distribution width, suggesting high resolution. When PDS is performed on a binary mixture of the double-labeled ND devoid of MPs and the un-labeled ND with incorporated double-labeled MPs, the overall amplitude of dipolar signals is increased, leading to a critical enhancement of the distance resolution. A theoretical foundation is provided to validate the analysis. With this approach, the determination of MP structures can be studied at high resolution in NDs. Spin-labeled nanodiscs improve DEER distance measurement of membrane proteins.![]()
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Affiliation(s)
- Chieh-Chin Li
- Department of Chemistry
- Frontier Research Center on Fundamental and Applied Sciences of Matters
- National Tsing Hua University
- Hsinchu 30013
- Taiwan
| | - Chien-Lun Hung
- Department of Chemistry
- Frontier Research Center on Fundamental and Applied Sciences of Matters
- National Tsing Hua University
- Hsinchu 30013
- Taiwan
| | - Pei-Shan Yeh
- Department of Chemistry
- Frontier Research Center on Fundamental and Applied Sciences of Matters
- National Tsing Hua University
- Hsinchu 30013
- Taiwan
| | - Chi-En Li
- Department of Chemistry
- Frontier Research Center on Fundamental and Applied Sciences of Matters
- National Tsing Hua University
- Hsinchu 30013
- Taiwan
| | - Yun-Wei Chiang
- Department of Chemistry
- Frontier Research Center on Fundamental and Applied Sciences of Matters
- National Tsing Hua University
- Hsinchu 30013
- Taiwan
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61
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Si Z, Zhang J, Shivakoti S, Atanasov I, Tao CL, Hui WH, Zhou K, Yu X, Li W, Luo M, Bi GQ, Zhou ZH. Different functional states of fusion protein gB revealed on human cytomegalovirus by cryo electron tomography with Volta phase plate. PLoS Pathog 2018; 14:e1007452. [PMID: 30507948 PMCID: PMC6307773 DOI: 10.1371/journal.ppat.1007452] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 12/27/2018] [Accepted: 11/02/2018] [Indexed: 11/25/2022] Open
Abstract
Human cytomegalovirus (HCMV) enters host by glycoprotein B (gB)-mediated membrane fusion upon receptor-binding to gH/gL-related complexes, causing devastating diseases such as birth defects. Although an X-ray crystal structure of the recombinant gB ectodomain at postfusion conformation is available, the structures of prefusion gB and its complex with gH/gL on the viral envelope remain elusive. Here, we demonstrate the utility of cryo electron tomography (cryoET) with energy filtering and the cutting-edge technologies of Volta phase plate (VPP) and direct electron-counting detection to capture metastable prefusion viral fusion proteins and report the structures of glycoproteins in the native environment of HCMV virions. We established the validity of our approach by obtaining cryoET in situ structures of the vesicular stomatitis virus (VSV) glycoprotein G trimer (171 kD) in prefusion and postfusion conformations, which agree with the known crystal structures of purified G trimers in both conformations. The excellent contrast afforded by these technologies has enabled us to identify gB trimers (303kD) in two distinct conformations in HCMV tomograms and obtain their in situ structures at up to 21 Å resolution through subtomographic averaging. The predominant conformation (79%), which we designate as gB prefusion conformation, fashions a globular endodomain and a Christmas tree-shaped ectodomain, while the minority conformation (21%) has a columnar tree-shaped ectodomain that matches the crystal structure of the "postfusion" gB ectodomain. We also observed prefusion gB in complex with an "L"-shaped density attributed to the gH/gL complex. Integration of these structures of HCMV glycoproteins in multiple functional states and oligomeric forms with existing biochemical data and domain organization of other class III viral fusion proteins suggests that gH/gL receptor-binding triggers conformational changes of gB endodomain, which in turn triggers two essential steps to actuate virus-cell membrane fusion: exposure of gB fusion loops and unfurling of gB ectodomain.
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Affiliation(s)
- Zhu Si
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P.R. China
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Jiayan Zhang
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
- Molecular Biology Institute, UCLA, Los Angeles, CA, United States of America
| | - Sakar Shivakoti
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Ivo Atanasov
- California NanoSystems Institute, UCLA, Los Angeles, CA, United States of America
| | - Chang-Lu Tao
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P.R. China
| | - Wong H. Hui
- California NanoSystems Institute, UCLA, Los Angeles, CA, United States of America
| | - Kang Zhou
- California NanoSystems Institute, UCLA, Los Angeles, CA, United States of America
| | - Xuekui Yu
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Weike Li
- Department of Chemistry, Georgia State University, Atlanta, GA, United States of America
| | - Ming Luo
- Department of Chemistry, Georgia State University, Atlanta, GA, United States of America
| | - Guo-Qiang Bi
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P.R. China
| | - Z. Hong Zhou
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
- Molecular Biology Institute, UCLA, Los Angeles, CA, United States of America
- California NanoSystems Institute, UCLA, Los Angeles, CA, United States of America
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Pattnaik GP, Chakraborty H. Coronin 1 derived tryptophan-aspartic acid containing peptides inhibit membrane fusion. Chem Phys Lipids 2018; 217:35-42. [DOI: 10.1016/j.chemphyslip.2018.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/26/2018] [Accepted: 10/26/2018] [Indexed: 11/16/2022]
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Fan Q, Kopp SJ, Byskosh NC, Connolly SA, Longnecker R. Natural Selection of Glycoprotein B Mutations That Rescue the Small-Plaque Phenotype of a Fusion-Impaired Herpes Simplex Virus Mutant. mBio 2018; 9:e01948-18. [PMID: 30327436 PMCID: PMC6191544 DOI: 10.1128/mbio.01948-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/10/2018] [Indexed: 11/20/2022] Open
Abstract
Glycoprotein B (gB) is a conserved viral fusion protein that is required for herpesvirus entry. To mediate fusion with the cellular membrane, gB refolds from a prefusion to a postfusion conformation. We hypothesize that an interaction between the C-terminal arm and the central coiled coil of the herpes simplex virus 1 (HSV-1) gB ectodomain is critical for fusion. We previously reported that three mutations in the C-terminal arm (I671A/H681A/F683A, called gB3A) greatly reduced cell-cell fusion and that virus carrying these mutations had a small-plaque phenotype and delayed entry into cells. By serially passaging gB3A virus, we selected three revertant viruses with larger plaques. These revertant viruses acquired mutations in gB that restore the fusion function of gB3A, including gB-A683V, gB-S383F/G645R/V705I/A855V, and gB-T509M/N709H. V705I and N709H are novel mutations that map to the portion of domain V that enters domain I in the postfusion structure. S383F, G645R, and T509M are novel mutations that map to an intersection of three domains in a prefusion model of gB. We introduced these second-site mutations individually and in combination into wild-type gB and gB3A to examine the impact of the mutations on fusion and expression. V705I and A855V (a known hyperfusogenic mutation) restored the fusion function of gB3A, whereas S383F and G645R dampened fusion and T509M and N709H worked in concert to restore gB3A fusion. The results identify two regions in the gB ectodomain that modulate the fusion activity of gB, potentially by impacting intramolecular interactions and stability of the prefusion and/or postfusion gB trimer.IMPORTANCE Glycoprotein B (gB) is an essential viral protein that is conserved in all herpesviruses and is required for virus entry. gB is thought to undergo a conformational change that provides the energy to fuse the viral and cellular membranes; however, the details of this conformational change and the structure of the prefusion and intermediate conformations of gB are not known. Previously, we demonstrated that mutations in the gB "arm" region inhibit fusion and impart a small-plaque phenotype. Using serial passage of a virus carrying these mutations, we identified revertants with restored plaque size. The revertant viruses acquired novel mutations in gB that restored fusion function and mapped to two sites in the gB ectodomain. This work supports our hypothesis that an interaction between the gB arm and the core of gB is critical for gB refolding and provides details about the function of gB in herpesvirus-mediated fusion and subsequent virus entry.
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Affiliation(s)
- Qing Fan
- Department of Microbiology-Immunology, Feinberg School of Medicine of Northwestern University, Chicago, Illinois, USA
| | - Sarah J Kopp
- Department of Microbiology-Immunology, Feinberg School of Medicine of Northwestern University, Chicago, Illinois, USA
| | - Nina C Byskosh
- Department of Microbiology-Immunology, Feinberg School of Medicine of Northwestern University, Chicago, Illinois, USA
| | - Sarah A Connolly
- Department of Health Sciences, Department of Biological Sciences, DePaul University, Chicago, Illinois, USA
| | - Richard Longnecker
- Department of Microbiology-Immunology, Feinberg School of Medicine of Northwestern University, Chicago, Illinois, USA
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