201
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Calcium-triggered fusion of lipid membranes is enabled by amphiphilic nanoparticles. Proc Natl Acad Sci U S A 2020; 117:18470-18476. [PMID: 32690682 DOI: 10.1073/pnas.1902597117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Lipid membrane fusion is an essential process for a number of critical biological functions. The overall process is thermodynamically favorable but faces multiple kinetic barriers along the way. Inspired by nature's engineered proteins such as SNAP receptor [soluble N-ethylmale-imide-sensitive factor-attachment protein receptor (SNARE)] complexes or viral fusogenic proteins that actively promote the development of membrane proximity, nucleation of a stalk, and triggered expansion of the fusion pore, here we introduce a synthetic fusogen that can modulate membrane fusion and equivalently prime lipid membranes for calcium-triggered fusion. Our fusogen consists of a gold nanoparticle functionalized with an amphiphilic monolayer of alkanethiol ligands that had previously been shown to fuse with lipid bilayers. While previous efforts to develop synthetic fusogens have only replicated the initial steps of the fusion cascade, we use molecular simulations and complementary experimental techniques to demonstrate that these nanoparticles can induce the formation of a lipid stalk and also drive its expansion into a fusion pore upon the addition of excess calcium. These results have important implications in general understanding of stimuli-triggered fusion and the development of synthetic fusogens for biomedical applications.
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202
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Amraei R, Rahimi N. COVID-19, Renin-Angiotensin System and Endothelial Dysfunction. Cells 2020; 9:E1652. [PMID: 32660065 PMCID: PMC7407648 DOI: 10.3390/cells9071652] [Citation(s) in RCA: 188] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/04/2020] [Accepted: 07/07/2020] [Indexed: 01/08/2023] Open
Abstract
The newly emergent novel coronavirus disease 2019 (COVID-19) outbreak, which is caused by SARS-CoV-2 virus, has posed a serious threat to global public health and caused worldwide social and economic breakdown. Angiotensin-converting enzyme 2 (ACE2) is expressed in human vascular endothelium, respiratory epithelium, and other cell types, and is thought to be a primary mechanism of SARS-CoV-2 entry and infection. In physiological condition, ACE2 via its carboxypeptidase activity generates angiotensin fragments (Ang 1-9 and Ang 1-7), and plays an essential role in the renin-angiotensin system (RAS), which is a critical regulator of cardiovascular homeostasis. SARS-CoV-2 via its surface spike glycoprotein interacts with ACE2 and invades the host cells. Once inside the host cells, SARS-CoV-2 induces acute respiratory distress syndrome (ARDS), stimulates immune response (i.e., cytokine storm) and vascular damage. SARS-CoV-2 induced endothelial cell injury could exacerbate endothelial dysfunction, which is a hallmark of aging, hypertension, and obesity, leading to further complications. The pathophysiology of endothelial dysfunction and injury offers insights into COVID-19 associated mortality. Here we reviewed the molecular basis of SARS-CoV-2 infection, the roles of ACE2, RAS signaling, and a possible link between the pre-existing endothelial dysfunction and SARS-CoV-2 induced endothelial injury in COVID-19 associated mortality. We also surveyed the roles of cell adhesion molecules (CAMs), including CD209L/L-SIGN and CD209/DC-SIGN in SARS-CoV-2 infection and other related viruses. Understanding the molecular mechanisms of infection, the vascular damage caused by SARS-CoV-2 and pathways involved in the regulation of endothelial dysfunction could lead to new therapeutic strategies against COVID-19.
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Affiliation(s)
- Razie Amraei
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA 02118, USA
| | - Nader Rahimi
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, MA 02118, USA
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203
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Antanasijevic A, Durst MA, Cheng H, Gaisina IN, Perez JT, Manicassamy B, Rong L, Lavie A, Caffrey M. Structure of avian influenza hemagglutinin in complex with a small molecule entry inhibitor. Life Sci Alliance 2020; 3:3/8/e202000724. [PMID: 32611549 PMCID: PMC7335401 DOI: 10.26508/lsa.202000724] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/14/2022] Open
Abstract
The binding properties of fusion inhibitor CBS1117 to hemagglutinin by x-ray crystallography, NMR, and mutagenesis give insights into mechanism and guidance for chemical optimization. HA plays a critical role in influenza infection and, thus HA is a potential target for antivirals. Recently, our laboratories have described a novel fusion inhibitor, termed CBS1117, with EC50 ∼3 μM against group 1 HA. In this work, we characterize the binding properties of CBS1117 to avian H5 HA by x-ray crystallography, NMR, and mutagenesis. The x-ray structure of the complex shows that the compound binds near the HA fusion peptide, a region that plays a critical role in HA-mediated fusion. NMR studies demonstrate binding of CBS1117 to H5 HA in solution and show extensive hydrophobic contacts between the compound and HA surface. Mutagenesis studies further support the location of the compound binding site proximal to the HA fusion peptide and identify additional amino acids that are important to compound binding. Together, this work gives new insights into the CBS1117 mechanism of action and can be exploited to further optimize this compound and better understand the group specific activity of small-molecule inhibitors of HA-mediated entry.
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Affiliation(s)
- Aleksandar Antanasijevic
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Matthew A Durst
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Han Cheng
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, USA
| | | | - Jasmine T Perez
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | - Balaji Manicassamy
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | - Lijun Rong
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, USA
| | - Arnon Lavie
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Michael Caffrey
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
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204
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Structure, interactions and membrane topology of HIV gp41 ectodomain sequences. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183274. [DOI: 10.1016/j.bbamem.2020.183274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 11/21/2022]
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205
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Barrett CT, Dutch RE. Viral Membrane Fusion and the Transmembrane Domain. Viruses 2020; 12:v12070693. [PMID: 32604992 PMCID: PMC7412173 DOI: 10.3390/v12070693] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/05/2023] Open
Abstract
Initiation of host cell infection by an enveloped virus requires a viral-to-host cell membrane fusion event. This event is mediated by at least one viral transmembrane glycoprotein, termed the fusion protein, which is a key therapeutic target. Viral fusion proteins have been studied for decades, and numerous critical insights into their function have been elucidated. However, the transmembrane region remains one of the most poorly understood facets of these proteins. In the past ten years, the field has made significant advances in understanding the role of the membrane-spanning region of viral fusion proteins. We summarize developments made in the past decade that have contributed to the understanding of the transmembrane region of viral fusion proteins, highlighting not only their critical role in the membrane fusion process, but further demonstrating their involvement in several aspects of the viral lifecycle.
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206
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Di Marino D, Bruno A, Grimaldi M, Scrima M, Stillitano I, Amodio G, Della Sala G, Romagnoli A, De Santis A, Moltedo O, Remondelli P, Boccia G, D'Errico G, D'Ursi AM, Limongelli V. Binding of the Anti-FIV Peptide C8 to Differently Charged Membrane Models: From First Docking to Membrane Tubulation. Front Chem 2020; 8:493. [PMID: 32676493 PMCID: PMC7333769 DOI: 10.3389/fchem.2020.00493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/13/2020] [Indexed: 12/11/2022] Open
Abstract
Gp36 is the virus envelope glycoproteins catalyzing the fusion of the feline immunodeficiency virus with the host cells. The peptide C8 is a tryptophan-rich peptide corresponding to the fragment 770W-I777 of gp36 exerting antiviral activity by binding the membrane cell and inhibiting the virus entry. Several factors, including the membrane surface charge, regulate the binding of C8 to the lipid membrane. Based on the evidence that imperceptible variation of membrane charge may induce a dramatic effect in several critical biological events, in the present work we investigate the effect induced by systematic variation of charge in phospholipid bilayers on the aptitude of C8 to interact with lipid membranes, the tendency of C8 to assume specific conformational states and the re-organization of the lipid bilayer upon the interaction with C8. Accordingly, employing a bottom-up multiscale protocol, including CD, NMR, ESR spectroscopy, atomistic molecular dynamics simulations, and confocal microscopy, we studied C8 in six membrane models composed of different ratios of zwitterionic/negatively charged phospholipids. Our data show that charge content modulates C8-membrane binding with significant effects on the peptide conformations. C8 in micelle solution or in SUV formed by DPC or DOPC zwitterionic phospholipids assumes regular β-turn structures that are progressively destabilized as the concentration of negatively charged SDS or DOPG phospholipids exceed 40%. Interaction of C8 with zwitterionic membrane surface is mediated by Trp1 and Trp4 that are deepened in the membrane, forming H-bonds and cation-π interactions with the DOPC polar heads. Additional stabilizing salt bridge interactions involve Glu2 and Asp3. MD and ESR data show that the C8-membrane affinity increases as the concentration of zwitterionic phospholipid increases. In the lipid membrane characterized by an excess of zwitterionic phospholipids, C8 is adsorbed at the membrane interface, inducing a stiffening of the outer region of the DOPC bilayer. However, the bound of C8 significantly perturbs the whole organization of lipid bilayer resulting in membrane remodeling. These events, measurable as a variation of the bilayer thickness, are the onset mechanism of the membrane fusion and vesicle tubulation observed in confocal microscopy by imaging zwitterionic MLVs in the presence of C8 peptide.
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Affiliation(s)
- Daniele Di Marino
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
| | - Agostino Bruno
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | | | - Mario Scrima
- Department of Pharmacy, University of Salerno, Fisciano, Italy
| | | | - Giuseppina Amodio
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Grazia Della Sala
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Alice Romagnoli
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center (NY-MaSBiC), Polytechnic University of Marche, Ancona, Italy
| | - Augusta De Santis
- Department of Chemical Science, University of Naples Federico II, Naples, Italy
| | - Ornella Moltedo
- Department of Pharmacy, University of Salerno, Fisciano, Italy
| | - Paolo Remondelli
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Giovanni Boccia
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Gerardino D'Errico
- Department of Chemical Science, University of Naples Federico II, Naples, Italy
| | | | - Vittorio Limongelli
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy.,Faculty of Biomedical Sciences, Institute of Computational Science, Università della Svizzera italiana (USI), Lugano, Switzerland
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207
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Wang W, Tan J, Ye S. Unsaturated Lipid Accelerates Formation of Oligomeric β-Sheet Structure of GP41 Fusion Peptide in Model Cell Membrane. J Phys Chem B 2020; 124:5169-5176. [PMID: 32453953 DOI: 10.1021/acs.jpcb.0c02464] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane fusion of the viral and host cell membranes is the initial step of virus infection and is catalyzed by fusion peptides. Although the β-sheet structure of fusion peptides has been proposed to be the most important fusion-active conformation, it is still very challenging to experimentally identify different types of β-sheet structures at the cell membrane surface in situ and in real time. In this work, we demonstrate that the interface-sensitive amide II spectral signals of protein backbones, generated by the sum frequency generation vibrational spectroscopy, provide a sensitive probe for directly capturing the formation of oligomeric β-sheet structure of fusion peptides. Using human immunodeficiency virus (HIV) glycoprotein GP41 fusing peptide (FP23) as the model, we find that formation speed of oligomeric β-sheet structure depends on lipid unsaturation. The unsaturated lipid such as POPG can accelerate formation of oligomeric β-sheet structure of FP23. The β-sheet structure is more deeply inserted into the hydrophobic region of the POPG bilayer than the α-helical segment. This work will pave the way for future researches on capturing intermediate structures during membrane fusion processes and revealing the fusion mechanism.
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Affiliation(s)
- Wenting Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Junjun Tan
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Shuji Ye
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
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208
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Lin HH, Huang LM, Wu SC. A quantitative luciferase-based cell-cell fusion assay to measure four-serotype dengue virus E protein-triggered membrane fusion. Hum Vaccin Immunother 2020; 16:2176-2182. [PMID: 32530355 PMCID: PMC7553686 DOI: 10.1080/21645515.2020.1748989] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The class II membrane fusion induced by flavivirus E proteins is a unique pH-dependent membrane fusion process differently from the class I or III membrane fusion by other enveloped virus proteins. The fusion peptide on the DII of the flavivirus E proteins can insert into the cell membrane as a cell entry process besides the receptor bindings. A traditional assay using C6/36 mosquito cells infected by dengue viruses has been previously reported but did not provide efficient quantitation to measure the virus-triggered membrane fusion. Here we reported the development of a quantitative cell fusion assay for four serotypes of dengue viruses and the recently emerged Zika viruses. We used a pCI-neo vector encoding the prME genes of dengue and Zika viruses and investigated the cell fusion in transfected 293, Vero and CHO cells. Donor cells were co-transfection of the prME genes of dengue and Zika prME gene and T7 RNA polymerase to react with the indicator cells transfected with the luciferase gene under the control of the T7 promoter. Quantification of the virus-induced cell fusion was determined by the luciferase expression levels under a switch of pH from 7.4 to 5.4 in the co-cultured donor and indicator cells. The quantitative luciferase-based assay was applied to measure the anti-fusion activity by two monoclonal antibodies mAb 4G2 and mAb DB42 against dengue virus infections. This assay could quality as a quantitative bioassay for testing the potency of anti-fusion monoclonal antibodies.
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Affiliation(s)
- Hsiao-Han Lin
- Institute of Biotechnology, National Tsing Hua University , Hsinchu, Taiwan
| | - Li-Min Huang
- Department of Pediatrics, National Taiwan University Children's Hospital , Taipei, Taiwan
| | - Suh-Chin Wu
- Institute of Biotechnology, National Tsing Hua University , Hsinchu, Taiwan.,Department of Medical Science, National Tsing Hua University , Hsinchu, Taiwan
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209
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McCallum M, Walls AC, Corti D, Veesler D. Closing coronavirus spike glycoproteins by structure-guided design. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.06.03.129817. [PMID: 32577661 PMCID: PMC7302216 DOI: 10.1101/2020.06.03.129817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The recent spillover of SARS-CoV-2 in the human population resulted in the ongoing COVID-19 pandemic which has already caused 4.9 million infections and more than 326,000 fatalities. To initiate infection the SARS-CoV-2 spike (S) glycoprotein promotes attachment to the host cell surface, determining host and tissue tropism, and fusion of the viral and host membranes. Although SARS-CoV-2 S is the main target of neutralizing antibodies and the focus of vaccine design, its stability and conformational dynamics are limiting factors for developing countermeasures against this virus. We report here the design of a prefusion SARS-CoV-2 S ectodomain trimer construct covalently stabilized in the closed conformation. Structural and antigenicity analysis showed we successfully shut S in the closed state without otherwise altering its architecture. Finally, we show that this engineering strategy is applicable to other β-coronavirus S glycoproteins and might become an important tool for vaccine design, structural biology, serology and immunology studies.
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Affiliation(s)
- Matthew McCallum
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Alexandra C Walls
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Davide Corti
- Humabs Biomed SA, a subsidiary of Vir Biotechnology, 6500 Bellinzona, Switzerland
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
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210
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Tang T, Bidon M, Jaimes JA, Whittaker GR, Daniel S. Coronavirus membrane fusion mechanism offers a potential target for antiviral development. Antiviral Res 2020. [PMID: 32272173 DOI: 10.1016/j.antiviral.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has focused attention on the need to develop effective therapies against the causative agent, SARS-CoV-2, and also against other pathogenic coronaviruses (CoV) that have emerged in the past or might appear in future. Researchers are therefore focusing on steps in the CoV replication cycle that may be vulnerable to inhibition by broad-spectrum or specific antiviral agents. The conserved nature of the fusion domain and mechanism across the CoV family make it a valuable target to elucidate and develop pan-CoV therapeutics. In this article, we review the role of the CoV spike protein in mediating fusion of the viral and host cell membranes, summarizing the results of research on SARS-CoV, MERS-CoV, and recent peer-reviewed studies of SARS-CoV-2, and suggest that the fusion mechanism be investigated as a potential antiviral target. We also provide a supplemental file containing background information on the biology, epidemiology, and clinical features of all human-infecting coronaviruses, along with a phylogenetic tree of these coronaviruses.
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Affiliation(s)
- Tiffany Tang
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Miya Bidon
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Javier A Jaimes
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, 14853, USA
| | - Gary R Whittaker
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, 14853, USA
| | - Susan Daniel
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA.
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211
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Tang T, Bidon M, Jaimes JA, Whittaker GR, Daniel S. Coronavirus membrane fusion mechanism offers a potential target for antiviral development. Antiviral Res 2020; 178:104792. [PMID: 32272173 PMCID: PMC7194977 DOI: 10.1016/j.antiviral.2020.104792] [Citation(s) in RCA: 519] [Impact Index Per Article: 129.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/05/2020] [Accepted: 04/05/2020] [Indexed: 12/14/2022]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has focused attention on the need to develop effective therapies against the causative agent, SARS-CoV-2, and also against other pathogenic coronaviruses (CoV) that have emerged in the past or might appear in future. Researchers are therefore focusing on steps in the CoV replication cycle that may be vulnerable to inhibition by broad-spectrum or specific antiviral agents. The conserved nature of the fusion domain and mechanism across the CoV family make it a valuable target to elucidate and develop pan-CoV therapeutics. In this article, we review the role of the CoV spike protein in mediating fusion of the viral and host cell membranes, summarizing the results of research on SARS-CoV, MERS-CoV, and recent peer-reviewed studies of SARS-CoV-2, and suggest that the fusion mechanism be investigated as a potential antiviral target. We also provide a supplemental file containing background information on the biology, epidemiology, and clinical features of all human-infecting coronaviruses, along with a phylogenetic tree of these coronaviruses.
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Affiliation(s)
- Tiffany Tang
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Miya Bidon
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Javier A Jaimes
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, 14853, USA
| | - Gary R Whittaker
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, 14853, USA
| | - Susan Daniel
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA.
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212
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Akimov SA, Molotkovsky RJ, Kuzmin PI, Galimzyanov TR, Batishchev OV. Continuum Models of Membrane Fusion: Evolution of the Theory. Int J Mol Sci 2020; 21:E3875. [PMID: 32485905 PMCID: PMC7312925 DOI: 10.3390/ijms21113875] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 12/18/2022] Open
Abstract
Starting from fertilization, through tissue growth, hormone secretion, synaptic transmission, and sometimes morbid events of carcinogenesis and viral infections, membrane fusion regulates the whole life of high organisms. Despite that, a lot of fusion processes still lack well-established models and even a list of main actors. A merger of membranes requires their topological rearrangements controlled by elastic properties of a lipid bilayer. That is why continuum models based on theories of membrane elasticity are actively applied for the construction of physical models of membrane fusion. Started from the view on the membrane as a structureless film with postulated geometry of fusion intermediates, they developed along with experimental and computational techniques to a powerful tool for prediction of the whole process with molecular accuracy. In the present review, focusing on fusion processes occurring in eukaryotic cells, we scrutinize the history of these models, their evolution and complication, as well as open questions and remaining theoretical problems. We show that modern approaches in this field allow continuum models of membrane fusion to stand shoulder to shoulder with molecular dynamics simulations, and provide the deepest understanding of this process in multiple biological systems.
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Affiliation(s)
- Sergey A. Akimov
- Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia; (R.J.M.); (P.I.K.); (T.R.G.); (O.V.B.)
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213
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Su X, Wang Q, Wen Y, Jiang S, Lu L. Protein- and Peptide-Based Virus Inactivators: Inactivating Viruses Before Their Entry Into Cells. Front Microbiol 2020; 11:1063. [PMID: 32523582 PMCID: PMC7261908 DOI: 10.3389/fmicb.2020.01063] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/29/2020] [Indexed: 12/20/2022] Open
Abstract
Infectious diseases caused by human immunodeficiency virus (HIV) and other highly pathogenic enveloped viruses, have threatened the global public health. Most antiviral drugs act as passive defenders to inhibit viral replication inside the cell, while a few of them function as gate keepers to combat viruses outside the cell, including fusion inhibitors, e.g., enfuvirtide, and receptor antagonists, e.g., maraviroc, as well as virus inactivators (including attachment inhibitors). Different from fusion inhibitors and receptor antagonists that must act in the presence of target cells, virus inactivators can actively inactivate cell-free virions in the blood, through interaction with one or more sites in the envelope glycoproteins (Envs) on virions. Notably, a number of protein- and peptide-based virus inactivators (PPVIs) under development are expected to have a better utilization rate than the current antiviral drugs and be safer for in vivo human application than the chemical-based virus inactivators. Here we have highlighted recent progress in developing PPVIs against several important enveloped viruses, including HIV, influenza virus, Zika virus (ZIKV), dengue virus (DENV), and herpes simplex virus (HSV), and the potential use of PPVIs for urgent treatment of infection by newly emerging or re-emerging viruses.
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Affiliation(s)
- Xiaojie Su
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qian Wang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yumei Wen
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China.,Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Fudan University, Shanghai, China
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214
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Glycoprotein 5 Is Cleaved by Cathepsin E during Porcine Reproductive and Respiratory Syndrome Virus Membrane Fusion. J Virol 2020; 94:JVI.00097-20. [PMID: 32102888 DOI: 10.1128/jvi.00097-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 02/24/2020] [Indexed: 12/26/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a serious viral disease affecting the global swine industry. Its causative agent, PRRS virus (PRRSV), is an enveloped virus, and therefore membrane fusion between its envelope and host cell target membrane is critical for viral infection. Though much research has focused on PRRSV infection, the detailed mechanisms involved in its membrane fusion remain to be elucidated. In the present study, we performed confocal microscopy in combination with a constitutively active (CA) or dominant negative (DN) mutant, specific inhibitors, and small interfering RNAs (siRNAs), as well as multiple other approaches, to explore PRRSV membrane fusion. We first observed that PRRSV membrane fusion occurred in Rab11-recycling endosomes during early infection using labeled virions and subcellular markers. We further demonstrated that low pH and cathepsin E in Rab11-recycling endosomes are critical for PRRSV membrane fusion. Moreover, PRRSV glycoprotein 5 (GP5) is identified as being cleaved by cathepsin E during this process. Taken together, our findings provide in-depth information regarding PRRSV pathogenesis, which support a novel basis for the development of antiviral drugs and vaccines.IMPORTANCE PRRS, caused by PRRSV, is an economically critical factor in pig farming worldwide. As PRRSV is a lipid membrane-wrapped virus, merging of the PRRSV envelope with the host cell membrane is indispensable for viral infection. However, there is a lack of knowledge on its membrane fusion. Here, we first explored when and where PRRSV membrane fusion occurs. Furthermore, we determined which host cell factors were involved in the process. Importantly, PRRSV GP5 is shown to be cleaved by cathepsin E during membrane fusion. Our work not only provides information on PRRSV membrane fusion for the first time but also deepens our understanding of the molecular mechanisms of PRRSV infection, which provides a foundation for future applications in the prevention and control of PRRS.
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215
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Wang L, Wang R, Wang L, Ben H, Yu L, Gao F, Shi X, Yin C, Zhang F, Xiang Y, Zhang L. Structural Basis for Neutralization and Protection by a Zika Virus-Specific Human Antibody. Cell Rep 2020; 26:3360-3368.e5. [PMID: 30893607 DOI: 10.1016/j.celrep.2019.02.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 11/22/2018] [Accepted: 02/13/2019] [Indexed: 12/26/2022] Open
Abstract
We previously reported a human monoclonal antibody, ZK2B10, capable of protection against Zika virus (ZIKV) infection and microcephaly in developing mouse embryos. Here, we report the structural features and mechanism of action of ZK2B10. The crystal structure at a resolution of 2.32 Å revealed that the epitope is located on the lateral ridge of DIII of the envelope glycoprotein. Cryo-EM structure with mature ZIKV showed that the antibody binds to DIIIs around the icosahedral 2-fold, 3-fold, and 5-fold axes, a distinct feature compared to those reported for DIII-specific antibodies. The binding of ZK2B10 to ZIKV has no detectable effect on viral attachment to target cells or on conformational changes of the E glycoprotein in the acidic environment, suggesting that ZK2B10 functions at steps between the formation of the fusion intermediate and membrane fusion. These results provide structural and mechanistic insights into how ZK2B10 mediates protection against ZIKV infection.
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Affiliation(s)
- Lin Wang
- Beijing Advanced Innovation Center for Structural Biology, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Ruoke Wang
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Lei Wang
- Beijing Advanced Innovation Center for Structural Biology, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Haijing Ben
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Lei Yu
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China
| | - Fei Gao
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xuanling Shi
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chibiao Yin
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China
| | - Fuchun Zhang
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China
| | - Ye Xiang
- Beijing Advanced Innovation Center for Structural Biology, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
| | - Linqi Zhang
- Comprehensive AIDS Research Center, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Center for Global Health and Infectious Diseases, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
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216
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Goblirsch BR, Wiener MC. Ste24: An Integral Membrane Protein Zinc Metalloprotease with Provocative Structure and Emergent Biology. J Mol Biol 2020; 432:5079-5090. [PMID: 32199981 PMCID: PMC7172729 DOI: 10.1016/j.jmb.2020.03.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/06/2020] [Accepted: 03/12/2020] [Indexed: 01/30/2023]
Abstract
Ste24, an integral membrane protein zinc metalloprotease, is found in every kingdom of eukaryotes. It was discovered approximately 20 years ago by yeast genetic screens identifying it as a factor responsible for processing the yeast mating a-factor pheromone. In animals, Ste24 processes prelamin A, a component of the nuclear lamina; mutations in the human ortholog of Ste24 diminish its activity, giving rise to genetic diseases of accelerated aging (progerias). Additionally, lipodystrophy, acquired from the standard highly active antiretroviral therapy used to treat AIDS patients, likely results from off-target interactions of HIV (aspartyl) protease inhibitor drugs with Ste24. Ste24 possesses a novel “α-barrel” structure, consisting of a ring of seven transmembrane α-helices enclosing a large (> 12,000 Å3) interior volume that contains the active-site and substrate-binding region; this “membrane-interior reaction chamber” is unprecedented in integral membrane protein structures. Additionally, the surface of the membrane-interior reaction chamber possesses a strikingly large negative electrostatic surface potential, adding additional “functional mystery.” Recent publications implicate Ste24 as a key factor in several endoplasmic reticulum processes, including the unfolded protein response, a cellular stress response of the endoplasmic reticulum, and removal of misfolded proteins from the translocon. Ste24, with its provocative structure, enigmatic mechanism, and recently emergent new biological roles including “translocon unclogger” and (non-enyzmatic) broad-spectrum viral restriction factor, presents far differently than before 2016, when it was viewed as a “CAAX protease” responsible for cleavage of prenylated (farnesylated or geranylgeranylated) substrates. The emphasis of this review is on Ste24 of the “Post-CAAX-Protease Era.” Ste24 is a eukaryotic integral membrane protein of novel structure. Ste24 is a gluzincin ZMP whose structure/function relationships are poorly explored. ZMP core, ZMP accessory, and “ɑ-barrel modules form the Ste24 tripartite architecture. Emergent biology of Ste24 includes roles as a translocon unclogger and a viral restriction factor.
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Affiliation(s)
- Brandon R Goblirsch
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Michael C Wiener
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
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217
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NMR Structure of the FIV gp36 C-Terminal Heptad Repeat and Membrane-Proximal External Region. Int J Mol Sci 2020; 21:ijms21062037. [PMID: 32188158 PMCID: PMC7139756 DOI: 10.3390/ijms21062037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 12/13/2022] Open
Abstract
Feline immunodeficiency virus (FIV), a lentivirus causing an immunodeficiency syndrome in cats, represents a relevant model of pre-screening therapies for human immunodeficiency virus (HIV). The envelope glycoproteins gp36 in FIV and gp41 in HIV mediate the fusion of the virus with the host cell membrane. They have a common structural framework in the C-terminal region that includes a Trp-rich membrane-proximal external region (MPER) and a C-terminal heptad repeat (CHR). MPER is essential for the correct positioning of gp36 on the lipid membrane, whereas CHR is essential for the stabilization of the low-energy six-helical bundle (6HB) that is necessary for the fusion of the virus envelope with the cell membrane. Conformational data for gp36 are missing, and several aspects of the MPER structure of different lentiviruses are still debated. In the present work, we report the structural investigation of a gp36 construct that includes the MPER and part of the CHR domain (737-786gp36 CHR–MPER). Using 2D and 3D homo and heteronuclear NMR spectra on 15N and 13C double-labelled samples, we solved the NMR structure in micelles composed of dodecyl phosphocholine (DPC) and sodium dodecyl sulfate (SDS) 90/10 M: M. The structure of 737-786gp36 CHR–MPER is characterized by a helix–turn–helix motif, with a regular α-helix and a moderately flexible 310 helix, characterizing the CHR and the MPER domains, respectively. The two helices are linked by a flexible loop regulating their orientation at a ~43° angle. We investigated the positioning of 737-786gp36 CHR–MPER on the lipid membrane using spin label-enhanced NMR and ESR spectroscopies. On a different scale, using confocal microscopy imaging, we studied the effect of 737-786gp36 CHR–MPER on 1,2-dioleoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-phospho-(1’-rac-glycerol) (DOPC/DOPG) multilamellar vesicles (MLVs). This effect results in membrane budding and tubulation that is reminiscent of a membrane-plasticizing role that is typical of MPER domains during the event in which the virus envelope merges with the host cell membrane.
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218
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Abstract
Influenza A virus (IAV) is an enveloped virus of the Orthomyxoviridae with a negative-sense single-stranded RNA genome. During virus cell entry, viral and cellular cues are delivered in a stepwise manner within two distinct cellular compartments-the endosomes and the cytosol. Endosome maturation primes the viral core for uncoating by cytosolic host proteins and host-mediated virus disaggregation is essential for genome import and replication in the nucleus. Recent evidence shows that two well-known cellular proteins-histone deacetylase 6 (HDAC6) and karyopherin-β2 (kapβ2)-uncoat influenza virus. HDAC6 is 1 of 11 HDACs and an X-linked, cytosolic lysine deacetylase. Under normal cellular conditions HDAC6 is the tubulin deacetylase. Under proteasomal stress HDAC6 binds unanchored ubiquitin, dynein and myosin II to sequester misfolded protein aggregates for autophagy. Kapβ2 is a member of the importin β family that transports RNA-binding proteins into the nucleus by binding to disordered nuclear localization signals (NLSs) known as PY-NLS. Kapβ2 is emerging as a universal uncoating factor for IAV and human immunodeficiency virus type 1 (HIV-1). Kapβ2 can also reverse liquid-liquid phase separation (LLPS) of RNA-binding proteins by promoting their disaggregation. Thus, it is becoming evident that key players in the management of cellular condensates and membraneless organelles are potent virus uncoating factors. This emerging concept reveals implications in viral pathogenesis, as well as, the promise for cell-targeted therapeutic strategies to block universal virus uncoating pathways hijacked by enveloped RNA viruses.
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Affiliation(s)
- Yohei Yamauchi
- School of Cellular & Molecular Medicine, University of Bristol, Bristol, United Kingdom.
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219
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Abstract
Paramyxoviruses, including human parainfluenza virus type 3, are internalized into host cells by fusion between viral and target cell membranes. The receptor binding protein, hemagglutinin-neuraminidase (HN), upon binding to its cell receptor, triggers conformational changes in the fusion protein (F). This action of HN activates F to reach its fusion-competent state. Using small molecules that interact with HN, we can induce the premature activation of F and inactivate the virus. To obtain highly active pretriggering compounds, we carried out a virtual modeling screen for molecules that interact with a sialic acid binding site on HN that we propose to be the site involved in activating F. We use cryo-electron tomography of authentic intact viral particles for the first time to directly assess the mechanism of action of this treatment on the conformation of the viral F protein and present the first direct observation of the induced conformational rearrangement in the viral F protein. The receptor binding protein of parainfluenza virus, hemagglutinin-neuraminidase (HN), is responsible for actively triggering the viral fusion protein (F) to undergo a conformational change leading to insertion into the target cell and fusion of the virus with the target cell membrane. For proper viral entry to occur, this process must occur when HN is engaged with host cell receptors at the cell surface. It is possible to interfere with this process through premature activation of the F protein, distant from the target cell receptor. Conformational changes in the F protein and adoption of the postfusion form of the protein prior to receptor engagement of HN at the host cell membrane inactivate the virus. We previously identified small molecules that interact with HN and induce it to activate F in an untimely fashion, validating a new antiviral strategy. To obtain highly active pretriggering candidate molecules we carried out a virtual modeling screen for molecules that interact with sialic acid binding site II on HN, which we propose to be the site responsible for activating F. To directly assess the mechanism of action of one such highly effective new premature activating compound, PAC-3066, we use cryo-electron tomography on authentic intact viral particles for the first time to examine the effects of PAC-3066 treatment on the conformation of the viral F protein. We present the first direct observation of the conformational rearrangement induced in the viral F protein.
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220
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Henderson R, Lu M, Zhou Y, Mu Z, Parks R, Han Q, Hsu AL, Carter E, Blanchard SC, Edwards RJ, Wiehe K, Saunders KO, Borgnia MJ, Bartesaghi A, Mothes W, Haynes BF, Acharya P, Munir Alam S. Disruption of the HIV-1 Envelope allosteric network blocks CD4-induced rearrangements. Nat Commun 2020; 11:520. [PMID: 31980614 PMCID: PMC6981184 DOI: 10.1038/s41467-019-14196-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/18/2019] [Indexed: 11/24/2022] Open
Abstract
The trimeric HIV-1 Envelope protein (Env) mediates viral-host cell fusion via a network of conformational transitions, with allosteric elements in each protomer orchestrating host receptor-induced exposure of the co-receptor binding site and fusion elements. To understand the molecular details of this allostery, here, we introduce Env mutations aimed to prevent CD4-induced rearrangements in the HIV-1 BG505 Env trimer. Binding analysis and single-molecule Förster Resonance Energy Transfer confirm that these mutations prevent CD4-induced transitions of the HIV-1 Env. Structural analysis by single-particle cryo-electron microscopy performed on the BG505 SOSIP mutant Env proteins shows rearrangements in the gp120 topological layer contacts with gp41. Displacement of a conserved tryptophan (W571) from its typical pocket in these Env mutants renders the Env insensitive to CD4 binding. These results reveal the critical function of W571 as a conformational switch in Env allostery and receptor-mediated viral entry and provide insights on Env conformation that are relevant for vaccine design.
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Affiliation(s)
- Rory Henderson
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA.
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
| | - Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC, 27708, USA
| | - Zekun Mu
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Robert Parks
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Qifeng Han
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Allen L Hsu
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Elizabeth Carter
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10021, USA
- St. Jude Children's Research Hospital, Department of Structural Biology, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
| | - R J Edwards
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kevin Wiehe
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kevin O Saunders
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Surgery, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Mario J Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Alberto Bartesaghi
- Department of Computer Science, Duke University, Durham, NC, 27708, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Barton F Haynes
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Surgery, Duke University School of Medicine, Durham, NC, 27710, USA.
| | - S Munir Alam
- Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA.
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Pathology, Duke University School of Medicine, Durham, NC, 27710, USA.
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221
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Outlaw VK, Lemke JT, Zhu Y, Gellman SH, Porotto M, Moscona A. Structure-Guided Improvement of a Dual HPIV3/RSV Fusion Inhibitor. J Am Chem Soc 2020; 142:2140-2144. [PMID: 31951396 DOI: 10.1021/jacs.9b11548] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human parainfluenza virus 3 (HPIV3) and respiratory syncytial virus (RSV) are leading causes of lower respiratory tract infections. There are currently no vaccines or antiviral therapeutics to treat HPIV3 or RSV infections. We recently reported a peptide (VIQKI), derived from the C-terminal heptad repeat (HRC) domain of the HPIV3 fusion (F) glycoprotein that inhibits infection by both HPIV3 and RSV. The dual inhibitory activity of VIQKI is due to its unique ability to bind to the N-terminal heptad repeat (HRN) domains of both HPIV3 and RSV F, thereby preventing the native HRN-HRC interactions required for viral entry. Here we describe the structure-guided design of dual inhibitors of HPIV3 and RSV fusion with improved efficacy. We show that VIQKI derivatives possessing one (I456F) or two (I454F/I456F) phenylalanine substitutions near the N-terminus exhibit more stable assemblies with the RSV-HRN domain and enhanced antiviral efficacy against both HPIV3 and RSV infection. Cocrystal structures of the new Phe-substituted inhibitors coassembled with HPIV3 or RSV-HRN domains reveal that the I456F substitution makes intimate hydrophobic contact with the core trimers of both HPIV3 and RSV F.
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Affiliation(s)
- Victor K Outlaw
- Department of Chemistry , University of Wisconsin , Madison , Wisconsin 53706 , United States
| | - Jennifer T Lemke
- Department of Chemistry , University of Wisconsin , Madison , Wisconsin 53706 , United States
| | - Yun Zhu
- Department of Pediatrics , Columbia University Medical Center , New York , New York 10032 , United States.,Beijing Pediatric Research Institute , Beijing Children's Hospital, Capital Medical University , Beijing 100045 , China
| | - Samuel H Gellman
- Department of Chemistry , University of Wisconsin , Madison , Wisconsin 53706 , United States
| | - Matteo Porotto
- Department of Pediatrics , Columbia University Medical Center , New York , New York 10032 , United States.,Center for Host-Pathogen Interaction , Columbia University Medical Center , New York , New York 10032 , United States.,Department of Experimental Medicine , University of Campania "Luigi Vanvitelli" , 81100 Caserta , Italy
| | - Anne Moscona
- Department of Pediatrics , Columbia University Medical Center , New York , New York 10032 , United States.,Center for Host-Pathogen Interaction , Columbia University Medical Center , New York , New York 10032 , United States.,Department of Microbiology & Immunology , Columbia University Medical Center , New York , New York 10032 , United States.,Department of Physiology & Cellular Biophysics , Columbia University Medical Center , New York , New York 10032 , United States
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222
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Rathore SS, Liu Y, Yu H, Wan C, Lee M, Yin Q, Stowell MHB, Shen J. Intracellular Vesicle Fusion Requires a Membrane-Destabilizing Peptide Located at the Juxtamembrane Region of the v-SNARE. Cell Rep 2019; 29:4583-4592.e3. [PMID: 31875562 PMCID: PMC6990648 DOI: 10.1016/j.celrep.2019.11.107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/13/2019] [Accepted: 11/26/2019] [Indexed: 12/11/2022] Open
Abstract
Intracellular vesicle fusion is mediated by soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) and Sec1/Munc18 (SM) proteins. It is generally accepted that membrane fusion occurs when the vesicle and target membranes are brought into close proximity by SNAREs and SM proteins. In this work, we demonstrate that, for fusion to occur, membrane bilayers must be destabilized by a conserved membrane-embedded motif located at the juxtamembrane region of the vesicle-anchored v-SNARE. Comprised of basic and hydrophobic residues, the juxtamembrane motif perturbs the lipid bilayer structure and promotes SNARE-SM-mediated membrane fusion. The juxtamembrane motif can be functionally substituted with an unrelated membrane-disrupting peptide in the membrane fusion reaction. These findings establish the juxtamembrane motif of the v-SNARE as a membrane-destabilizing peptide. Requirement of membrane-destabilizing peptides is likely a common feature of biological membrane fusion.
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Affiliation(s)
- Shailendra S Rathore
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA
| | - Yinghui Liu
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA; Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Haijia Yu
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA; Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA
| | - MyeongSeon Lee
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA
| | - Qian Yin
- Department of Biological Sciences and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Michael H B Stowell
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA
| | - Jingshi Shen
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, 347 UCB, Boulder, CO 80309, USA.
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223
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Hemagglutinin Quantitative ELISA-based Potency Assay for Trivalent Seasonal Influenza Vaccine Using Group-Specific Universal Monoclonal Antibodies. Sci Rep 2019; 9:19675. [PMID: 31873147 PMCID: PMC6927952 DOI: 10.1038/s41598-019-56169-5] [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: 09/24/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
The assurance of vaccine potency is important for the timely release and distribution of influenza vaccines. As an alternative to Single Radial Immunodiffusion (SRID), we report a new quantitative enzyme-linked immunosorbent assay (ELISA) for seasonal trivalent influenza vaccine (TIV). The consensus hemagglutinin (cHA) stalks for group 1 influenza A virus (IAV), group 2 IAV, and influenza B virus (IBV) were designed and produced in bacterial recombinant host in a soluble form, and monoclonal antibodies (mAbs) were generated. The group-specific ‘universal’ mAbs (uAbs) bound to various subtypes of HAs in the same group from recombinant hosts, embryonated eggs, and commercial vaccine lots. The calibration curves were generated to assess the sensitivity, specificity, accuracy, and linear dynamic range. The quantitative ELISA was validated for the potency assay of individual components of TIV- H1, H3, and IBV- with good correlation with the SRID method. This new assay could be extended to pandemic or pre-pandemic mock-up vaccines of H5 of group 1 and H7 virus of group 2, and novel HA stalk-based universal vaccines.
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224
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Liu N, Girvin ME, Brenowitz M, Lai JR. Conformational and lipid bilayer-perturbing properties of Marburg virus GP2 segments containing the fusion loop and membrane-proximal external region/transmembrane domain. Heliyon 2019; 5:e03018. [PMID: 31890962 PMCID: PMC6926192 DOI: 10.1016/j.heliyon.2019.e03018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 11/04/2019] [Accepted: 12/06/2019] [Indexed: 12/13/2022] Open
Abstract
Fusion of host and viral membranes is a crucial step during infection by enveloped viruses. In the structurally-defined "class I″ viral glycoproteins, the formation of a highly stable α-helical bundle by the ectodomain of the fusion subunit (e.g., GP2 for Marburg virus, MARV) is postulated to provide the energetic driving force to overcome barriers associated with membrane fusion. Upon cell binding, the fusion subunit is proposed to form an extended intermediate that bridges both the viral and host membranes, and collapse of this extended intermediate brings the two membranes into proximity. While there is much high-resolution structural data available for prefusion and post-fusion structures of viral glycoproteins, little information is available about intermediate conformations especially in the context of the fusion loop/peptide (FL or FP) and membrane-proximal external region (MPER)/transmembrane (TM) segments. We present structural and functional studies on segments of MARV GP2 that encompass the FL and MPER/TM in detergent micelles and lipid bicelles. A protein that contains most elements of GP2 ("MGP2-full") is α-helical in membrane-mimicking environments and has pH-dependent membrane lytic activity. MGP2-full is monomeric under such conditions, contrasting with the trimeric species that has been described previously for MARV GP2 ectodomain in aqueous buffer. Variants of MARV GP2 containing the N- and C-terminal halves ("MGP2-FNL" and "MGP2-CMT", respectively) have similar properties. This work provides novel insight into conformational and membrane-perturbing properties of the MARV fusion subunit and how they may relate to viral membrane fusion.
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Affiliation(s)
- Nina Liu
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Mark E Girvin
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Michael Brenowitz
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.,Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Jonathan R Lai
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
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225
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Cryo-EM Structures of Eastern Equine Encephalitis Virus Reveal Mechanisms of Virus Disassembly and Antibody Neutralization. Cell Rep 2019; 25:3136-3147.e5. [PMID: 30540945 PMCID: PMC6302666 DOI: 10.1016/j.celrep.2018.11.067] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/01/2018] [Accepted: 11/15/2018] [Indexed: 01/08/2023] Open
Abstract
Alphaviruses are enveloped pathogens that cause arthritis and encephalitis. Here, we report a 4.4-Å cryoelectron microscopy (cryo-EM) structure of eastern equine encephalitis virus (EEEV), an alphavirus that causes fatal encephalitis in humans. Our analysis provides insights into viral entry into host cells. The envelope protein E2 showed a binding site for the cellular attachment factor heparan sulfate. The presence of a cryptic E2 glycan suggests how EEEV escapes surveillance by lectin-expressing myeloid lineage cells, which are sentinels of the immune system. A mechanism for nucleocapsid core release and disassembly upon viral entry was inferred based on pH changes and capsid dissociation from envelope proteins. The EEEV capsid structure showed a viral RNA genome binding site adjacent to a ribosome binding site for viral genome translation following genome release. Using five Fab-EEEV complexes derived from neutralizing antibodies, our investigation provides insights into EEEV host cell interactions and protective epitopes relevant to vaccine design. EEEV cryo-EM structure shows the basis of receptor binding and pH-triggered disassembly Cryptic envelope protein glycosylation interferes with immune detection EEEV RNA genome binding site on capsid protein has an extended conformation Antibody inhibition of EEEV entry involves cross-linking of viral envelope proteins
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Sen N, Kanitkar TR, Roy AA, Soni N, Amritkar K, Supekar S, Nair S, Singh G, Madhusudhan MS. Predicting and designing therapeutics against the Nipah virus. PLoS Negl Trop Dis 2019; 13:e0007419. [PMID: 31830030 PMCID: PMC6907750 DOI: 10.1371/journal.pntd.0007419] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 11/04/2019] [Indexed: 11/28/2022] Open
Abstract
Despite Nipah virus outbreaks having high mortality rates (>70% in Southeast Asia), there are no licensed drugs against it. In this study, we have considered all 9 Nipah proteins as potential therapeutic targets and computationally identified 4 putative peptide inhibitors (against G, F and M proteins) and 146 small molecule inhibitors (against F, G, M, N, and P proteins). The computations include extensive homology/ab initio modeling, peptide design and small molecule docking. An important contribution of this study is the increased structural characterization of Nipah proteins by approximately 90% of what is deposited in the PDB. In addition, we have carried out molecular dynamics simulations on all the designed protein-peptide complexes and on 13 of the top shortlisted small molecule ligands to check for stability and to estimate binding strengths. Details, including atomic coordinates of all the proteins and their ligand bound complexes, can be accessed at http://cospi.iiserpune.ac.in/Nipah. Our strategy was to tackle the development of therapeutics on a proteome wide scale and the lead compounds identified could be attractive starting points for drug development. To counter the threat of drug resistance, we have analysed the sequences of the viral strains from different outbreaks, to check whether they would be sensitive to the binding of the proposed inhibitors.
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Affiliation(s)
- Neeladri Sen
- Indian Institute of Science Education and Research, Pune, India
| | | | | | - Neelesh Soni
- Indian Institute of Science Education and Research, Pune, India
| | | | - Shreyas Supekar
- Indian Institute of Science Education and Research, Pune, India
| | - Sanjana Nair
- Indian Institute of Science Education and Research, Pune, India
| | - Gulzar Singh
- Indian Institute of Science Education and Research, Pune, India
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227
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Collier DA, Monit C, Gupta RK. The Impact of HIV-1 Drug Escape on the Global Treatment Landscape. Cell Host Microbe 2019; 26:48-60. [PMID: 31295424 DOI: 10.1016/j.chom.2019.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The rising prevalence of HIV drug resistance (HIVDR) could threaten gains made in combating the HIV epidemic and compromise the 90-90-90 target proposed by United Nations Programme on HIV/AIDS (UNAIDS) to have achieved virological suppression in 90% of all persons receiving antiretroviral therapy (ART) by the year 2020. HIVDR has implications for the persistence of HIV, the selection of current and future ART drug regimens, and strategies of vaccine and cure development. Focusing on drug classes that are in clinical use, this Review critically summarizes what is known about the mechanisms the virus utilizes to escape drug control. Armed with this knowledge, strategies to limit the expansion of HIVDR are proposed.
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Affiliation(s)
- D A Collier
- Division of Infection and Immunity, University College London, London, UK
| | - C Monit
- Division of Infection and Immunity, University College London, London, UK
| | - R K Gupta
- Department of Medicine, University of Cambridge, Cambridge, UK.
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228
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Russell AE, Sneider A, Witwer KW, Bergese P, Bhattacharyya SN, Cocks A, Cocucci E, Erdbrügger U, Falcon-Perez JM, Freeman DW, Gallagher TM, Hu S, Huang Y, Jay SM, Kano SI, Lavieu G, Leszczynska A, Llorente AM, Lu Q, Mahairaki V, Muth DC, Noren Hooten N, Ostrowski M, Prada I, Sahoo S, Schøyen TH, Sheng L, Tesch D, Van Niel G, Vandenbroucke RE, Verweij FJ, Villar AV, Wauben M, Wehman AM, Yin H, Carter DRF, Vader P. Biological membranes in EV biogenesis, stability, uptake, and cargo transfer: an ISEV position paper arising from the ISEV membranes and EVs workshop. J Extracell Vesicles 2019; 8:1684862. [PMID: 31762963 PMCID: PMC6853251 DOI: 10.1080/20013078.2019.1684862] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/23/2019] [Accepted: 10/04/2019] [Indexed: 02/07/2023] Open
Abstract
Paracrine and endocrine roles have increasingly been ascribed to extracellular vesicles (EVs) generated by multicellular organisms. Central to the biogenesis, content, and function of EVs are their delimiting lipid bilayer membranes. To evaluate research progress on membranes and EVs, the International Society for Extracellular Vesicles (ISEV) conducted a workshop in March 2018 in Baltimore, Maryland, USA, bringing together key opinion leaders and hands-on researchers who were selected on the basis of submitted applications. The workshop was accompanied by two scientific surveys and covered four broad topics: EV biogenesis and release; EV uptake and fusion; technologies and strategies used to study EV membranes; and EV transfer and functional assays. In this ISEV position paper, we synthesize the results of the workshop and the related surveys to outline important outstanding questions about EV membranes and describe areas of consensus. The workshop discussions and survey responses reveal that while much progress has been made in the field, there are still several concepts that divide opinion. Good consensus exists in some areas, including particular aspects of EV biogenesis, uptake and downstream signalling. Areas with little to no consensus include EV storage and stability, as well as whether and how EVs fuse with target cells. Further research is needed in these key areas, as a better understanding of membrane biology will contribute substantially towards advancing the field of extracellular vesicles.
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Affiliation(s)
- Ashley E. Russell
- Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alexandra Sneider
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Kenneth W. Witwer
- Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Paolo Bergese
- Department of Molecular and Translational Medicine, Università degli Studi di Brescia, CSGI and INSTM, Brescia, Italy
| | | | | | - Emanuele Cocucci
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, Columbus, OH, USA
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | | | - Juan M. Falcon-Perez
- Exosomes laboratory and Metabolomics Platform, CIC bioGUNE, CIBERehd, Bizkaia, Spain
- IKERBASQUE, Basque Foundation for Science, Bizkaia, Spain
| | - David W. Freeman
- Laboratory of Epidemiology and Population Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Thomas M. Gallagher
- Department of Microbiology and Immunology, Loyola University Chicago, Chicago, IL, USA
| | - Shuaishuai Hu
- School of Biological and Healthy Sciences, Technological University Dublin, Dublin, Ireland
| | - Yiyao Huang
- Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Clinical Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Steven M. Jay
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | - Shin-ichi Kano
- Department of Psychiatry and Behavioral Neurobiology, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Gregory Lavieu
- INSERM U932, Institut Curie, PSL Research University, France
| | | | - Alicia M. Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Quan Lu
- Program in Molecular and Integrative Physiological Sciences Departments of Environmental Health, Genetics & Complex Diseases Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Vasiliki Mahairaki
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Dillon C. Muth
- Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nicole Noren Hooten
- Laboratory of Epidemiology and Population Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Matias Ostrowski
- INBIRS Institute, UBA-CONICET School of Medicine University of Buenos Aires, Buenos Aires, Argentina
| | | | - Susmita Sahoo
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tine Hiorth Schøyen
- Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- K. G. Jebsen - Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Lifu Sheng
- Department of Pathology, University of Washington School of Medicine, Seattle, WA, USA
| | - Deanna Tesch
- Department of Chemistry, Shaw University, Raleigh, NC, USA
| | - Guillaume Van Niel
- Institute for Psychiatry and Neuroscience of Paris, INSERM U1266, Hopital Saint-Anne, Université Descartes, Paris, France
| | - Roosmarijn E. Vandenbroucke
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Frederik J. Verweij
- Institute for Psychiatry and Neuroscience of Paris, INSERM U1266, Hopital Saint-Anne, Université Descartes, Paris, France
| | - Ana V. Villar
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC) CSIC-Universidad de Cantabria and Departamento de Fisiología y Farmacología, Universidad de Cantabria, Santander, Spain
| | - Marca Wauben
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Ann M. Wehman
- Rudolf Virchow Center, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | | | - Pieter Vader
- Laboratory of Clinical Chemistry and Haematology & Department of Experimental Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Antanasijevic A, Durst MA, Lavie A, Caffrey M. Identification of a pH sensor in Influenza hemagglutinin using X-ray crystallography. J Struct Biol 2019; 209:107412. [PMID: 31689502 PMCID: PMC7111647 DOI: 10.1016/j.jsb.2019.107412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 11/15/2022]
Abstract
X-ray crystallography identifies a conserved histidine, HA1-H38, that changes side chain conformation at low pH. We attribute the observed conformational change to cation-cation repulsion between protonated HA1-H18 and HA1-H38. We suggest that the HA1-H18 and HA1-H38 pair plays a role in the pathway toward the postfusion conformation of HA.
Hemagglutnin (HA) mediates entry of influenza virus through a series of conformational changes triggered by the low pH of the endosome. The residue or combination of residues acting as pH sensors has not yet been fully elucidated. In this work, we assay pH effects on the structure of H5 HA by soaking HA crystallized at pH 6.5 in a series of buffers with lower pH, mimicking the conditions of the endosome. We find that HA1-H38, which is conserved in Group 1 HA, undergoes a striking change in side chain conformation, which we attribute to its protonation and cation-cation repulsion with conserved HA1-H18. This work suggests that x-ray crystallography can be applied for studying small-scale pH-induced conformational changes providing valuable information on the location of pH sensors in HA. Importantly, the observed change in HA1-H38 conformation is further evidence that the pH-induced conformational changes of HA are the result of a series of protonation events to conserved and non-conserved pH sensors.
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Affiliation(s)
- Aleksandar Antanasijevic
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland Ave, 60607 Chicago, USA
| | - Matthew A Durst
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland Ave, 60607 Chicago, USA
| | - Arnon Lavie
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland Ave, 60607 Chicago, USA.
| | - Michael Caffrey
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland Ave, 60607 Chicago, USA.
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Gaikwad AS, Anderson AL, Merriner DJ, O'Connor AE, Houston BJ, Aitken RJ, O'Bryan MK, Nixon B. GLIPR1L1 is an IZUMO-binding protein required for optimal fertilization in the mouse. BMC Biol 2019; 17:86. [PMID: 31672133 PMCID: PMC6824042 DOI: 10.1186/s12915-019-0701-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/19/2019] [Indexed: 12/19/2022] Open
Abstract
Background The sperm protein IZUMO1 (Izumo sperm-egg fusion 1) and its recently identified binding partner on the oolemma, IZUMO1R, are among the first ligand-receptor pairs shown to be essential for gamete recognition and adhesion. However, the IZUMO1-IZUMO1R interaction does not appear to be directly responsible for promoting the fusion of the gamete membranes, suggesting that this critical phase of the fertilization cascade requires the concerted action of alternative fusogenic machinery. It has therefore been proposed that IZUMO1 may play a secondary role in the organization and/or stabilization of higher-order heteromeric complexes in spermatozoa that are required for membrane fusion. Results Here, we show that fertilization-competent (acrosome reacted) mouse spermatozoa harbor several high molecular weight protein complexes, a subset of which are readily able to adhere to solubilized oolemmal proteins. At least two of these complexes contain IZUMO1 in partnership with GLI pathogenesis-related 1 like 1 (GLIPR1L1). This interaction is associated with lipid rafts and is dynamically remodeled upon the induction of acrosomal exocytosis in preparation for sperm adhesion to the oolemma. Accordingly, the selective ablation of GLIPR1L1 leads to compromised sperm function characterized by a reduced ability to undergo the acrosome reaction and a failure of IZUMO1 redistribution. Conclusions Collectively, this study characterizes multimeric protein complexes on the sperm surface and identifies GLIPRL1L1 as a physiologically relevant regulator of IZUMO1 function and the fertilization process.
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Affiliation(s)
- Avinash S Gaikwad
- The School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Amanda L Anderson
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - D Jo Merriner
- The School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Anne E O'Connor
- The School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Brendan J Houston
- The School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - R John Aitken
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Moira K O'Bryan
- The School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia.
| | - Brett Nixon
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia.
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231
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Transmembrane Domain Dissociation Is Required for Hendra Virus F Protein Fusogenic Activity. J Virol 2019; 93:JVI.01069-19. [PMID: 31462574 DOI: 10.1128/jvi.01069-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
Hendra virus (HeV) is a zoonotic paramyxovirus that utilizes a trimeric fusion (F) protein within its lipid bilayer to mediate membrane merger with a cell membrane for entry. Previous HeV F studies showed that transmembrane domain (TMD) interactions are important for stabilizing the prefusion conformation of the protein prior to triggering. Thus, the current model for HeV F fusion suggests that modulation of TMD interactions is critical for initiation and completion of conformational changes that drive membrane fusion. HeV F constructs (T483C/V484C, V484C/N485C, and N485C/P486C) were generated with double cysteine substitutions near the N-terminal region of the TMD to study the effect of altered flexibility in this region. Oligomeric analysis showed that the double cysteine substitutions successfully promoted intersubunit disulfide bond formation in HeV F. Subsequent fusion assays indicated that the introduction of disulfide bonds in the mutants prohibited fusion events. Further testing confirmed that T483C/V484C and V484C/N485C were expressed at the cell surface at levels that would allow for fusion. Attempts to restore fusion with a reducing agent were unsuccessful, suggesting that the introduced disulfide bonds were likely buried in the membrane. Conformational analysis showed that T483C/V484C and V484C/N485C were able to bind a prefusion conformation-specific antibody prior to cell disruption, indicating that the introduced disulfide bonds did not significantly affect protein folding. This study is the first to report that TMD dissociation is required for HeV F fusogenic activity and strengthens our model for HeV fusion.IMPORTANCE The paramyxovirus Hendra virus (HeV) causes severe respiratory illness and encephalitis in humans. To develop therapeutics for HeV and related viral infections, further studies are needed to understand the mechanisms underlying paramyxovirus fusion events. Knowledge gained in studies of the HeV fusion (F) protein may be applicable to a broad span of enveloped viruses. In this study, we demonstrate that disulfide bonds introduced between the HeV F transmembrane domains (TMDs) block fusion. Depending on the location of these disulfide bonds, HeV F can still fold properly and bind a prefusion conformation-specific antibody prior to cell disruption. These findings support our current model for HeV membrane fusion and expand our knowledge of the TMD and its role in HeV F stability and fusion promotion.
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232
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Suttisintong K, Kaewchangwat N, Thanayupong E, Nerungsi C, Srikun O, Pungpo P. Recent Progress in the Development of HIV-1 Entry Inhibitors: From Small Molecules to Potent Anti-HIV Agents. Curr Top Med Chem 2019; 19:1599-1620. [DOI: 10.2174/1568026619666190712204050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 06/07/2019] [Accepted: 06/21/2019] [Indexed: 01/21/2023]
Abstract
Viral entry, the first process in the reproduction of viruses, primarily involves attachment of the viral envelope proteins to membranes of the host cell. The crucial components that play an important role in viral entry include viral surface glycoprotein gp120, viral transmembrane glycoprotein gp41, host cell glycoprotein (CD4), and host cell chemokine receptors (CCR5 and CXCR4). Inhibition of the multiple molecular interactions of these components can restrain viruses, such as HIV-1, from fusion with the host cell, blocking them from reproducing. This review article specifically focuses on the recent progress in the development of small-molecule HIV-1 entry inhibitors and incorporates important aspects of their structural modification that lead to the discovery of new molecular scaffolds with more potency.
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Affiliation(s)
- Khomson Suttisintong
- National Nanotechnology Center (NANOTEC), National Science and Technology, Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Narongpol Kaewchangwat
- National Nanotechnology Center (NANOTEC), National Science and Technology, Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Eknarin Thanayupong
- National Nanotechnology Center (NANOTEC), National Science and Technology, Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Chakkrapan Nerungsi
- The Government Pharmaceutical Organization, 75/1 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Onsiri Srikun
- The Government Pharmaceutical Organization, 75/1 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Pornpan Pungpo
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, 85 Sathonlamark Road, Warinchamrap, Ubon Ratchathani 34190, Thailand
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233
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Hartman R, Eilers BJ, Bollschweiler D, Munson-McGee JH, Engelhardt H, Young MJ, Lawrence CM. The Molecular Mechanism of Cellular Attachment for an Archaeal Virus. Structure 2019; 27:1634-1646.e3. [PMID: 31587916 DOI: 10.1016/j.str.2019.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/21/2019] [Accepted: 09/16/2019] [Indexed: 12/17/2022]
Abstract
Sulfolobus turreted icosahedral virus (STIV) is a model archaeal virus and member of the PRD1-adenovirus lineage. Although STIV employs pyramidal lysis structures to exit the host, knowledge of the viral entry process is lacking. We therefore initiated studies on STIV attachment and entry. Negative stain and cryoelectron micrographs showed virion attachment to pili-like structures emanating from the Sulfolobus host. Tomographic reconstruction and sub-tomogram averaging revealed pili recognition by the STIV C381 turret protein. Specifically, the triple jelly roll structure of C381 determined by X-ray crystallography shows that pilus recognition is mediated by conserved surface residues in the second and third domains. In addition, the STIV petal protein (C557), when present, occludes the pili binding site, suggesting that it functions as a maturation protein. Combined, these results demonstrate a role for the namesake STIV turrets in initial cellular attachment and provide the first molecular model for viral attachment in the archaeal domain of life.
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Affiliation(s)
- Ross Hartman
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Brian J Eilers
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Daniel Bollschweiler
- Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Martinsried, Germany
| | - Jacob H Munson-McGee
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Harald Engelhardt
- Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Martinsried, Germany
| | - Mark J Young
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA; Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
| | - C Martin Lawrence
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
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Gorman J, Mason RD, Nettey L, Cavett N, Chuang GY, Peng D, Tsybovsky Y, Verardi R, Nguyen R, Ambrozak D, Biris K, LaBranche CC, Ramesh A, Schramm CA, Zhou J, Bailer RT, Kepler TB, Montefiori DC, Shapiro L, Douek DC, Mascola JR, Roederer M, Kwong PD. Isolation and Structure of an Antibody that Fully Neutralizes Isolate SIVmac239 Reveals Functional Similarity of SIV and HIV Glycan Shields. Immunity 2019; 51:724-734.e4. [PMID: 31586542 DOI: 10.1016/j.immuni.2019.09.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 06/20/2019] [Accepted: 09/11/2019] [Indexed: 10/25/2022]
Abstract
HIV- and SIV-envelope (Env) trimers are both extensively glycosylated, and antibodies identified to date have been unable to fully neutralize SIVmac239. Here, we report the isolation, structure, and glycan interactions of antibody ITS90.03, a monoclonal antibody that completely neutralized the highly neutralization-resistant isolate, SIVmac239. The co-crystal structure of a fully glycosylated SIVmac239-gp120 core in complex with rhesus CD4 and the antigen-binding fragment of ITS90.03 at 2.5-Å resolution revealed that ITS90 recognized an epitope comprised of 45% glycan. SIV-gp120 core, rhesus CD4, and their complex could each be aligned structurally to their human counterparts. The structure revealed that glycans masked most of the SIV Env protein surface, with ITS90 targeting a glycan hole, which is occupied in ∼83% of SIV strains by glycan N238. Overall, the SIV glycan shield appears to functionally resemble its HIV counterpart in coverage of spike, shielding from antibody, and modulation of receptor accessibility.
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Affiliation(s)
- Jason Gorman
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rosemarie D Mason
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leonard Nettey
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole Cavett
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dongjun Peng
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yaroslav Tsybovsky
- Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Raffaello Verardi
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Richard Nguyen
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Ambrozak
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kristin Biris
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Celia C LaBranche
- Duke Human Vaccine Institute, Duke University School of Medicine, Duke University, Durham, NC 27710, USA
| | - Akshaya Ramesh
- Boston University School of Medicine, Boston University, Boston, MA 02118, USA
| | - Chaim A Schramm
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jing Zhou
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert T Bailer
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas B Kepler
- Boston University School of Medicine, Boston University, Boston, MA 02118, USA
| | - David C Montefiori
- Duke Human Vaccine Institute, Duke University School of Medicine, Duke University, Durham, NC 27710, USA
| | - Lawrence Shapiro
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Daniel C Douek
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - John R Mascola
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mario Roederer
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Peter D Kwong
- Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892, USA.
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Gray RDM, Albrecht D, Beerli C, Huttunen M, Cohen GH, White IJ, Burden JJ, Henriques R, Mercer J. Nanoscale polarization of the entry fusion complex of vaccinia virus drives efficient fusion. Nat Microbiol 2019; 4:1636-1644. [PMID: 31285583 DOI: 10.1038/s41564-019-0488-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 05/14/2019] [Indexed: 01/29/2023]
Abstract
To achieve efficient binding and subsequent fusion, most enveloped viruses encode between one and five proteins1. For many viruses, the clustering of fusion proteins-and their distribution on virus particles-is crucial for fusion activity2,3. Poxviruses, the most complex mammalian viruses, dedicate 15 proteins to binding and membrane fusion4. However, the spatial organization of these proteins and how this influences fusion activity is unknown. Here, we show that the membrane of vaccinia virus is organized into distinct functional domains that are critical for the efficiency of membrane fusion. Using super-resolution microscopy and single-particle analysis, we found that the fusion machinery of vaccinia virus resides exclusively in clusters at virion tips. Repression of individual components of the fusion complex disrupts fusion-machinery polarization, consistent with the reported loss of fusion activity5. Furthermore, we show that displacement of functional fusion complexes from virion tips disrupts the formation of fusion pores and infection kinetics. Our results demonstrate how the protein architecture of poxviruses directly contributes to the efficiency of membrane fusion, and suggest that nanoscale organization may be an intrinsic property of these viruses to assure successful infection.
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Affiliation(s)
- Robert D M Gray
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
- CoMPLEX, University College London, London, UK
| | - David Albrecht
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Corina Beerli
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Moona Huttunen
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Gary H Cohen
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ian J White
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Jemima J Burden
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Ricardo Henriques
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
- Department of Cell and Developmental Biology, University College London, London, UK.
| | - Jason Mercer
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
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236
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An antibody against the F glycoprotein inhibits Nipah and Hendra virus infections. Nat Struct Mol Biol 2019; 26:980-987. [PMID: 31570878 PMCID: PMC6858553 DOI: 10.1038/s41594-019-0308-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 08/21/2019] [Indexed: 12/02/2022]
Abstract
Nipah virus (NiV) and Hendra virus (HeV) are zoonotic henipaviruses (HNVs) responsible for outbreaks of encephalitis and respiratory illness with fatality rates of 50–100%. No vaccines or licensed therapeutics currently exist to protect humans against NiV or HeV. HNVs enter host cells by fusing the viral and cellular membranes via the concerted action of the attachment (G) and fusion (F) glycoproteins, the main targets of the humoral immune response. Here, we describe the isolation and humanization of a potent monoclonal antibody cross-neutralizing NiV and HeV. Cryo-electron microscopy, triggering and fusion studies show the antibody binds to a prefusion-specific quaternary epitope, conserved in NiV F and HeV F glycoproteins, and prevents membrane fusion and viral entry. This work supports the importance of the HNV prefusion F conformation for eliciting a robust immune response and paves the way for using this antibody for prophylaxis and post-exposure therapy with NiV- and HeV-infected individuals. An antibody that recognizes the F glycoproteins from Nipah and Hendra viruses can neutralize both viruses and recognizes a quaternary epitope in the prefusion F trimer, preventing conformational changes required for fusion.
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237
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Trimeric heptad repeat synthetic peptides HR1 and HR2 efficiently inhibit HIV-1 entry. Biosci Rep 2019; 39:BSR20192196. [PMID: 31477581 PMCID: PMC6757187 DOI: 10.1042/bsr20192196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/30/2019] [Accepted: 08/06/2019] [Indexed: 12/16/2022] Open
Abstract
The trimeric heptad repeat domains HR1 and HR2 of the human immunodeficiency virus 1 (HIV-1) gp41 play a key role in HIV-1-entry by membrane fusion. To develop efficient inhibitors against this step, the corresponding trimeric-N36 and C34 peptides were designed and synthesized. Analysis by circular dichroism of monomeric and trimeric N36 and C34 peptides showed their capacities to adopt α-helical structures and to establish physical interactions. At the virological level, while trimeric-C34 conserves the same high anti-fusion activity as monomeric-C34, trimerization of N36-peptide induced a significant increase, reaching 500-times higher in anti-fusion activity, against R5-tropic virus-mediated fusion. This result was associated with increased stability of the N36 trimer peptide with respect to the monomeric form, as demonstrated by the comparative kinetics of their antiviral activities during 6-day incubation in a physiological medium. Collectively, our findings demonstrate that while the trimerization of C34 peptide had no beneficial effect on its stability and antiviral activity, the trimerization of N36 peptide strengthened both stability and antiviral activity. This approach, promotes trimers as new promising HIV-1 inhibitors and point to future development aimed toward innovative peptide fusion inhibitors, microbicides or as immunogens.
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238
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Zhukovsky MA, Filograna A, Luini A, Corda D, Valente C. Phosphatidic acid in membrane rearrangements. FEBS Lett 2019; 593:2428-2451. [PMID: 31365767 DOI: 10.1002/1873-3468.13563] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/16/2022]
Abstract
Phosphatidic acid (PA) is the simplest cellular glycerophospholipid characterized by unique biophysical properties: a small headgroup; negative charge; and a phosphomonoester group. Upon interaction with lysine or arginine, PA charge increases from -1 to -2 and this change stabilizes protein-lipid interactions. The biochemical properties of PA also allow interactions with lipids in several subcellular compartments. Based on this feature, PA is involved in the regulation and amplification of many cellular signalling pathways and functions, as well as in membrane rearrangements. Thereby, PA can influence membrane fusion and fission through four main mechanisms: it is a substrate for enzymes producing lipids (lysophosphatidic acid and diacylglycerol) that are involved in fission or fusion; it contributes to membrane rearrangements by generating negative membrane curvature; it interacts with proteins required for membrane fusion and fission; and it activates enzymes whose products are involved in membrane rearrangements. Here, we discuss the biophysical properties of PA in the context of the above four roles of PA in membrane fusion and fission.
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Affiliation(s)
- Mikhail A Zhukovsky
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Angela Filograna
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Alberto Luini
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Daniela Corda
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
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239
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Abstract
Coronaviruses (CoVs) have caused outbreaks of deadly pneumonia in humans since the beginning of the 21st century. The severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in 2002 and was responsible for an epidemic that spread to five continents with a fatality rate of 10% before being contained in 2003 (with additional cases reported in 2004). The Middle-East respiratory syndrome coronavirus (MERS-CoV) emerged in the Arabian Peninsula in 2012 and has caused recurrent outbreaks in humans with a fatality rate of 35%. SARS-CoV and MERS-CoV are zoonotic viruses that crossed the species barrier using bats/palm civets and dromedary camels, respectively. No specific treatments or vaccines have been approved against any of the six human coronaviruses, highlighting the need to investigate the principles governing viral entry and cross-species transmission as well as to prepare for zoonotic outbreaks which are likely to occur due to the large reservoir of CoVs found in mammals and birds. Here, we review our understanding of the infection mechanism used by coronaviruses derived from recent structural and biochemical studies.
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Affiliation(s)
- M Alejandra Tortorici
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institut Pasteur, Unité de Virologie Structurale, Paris, France; CNRS UMR 3569, Unité de Virologie Structurale, Paris, France
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, United States.
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240
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Abstract
Single-molecule Förster resonance energy transfer (smFRET) imaging has emerged as a powerful tool to probe conformational dynamics of viral proteins, identify novel structural intermediates that are hiding in averaging population-based measurements, permit access to the energetics of transitions and as such to the precise molecular mechanisms of viral replication. One strength of smFRET is the capability of characterizing biological molecules in their fully hydrated/native state, which are not necessarily available to other structural methods. Elegant experimental design for physiologically relevant conditions, such as intact virions, has permitted the detection of previously unknown conformational states of viral glycoproteins, revealed asymmetric intermediates, and allowed access to the real-time imaging of conformational changes during viral fusion. As more laboratories are applying smFRET, our understanding of the molecular mechanisms and the dynamic nature of viral proteins throughout the virus life cycle are predicted to improve and assist the development of novel antiviral therapies and vaccine design.
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Affiliation(s)
- Maolin Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, United States.
| | - Xiaochu Ma
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, United States
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, United States.
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241
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Outlaw VK, Bottom-Tanzer S, Kreitler DF, Gellman SH, Porotto M, Moscona A. Dual Inhibition of Human Parainfluenza Type 3 and Respiratory Syncytial Virus Infectivity with a Single Agent. J Am Chem Soc 2019; 141:12648-12656. [PMID: 31268705 PMCID: PMC7192198 DOI: 10.1021/jacs.9b04615] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human parainfluenza virus 3 (HPIV3) and respiratory syncytial virus (RSV) cause lower respiratory infection in infants and young children. There are no vaccines for these pathogens, and existing treatments have limited or questionable efficacy. Infection by HPIV3 or RSV requires fusion of the viral and cell membranes, a process mediated by a trimeric fusion glycoprotein (F) displayed on the viral envelope. Once triggered, the pre-fusion form of F undergoes a series of conformational changes that first extend the molecule to allow for insertion of the hydrophobic fusion peptide into the target cell membrane and then refold the trimeric assembly into an energetically stable post-fusion state, a process that drives the merger of the viral and host cell membranes. Peptides derived from defined regions of HPIV3 F inhibit infection by HPIV3 by interfering with the structural transitions of the trimeric F assembly. Here we describe lipopeptides derived from the C-terminal heptad repeat (HRC) domain of HPIV3 F that potently inhibit infection by both HPIV3 and RSV. The lead peptide inhibits RSV infection as effectively as does a peptide corresponding to the RSV HRC domain itself. We show that the inhibitors bind to the N-terminal heptad repeat (HRN) domains of both HPIV3 and RSV F with high affinity. Co-crystal structures of inhibitors bound to the HRN domains of HPIV3 or RSV F reveal remarkably different modes of binding in the N-terminal segment of the inhibitor.
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Affiliation(s)
- Victor K. Outlaw
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706, United States
| | - Samantha Bottom-Tanzer
- Department of Pediatrics, Columbia University Medical Center, New York, New York, 10032, United States
- Center for Host–Pathogen Interaction, Columbia University Medical Center, New York, New York, 10032, United States
| | - Dale F. Kreitler
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706, United States
| | - Samuel H. Gellman
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706, United States
| | - Matteo Porotto
- Department of Pediatrics, Columbia University Medical Center, New York, New York, 10032, United States
- Center for Host–Pathogen Interaction, Columbia University Medical Center, New York, New York, 10032, United States
- Department of Experimental Medicine, University of Campania ‘Luigi Vanvitelli’, Italy
| | - Anne Moscona
- Department of Pediatrics, Columbia University Medical Center, New York, New York, 10032, United States
- Center for Host–Pathogen Interaction, Columbia University Medical Center, New York, New York, 10032, United States
- Department of Microbiology & Immunology, Columbia University Medical Center, New York, New York, 10032, United States
- Department of Physiology & Cellular Biophysics, Columbia University Medical Center, New York, New York, 10032, United States
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242
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Chen Q, Huang X, Wei R, Zhang L, Yin C. Characterization of influenza virus PR8 strain cultured in embryonated eggs by cryo-electron tomography. Biochem Biophys Res Commun 2019; 516:57-62. [PMID: 31196621 DOI: 10.1016/j.bbrc.2019.05.161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 10/26/2022]
Abstract
Influenza A viruses, as causative agents of seasonal epidemics and periodic worldwide pandemics, cause enormous mortality loss globally. The PR8 strain cultured in chicken eggs is widely used for scientific research and the production of influenza vaccines. Here, based on Cryo-electron Tomography (CET), we analyzed the morphological and structural characteristics of the influenza virus PR8 strain at different pHs. We found that a large number of defective virions were propagated in embryonated eggs. By comparing virions with/without the matrix layer, it was revealed that the matrix layer played an essential role in the structural integrity of virions and RNPs encapsulation during the influenza virus life cycle. We also utilized hemagglutinin receptor-containing liposomes to mimic the membrane fusion process. Several potential intermediates of HA during membrane fusion were observed at acidic pH. Our observations afford insight into the architecture and function of influenza virus.
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Affiliation(s)
- Qiang Chen
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China.
| | - Xinrui Huang
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China
| | - Risheng Wei
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China
| | - Lei Zhang
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China
| | - Changcheng Yin
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China; Center for Protein Science, Peking University, Beijing, 100871, China.
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243
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Lee M, Morgan CA, Hong M. Fully hydrophobic HIV gp41 adopts a hemifusion-like conformation in phospholipid bilayers. J Biol Chem 2019; 294:14732-14744. [PMID: 31409642 DOI: 10.1074/jbc.ra119.009542] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/04/2019] [Indexed: 11/06/2022] Open
Abstract
The HIV envelope glycoprotein mediates virus entry into target cells by fusing the virus lipid envelope with the cell membrane. This process requires large-scale conformational changes of the fusion protein gp41. Current understanding of the mechanisms with which gp41 induces membrane merger is limited by the fact that the hydrophobic N-terminal fusion peptide (FP) and C-terminal transmembrane domain (TMD) of the protein are challenging to characterize structurally in the lipid bilayer. Here we have expressed a gp41 construct that contains both termini, including the FP, the fusion peptide-proximal region (FPPR), the membrane-proximal external region (MPER), and the TMD. These hydrophobic domains are linked together by a shortened water-soluble ectodomain. We reconstituted this "short NC" gp41 into a virus-mimetic lipid membrane and conducted solid-state NMR experiments to probe the membrane-bound conformation and topology of the protein. 13C chemical shifts indicate that the C-terminal MPER-TMD is predominantly α-helical, whereas the N-terminal FP-FPPR exhibits β-sheet character. Water and lipid 1H polarization transfer to the protein revealed that the TMD is well-inserted into the lipid bilayer, whereas the FPPR and MPER are exposed to the membrane surface. Importantly, correlation signals between the FP-FPPR and the MPER are observed, providing evidence that the ectodomain is sufficiently collapsed to bring the N- and C-terminal hydrophobic domains into close proximity. These results support a hemifusion-like model of the short NC gp41 in which the ectodomain forms a partially folded hairpin that places the FPPR and MPER on the opposing surfaces of two lipid membranes.
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Affiliation(s)
- Myungwoon Lee
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Chloe A Morgan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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244
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A Hydrophobic Target: Using the Paramyxovirus Fusion Protein Transmembrane Domain To Modulate Fusion Protein Stability. J Virol 2019; 93:JVI.00863-19. [PMID: 31217248 DOI: 10.1128/jvi.00863-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 06/12/2019] [Indexed: 12/15/2022] Open
Abstract
Enveloped viruses utilize surface glycoproteins to bind and fuse with a target cell membrane. The zoonotic Hendra virus (HeV), a member of the family Paramyxoviridae, utilizes the attachment protein (G) and the fusion protein (F) to perform these critical functions. Upon triggering, the trimeric F protein undergoes a large, irreversible conformation change to drive membrane fusion. Previously, we have shown that the transmembrane (TM) domain of the F protein, separate from the rest of the protein, is present in a monomer-trimer equilibrium. This TM-TM association contributes to the stability of the prefusion form of the protein, supporting a role for TM-TM interactions in the control of F protein conformational changes. To determine the impact of disrupting TM-TM interactions, constructs expressing the HeV F TM with limited flanking sequences were synthesized. Coexpression of these constructs with HeV F resulted in dramatic reductions in the stability of F protein expression and fusion activity. In contrast, no effects were observed when the HeV F TM constructs were coexpressed with the nonhomologous parainfluenza virus 5 (PIV5) fusion protein, indicating a requirement for specific interactions. To further examine this, a TM peptide homologous to the PIV5 F TM domain was synthesized. Addition of the peptide prior to infection inhibited infection with PIV5 but did not significantly affect infection with human metapneumovirus, a related virus. These results indicate that targeted disruption of TM-TM interactions significantly impact viral fusion protein stability and function, presenting these interactions as a novel target for antiviral development.IMPORTANCE Enveloped viruses require virus-cell membrane fusion to release the viral genome and replicate. The viral fusion protein triggers from the pre- to the postfusion conformation, an essentially irreversible change, to drive membrane fusion. We found that small proteins containing the TM and a limited flanking region homologous to the fusion protein of the zoonotic Hendra virus reduced protein expression and fusion activity. The introduction of exogenous TM peptides may displace a TM domain, disrupting native TM-TM interactions and globally destabilizing the fusion protein. Supporting this hypothesis, we showed that a sequence-specific transmembrane peptide dramatically reduced viral infection in another enveloped virus model, suggesting a broader inhibitory mechanism. Viral fusion protein TM-TM interactions are important for protein function, and disruption of these interactions dramatically reduces protein stability.
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245
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Gorai B, Das S, Maiti PK. Prediction and validation of HIV-1 gp41 ecto-transmembrane domain post-fusion trimeric structure using molecular modeling. J Biomol Struct Dyn 2019; 38:2592-2603. [DOI: 10.1080/07391102.2019.1635916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Biswajit Gorai
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Satyabrata Das
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Prabal K. Maiti
- Department of Physics, Indian Institute of Science, Bangalore, Karnataka, India
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246
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Chen B. Molecular Mechanism of HIV-1 Entry. Trends Microbiol 2019; 27:878-891. [PMID: 31262533 DOI: 10.1016/j.tim.2019.06.002] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/20/2019] [Accepted: 06/05/2019] [Indexed: 11/19/2022]
Abstract
HIV-1 envelope glycoprotein [Env; trimeric (gp160)3 cleaved to (gp120/gp41)3] attaches the virion to a susceptible cell and induces fusion of viral and cell membranes to initiate infection. It interacts with the primary receptor CD4 and coreceptor (e.g., chemokine receptor CCR5 or CXCR4) to allow viral entry by triggering large structural rearrangements and unleashing the fusogenic potential of gp41 to induce membrane fusion. Recent advances in structural biology of HIV-1 Env and its complexes with the cellular receptors have revealed molecular details of HIV-1 entry and yielded new mechanistic insights. In this review, I summarize our latest understanding of the HIV-1 membrane fusion process and discuss possible pathways for productive viral entry.
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Affiliation(s)
- Bing Chen
- Division of Molecular Medicine, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, MA 02115, USA.
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247
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Cingolani G, McCauley M, Lobley A, Bryer AJ, Wesolowski J, Greco DL, Lokareddy RK, Ronzone E, Perilla JR, Paumet F. Structural basis for the homotypic fusion of chlamydial inclusions by the SNARE-like protein IncA. Nat Commun 2019; 10:2747. [PMID: 31227715 PMCID: PMC6588587 DOI: 10.1038/s41467-019-10806-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/29/2019] [Indexed: 11/29/2022] Open
Abstract
Many intracellular bacteria, including Chlamydia, establish a parasitic membrane-bound organelle inside the host cell that is essential for the bacteria’s survival. Chlamydia trachomatis forms inclusions that are decorated with poorly characterized membrane proteins known as Incs. The prototypical Inc, called IncA, enhances Chlamydia pathogenicity by promoting the homotypic fusion of inclusions and shares structural and functional similarity to eukaryotic SNAREs. Here, we present the atomic structure of the cytoplasmic domain of IncA, which reveals a non-canonical four-helix bundle. Structure-based mutagenesis, molecular dynamics simulation, and functional cellular assays identify an intramolecular clamp that is essential for IncA-mediated homotypic membrane fusion during infection. Chlamydia trachomatis forms membrane-bound inclusions inside the host cell that are decorated with IncA, a SNARE-like protein that promotes the fusion of inclusions. Here, Cingolani et al. show that the protein folds into a non-canonical four-helix bundle and identify an intramolecular clamp required for membrane fusion.
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Affiliation(s)
- Gino Cingolani
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA. .,Institute of Biomembranes and Bioenergetics, National Research Council, Via Amendola 165/A, 70126, Bari, Italy.
| | - Michael McCauley
- Thomas Jefferson University, Department of Microbiology and Immunology, Philadelphia, PA, 19107, USA.,Janssen Research and Development, Spring House, PA, 19477, USA
| | - Anna Lobley
- Thomas Jefferson University, Department of Microbiology and Immunology, Philadelphia, PA, 19107, USA
| | - Alexander J Bryer
- The University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, 19716, USA
| | - Jordan Wesolowski
- Thomas Jefferson University, Department of Microbiology and Immunology, Philadelphia, PA, 19107, USA
| | - Deanna L Greco
- The University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, 19716, USA
| | - Ravi K Lokareddy
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Erik Ronzone
- Thomas Jefferson University, Department of Microbiology and Immunology, Philadelphia, PA, 19107, USA.,VUE Health, Boston, MA, 02110, USA
| | - Juan R Perilla
- The University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, 19716, USA
| | - Fabienne Paumet
- Thomas Jefferson University, Department of Microbiology and Immunology, Philadelphia, PA, 19107, USA.
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248
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Chang HW, Yang CH, Luo YC, Su BG, Cheng HY, Tung SY, Carillo KJD, Liao YT, Tzou DLM, Wang HC, Chang W. Vaccinia viral A26 protein is a fusion suppressor of mature virus and triggers membrane fusion through conformational change at low pH. PLoS Pathog 2019; 15:e1007826. [PMID: 31220181 PMCID: PMC6605681 DOI: 10.1371/journal.ppat.1007826] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/02/2019] [Accepted: 05/07/2019] [Indexed: 11/24/2022] Open
Abstract
Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis. Vaccinia virus is a complex large DNA virus with a large number of viral membrane proteins to facilitate cell entry. Although it is well established that vaccinia mature virus uses endocytosis to enter cells, it remains unclear how it triggers membrane fusion in the acidic environment of endosomes. Recently, we hypothesized that A26 protein in vaccinia mature virus functions as an acid-sensitive membrane fusion suppressor, which suggests a novel viral regulation not present in other enveloped viruses. We postulated that conformational changes of A26 protein at low pH result in de-repression of viral fusion complex activity to trigger viral and endosomal membrane fusion. Here, we provide structural, biochemical and biological evidence demonstrating that vaccinia A26 protein does indeed function as an acid-sensitive fusion suppressor protein to regulate vaccinia mature virus membrane fusion during endocytosis. Our data reveal an important and unique “checkpoint” for vaccinia mature virus endocytosis that has not been described for other viruses. Furthermore, by isolating adaptive vaccinia mutants that escaped endocytic blockage, we discovered that mutations within the A26L gene serve as an effective strategy for switching the viral infection route from endocytosis to plasma membrane fusion, expanding viral host range.
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Affiliation(s)
- Hung-Wei Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chun Luo
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Bo-Gang Su
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Huei-Yin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Yun Tung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kathleen Joyce D. Carillo
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
| | - Yi-Ting Liao
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
| | - Der-Lii M. Tzou
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, Taiwan
| | - Hao-Ching Wang
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
- * E-mail: (HCW); (WC)
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (HCW); (WC)
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Kim H, Nobeyama T, Honda S, Yasuda K, Morone N, Murakami T. Membrane fusogenic high-density lipoprotein nanoparticles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183008. [PMID: 31207206 DOI: 10.1016/j.bbamem.2019.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/23/2019] [Accepted: 06/11/2019] [Indexed: 11/30/2022]
Abstract
Membrane fusion under mildly acidic pH occurs naturally during viral infection in cells and has been exploited in the field of nanoparticle-mediated drug delivery to circumvent endosomal entrapment of the cargo. Herein, we aimed to confer virus-like fusogenic activity to HDL in the form of a ca. 10-nm disc comprising a discoidal lipid bilayer and two copies of a lipid-binding protein at the edge. A series of HDL mutants were prepared with a mixture of three lipids and a cell-penetrating peptide (TAT, penetratin, or Arg8) fused to the protein. In a lipid-mixing assay with anionic liposomes at pH 5.5, one HDL mutant showed the fusogenic activity higher than known fusogenic liposomes. In live mammalian cells, this HDL mutant showed high plasma membrane-binding activity in the presence of serum independent of pH. In the absence of serum, a mildly acidic pH dependency for binding to the plasma membrane and the subsequent lipid mixing between them was observed for this mutant. We propose a novel strategy to develop HDL-based drug carriers by taking advantage of the HDL lipid/protein composite structure.
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Affiliation(s)
- Hyungjin Kim
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University Institute for Advanced Study (KUIAS), Sakyo-ku, Kyoto 606-8501, Japan
| | - Tomohiro Nobeyama
- Department of Biotechnology, Graduate School of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Shinnosuke Honda
- Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kaori Yasuda
- Department of Biotechnology, Graduate School of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan; Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Nobuhiro Morone
- Medical Research Council Toxicology Unit, University of Cambridge, Leicester LE1 9HN, UK
| | - Tatsuya Murakami
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University Institute for Advanced Study (KUIAS), Sakyo-ku, Kyoto 606-8501, Japan; Department of Biotechnology, Graduate School of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan; Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
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250
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Dawson WK, Lazniewski M, Plewczynski D. RNA structure interactions and ribonucleoprotein processes of the influenza A virus. Brief Funct Genomics 2019; 17:402-414. [PMID: 29040388 PMCID: PMC6252904 DOI: 10.1093/bfgp/elx028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In one more years, we will ‘celebrate’ an exact centenary of the Spanish flu pandemic. With the rapid evolution of the influenza virus, the possibility of novel pandemic remains ever a concern. This review covers our current knowledge of the influenza A virus: on the role of RNA in translation, replication, what is known of the expressed proteins and the protein products generated from alternative splicing, and on the role of base pairing in RNA structure. We highlight the main events associated with viral entry into the cell, the transcription and replication process, an export of the viral genetic material from the nucleus and the final release of the virus. We discuss the observed potential roles of RNA secondary structure (the RNA base-pairing arrangement) and RNA/RNA interactions in this scheme.
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Affiliation(s)
- Wayne K Dawson
- Bio-information Lab, University of Tokyo.,University of Warsaw, Center of New Technologies (CeNT), Warsaw, Poland
| | - Michal Lazniewski
- University of Warsaw, Center of New Technologies (CeNT), Warsaw, Poland
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