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Calcraft T, Stanke-Scheffler N, Nans A, Lindemann D, Taylor IA, Rosenthal PB. Integrated cryoEM structure of a spumaretrovirus reveals cross-kingdom evolutionary relationships and the molecular basis for assembly and virus entry. Cell 2024; 187:4213-4230.e19. [PMID: 39013471 DOI: 10.1016/j.cell.2024.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/26/2024] [Accepted: 06/11/2024] [Indexed: 07/18/2024]
Abstract
Foamy viruses (FVs) are an ancient lineage of retroviruses, with an evolutionary history spanning over 450 million years. Vector systems based on Prototype Foamy Virus (PFV) are promising candidates for gene and oncolytic therapies. Structural studies of PFV contribute to the understanding of the mechanisms of FV replication, cell entry and infection, and retroviral evolution. Here we combine cryoEM and cryoET to determine high-resolution in situ structures of the PFV icosahedral capsid (CA) and envelope glycoprotein (Env), including its type III transmembrane anchor and membrane-proximal external region (MPER), and show how they are organized in an integrated structure of assembled PFV particles. The atomic models reveal an ancient retroviral capsid architecture and an unexpected relationship between Env and other class 1 fusion proteins of the Mononegavirales. Our results represent the de novo structure determination of an assembled retrovirus particle.
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Affiliation(s)
- Thomas Calcraft
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nicole Stanke-Scheffler
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Dirk Lindemann
- Institute of Medical Microbiology and Virology, University Hospital and Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany.
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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2
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Sugimoto S, Kawase M, Suwa R, Kume Y, Chishiki M, Ono T, Okabe H, Norito S, Hanaki KI, Hosoya M, Hashimoto K, Shirato K. Comparison of mutations in human parainfluenza viruses during passage in primary human bronchial/tracheal epithelial air-liquid interface cultures and cell lines. Microbiol Spectr 2024:e0116424. [PMID: 39078148 DOI: 10.1128/spectrum.01164-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 05/31/2024] [Indexed: 07/31/2024] Open
Abstract
Human parainfluenza virus (HPIV) causes respiratory infections, which are exacerbated in children and older people. Correct evaluation of viral characteristics is essential for the study of countermeasures. However, adaptation of viruses to cultured cells during isolation or propagation might select laboratory passage-associated mutations that modify the characteristics of the virus. It was previously reported that adaptation of HPIV3, but not other HPIVs, was avoided in human airway epithelia. To examine the influence of laboratory passage on the genomes of HPIV1-HPIV4, we evaluated the occurrence of mutations after passage in primary human bronchial/tracheal epithelial cell air-liquid interface (HBTEC-ALI) culture and conventional cultured cells (Vero cells expressing the transmembrane protease, serine 2, and normal Vero cells). The occurrence of mutations was significantly lower in HBTEC-ALI than in conventional culture. In HBTEC-ALI culture, most of the mutations were silent or remained at low variant frequency, resulting in less impact on the viral consensus sequence. In contrast, passage in conventional culture induced or selected genetic mutations at high frequency with passage-associated unique substitutions. High mutagenesis of hemagglutinin-neuraminidase was commonly observed in all four HPIVs, and mutations even occurred in a single passage. In addition, in HPIV1 and HPIV2, mutations in the large protein were more frequent. These results indicate that passage in HBTEC-ALI culture is more suitable than conventional culture for maintaining the original characteristics of clinical isolates in all four HPIVs, which can help with the understanding of viral pathogenesis. IMPORTANCE Adaptation of viruses to cultured cells can increase the risk of misinterpretation in virological characterization of clinical isolates. In human parainfluenza virus (HPIV) 3, it has been reported that the human airway epithelial and lung organoid models are preferable for the study of viral characteristics of clinical strains without mutations. Therefore, we analyzed clinical isolates of all four HPIVs for the occurrence of mutations after five laboratory passages in human bronchial/tracheal epithelial cell air-liquid interface (HBTEC-ALI) or conventional culture. We found a high risk of hemagglutinin-neuraminidase mutagenesis in all four HPIVs in conventional cultured cells. In addition, in HPIV1 and HPIV2, mutations of the large protein were also more frequent in conventional cultured cells than in HBTEC-ALI culture. HBTEC-ALI culture was useful for maintaining the original sequence and characteristics of clinical isolates in all four HPIVs. The present study contributes to the understanding of HPIV pathogenesis and antiviral strategies.
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Affiliation(s)
- Satoko Sugimoto
- Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan
- Research Center for Biosafety, Laboratory Animal, and Pathogen Bank, National Institute of Infectious Diseases, Tokyo, Japan
| | - Miyuki Kawase
- Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan
| | - Reiko Suwa
- Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yohei Kume
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Mina Chishiki
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Takashi Ono
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Hisao Okabe
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Sakurako Norito
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Ken-Ichi Hanaki
- Research Center for Biosafety, Laboratory Animal, and Pathogen Bank, National Institute of Infectious Diseases, Tokyo, Japan
| | - Mitsuaki Hosoya
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Koichi Hashimoto
- Department of Pediatrics, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Kazuya Shirato
- Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan
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3
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Zhou N, Chen L, Wang C, Lv M, Shan F, Li W, Wu Y, Du X, Fan J, Liu M, Shi M, Cao J, Zhai J, Chen W. Isolation, genome analysis and comparison of a novel parainfluenza virus 5 from a Siberian tiger ( Panthera tigris). Front Vet Sci 2024; 11:1356378. [PMID: 38686028 PMCID: PMC11057237 DOI: 10.3389/fvets.2024.1356378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/08/2024] [Indexed: 05/02/2024] Open
Abstract
Paramyxoviruses are important pathogens affecting various animals, including mammals and humans. Parainfluenza virus 5 (PIV5)-a member of the family Paramyxoviridae-is a major threat to the health of mammals and humans. However, studies on terrestrial wild animals infected with PIV5 are scanty. In this study, we utilized reverse transcription PCR to detect PIV5 infection in the visceral organ tissues of a Siberian tiger (Panthera tigris ssp. altaica) with vomiting, diarrhea, and dyspnea before its death. A novel PIV5 (named SR strain) with a slowly progressive cytopathic effect was isolated in Vero cells and validated using a transmission electron microscope. Full-length sequencing and analysis revealed that the whole genome of the PIV5 SR strain contained 15,246 nucleotides (nt) and seven non-overlapping genes (3'-N-V/P-M-F-SH-HN-L-5') encoding eight proteins. Phylogenetic analysis of three PIV5 strains identified in the same zoo confirmed that PIV5 strains SR and ZJQ-221 shared the closest genetic relationship as they were clustered in the same branch, while the recently found Siberian tiger strain SZ2 kept a certain distance and formed a relatively unique branch. Furthermore, mutations of nt and amino acids (aa) between strains ZJQ-221, SR, and SZ2 were identified. In summary, we report the identification and genomic characterization of a novel PIV5 strain SR isolated in a Siberian tiger, which may help future research on interspecific transmission mechanisms.
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Affiliation(s)
- Niu Zhou
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Liang Chen
- Agriculture and Rural Bureau of Yuanzhou District, Yichun, China
| | - Chen Wang
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Mengna Lv
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Fen Shan
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Wanping Li
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Yajiang Wu
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Xueqing Du
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | | | - Minting Liu
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Menghan Shi
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Jingjing Cao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Junqiong Zhai
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
| | - Wu Chen
- Guangzhou Zoo, Guangzhou, China
- Guangzhou Wildlife Research Center, Guangzhou, China
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4
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Guo Y, Wu S, Li W, Yang H, Shi T, Ju B, Zhang Z, Yan R. The cryo-EM structure of homotetrameric attachment glycoprotein from langya henipavirus. Nat Commun 2024; 15:812. [PMID: 38280880 PMCID: PMC10821904 DOI: 10.1038/s41467-024-45202-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/18/2024] [Indexed: 01/29/2024] Open
Abstract
Langya Henipavirus (LayV) infection is an emerging zoonotic disease that has been causing respiratory symptoms in China since 2019. For virus entry, LayV's genome encodes the fusion protein F and the attachment glycoprotein G. However, the structural and functional information regarding LayV-G remains unclear. In this study, we revealed that LayV-G cannot bind to the receptors found in other HNVs, such as ephrin B2/B3, and it shows different antigenicity from HeV-G and NiV-G. Furthermore, we determined the near full-length structure of LayV-G, which displays a distinct mushroom-shaped configuration, distinguishing it from other attachment glycoproteins of HNV. The stalk and transmembrane regions resemble the stem and root of mushroom and four downward-tilted head domains as mushroom cap potentially interact with the F protein and influence membrane fusion process. Our findings enhance the understanding of emerging HNVs that cause human diseases through zoonotic transmission and provide implication for LayV related vaccine development.
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Affiliation(s)
- Yingying Guo
- Department of Biochemistry, School of Medicine, Key University Laboratory of Metabolism and Health of Guangdong, Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
| | - Songyue Wu
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China
- The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Wenting Li
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China
- The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Haonan Yang
- Department of Biochemistry, School of Medicine, Key University Laboratory of Metabolism and Health of Guangdong, Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Tianhao Shi
- Department of Biochemistry, School of Medicine, Key University Laboratory of Metabolism and Health of Guangdong, Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Bin Ju
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China.
- The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen, China.
| | - Zheng Zhang
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, China.
- The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen, China.
| | - Renhong Yan
- Department of Biochemistry, School of Medicine, Key University Laboratory of Metabolism and Health of Guangdong, Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
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5
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Stelfox AJ, Oguntuyo KY, Rissanen I, Harlos K, Rambo R, Lee B, Bowden TA. Crystal structure and solution state of the C-terminal head region of the narmovirus receptor binding protein. mBio 2023; 14:e0139123. [PMID: 37737607 PMCID: PMC10653815 DOI: 10.1128/mbio.01391-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/05/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Genetically diverse paramyxoviruses are united in their presentation of a receptor-binding protein (RBP), which works in concert with the fusion protein to facilitate host-cell entry. The C-terminal head region of the paramyxoviral RBP, a primary determinant of host-cell tropism and inter-species transmission potential, forms structurally distinct classes dependent upon protein and glycan receptor specificity. Here, we reveal the architecture of the C-terminal head region of the RBPs from Nariva virus (NarV) and Mossman virus (MosV), two archetypal rodent-borne paramyxoviruses within the recently established genus Narmovirus, family Paramyxoviridae. Our analysis reveals that while narmoviruses retain the general architectural features associated with paramyxoviral RBPs, namely, a six-bladed β-propeller fold, they lack the structural motifs associated with known receptor-mediated host-cell entry pathways. This investigation indicates that the RBPs of narmoviruses exhibit pathobiological features that are distinct from those of other paramyxoviruses.
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Affiliation(s)
- Alice J. Stelfox
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- European Molecular Biology Laboratory, Grenoble, France
| | | | - Ilona Rissanen
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland
| | - Karl Harlos
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Robert Rambo
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Oxford, United Kingdom
| | - Benhur Lee
- Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Thomas A. Bowden
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
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6
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Han C, Xie Z, Lv Y, Liu D, Chen R. Direct interaction of the molecular chaperone GRP78/BiP with the Newcastle disease virus hemagglutinin-neuraminidase protein plays a vital role in viral attachment to and infection of culture cells. Front Immunol 2023; 14:1259237. [PMID: 37920471 PMCID: PMC10619984 DOI: 10.3389/fimmu.2023.1259237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 10/02/2023] [Indexed: 11/04/2023] Open
Abstract
Introduction Glucose Regulated Proteins/Binding protein (GRP78/Bip), a representative molecular chaperone, effectively influences and actively participates in the replication processes of many viruses. Little is known, however, about the functional involvement of GRP78 in the replication of Newcastle disease virus (NDV) and the underlying mechanisms. Methods The method of this study are to establish protein interactomes between host cell proteins and the NDV Hemagglutinin-neuraminidase (HN) protein, and to systematically investigate the regulatory role of the GRP78-HN protein interaction during the NDV replication cycle. Results Our study revealed that GRP78 is upregulated during NDV infection, and its direct interaction with HN is mediated by the N-terminal 326 amino acid region. Knockdown of GRP78 by small interfering RNAs (siRNAs) significantly suppressed NDV infection and replication. Conversely, overexpression of GRP78 resulted in a significant increase in NDV replication, demonstrating its role as a positive regulator in the NDV replication cycle. We further showed that the direct interaction between GRP78 and HN protein enhanced the attachment of NDV to cells, and masking of GRP78 expressed on the cell surface with specific polyclonal antibodies (pAbs) inhibited NDV attachment and replication. Discussion These findings highlight the essential role of GRP78 in the adsorption stage during the NDV infection cycle, and, importantly, identify the critical domain required for GRP78-HN interaction, providing novel insights into the molecular mechanisms involved in NDV replication and infection.
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Affiliation(s)
- Chenxin Han
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Zhaoqing Branch Centre of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China
| | - Ziwei Xie
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Zhaoqing Branch Centre of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China
| | - Yadi Lv
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Zhaoqing Branch Centre of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China
| | - Dingxiang Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Zhaoqing Branch Centre of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Ruiai Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Zhaoqing Branch Centre of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China
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7
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Structure and supramolecular organization of the canine distemper virus attachment glycoprotein. Proc Natl Acad Sci U S A 2023; 120:e2208866120. [PMID: 36716368 PMCID: PMC9963377 DOI: 10.1073/pnas.2208866120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Canine distemper virus (CDV) is an enveloped RNA morbillivirus that triggers respiratory, enteric, and high incidence of severe neurological disorders. CDV induces devastating outbreaks in wild and endangered animals as well as in domestic dogs in countries associated with suboptimal vaccination programs. The receptor-binding tetrameric attachment (H)-protein is part of the morbilliviral cell entry machinery. Here, we present the cryo-electron microscopy (cryo-EM) structure and supramolecular organization of the tetrameric CDV H-protein ectodomain. The structure reveals that the morbilliviral H-protein is composed of three main domains: stalk, neck, and heads. The most unexpected feature was the inherent asymmetric architecture of the CDV H-tetramer being shaped by the neck, which folds into an almost 90° bent conformation with respect to the stalk. Consequently, two non-contacting receptor-binding H-head dimers, which are also tilted toward each other, are located on one side of an intertwined four helical bundle stalk domain. Positioning of the four protomer polypeptide chains within the neck domain is guided by a glycine residue (G158), which forms a hinge point exclusively in two protomer polypeptide chains. Molecular dynamics simulations validated the stability of the asymmetric structure under near physiological conditions and molecular docking showed that two receptor-binding sites are fully accessible. Thus, this spatial organization of the CDV H-tetramer would allow for concomitant protein interactions with the stalk and head domains without steric clashes. In summary, the structure of the CDV H-protein ectodomain provides new insights into the morbilliviral cell entry system and offers a blueprint for next-generation structure-based antiviral drug discovery.
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Jang SS, Noh JY, Kim MC, Lim HA, Song MS, Kim HK. α2,3-Linked Sialic Acids Are the Potential Attachment Receptor for Shaan Virus Infection in MARC-145 Cells. Microbiol Spectr 2022; 10:e0125622. [PMID: 35924912 PMCID: PMC9430483 DOI: 10.1128/spectrum.01256-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/19/2022] [Indexed: 11/20/2022] Open
Abstract
Shaan virus (ShaV), a novel species of the genus Jeilongvirus, family Paramyxoviridae, was isolated from an insectivore bat (Miniopterus schreibersii) in Korea in 2016. ShaV particles contain a hemagglutinin-neuraminidase (HN) glycoprotein in their envelope that allows the virus to target cells. Typically, diverse paramyxoviruses with HN glycoprotein are reported to interact predominantly with sialic acids, but there are no studies of receptors for ShaV. In this study, the identification of potential receptors for ShaV was demonstrated using sialidase treatments, glycan microarray, magnetic bead-based virus binding assay, and neuraminidase inhibitor treatments. Pretreatment of MARC-145 cells with sialidase, which cleaves α2,3-linked sialic acids, showed higher inhibition of viral infection than α2,6-linked-specific sialidase. These data were supported by the binding of ShaV to predominantly α2,3-linked sialylated glycans in the screening of sialyl linkage patterns through glycan microarray. To further confirm the direct interaction between ShaV and α2,3-linked sialic acids, ShaV was incubated with α2,3- or α2,6-linked sialylated glycans conjugated to magnetic beads, and binding signals were detected only for α2,3-linked sialylated glycans. In addition, the potential of sialic acids as a receptor was demonstrated by the viral replication inhibitory effect of the neuraminidase inhibitor 2,3-dehydro-2-deoxy-N-acetylneuraminicacid (DANA) in the mature virion release steps. Collectively, these results support that α2,3-linked sialic acids are the potential receptor for ShaV infection in MARC-145 cells. IMPORTANCE Bats host major mammalian paramyxoviruses, and novel paramyxoviruses are increasingly being reported around the world. Shaan virus (ShaV), from the genus Jeilongvirus, family Paramyxoviridae, has a potential attachment glycoprotein, HN. Here, we identify that ShaV binds to sialic acid and demonstrate that α2,3-linked sialic acids are the potential receptor for ShaV infection. The presented data regarding ShaV receptor specificity will enable studies into the viral tropism for the host and contribute to the development of new antiviral strategies targeting viral receptors.
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Affiliation(s)
- Seong Sik Jang
- Department of Biological Sciences and Biotechnology, College of Natural Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Ji Yeong Noh
- Department of Biological Sciences and Biotechnology, College of Natural Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Min Chan Kim
- Department of Biological Sciences and Biotechnology, College of Natural Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyun A. Lim
- Department of Biological Sciences and Biotechnology, College of Natural Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Min Suk Song
- Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Republic of Korea
| | - Hye Kwon Kim
- Department of Biological Sciences and Biotechnology, College of Natural Science, Chungbuk National University, Cheongju, Republic of Korea
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9
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Park G, Lim JW, Park C, Yeom M, Lee S, Lyoo KS, Song D, Haam S. Cell-mimetic biosensors to detect avian influenza virus via viral fusion. Biosens Bioelectron 2022; 212:114407. [PMID: 35623252 DOI: 10.1016/j.bios.2022.114407] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/06/2022] [Accepted: 05/17/2022] [Indexed: 11/17/2022]
Abstract
Avian influenza virus (AIV) causes acute infectious diseases in poultry, critically impacting food supply. Highly pathogenic avian influenza viruses (HPAIVs), in particular, cause morbidity and mortality, resulting in significant economic losses in the poultry industry. To prevent the spread of HPAIVs, detection at early stages is critical to implement effective countermeasures such as quarantine and isolation. Through a viral fusion mechanism, cell-mimetic nanoparticles (CMPs), developed in the current study, can rapidly detect HPAIV and low pathogenic AIV (LPAIV). The CMPs comprise polymeric nanoparticles, which are constructed using sialic acid and fluorescence resonance energy transfer (FRET) dye pairs that expose the FRET off signal in response to LPAIV and HPAIV, after activation by enzymatic cleavage in the endosomal environment. The CMPs detect a wide variety of LPAIVs and HPAIVs in biological environments. Additionally, the cross-reactivity of CMPs is determined by testing their function with different viral species. Therefore, these findings demonstrate the significant potential of the proposed strategy for mimicking viral infection in vitro and using them as a highly effective diagnostic assay to rapidly detect LPAIV and HPAIV, preventing economic losses associated with viral outbreaks.
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Affiliation(s)
- Geunseon Park
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jong-Woo Lim
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Chaewon Park
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Minjoo Yeom
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sojeong Lee
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kwang-Soo Lyoo
- College of Veterinary Medicine, Jeonbuk National University, Iksan, 54596, Republic of Korea
| | - Daesub Song
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Seungjoo Haam
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
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10
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Novel Roles of the Nipah Virus Attachment Glycoprotein and Its Mobility in Early and Late Membrane Fusion Steps. mBio 2022; 13:e0322221. [PMID: 35506666 PMCID: PMC9239137 DOI: 10.1128/mbio.03222-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Paramyxoviridae family comprises important pathogens that include measles (MeV), mumps, parainfluenza, and the emerging deadly zoonotic Nipah virus (NiV) and Hendra virus (HeV). Paramyxoviral entry into cells requires viral-cell membrane fusion, and formation of paramyxoviral pathognomonic syncytia requires cell-cell membrane fusion. Both events are coordinated by intricate interactions between the tetrameric attachment (G/H/HN) and trimeric fusion (F) glycoproteins. We report that receptor binding induces conformational changes in NiV G that expose its stalk domain, which triggers F through a cascade from prefusion to prehairpin intermediate (PHI) to postfusion conformations, executing membrane fusion. To decipher how the NiV G stalk may trigger F, we introduced cysteines along the G stalk to increase tetrameric strength and restrict stalk mobility. While most point mutants displayed near-wild-type levels of cell surface expression and receptor binding, most yielded increased NiV G oligomeric strength, and showed remarkably strong defects in syncytium formation. Furthermore, most of these mutants displayed stronger F/G interactions and significant defects in their ability to trigger F, indicating that NiV G stalk mobility is key to proper F triggering via moderate G/F interactions. Also remarkably, a mutant capable of triggering F and of fusion pore formation yielded little syncytium formation, implicating G or G/F interactions in a late step occurring post fusion pore formation, such as the extensive fusion pore expansion required for syncytium formation. This study uncovers novel mechanisms by which the G stalk and its oligomerization/mobility affect G/F interactions, the triggering of F, and a late fusion pore expansion step-exciting novel findings for paramyxoviral attachment glycoproteins. IMPORTANCE The important Paramyxoviridae family includes measles, mumps, human parainfluenza, and the emerging deadly zoonotic Nipah virus (NiV) and Hendra virus (HeV). The deadly emerging NiV can cause neurologic and respiratory symptoms in humans with a >60% mortality rate. NiV has two surface proteins, the receptor binding protein (G) and fusion (F) glycoproteins. They mediate the required membrane fusion during viral entry into host cells and during syncytium formation, a hallmark of paramyxoviral and NiV infections. We previously discovered that the G stalk domain is important for triggering F (via largely unknown mechanisms) to induce membrane fusion. Here, we uncovered new roles and mechanisms by which the G stalk and its mobility modulate the triggering of F and also unexpectedly affect a very late step in membrane fusion, namely fusion pore expansion. Importantly, these novel findings may extend to other paramyxoviruses, offering new potential targets for therapeutic interventions.
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11
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Wang Z, Amaya M, Addetia A, Dang HV, Reggiano G, Yan L, Hickey AC, DiMaio F, Broder CC, Veesler D. Architecture and antigenicity of the Nipah virus attachment glycoprotein. Science 2022; 375:1373-1378. [PMID: 35239409 DOI: 10.1126/science.abm5561] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nipah virus (NiV) and Hendra virus (HeV) are zoonotic henipaviruses (HNVs) responsible for outbreaks of encephalitis and respiratory illness. The entry of HNVs into host cells requires the attachment (G) and fusion (F) glycoproteins, which are the main targets of antibody responses. To understand viral infection and host immunity, we determined a cryo-electron microscopy structure of the NiV G homotetrameric ectodomain in complex with the nAH1.3 broadly neutralizing antibody Fab fragment. We show that a cocktail of two nonoverlapping G-specific antibodies neutralizes NiV and HeV synergistically and limits the emergence of escape mutants. Analysis of polyclonal serum antibody responses elicited by vaccination of macaques with NiV G indicates that the receptor binding head domain is immunodominant. These results pave the way for implementing multipronged therapeutic strategies against these deadly pathogens.
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Affiliation(s)
- Zhaoqian Wang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Moushimi Amaya
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20814, USA
| | - Amin Addetia
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Ha V Dang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Gabriella Reggiano
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Lianying Yan
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20814, USA
| | - Andrew C Hickey
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA.,U.S. Public Health Services Commissioned Corps, Rockville, MD 20852, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Christopher C Broder
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.,Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
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12
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Unique Tropism and Entry Mechanism of Mumps Virus. Viruses 2021; 13:v13091746. [PMID: 34578327 PMCID: PMC8471308 DOI: 10.3390/v13091746] [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: 08/07/2021] [Revised: 08/28/2021] [Accepted: 08/30/2021] [Indexed: 12/19/2022] Open
Abstract
Mumps virus (MuV) is an important human pathogen that causes parotitis, orchitis, oophoritis, meningitis, encephalitis, and sensorineural hearing loss. Although mumps is a vaccine-preventable disease, sporadic outbreaks have occurred worldwide, even in highly vaccinated populations. MuV not only causes systemic infection but also has a unique tropism to glandular tissues and the central nervous system. In general, tropism can be defined by multiple factors in the viral life cycle, including its entry, interaction with host factors, and host-cell immune responses. Although the underlying mechanisms of MuV tropism remain to be fully understood, recent studies on virus-host interactions have provided insights into viral pathogenesis. This review was aimed at summarizing the entry process of MuV by focusing on the glycan receptors, particularly the recently identified receptors with a trisaccharide core motif, and their interactions with the viral attachment proteins. Here, we describe the receptor structures, their distribution in the human body, and the recently identified host factors for MuV and analyze their relationship with MuV tropism.
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13
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Dong J, Cross RW, Doyle MP, Kose N, Mousa JJ, Annand EJ, Borisevich V, Agans KN, Sutton R, Nargi R, Majedi M, Fenton KA, Reichard W, Bombardi RG, Geisbert TW, Crowe JE. Potent Henipavirus Neutralization by Antibodies Recognizing Diverse Sites on Hendra and Nipah Virus Receptor Binding Protein. Cell 2021; 183:1536-1550.e17. [PMID: 33306954 DOI: 10.1016/j.cell.2020.11.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 10/04/2020] [Accepted: 11/12/2020] [Indexed: 01/01/2023]
Abstract
Hendra (HeV) and Nipah (NiV) viruses are emerging zoonotic pathogens in the Henipavirus genus causing outbreaks of disease with very high case fatality rates. Here, we report the first naturally occurring human monoclonal antibodies (mAbs) against HeV receptor binding protein (RBP). All isolated mAbs neutralized HeV, and some also neutralized NiV. Epitope binning experiments identified five major antigenic sites on HeV-RBP. Animal studies demonstrated that the most potent cross-reactive neutralizing mAbs, HENV-26 and HENV-32, protected ferrets in lethal models of infection with NiV Bangladesh 3 days after exposure. We solved the crystal structures of mAb HENV-26 in complex with both HeV-RBP and NiV-RBP and of mAb HENV-32 in complex with HeV-RBP. The studies reveal diverse sites of vulnerability on RBP recognized by potent human mAbs that inhibit virus by multiple mechanisms. These studies identify promising prophylactic antibodies and define protective epitopes that can be used in rational vaccine design.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/isolation & purification
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/immunology
- Antigens, Viral/immunology
- Binding Sites
- Binding, Competitive
- Brain/pathology
- Chiroptera/virology
- Cross Reactions/immunology
- Crystallography, X-Ray
- Ephrin-B2/metabolism
- Female
- Ferrets/virology
- Hendra Virus/immunology
- Henipavirus/immunology
- Humans
- Interferometry
- Liver/pathology
- Models, Molecular
- Neutralization Tests
- Nipah Virus/immunology
- Protein Binding
- Protein Conformation
- Protein Domains
- Receptors, Virus/chemistry
- Receptors, Virus/immunology
- Receptors, Virus/metabolism
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Affiliation(s)
- Jinhui Dong
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Robert W Cross
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Michael P Doyle
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Nurgun Kose
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jarrod J Mousa
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Edward J Annand
- Sydney School of Veterinary Science and Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia; Black Mountain Laboratories & Australian Centre for Disease Preparedness, Health and Biosecurity, CSIRO, Canberra, ACT, Australia
| | - Viktoriya Borisevich
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Krystle N Agans
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Rachel Sutton
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rachel Nargi
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mahsa Majedi
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Karla A Fenton
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Walter Reichard
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Robin G Bombardi
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Thomas W Geisbert
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - James E Crowe
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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14
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Marcink TC, Wang T, des Georges A, Porotto M, Moscona A. Human parainfluenza virus fusion complex glycoproteins imaged in action on authentic viral surfaces. PLoS Pathog 2020; 16:e1008883. [PMID: 32956394 PMCID: PMC7529294 DOI: 10.1371/journal.ppat.1008883] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 10/01/2020] [Accepted: 08/13/2020] [Indexed: 01/21/2023] Open
Abstract
Infection by human parainfluenza viruses (HPIVs) causes widespread lower respiratory diseases, including croup, bronchiolitis, and pneumonia, and there are no vaccines or effective treatments for these viruses. HPIV3 is a member of the Respirovirus species of the Paramyxoviridae family. These viruses are pleomorphic, enveloped viruses with genomes composed of single-stranded negative-sense RNA. During viral entry, the first step of infection, the viral fusion complex, comprised of the receptor-binding glycoprotein hemagglutinin-neuraminidase (HN) and the fusion glycoprotein (F), mediates fusion upon receptor binding. The HPIV3 transmembrane protein HN, like the receptor-binding proteins of other related viruses that enter host cells using membrane fusion, binds to a receptor molecule on the host cell plasma membrane, which triggers the F glycoprotein to undergo major conformational rearrangements, promoting viral entry. Subsequent fusion of the viral and host membranes allows delivery of the viral genetic material into the host cell. The intermediate states in viral entry are transient and thermodynamically unstable, making it impossible to understand these transitions using standard methods, yet understanding these transition states is important for expanding our knowledge of the viral entry process. In this study, we use cryo-electron tomography (cryo-ET) to dissect the stepwise process by which the receptor-binding protein triggers F-mediated fusion, when forming a complex with receptor-bearing membranes. Using an on-grid antibody capture method that facilitates examination of fresh, biologically active strains of virus directly from supernatant fluids and a series of biological tools that permit the capture of intermediate states in the fusion process, we visualize the series of events that occur when a pristine, authentic viral particle interacts with target receptors and proceeds from the viral entry steps of receptor engagement to membrane fusion.
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Affiliation(s)
- Tara C. Marcink
- Department of Pediatrics, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Center for Host-Pathogen Interaction, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
| | - Tong Wang
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, United States of America
| | - Amedee des Georges
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, United States of America
- Department of Chemistry and Biochemistry, City College of New York, New York, New York, United States of America
| | - Matteo Porotto
- Department of Pediatrics, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Center for Host-Pathogen Interaction, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Anne Moscona
- Department of Pediatrics, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Center for Host-Pathogen Interaction, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Department of Microbiology & Immunology, Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
- Department of Physiology & Columbia University Vagelos College of Physicians & Surgeons, New York, New York, United States of America
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15
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Chi M, Liu Y, Wen H, Zhao L, Song Y, Liu N, Chi L, Wang Z. Role of the head-stalk linker region (aa115-122) of Newcastle disease virus haemagglutinin-neuraminidase in regulating fusion triggering. J Gen Virol 2020; 101:5-20. [PMID: 31702540 DOI: 10.1099/jgv.0.001349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
To gain insights into the role of the head-stalk linker region in the fusion triggering, we constructed mutants by deleting or substituting the linker region (115-NGAANNSG-122) of Newcastle disease virus (NDV) haemagglutinin-neuraminidase (HN) with the corresponding sequences of other paramyxoviruses. The results showed that these HN mutants exhibited different levels of fusion-triggering activity, but most of them maintained comparable levels with wide-type HN in both receptor recognition and neuraminidase activity. We tried to figure out reasons for fusion alteration through assessing the expression and the oligomeric state of HN mutants. Moreover, four mutants with significant fusion changes were introduced into the headless HN stem (HN1-123) to intensively investigate the role of the linker region in fusion triggering. Consequently, the stability of HN oligomers and the structural integrity of the 4 helical-bundle of stalk have complicated influences on the alteration of fusion-triggering activities for different mutants. These data suggested that the head-stalk linker could regulate the fusion triggering at both full-length and headless HN levels.
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Affiliation(s)
- Miaomiao Chi
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Ying Liu
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Hongling Wen
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Li Zhao
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Yanyan Song
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Na Liu
- Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
| | - Lianli Chi
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Jinan 250100, PR China
| | - Zhiyu Wang
- The Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan 250012, PR China.,Department of Virology, School of Public Health, Shandong University, Jinan 250012, PR China
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16
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Aggarwal M, Plemper RK. Structural Insight into Paramyxovirus and Pneumovirus Entry Inhibition. Viruses 2020; 12:E342. [PMID: 32245118 PMCID: PMC7150754 DOI: 10.3390/v12030342] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 01/04/2023] Open
Abstract
Paramyxoviruses and pneumoviruses infect cells through fusion (F) protein-mediated merger of the viral envelope with target membranes. Members of these families include a range of major human and animal pathogens, such as respiratory syncytial virus (RSV), measles virus (MeV), human parainfluenza viruses (HPIVs), and highly pathogenic Nipah virus (NiV). High-resolution F protein structures in both the metastable pre- and the postfusion conformation have been solved for several members of the families and a number of F-targeting entry inhibitors have progressed to advanced development or clinical testing. However, small-molecule RSV entry inhibitors have overall disappointed in clinical trials and viral resistance developed rapidly in experimental settings and patients, raising the question of whether the available structural information may provide a path to counteract viral escape through proactive inhibitor engineering. This article will summarize current mechanistic insight into F-mediated membrane fusion and examine the contribution of structural information to the development of small-molecule F inhibitors. Implications are outlined for future drug target selection and rational drug engineering strategies.
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Affiliation(s)
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA;
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17
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Structure of a paramyxovirus polymerase complex reveals a unique methyltransferase-CTD conformation. Proc Natl Acad Sci U S A 2020; 117:4931-4941. [PMID: 32075920 PMCID: PMC7060699 DOI: 10.1073/pnas.1919837117] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Paramyxoviruses are enveloped, nonsegmented, negative-strand RNA viruses that cause a wide spectrum of human and animal diseases. The viral genome, packaged by the nucleoprotein (N), serves as a template for the polymerase complex, composed of the large protein (L) and the homo-tetrameric phosphoprotein (P). The ∼250-kDa L possesses all enzymatic activities necessary for its function but requires P in vivo. Structural information is available for individual P domains from different paramyxoviruses, but how P interacts with L and how that affects the activity of L is largely unknown due to the lack of high-resolution structures of this complex in this viral family. In this study we determined the structure of the L-P complex from parainfluenza virus 5 (PIV5) at 4.3-Å resolution using cryoelectron microscopy, as well as the oligomerization domain (OD) of P at 1.4-Å resolution using X-ray crystallography. P-OD associates with the RNA-dependent RNA polymerase domain of L and protrudes away from it, while the X domain of one chain of P is bound near the L nucleotide entry site. The methyltransferase (MTase) domain and the C-terminal domain (CTD) of L adopt a unique conformation, positioning the MTase active site immediately above the poly-ribonucleotidyltransferase domain and near the likely exit site for the product RNA 5' end. Our study reveals a potential mechanism that mononegavirus polymerases may employ to switch between transcription and genome replication. This knowledge will assist in the design and development of antivirals against paramyxoviruses.
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18
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Azarm KD, Lee B. Differential Features of Fusion Activation within the Paramyxoviridae. Viruses 2020; 12:v12020161. [PMID: 32019182 PMCID: PMC7077268 DOI: 10.3390/v12020161] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/25/2020] [Accepted: 01/29/2020] [Indexed: 12/13/2022] Open
Abstract
Paramyxovirus (PMV) entry requires the coordinated action of two envelope glycoproteins, the receptor binding protein (RBP) and fusion protein (F). The sequence of events that occurs during the PMV entry process is tightly regulated. This regulation ensures entry will only initiate when the virion is in the vicinity of a target cell membrane. Here, we review recent structural and mechanistic studies to delineate the entry features that are shared and distinct amongst the Paramyxoviridae. In general, we observe overarching distinctions between the protein-using RBPs and the sialic acid- (SA-) using RBPs, including how their stalk domains differentially trigger F. Moreover, through sequence comparisons, we identify greater structural and functional conservation amongst the PMV fusion proteins, as compared to the RBPs. When examining the relative contributions to sequence conservation of the globular head versus stalk domains of the RBP, we observe that, for the protein-using PMVs, the stalk domains exhibit higher conservation and find the opposite trend is true for SA-using PMVs. A better understanding of conserved and distinct features that govern the entry of protein-using versus SA-using PMVs will inform the rational design of broader spectrum therapeutics that impede this process.
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19
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Navaratnarajah CK, Generous AR, Yousaf I, Cattaneo R. Receptor-mediated cell entry of paramyxoviruses: Mechanisms, and consequences for tropism and pathogenesis. J Biol Chem 2020; 295:2771-2786. [PMID: 31949044 DOI: 10.1074/jbc.rev119.009961] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Research in the last decade has uncovered many new paramyxoviruses, airborne agents that cause epidemic diseases in animals including humans. Most paramyxoviruses enter epithelial cells of the airway using sialic acid as a receptor and cause only mild disease. However, others cross the epithelial barrier and cause more severe disease. For some of these viruses, the host receptors have been identified, and the mechanisms of cell entry have been elucidated. The tetrameric attachment proteins of paramyxoviruses have vastly different binding affinities for their cognate receptors, which they contact through different binding surfaces. Nevertheless, all input signals are converted to the same output: conformational changes that trigger refolding of trimeric fusion proteins and membrane fusion. Experiments with selectively receptor-blinded viruses inoculated into their natural hosts have provided insights into tropism, identifying the cells and tissues that support growth and revealing the mechanisms of pathogenesis. These analyses also shed light on diabolically elegant mechanisms used by morbilliviruses, including the measles virus, to promote massive amplification within the host, followed by efficient aerosolization and rapid spread through host populations. In another paradigm of receptor-facilitated severe disease, henipaviruses, including Nipah and Hendra viruses, use different members of one protein family to cause zoonoses. Specific properties of different paramyxoviruses, like neurotoxicity and immunosuppression, are now understood in the light of receptor specificity. We propose that research on the specific receptors for several newly identified members of the Paramyxoviridae family that may not bind sialic acid is needed to anticipate their zoonotic potential and to generate effective vaccines and antiviral compounds.
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Affiliation(s)
| | - Alex R Generous
- Mayo Clinic Graduate School of Biomedical Sciences, Virology and Gene Therapy Track, Mayo Clinic, Rochester, Minnesota 55905
| | - Iris Yousaf
- Mayo Clinic Graduate School of Biomedical Sciences, Virology and Gene Therapy Track, Mayo Clinic, Rochester, Minnesota 55905
| | - Roberto Cattaneo
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota 55905.
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20
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Disruption of the Dimer-Dimer Interaction of the Mumps Virus Attachment Protein Head Domain, Aided by an Anion Located at the Interface, Compromises Membrane Fusion Triggering. J Virol 2020; 94:JVI.01732-19. [PMID: 31619562 DOI: 10.1128/jvi.01732-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 12/26/2022] Open
Abstract
Mumps virus (MuV), an enveloped negative-strand RNA virus belonging to the family Paramyxoviridae, enters the host cell through membrane fusion mediated by two viral envelope proteins, an attachment protein hemagglutinin-neuraminidase (MuV-HN) and a fusion (F) protein. However, how the binding of MuV-HN to glycan receptors triggers membrane fusion is not well understood. The crystal structure of the MuV-HN head domain forms a tetramer (dimer of dimers) like other paramyxovirus attachment proteins. In the structure, a sulfate ion (SO4 2-) was found at the interface between two dimers, which may be replaced by a hydrogen phosphate ion (HPO4 2-) under physiological conditions. The anion is captured by the side chain of a positively charged arginine residue at position 139 of one monomer each from both dimers. Substitution of alanine or lysine for arginine at this position compromised the fusion support activity of MuV-HN without affecting its cell surface expression, glycan-receptor binding, and interaction with the F protein. Furthermore, the substitution appeared to affect the tetramer formation of the head domain as revealed by blue native-PAGE analysis. These results, together with our previous similar findings with the measles virus attachment protein head domain, suggest that the dimer-dimer interaction within the tetramer may play an important role in triggering membrane fusion during paramyxovirus entry.IMPORTANCE Despite the use of effective live vaccines, mumps outbreaks still occur worldwide. Mumps virus (MuV) infection typically causes flu-like symptoms and parotid gland swelling but sometimes leads to orchitis, oophoritis, and neurological complications, such as meningitis, encephalitis, and deafness. MuV enters the host cell through membrane fusion mediated by two viral proteins, a receptor-binding attachment protein, and a fusion protein, but its detailed mechanism is not fully understood. In this study, we show that the tetramer (dimer of dimers) formation of the MuV attachment protein head domain is supported by an anion located at the interface between two dimers and that the dimer-dimer interaction plays an important role in triggering the activation of the fusion protein and causing membrane fusion. These results not only further our understanding of MuV entry but provide useful information about a possible target for antiviral drugs.
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21
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Pryce R, Azarm K, Rissanen I, Harlos K, Bowden TA, Lee B. A key region of molecular specificity orchestrates unique ephrin-B1 utilization by Cedar virus. Life Sci Alliance 2020; 3:e201900578. [PMID: 31862858 PMCID: PMC6925387 DOI: 10.26508/lsa.201900578] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 01/13/2023] Open
Abstract
The emergent zoonotic henipaviruses, Hendra, and Nipah are responsible for frequent and fatal disease outbreaks in domestic animals and humans. Specificity of henipavirus attachment glycoproteins (G) for highly species-conserved ephrin ligands underpins their broad host range and is associated with systemic and neurological disease pathologies. Here, we demonstrate that Cedar virus (CedV)-a related henipavirus that is ostensibly nonpathogenic-possesses an idiosyncratic entry receptor repertoire that includes the common henipaviral receptor, ephrin-B2, but, distinct from pathogenic henipaviruses, does not include ephrin-B3. Uniquely among known henipaviruses, CedV can use ephrin-B1 for cellular entry. Structural analyses of CedV-G reveal a key region of molecular specificity that directs ephrin-B1 utilization, while preserving a universal mode of ephrin-B2 recognition. The structural and functional insights presented uncover diversity within the known henipavirus receptor repertoire and suggest that only modest structural changes may be required to modulate receptor specificities within this group of lethal human pathogens.
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Affiliation(s)
- Rhys Pryce
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | | | - Ilona Rissanen
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
- Helsinki Institute for Life Science, University of Helsinki, Biocenter 3, Helsinki, Finland
| | - Karl Harlos
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Thomas A Bowden
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK
| | - Benhur Lee
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Virus Network Center of Excellence, Center for Virology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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22
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A structure-based rationale for sialic acid independent host-cell entry of Sosuga virus. Proc Natl Acad Sci U S A 2019; 116:21514-21520. [PMID: 31591233 PMCID: PMC6815108 DOI: 10.1073/pnas.1906717116] [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] [Indexed: 12/30/2022] Open
Abstract
The bat-borne paramyxovirus, Sosuga virus (SosV), is one of many paramyxoviruses recently identified and classified within the newly established genus Pararubulavirus, family Paramyxoviridae The envelope surface of SosV presents a receptor-binding protein (RBP), SosV-RBP, which facilitates host-cell attachment and entry. Unlike closely related hemagglutinin neuraminidase RBPs from other genera of the Paramyxoviridae, SosV-RBP and other pararubulavirus RBPs lack many of the stringently conserved residues required for sialic acid recognition and hydrolysis. We determined the crystal structure of the globular head region of SosV-RBP, revealing that while the glycoprotein presents a classical paramyxoviral six-bladed β-propeller fold and structurally classifies in close proximity to paramyxoviral RBPs with hemagglutinin-neuraminidase (HN) functionality, it presents a receptor-binding face incongruent with sialic acid recognition. Hemadsorption and neuraminidase activity analysis confirms the limited capacity of SosV-RBP to interact with sialic acid in vitro and indicates that SosV-RBP undergoes a nonclassical route of host-cell entry. The close overall structural conservation of SosV-RBP with other classical HN RBPs supports a model by which pararubulaviruses only recently diverged from sialic acid binding functionality.
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Duro N, Varma S. Role of Structural Fluctuations in Allosteric Stimulation of Paramyxovirus Hemagglutinin-Neuraminidase. Structure 2019; 27:1601-1611.e2. [DOI: 10.1016/j.str.2019.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/29/2019] [Accepted: 07/15/2019] [Indexed: 11/29/2022]
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24
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Chibanga VP, Dirr L, Guillon P, El-Deeb IM, Bailly B, Thomson RJ, von Itzstein M. New antiviral approaches for human parainfluenza: Inhibiting the haemagglutinin-neuraminidase. Antiviral Res 2019; 167:89-97. [DOI: 10.1016/j.antiviral.2019.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 10/27/2022]
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25
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Pees M, Schmidt V, Papp T, Gellért Á, Abbas M, Starck JM, Neul A, Marschang RE. Three genetically distinct ferlaviruses have varying effects on infected corn snakes (Pantherophis guttatus). PLoS One 2019; 14:e0217164. [PMID: 31163032 PMCID: PMC6548425 DOI: 10.1371/journal.pone.0217164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 05/06/2019] [Indexed: 01/10/2023] Open
Abstract
Ferlaviruses are important pathogens in snakes and other reptiles. They cause respiratory and neurological disease in infected animals and can cause severe disease outbreaks. Isolates from this genus can be divided into four genogroups–A, B, and C, as well as a more distantly related sister group, “tortoise”. Sequences from large portions (5.3 kb) of the genomes of a variety of ferlavirus isolates from genogroups A, B, and C, including the genes coding the surface glycoproteins F and HN as well as the L protein were determined and compared. In silico analyses of the glycoproteins of genogroup A, B, and C isolates were carried out. Three isolates representing these three genogroups were used in transmission studies with corn snakes (Pantherophis guttatus), and clinical signs, gross and histopathology, electronmicroscopic changes in the lungs, and isolation of bacteria from the lungs were evaluated. Analysis of the sequences supported the previous categorization of ferlaviruses into four genogroups, and criteria for definition of ferlavirus genogroups and species were established based on sequence identities (80% resp. 90%). Analysis of the ferlavirus glycoprotein models showed parallels to corresponding regions of other paramyxoviruses. The transmission studies showed clear differences in the pathogenicities of the three virus isolates used. The genogroup B isolate was the most and the group A virus the least pathogenic. Reasons for these differences were not clear based on the differences in the putative structures of their respective glycoproteins, although e.g. residue and consequential structure variation of an extended cleavage site or changes in electrostatic charges at enzyme binding sites could play a role. The presence of bacteria in the lungs of the infected animals also clearly corresponded to increased pathogenicity. This study contributes to knowledge about the structure and phylogeny of ferlaviruses and lucidly demonstrates differences in pathogenicity between strains of different genogroups.
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Affiliation(s)
- Michael Pees
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
- * E-mail:
| | - Volker Schmidt
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
| | - Tibor Papp
- Institute for Veterinary Medical Research, Centre for Agricultural Research, the Hungarian Academy of Sciences, Budapest, Hungary
| | - Ákos Gellért
- Institute for Veterinary Medical Research, Centre for Agricultural Research, the Hungarian Academy of Sciences, Budapest, Hungary
| | - Maha Abbas
- Institute for Environmental and Animal Hygiene, University of Hohenheim, Stuttgart, Germany
| | | | - Annkatrin Neul
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
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26
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Abstract
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract disease in young children and elderly people. Although the virus was isolated in 1955, an effective RSV vaccine has not been developed, and the only licensed intervention is passive immunoprophylaxis of high-risk infants with a humanized monoclonal antibody. During the past 5 years, however, there has been substantial progress in our understanding of the structure and function of the RSV glycoproteins and their interactions with host cell factors that mediate entry. This period has coincided with renewed interest in developing effective interventions, including the isolation of potent monoclonal antibodies and small molecules and the design of novel vaccine candidates. In this Review, we summarize the recent findings that have begun to elucidate RSV entry mechanisms, describe progress on the development of new interventions and conclude with a perspective on gaps in our knowledge that require further investigation.
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Affiliation(s)
- Michael B Battles
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.
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27
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Regulatory Role of the Morbillivirus Attachment Protein Head-to-Stalk Linker Module in Membrane Fusion Triggering. J Virol 2018; 92:JVI.00679-18. [PMID: 29997204 DOI: 10.1128/jvi.00679-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/05/2018] [Indexed: 12/12/2022] Open
Abstract
Morbillivirus (e.g., measles virus [MeV] and canine distemper virus [CDV]) host cell entry is coordinated by two interacting envelope glycoproteins, namely, an attachment (H) protein and a fusion (F) protein. The ectodomain of H proteins consists of stalk, connector, and head domains that assemble into functional noncovalent dimer-of-dimers. The role of the C-terminal module of the H-stalk domain (termed linker) and the connector, although putatively able to assume flexible structures and allow receptor-induced structural rearrangements, remains largely unexplored. Here, we carried out a nonconservative mutagenesis scan analysis of the MeV and CDV H-linker/connector domains. Our data demonstrated that replacing isoleucine 146 in H-linker (H-I146) with any charged amino acids prevented virus-mediated membrane fusion activity, despite proper trafficking of the mutants to the cell surface and preserved binding efficiency to the SLAM/CD150 receptor. Nondenaturing electrophoresis revealed that these charged amino acid changes led to the formation of irregular covalent H tetramers rather than functional dimer-of-dimers formed when isoleucine or other hydrophobic amino acids were present at residue position 146. Remarkably, we next demonstrated that covalent H tetramerization per se was not the only mechanism preventing F activation. Indeed, the neutral glycine mutant (H-I146G), which exhibited strong covalent tetramerization propensity, maintained limited fusion promotion activity. Conversely, charged H-I146 mutants, which additionally carried alanine substitution of natural cysteines (H-C139A and H-C154A) and thus were unable to form covalently linked tetramers, were fusion activation defective. Our data suggest a dual regulatory role of the hydrophobic residue at position 146 of the morbillivirus head-to-stalk H-linker module: securing the assembly of productive dimer-of-dimers and contributing to receptor-induced F-triggering activity.IMPORTANCE MeV and CDV remain important human and animal pathogens. Development of antivirals may significantly support current global vaccination campaigns. Cell entry is orchestrated by two interacting glycoproteins (H and F). The current hypothesis postulates that tetrameric H ectodomains (composed of stalk, connector, and head domains) undergo receptor-induced rearrangements to productively trigger F; these conformational changes may be regulated by the H-stalk C-terminal module (linker) and the following connector domain. Mutagenesis scan analysis of both microdomains revealed that replacing amino acid 146 in the H-linker region with nonhydrophobic residues produced covalent H tetramers which were compromised in triggering membrane fusion activity. However, these mutant proteins retained their ability to traffic to the cell surface and to bind to the virus receptor. These data suggest that the morbillivirus linker module contributes to the folding of functional pre-F-triggering H tetramers. Furthermore, such structures might be critical to convert receptor engagement into F activation.
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28
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Kim H, Na W, Yeom M, Choi J, Kim J, Lim J, Yun D, Chun H, Park G, Park C, Kim J, Jeong DG, Le VP, Lee K, Lee JM, Jeong HH, Song D, Haam S. Host Cell Mimic Polymersomes for Rapid Detection of Highly Pathogenic Influenza Virus via a Viral Fusion and Cell Entry Mechanism. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1800960. [PMID: 32313543 PMCID: PMC7161833 DOI: 10.1002/adfm.201800960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/13/2018] [Indexed: 05/31/2023]
Abstract
Highly pathogenic avian influenza virus (HPAIV) infections have occurred continuously and crossed the species barrier to humans, leading to fatalities. A polymerase chain reaction based molecular test is currently the most sensitive diagnostic tool for HPAIV; however, the results must be analyzed in centralized diagnosis systems by a trained individual. This requirement leads to delays in quarantine and isolation. To control the spread of HPAIV, rapid and accurate diagnostics suitable for field testing are needed, and the tests must facilitate a differential diagnosis between HPAIV and low pathogenic avian influenza virus (LPAIV), which undergo cleavage specifically by trypsin- or furin-like proteases, respectively. In this study, a differential avian influenza virus rapid test kit is developed and evaluated in vitro and using clinical specimens from HPAIV H5N1-infected animals. It is demonstrated that this rapid test kit provides highly sensitive and specific detection of HPAIV and LPAIV and is thus a useful field diagnostic tool for H5N1 HPAIV outbreaks and for rapid quarantine control of the disease.
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Affiliation(s)
- Hyun‐Ouk Kim
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Woonsung Na
- Department of PharmacyCollege of PharmacyKorea UniversitySejong30019Republic of Korea
| | - Minjoo Yeom
- Department of PharmacyCollege of PharmacyKorea UniversitySejong30019Republic of Korea
| | - Jihye Choi
- Research Institute of Radiological ScienceCollege of MedicineYonsei UniversitySeoul03722Republic of Korea
| | - Jihye Kim
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Jong‐Woo Lim
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Dayeon Yun
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Haejin Chun
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Geunseon Park
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Chaewon Park
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Jeong‐Ki Kim
- Department of PharmacyCollege of PharmacyKorea UniversitySejong30019Republic of Korea
| | - Dae Gwin Jeong
- Infectious Disease Research CenterKorea Research Institute of Bioscience and BiotechnologyDaejeon34141South Korea
| | - Van Phan Le
- Department of Microbiology and Infectious DiseasesCollege of Veterinary MedicineVietnam National University of AgricultureHanoi100000Vietnam
| | - Kwangyeol Lee
- Department of ChemistryKorea UniversitySeoul02841Republic of Korea
- Center for Molecular Spectroscopy and DynamicsInstitute for Basic Science (IBS)Seoul02841Republic of Korea
| | - Jae Myun Lee
- Department of MicrobiologyYonsei University College of MedicineSeoul03722Republic of Korea
| | | | - Daesub Song
- Department of PharmacyCollege of PharmacyKorea UniversitySejong30019Republic of Korea
| | - Seungjoo Haam
- Department of Chemical & Biomolecular EngineeringYonsei UniversitySeoul03722Republic of Korea
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29
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Ke Z, Strauss JD, Hampton CM, Brindley MA, Dillard RS, Leon F, Lamb KM, Plemper RK, Wright ER. Promotion of virus assembly and organization by the measles virus matrix protein. Nat Commun 2018; 9:1736. [PMID: 29712906 PMCID: PMC5928126 DOI: 10.1038/s41467-018-04058-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 03/29/2018] [Indexed: 12/05/2022] Open
Abstract
Measles virus (MeV) remains a major human pathogen, but there are presently no licensed antivirals to treat MeV or other paramyxoviruses. Here, we use cryo-electron tomography (cryo-ET) to elucidate the principles governing paramyxovirus assembly in MeV-infected human cells. The three-dimensional (3D) arrangement of the MeV structural proteins including the surface glycoproteins (F and H), matrix protein (M), and the ribonucleoprotein complex (RNP) are characterized at stages of virus assembly and budding, and in released virus particles. The M protein is observed as an organized two-dimensional (2D) paracrystalline array associated with the membrane. A two-layered F–M lattice is revealed suggesting that interactions between F and M may coordinate processes essential for MeV assembly. The RNP complex remains associated with and in close proximity to the M lattice. In this model, the M lattice facilitates the well-ordered incorporation and concentration of the surface glycoproteins and the RNP at sites of virus assembly. Virus assembly is technically challenging to study. Here the authors use cryo-electron tomography of measles virus-infected human cells to determine native-state virus structure and they locate well-ordered M lattices that organize viral glycoproteins, RNP, and drive assembly.
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Affiliation(s)
- Zunlong Ke
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Joshua D Strauss
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Cheri M Hampton
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Melinda A Brindley
- Department of Infectious Diseases, Department of Population Health and Center for Vaccines and Immunology, University of Georgia, Athens, GA, 30602, USA.,Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA
| | - Rebecca S Dillard
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Fredrick Leon
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Kristen M Lamb
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303, USA.
| | - Elizabeth R Wright
- Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA. .,Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, GA, 30322, USA.
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30
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Functional analysis of amino acids at stalk/head interface of human parainfluenza virus type 3 hemagglutinin-neuraminidase protein in the membrane fusion process. Virus Genes 2018. [PMID: 29516315 DOI: 10.1007/s11262-018-1546-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Human parainfluenza virus type 3 (hPIV3) is an important respiratory pathogen that causes the majority of viral pneumonia of infants and young children. hPIV3 can infect host cells through the synergistic action of hemagglutinin-neuraminidase (HN) protein and the homotypic fusion (F) protein on the viral surface. HN protein plays a variety of roles during the virus invasion process, such as promoting viral particles to bind to receptors, cleaving sialic acid, and activating the F protein. Crystal structure research shows that HN tetramer adopted a "heads-down" conformation, at least two heads dimmer on flank of the four-helix bundle stalk, which forms a symmetrical interaction interface. The stalk region determines interactions and activation of F protein in specificity, and the heads in down position statically shield these residues. In order to make further research on the function of these amino acids at the hPIV3 HN stalk/head interface, fifteen mutations (8 sites from stalk and 7 sites from head) were engineered into this interface by site-directed mutagenesis in this study. Alanine substitution in this region of hPIV3 HN had various effects on cell fusion promotion, receptor binding, and neuraminidase activity. Besides, L151A also affected surface protein expression efficiency. Moreover, I112A, D120A, and R122A mutations of the stalk region that were masked by global head in down position had influence on the interaction between F and HN proteins.
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31
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Wong JJW, Young TA, Zhang J, Liu S, Leser GP, Komives EA, Lamb RA, Zhou ZH, Salafsky J, Jardetzky TS. Monomeric ephrinB2 binding induces allosteric changes in Nipah virus G that precede its full activation. Nat Commun 2017; 8:781. [PMID: 28974687 PMCID: PMC5626764 DOI: 10.1038/s41467-017-00863-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/01/2017] [Indexed: 11/09/2022] Open
Abstract
Nipah virus is an emergent paramyxovirus that causes deadly encephalitis and respiratory infections in humans. Two glycoproteins coordinate the infection of host cells, an attachment protein (G), which binds to cell surface receptors, and a fusion (F) protein, which carries out the process of virus-cell membrane fusion. The G protein binds to ephrin B2/3 receptors, inducing G conformational changes that trigger F protein refolding. Using an optical approach based on second harmonic generation, we show that monomeric and dimeric receptors activate distinct conformational changes in G. The monomeric receptor-induced changes are not detected by conformation-sensitive monoclonal antibodies or through electron microscopy analysis of G:ephrinB2 complexes. However, hydrogen/deuterium exchange experiments confirm the second harmonic generation observations and reveal allosteric changes in the G receptor binding and F-activating stalk domains, providing insights into the pathway of receptor-activated virus entry.Nipah virus causes encephalitis in humans. Here the authors use a multidisciplinary approach to study the binding of the viral attachment protein G to its host receptor ephrinB2 and show that monomeric and dimeric receptors activate distinct conformational changes in G and discuss implications for receptor-activated virus entry.
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Affiliation(s)
- Joyce J W Wong
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | | | - Jiayan Zhang
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Shiheng Liu
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - George P Leser
- Howard Hughes Medical Institute, Northwestern University, Evanston, IL, 60208-3500, USA
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208-3500, USA
| | - Elizabeth A Komives
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA, 92093, USA
| | - Robert A Lamb
- Howard Hughes Medical Institute, Northwestern University, Evanston, IL, 60208-3500, USA
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208-3500, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | | | - Theodore S Jardetzky
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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32
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Zengel J, Phan SI, Pickar A, Xu P, He B. Immunogenicity of mumps virus vaccine candidates matching circulating genotypes in the United States and China. Vaccine 2017; 35:3988-3994. [PMID: 28623030 PMCID: PMC5785236 DOI: 10.1016/j.vaccine.2017.05.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/04/2017] [Accepted: 05/30/2017] [Indexed: 01/08/2023]
Abstract
Mumps virus (MuV) causes acute infection in humans with characteristic swelling of the parotid gland. While vaccination has greatly reduced the incidence of MuV infection, there have been multiple large outbreaks of mumps virus (MuV) in highly vaccinated populations. The most common vaccine strain, Jeryl Lynn, belongs to genotype A, which is no longer a circulating genotype. We have developed two vaccine candidates that match the circulating genotypes in the United States (genotype G) and China (genotype F). We found that there was a significant decrease in the ability of the Jeryl Lynn vaccine to produce neutralizing antibody responses to non-matched viruses, when compared to either of our vaccine candidates. Our data suggests that an updated vaccine may allow for better immunity against the circulating MuV genotypes G and F.
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Affiliation(s)
- James Zengel
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| | - Shannon I Phan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States
| | - Adrian Pickar
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States; Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Pei Xu
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States; Marjorie B. Kovler Viral Oncology Labs, The University of Chicago, Chicago, IL 60637, United States
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, United States.
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33
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Rissanen I, Ahmed AA, Azarm K, Beaty S, Hong P, Nambulli S, Duprex WP, Lee B, Bowden TA. Idiosyncratic Mòjiāng virus attachment glycoprotein directs a host-cell entry pathway distinct from genetically related henipaviruses. Nat Commun 2017; 8:16060. [PMID: 28699636 PMCID: PMC5510225 DOI: 10.1038/ncomms16060] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 05/25/2017] [Indexed: 12/28/2022] Open
Abstract
In 2012, cases of lethal pneumonia among Chinese miners prompted the isolation of a rat-borne henipavirus (HNV), Mòjiāng virus (MojV). Although MojV is genetically related to highly pathogenic bat-borne henipaviruses, the absence of a conserved ephrin receptor-binding motif in the MojV attachment glycoprotein (MojV-G) indicates a differing host-cell recognition mechanism. Here we find that MojV-G displays a six-bladed β-propeller fold bearing limited similarity to known paramyxoviral attachment glycoproteins, in particular at host receptor-binding surfaces. We confirm the inability of MojV-G to interact with known paramyxoviral receptors in vitro, indicating an independence from well-characterized ephrinB2/B3, sialic acid and CD150-mediated entry pathways. Furthermore, we find that MojV-G is antigenically distinct, indicating that MojV would less likely be detected in existing large-scale serological screening studies focused on well-established HNVs. Altogether, these data indicate a unique host-cell entry pathway for this emerging and potentially pathogenic HNV. The attachment glycoprotein (HNV-G) of henipaviruses interacts with host receptors at the cell surface and is a major determinant of species tropism. Here the authors provide structural and functional evidence that the emergent henipavirus, Mòjiang virus, uses an entry mechanism that is independent of known paramyoxviral cellular receptors.
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Affiliation(s)
- Ilona Rissanen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
| | - Asim A Ahmed
- Division of Infectious Disease, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Kristopher Azarm
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, #1124, New York, New York 10029, USA
| | - Shannon Beaty
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, #1124, New York, New York 10029, USA
| | - Patrick Hong
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, #1124, New York, New York 10029, USA
| | - Sham Nambulli
- Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - W Paul Duprex
- Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Benhur Lee
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, #1124, New York, New York 10029, USA
| | - Thomas A Bowden
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, Oxfordshire OX3 7BN, UK
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34
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Cox RM, Plemper RK. Structure and organization of paramyxovirus particles. Curr Opin Virol 2017; 24:105-114. [PMID: 28601688 DOI: 10.1016/j.coviro.2017.05.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/08/2017] [Accepted: 05/24/2017] [Indexed: 11/25/2022]
Abstract
The paramyxovirus family comprises major human and animal pathogens such as measles virus (MeV), mumps virus (MuV), the parainfluenzaviruses, Newcastle disease virus (NDV), and the highly pathogenic zoonotic hendra (HeV) and nipah (NiV) viruses. Paramyxovirus particles are pleomorphic, with a lipid envelope, nonsegmented RNA genomes of negative polarity, and densely packed glycoproteins on the virion surface. A number of crystal structures of different paramyxovirus proteins and protein fragments were solved, but the available information concerning overall virion organization remains limited. However, recent studies have reported cryo-electron tomography-based reconstructions of Sendai virus (SeV), MeV, NDV, and human parainfluenza virus type 3 (HPIV3) particles and a surface assessment of NiV-derived virus-like particles (VLPs), which have yielded innovative hypotheses concerning paramyxovirus particle assembly, budding, and organization. Following a summary of the current insight into paramyxovirus virion morphology, this review will focus on discussing the implications of these particle reconstructions on the present models of paramyxovirus assembly and infection.
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Affiliation(s)
- Robert M Cox
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, United States
| | - Richard K Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, United States.
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Tahara M, Takeda M. [Measles Virus]. Uirusu 2017; 67:3-16. [PMID: 29593149 DOI: 10.2222/jsv.67.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Measles virus (MeV) is exceptionally contagious and still a major cause of death in child.However, recently significant progress towards the elimination of measles has been made through increased vaccination coverage of measles-containing vaccines. The hemagglutinin (H) protein of MeV interacts with a cellular receptor, and this interaction is the first step of infection. MeV uses two different receptors, signaling lymphocyte activation molecule (SLAM) and nectin-4 expressed on immune cells and epithelial cells, respectively. The interactions of MeV with these receptors nicely explain the immune suppressive and high contagious properties of MeV. Binding of the H protein to a receptor triggers conformational changes in the fusion (F) protein, inducing fusion between viral and host plasma membranes for entry. The stalk region of the H protein plays a key role in the F protein-triggering. Recent studies of the H protein epitopes have revealed that the receptor binding site of the H protein constitutes a major neutralizing epitope. The interaction with two proteinaceous receptors probably imposes strong functional constraints on this epitope for amino acid changes. This would be a reason why measles vaccines, which are derived from MV strains isolated more than 60 years ago, are still highly effective against all MV strains currently circulating.
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Affiliation(s)
- Maino Tahara
- Department of Virology III, National Institute of Infectious Diseases
| | - Makoto Takeda
- Department of Virology III, National Institute of Infectious Diseases
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Site-specific glycosylation of the Newcastle disease virus haemagglutinin-neuraminidase. Glycoconj J 2016; 34:181-197. [DOI: 10.1007/s10719-016-9750-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 12/14/2022]
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Multiple Strategies Reveal a Bidentate Interaction between the Nipah Virus Attachment and Fusion Glycoproteins. J Virol 2016; 90:10762-10773. [PMID: 27654290 DOI: 10.1128/jvi.01469-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/14/2016] [Indexed: 11/20/2022] Open
Abstract
The paramyxoviral family contains many medically important viruses, including measles virus, mumps virus, parainfluenza viruses, respiratory syncytial virus, human metapneumovirus, and the deadly zoonotic henipaviruses Hendra and Nipah virus (NiV). To both enter host cells and spread from cell to cell within infected hosts, the vast majority of paramyxoviruses utilize two viral envelope glycoproteins: the attachment glycoprotein (G, H, or hemagglutinin-neuraminidase [HN]) and the fusion glycoprotein (F). Binding of G/H/HN to a host cell receptor triggers structural changes in G/H/HN that in turn trigger F to undergo a series of conformational changes that result in virus-cell (viral entry) or cell-cell (syncytium formation) membrane fusion. The actual regions of G/H/HN and F that interact during the membrane fusion process remain relatively unknown though it is generally thought that the paramyxoviral G/H/HN stalk region interacts with the F head region. Studies to determine such interactive regions have relied heavily on coimmunoprecipitation approaches, whose limitations include the use of detergents and the micelle-mediated association of proteins. Here, we developed a flow-cytometric strategy capable of detecting membrane protein-protein interactions by interchangeably using the full-length form of G and a soluble form of F, or vice versa. Using both coimmunoprecipitation and flow-cytometric strategies, we found a bidentate interaction between NiV G and F, where both the stalk and head regions of NiV G interact with F. This is a new structural-biological finding for the paramyxoviruses. Additionally, our studies disclosed regions of the NiV G and F glycoproteins dispensable for the G and F interactions. IMPORTANCE Nipah virus (NiV) is a zoonotic paramyxovirus that causes high mortality rates in humans, with no approved treatment or vaccine available for human use. Viral entry into host cells relies on two viral envelope glycoproteins: the attachment (G) and fusion (F) glycoproteins. Binding of G to the ephrinB2 or ephrinB3 cell receptors triggers conformational changes in G that in turn cause F to undergo conformational changes that result in virus-host cell membrane fusion and viral entry. It is currently unknown, however, which specific regions of G and F interact during membrane fusion. Past efforts to determine the interacting regions have relied mainly on coimmunoprecipitation, a technique with some pitfalls. We developed a flow-cytometric assay to study membrane protein-protein interactions, and using this assay we report a bidentate interaction whereby both the head and stalk regions of NiV G interact with NiV F, a new finding for the paramyxovirus family.
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Adu-Gyamfi E, Kim LS, Jardetzky TS, Lamb RA. Flexibility of the Head-Stalk Linker Domain of Paramyxovirus HN Glycoprotein Is Essential for Triggering Virus Fusion. J Virol 2016; 90:9172-81. [PMID: 27489276 PMCID: PMC5044854 DOI: 10.1128/jvi.01187-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 07/25/2016] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED The Paramyxoviridae comprise a large family of enveloped, negative-sense, single-stranded RNA viruses with significant economic and public health implications. For nearly all paramyxoviruses, infection is initiated by fusion of the viral and host cell plasma membranes in a pH-independent fashion. Fusion is orchestrated by the receptor binding protein hemagglutinin-neuraminidase (HN; also called H or G depending on the virus type) protein and a fusion (F) protein, the latter undergoing a major refolding process to merge the two membranes. Mechanistic details regarding the coupling of receptor binding to F activation are not fully understood. Here, we have identified the flexible loop region connecting the bulky enzymatically active head and the four-helix bundle stalk to be essential for fusion promotion. Proline substitution in this region of HN of parainfluenza virus 5 (PIV5) and Newcastle disease virus HN abolishes cell-cell fusion, whereas HN retains receptor binding and neuraminidase activity. By using reverse genetics, we engineered recombinant PIV5-EGFP viruses with mutations in the head-stalk linker region of HN. Mutations in this region abolished virus recovery and infectivity. In sum, our data suggest that the loop region acts as a "hinge" around which the bulky head of HN swings to-and-fro to facilitate timely HN-mediate F-triggering, a notion consistent with the stalk-mediated activation model of paramyxovirus fusion. IMPORTANCE Paramyxovirus fusion with the host cell plasma membrane is essential for virus infection. Membrane fusion is orchestrated via interaction of the receptor binding protein (HN, H, or G) with the viral fusion glycoprotein (F). Two distinct models have been suggested to describe the mechanism of fusion: these include "the clamp" and the "provocateur" model of activation. By using biochemical and reverse genetics tools, we have obtained strong evidence in favor of the HN stalk-mediated activation of paramyxovirus fusion. Specifically, our data strongly support the notion that the short linker between the head and stalk plays a role in "conformational switching" of the head group to facilitate F-HN interaction and triggering.
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Affiliation(s)
- Emmanuel Adu-Gyamfi
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Lori S Kim
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Theodore S Jardetzky
- Howard Hughes Medical Institute, Northwestern University, Evanston, Illinois, USA
| | - Robert A Lamb
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA Department of Structural Biology, Stanford University, Stanford, California, USA
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Mutagenesis of Paramyxovirus Hemagglutinin-Neuraminidase Membrane-Proximal Stalk Region Influences Stability, Receptor Binding, and Neuraminidase Activity. J Virol 2016; 90:7778-88. [PMID: 27334593 DOI: 10.1128/jvi.00896-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 06/13/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Paramyxoviridae consist of a large family of enveloped, negative-sense, nonsegmented single-stranded RNA viruses that account for a significant number of human and animal diseases. The fusion process for nearly all paramyxoviruses involves the mixing of the host cell plasma membrane and the virus envelope in a pH-independent fashion. Fusion is orchestrated via the concerted action of two surface glycoproteins: an attachment protein called hemagglutinin-neuraminidase (HN [also called H or G depending on virus type and substrate]), which acts as a receptor binding protein, and a fusion (F) protein, which undergoes a major irreversible refolding process to merge the two membranes. Recent biochemical evidence suggests that receptor binding by HN is dispensable for cell-cell fusion. However, factors that influence the stability and/or conformation of the HN 4-helix bundle (4HB) stalk have not been studied. Here, we used oxidative cross-linking as well as functional assays to investigate the role of the structurally unresolved membrane-proximal stalk region (MPSR) (residues 37 to 58) of HN in the context of headless and full-length HN membrane fusion promotion. Our data suggest that the receptor binding head serves to stabilize the stalk to regulate fusion. Moreover, we found that the MPSR of HN modulates receptor binding and neuraminidase activity without a corresponding regulation of F triggering. IMPORTANCE Paramyxoviruses require two viral membrane glycoproteins, the attachment protein variously called HN, H, or G and the fusion protein (F), to couple host receptor recognition to virus-cell fusion. The HN protein has a globular head that is attached to a membrane-anchored flexible stalk of ∼80 residues and has three activities: receptor binding, neuraminidase, and fusion activation. In this report, we have identified the functional significance of the membrane-proximal stalk region (MPSR) (HN, residues 37 to 56) of the paramyxovirus parainfluenza virus (PIV5), a region of the HN stalk that has not had its structure determined by X-ray crystallography. Our data suggest that the MPSR influences receptor binding and neuraminidase activity via an indirect mechanism. Moreover, the receptor binding head group stabilizes the 4HB stalk as part of the general mechanism to fine-tune F-activation.
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Immobilization of the N-terminal helix stabilizes prefusion paramyxovirus fusion proteins. Proc Natl Acad Sci U S A 2016; 113:E3844-51. [PMID: 27335462 DOI: 10.1073/pnas.1608349113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Parainfluenza virus 5 (PIV5) is an enveloped, single-stranded, negative-sense RNA virus of the Paramyxoviridae family. PIV5 fusion and entry are mediated by the coordinated action of the receptor-binding protein, hemagglutinin-neuraminidase (HN), and the fusion protein (F). Upon triggering by HN, F undergoes an irreversible ATP- and pH-independent conformational change, going down an energy gradient from a metastable prefusion state to a highly stable postfusion state. Previous studies have highlighted key conformational changes in the F-protein refolding pathway, but a detailed understanding of prefusion F-protein metastability remains elusive. Here, using two previously described F-protein mutations (S443D or P22L), we examine the capacity to modulate PIV5 F stability and the mechanisms by which these point mutants act. The S443D mutation destabilizes prefusion F proteins by disrupting a hydrogen bond network at the base of the F-protein globular head. The introduction of a P22L mutation robustly rescues destabilized F proteins through a local hydrophobic interaction between the N-terminal helix and a hydrophobic pocket. Prefusion stabilization conferred by a P22L-homologous mutation is demonstrated in the F protein of Newcastle disease virus, a paramyxovirus of a different genus, suggesting a conserved stabilizing structural element within the paramyxovirus family. Taken together, the available data suggest that movement of the N-terminal helix is a necessary early step for paramyxovirus F-protein refolding and presents a novel target for structure-based drug design.
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Measles Virus Fusion Protein: Structure, Function and Inhibition. Viruses 2016; 8:112. [PMID: 27110811 PMCID: PMC4848605 DOI: 10.3390/v8040112] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 03/26/2016] [Accepted: 04/14/2016] [Indexed: 01/02/2023] Open
Abstract
Measles virus (MeV), a highly contagious member of the Paramyxoviridae family, causes measles in humans. The Paramyxoviridae family of negative single-stranded enveloped viruses includes several important human and animal pathogens, with MeV causing approximately 120,000 deaths annually. MeV and canine distemper virus (CDV)-mediated diseases can be prevented by vaccination. However, sub-optimal vaccine delivery continues to foster MeV outbreaks. Post-exposure prophylaxis with antivirals has been proposed as a novel strategy to complement vaccination programs by filling herd immunity gaps. Recent research has shown that membrane fusion induced by the morbillivirus glycoproteins is the first critical step for viral entry and infection, and determines cell pathology and disease outcome. Our molecular understanding of morbillivirus-associated membrane fusion has greatly progressed towards the feasibility to control this process by treating the fusion glycoprotein with inhibitory molecules. Current approaches to develop anti-membrane fusion drugs and our knowledge on drug resistance mechanisms strongly suggest that combined therapies will be a prerequisite. Thus, discovery of additional anti-fusion and/or anti-attachment protein small-molecule compounds may eventually translate into realistic therapeutic options.
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Peña J, Chen-Harris H, Allen JE, Hwang M, Elsheikh M, Mabery S, Bielefeldt-Ohmann H, Zemla AT, Bowen RA, Borucki MK. Sendai virus intra-host population dynamics and host immunocompetence influence viral virulence during in vivo passage. Virus Evol 2016; 2:vew008. [PMID: 27774301 PMCID: PMC4989884 DOI: 10.1093/ve/vew008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In vivo serial passage of non-pathogenic viruses has been shown to lead to increased viral virulence, and although the precise mechanism(s) are not clear, it is known that both host and viral factors are associated with increased pathogenicity. Under- or overnutrition leads to a decreased or dysregulated immune response and can increase viral mutant spectrum diversity and virulence. The objective of this study was to identify the role of viral mutant spectra dynamics and host immunocompetence in the development of pathogenicity during in vivo passage. Because the nutritional status of the host has been shown to affect the development of viral virulence, the diet of animal model reflected two extremes of diets which exist in the global population, malnutrition and obesity. Sendai virus was serially passaged in groups of mice with differing nutritional status followed by transmission of the passaged virus to a second host species, guinea pigs. Viral population dynamics were characterized using deep sequence analysis and computational modeling. Histopathology, viral titer and cytokine assays were used to characterize viral virulence. Viral virulence increased with passage and the virulent phenotype persisted upon passage to a second host species. Additionally, nutritional status of mice during passage influenced the phenotype. Sequencing revealed the presence of several non-synonymous changes in the consensus sequence associated with passage, a majority of which occurred in the hemagglutinin-neuraminidase and polymerase genes, as well as the presence of persistent high frequency variants in the viral population. In particular, an N1124D change in the consensus sequences of the polymerase gene was detected by passage 10 in a majority of the animals. In vivo comparison of an 1124D plaque isolate to a clone with 1124N genotype indicated that 1124D was associated with increased virulence.
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Affiliation(s)
- José Peña
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | | | | | - Mona Hwang
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Maher Elsheikh
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Shalini Mabery
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Helle Bielefeldt-Ohmann
- Australian Infectious Diseases Research Centre, University of Queensland , Brisbane, Australia; and
| | - Adam T Zemla
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Richard A Bowen
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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Canine Distemper Virus Fusion Activation: Critical Role of Residue E123 of CD150/SLAM. J Virol 2015; 90:1622-37. [PMID: 26608324 DOI: 10.1128/jvi.02405-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 11/18/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Measles virus (MeV) and canine distemper virus (CDV) possess tetrameric attachment proteins (H) and trimeric fusion proteins, which cooperate with either SLAM or nectin 4 receptors to trigger membrane fusion for cell entry. While the MeV H-SLAM cocrystal structure revealed the binding interface, two distinct oligomeric H assemblies were also determined. In one of the conformations, two SLAM units were sandwiched between two discrete H head domains, thus spotlighting two binding interfaces ("front" and "back"). Here, we investigated the functional relevance of both interfaces in activating the CDV membrane fusion machinery. While alanine-scanning mutagenesis identified five critical regulatory residues in the front H-binding site of SLAM, the replacement of a conserved glutamate residue (E at position 123, replaced with A [E123A]) led to the most pronounced impact on fusion promotion. Intriguingly, while determination of the interaction of H with the receptor using soluble constructs revealed reduced binding for the identified SLAM mutants, no effect was recorded when physical interaction was investigated with the full-length counterparts of both molecules. Conversely, although mutagenesis of three strategically selected residues within the back H-binding site of SLAM did not substantially affect fusion triggering, nevertheless, the mutants weakened the H-SLAM interaction recorded with the membrane-anchored protein constructs. Collectively, our findings support a mode of binding between the attachment protein and the V domain of SLAM that is common to all morbilliviruses and suggest a major role of the SLAM residue E123, located at the front H-binding site, in triggering the fusion machinery. However, our data additionally support the hypothesis that other microdomain(s) of both glycoproteins (including the back H-binding site) might be required to achieve fully productive H-SLAM interactions. IMPORTANCE A complete understanding of the measles virus and canine distemper virus (CDV) cell entry molecular framework is still lacking, thus impeding the rational design of antivirals. Both viruses share many biological features that partially rely on the use of analogous Ig-like host cell receptors, namely, SLAM and nectin 4, for entering immune and epithelial cells, respectively. Here, we provide evidence that the mode of binding between the membrane-distal V domain of SLAM and the attachment protein (H) of morbilliviruses is very likely conserved. Moreover, although structural information revealed two discrete conformational states of H, one of the structures displayed two H-SLAM binding interfaces ("front" and "back"). Our data not only spotlight the front H-binding site of SLAM as the main determinant of membrane fusion promotion but suggest that the triggering efficiency of the viral entry machinery may rely on a local conformational change within the front H-SLAM interactive site rather than the binding affinity.
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A Structurally Unresolved Head Segment of Defined Length Favors Proper Measles Virus Hemagglutinin Tetramerization and Efficient Membrane Fusion Triggering. J Virol 2015; 90:68-75. [PMID: 26446605 DOI: 10.1128/jvi.02253-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/05/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Paramyxoviruses include several insidious and ubiquitous pathogens of humans and animals, with measles virus (MeV) being a prominent one. The MeV membrane fusion apparatus consists of a receptor binding protein (hemagglutinin [H]) tetramer and a fusion (F) protein trimer. Four globular MeV H heads are connected to a tetrameric stalk through flexible linkers. We sought here to characterize the function of a 17-residue H-head segment proximal to the stalk that was unresolved in all five MeV H-head crystal or cocrystal structures. In particular, we assessed whether its primary sequence and length are critical for proper protein oligomerization and intracellular transport or for membrane fusion triggering. Extensive alanine substitutions had no effect on fusion triggering, suggesting that sequence identity is not critical for this function. Excessive shortening of this segment reduced or completely abrogated fusion trigger function, while length compensation restored it. We then characterized the mechanism of function loss. Mutated H proteins were efficiently transported to the cell surface, but certain alterations enhancing linker flexibility resulted in accumulation of high-molecular-weight H oligomers. Some oligomers had reduced fusion trigger capacity, while others retained this function. Thus, length and rigidity of the unresolved head segment favor proper H tetramerization and counteract interactions between subunits from different tetramers. The structurally unresolved H-head segment, together with the top of the stalk, may act as a leash to provide the right degree of freedom for the heads of individual tetramers to adopt a triggering-permissive conformation while avoiding improper contacts with heads of neighboring tetramers. IMPORTANCE Understanding the molecular mechanism of membrane fusion triggering may allow development of new antiviral strategies. The fusion apparatus of paramyxoviruses consists of a receptor binding tetramer and a fusion protein trimer. Structural analyses of the receptor binding hemagglutinin-neuraminidases of certain paramyxoviruses suggest that fusion triggering is preceded by relocation of its head domains, facilitated by flexible linkers. Having noted a structurally unresolved 17-residue segment linking the globular heads to the tetrameric stalk of the measles virus hemagglutinin (H), we asked whether and how it may facilitate membrane fusion triggering. We conclude that, together with the top of the stalk, the flexible linker keeps H heads on a leash long enough to adopt a triggering-permissive conformation but short enough to limit roaming and improper contacts with heads of neighboring tetramers. All morbillivirus H-protein heads appear to be connected to their stalks through a "leash," suggesting a conserved triggering mechanism.
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The Fusion Protein Specificity of the Parainfluenza Virus Hemagglutinin-Neuraminidase Protein Is Not Solely Defined by the Primary Structure of Its Stalk Domain. J Virol 2015; 89:12374-87. [PMID: 26423949 DOI: 10.1128/jvi.01448-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/24/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Virus-specific interaction between the attachment protein (HN) and the fusion protein (F) is prerequisite for the induction of membrane fusion by parainfluenza viruses. This HN-F interaction presumably is mediated by particular amino acids in the HN stalk domain and those in the F head domain. We found in the present study, however, that a simian virus 41 (SV41) F-specific chimeric HPIV2 HN protein, SCA, whose cytoplasmic, transmembrane, and stalk domains were derived from the SV41 HN protein, could not induce cell-cell fusion of BHK-21 cells when coexpressed with an SV41 HN-specific chimeric PIV5 F protein, no. 36. Similarly, a headless form of the SV41 HN protein failed to induce fusion with chimera no. 36, whereas it was able to induce fusion with the SV41 F protein. Interestingly, replacement of 13 amino acids of the SCA head domain, which are located at or around the dimer interface of the head domain, with SV41 HN counterparts resulted in a chimeric HN protein, SCA-RII, which induced fusion with chimera no. 36 but not with the SV41 F protein. More interestingly, retroreplacement of 11 out of the 13 amino acids of SCA-RII with the SCA counterparts resulted in another chimeric HN protein, IM18, which induced fusion either with chimera no. 36 or with the SV41 F protein, similar to the SV41 HN protein. Thus, we conclude that the F protein specificity of the HN protein that is observed in the fusion event is not solely defined by the primary structure of the HN stalk domain. IMPORTANCE It is appreciated that the HN head domain initially conceals the HN stalk domain but exposes it after the head domain has bound to the receptors, which allows particular amino acids in the stalk domain to interact with the F protein and trigger it to induce fusion. However, other regulatory roles of the HN head domain in the fusion event have been ill defined. We have shown in the current study that removal of the head domain or amino acid substitutions in a particular region of the head domain drastically change the F protein specificity of the HN protein, suggesting that the ability of a given HN protein to interact with an F protein is defined not only by the primary structure of the HN stalk domain but also by its conformation. This notion seems to account for the unidirectional substitutability among rubulavirus HN proteins in triggering noncognate F proteins.
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Vermeire T, Vermaere S, Van Gucht S, Hutse V, Martens L, Vandermarliere E. Computational analysis of mumps surface proteins reveals their interaction mechanism. J Clin Virol 2015. [DOI: 10.1016/j.jcv.2015.07.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ader-Ebert N, Khosravi M, Herren M, Avila M, Alves L, Bringolf F, Örvell C, Langedijk JP, Zurbriggen A, Plemper RK, Plattet P. Sequential conformational changes in the morbillivirus attachment protein initiate the membrane fusion process. PLoS Pathog 2015; 11:e1004880. [PMID: 25946112 PMCID: PMC4422687 DOI: 10.1371/journal.ppat.1004880] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/14/2015] [Indexed: 11/18/2022] Open
Abstract
Despite large vaccination campaigns, measles virus (MeV) and canine distemper virus (CDV) cause major morbidity and mortality in humans and animals, respectively. The MeV and CDV cell entry system relies on two interacting envelope glycoproteins: the attachment protein (H), consisting of stalk and head domains, co-operates with the fusion protein (F) to mediate membrane fusion. However, how receptor-binding by the H-protein leads to F-triggering is not fully understood. Here, we report that an anti-CDV-H monoclonal antibody (mAb-1347), which targets the linear H-stalk segment 126-133, potently inhibits membrane fusion without interfering with H receptor-binding or F-interaction. Rather, mAb-1347 blocked the F-triggering function of H-proteins regardless of the presence or absence of the head domains. Remarkably, mAb-1347 binding to headless CDV H, as well as standard and engineered bioactive stalk-elongated CDV H-constructs treated with cells expressing the SLAM receptor, was enhanced. Despite proper cell surface expression, fusion promotion by most H-stalk mutants harboring alanine substitutions in the 126-138 "spacer" section was substantially impaired, consistent with deficient receptor-induced mAb-1347 binding enhancement. However, a previously reported F-triggering defective H-I98A variant still exhibited the receptor-induced "head-stalk" rearrangement. Collectively, our data spotlight a distinct mechanism for morbillivirus membrane fusion activation: prior to receptor contact, at least one of the morbillivirus H-head domains interacts with the membrane-distal "spacer" domain in the H-stalk, leaving the F-binding site located further membrane-proximal in the stalk fully accessible. This "head-to-spacer" interaction conformationally stabilizes H in an auto-repressed state, which enables intracellular H-stalk/F engagement while preventing the inherent H-stalk's bioactivity that may prematurely activate F. Receptor-contact disrupts the "head-to-spacer" interaction, which subsequently "unlocks" the stalk, allowing it to rearrange and trigger F. Overall, our study reveals essential mechanistic requirements governing the activation of the morbillivirus membrane fusion cascade and spotlights the H-stalk "spacer" microdomain as a possible drug target for antiviral therapy.
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Affiliation(s)
- Nadine Ader-Ebert
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Mojtaba Khosravi
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Michael Herren
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Mislay Avila
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Lisa Alves
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Fanny Bringolf
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Claes Örvell
- Division of Laboratory Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | | | - Andreas Zurbriggen
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Richard K. Plemper
- Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Philippe Plattet
- Division of Neurological Sciences, Department of Clinical Research and Veterinary Public Health (DCR-VPH), Vetsuisse Faculty, University of Bern, Bern, Switzerland
- * E-mail:
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Harrison SC. Viral membrane fusion. Virology 2015; 479-480:498-507. [PMID: 25866377 DOI: 10.1016/j.virol.2015.03.043] [Citation(s) in RCA: 519] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 02/23/2015] [Accepted: 03/10/2015] [Indexed: 11/27/2022]
Abstract
Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.
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Affiliation(s)
- Stephen C Harrison
- Boston Children׳s Hospital, Harvard Medical School, and Howard Hughes Medical Institute, 3 Blackfan Circle, Boston, MA 02115, United States.
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Molecular recognition of human ephrinB2 cell surface receptor by an emergent African henipavirus. Proc Natl Acad Sci U S A 2015; 112:E2156-65. [PMID: 25825759 DOI: 10.1073/pnas.1501690112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The discovery of African henipaviruses (HNVs) related to pathogenic Hendra virus (HeV) and Nipah virus (NiV) from Southeast Asia and Australia presents an open-ended health risk. Cell receptor use by emerging African HNVs at the stage of host-cell entry is a key parameter when considering the potential for spillover and infection of human populations. The attachment glycoprotein from a Ghanaian bat isolate (GhV-G) exhibits <30% sequence identity with Asiatic NiV-G/HeV-G. Here, through functional and structural analysis of GhV-G, we show how this African HNV targets the same human cell-surface receptor (ephrinB2) as the Asiatic HNVs. We first characterized this virus-receptor interaction crystallographically. Compared with extant HNV-G-ephrinB2 structures, there was significant structural variation in the six-bladed β-propeller scaffold of the GhV-G receptor-binding domain, but not the Greek key fold of the bound ephrinB2. Analysis revealed a surprisingly conserved mode of ephrinB2 interaction that reflects an ongoing evolutionary constraint among geographically distal and phylogenetically divergent HNVs to maintain the functionality of ephrinB2 recognition during virus-host entry. Interestingly, unlike NiV-G/HeV-G, we could not detect binding of GhV-G to ephrinB3. Comparative structure-function analysis further revealed several distinguishing features of HNV-G function: a secondary ephrinB2 interaction site that contributes to more efficient ephrinB2-mediated entry in NiV-G relative to GhV-G and cognate residues at the very C terminus of GhV-G (absent in Asiatic HNV-Gs) that are vital for efficient receptor-induced fusion, but not receptor binding per se. These data provide molecular-level details for evaluating the likelihood of African HNVs to spill over into human populations.
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Bose S, Jardetzky TS, Lamb RA. Timing is everything: Fine-tuned molecular machines orchestrate paramyxovirus entry. Virology 2015; 479-480:518-31. [PMID: 25771804 PMCID: PMC4424121 DOI: 10.1016/j.virol.2015.02.037] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/21/2015] [Accepted: 02/18/2015] [Indexed: 11/30/2022]
Abstract
The Paramyxoviridae include some of the great and ubiquitous disease-causing viruses of humans and animals. In most paramyxoviruses, two viral membrane glycoproteins, fusion protein (F) and receptor binding protein (HN, H or G) mediate a concerted process of recognition of host cell surface molecules followed by fusion of viral and cellular membranes, resulting in viral nucleocapsid entry into the cytoplasm. The interactions between the F and HN, H or G viral glycoproteins and host molecules are critical in determining host range, virulence and spread of these viruses. Recently, atomic structures, together with biochemical and biophysical studies, have provided major insights into how these two viral glycoproteins successfully interact with host receptors on cellular membranes and initiate the membrane fusion process to gain entry into cells. These studies highlight the conserved core mechanisms of paramyxovirus entry that provide the fundamental basis for rational anti-viral drug design and vaccine development. New structural and functional insights into paramyxovirus entry mechanisms. Current data on paramyxovirus glycoproteins suggest a core conserved entry mechanism. Diverse mechanisms preventing premature fusion activation exist in these viruses. Precise spacio-temporal interplay between paramyxovirus glycoproteins initiate entry.
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Affiliation(s)
- Sayantan Bose
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500, United States.
| | - Theodore S Jardetzky
- Department of Structural Biology and Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Robert A Lamb
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500, United States; Howard Hughes Medical Institute, Northwestern University, Evanston, IL 60208-3500, United States.
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