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Xia X, Cheng A, Wang M, Ou X, Sun D, Mao S, Huang J, Yang Q, Wu Y, Chen S, Zhang S, Zhu D, Jia R, Liu M, Zhao XX, Gao Q, Tian B. Functions of Viroporins in the Viral Life Cycle and Their Regulation of Host Cell Responses. Front Immunol 2022; 13:890549. [PMID: 35720341 PMCID: PMC9202500 DOI: 10.3389/fimmu.2022.890549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Viroporins are virally encoded transmembrane proteins that are essential for viral pathogenicity and can participate in various stages of the viral life cycle, thereby promoting viral proliferation. Viroporins have multifaceted effects on host cell biological functions, including altering cell membrane permeability, triggering inflammasome formation, inducing apoptosis and autophagy, and evading immune responses, thereby ensuring that the virus completes its life cycle. Viroporins are also virulence factors, and their complete or partial deletion often reduces virion release and reduces viral pathogenicity, highlighting the important role of these proteins in the viral life cycle. Thus, viroporins represent a common drug-protein target for inhibiting drugs and the development of antiviral therapies. This article reviews current studies on the functions of viroporins in the viral life cycle and their regulation of host cell responses, with the aim of improving the understanding of this growing family of viral proteins.
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Affiliation(s)
- Xiaoyan Xia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
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2
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Gorkhali R, Koirala P, Rijal S, Mainali A, Baral A, Bhattarai HK. Structure and Function of Major SARS-CoV-2 and SARS-CoV Proteins. Bioinform Biol Insights 2021; 15:11779322211025876. [PMID: 34220199 PMCID: PMC8221690 DOI: 10.1177/11779322211025876] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/25/2021] [Indexed: 01/20/2023] Open
Abstract
SARS-CoV-2 virus, the causative agent of COVID-19 pandemic, has a genomic organization consisting of 16 nonstructural proteins (nsps), 4 structural proteins, and 9 accessory proteins. Relative of SARS-CoV-2, SARS-CoV, has genomic organization, which is very similar. In this article, the function and structure of the proteins of SARS-CoV-2 and SARS-CoV are described in great detail. The nsps are expressed as a single or two polyproteins, which are then cleaved into individual proteins using two proteases of the virus, a chymotrypsin-like protease and a papain-like protease. The released proteins serve as centers of virus replication and transcription. Some of these nsps modulate the host’s translation and immune systems, while others help the virus evade the host immune system. Some of the nsps help form replication-transcription complex at double-membrane vesicles. Others, including one RNA-dependent RNA polymerase and one exonuclease, help in the polymerization of newly synthesized RNA of the virus and help minimize the mutation rate by proofreading. After synthesis of the viral RNA, it gets capped. The capping consists of adding GMP and a methylation mark, called cap 0 and additionally adding a methyl group to the terminal ribose called cap1. Capping is accomplished with the help of a helicase, which also helps remove a phosphate, two methyltransferases, and a scaffolding factor. Among the structural proteins, S protein forms the receptor of the virus, which latches on the angiotensin-converting enzyme 2 receptor of the host and N protein binds and protects the genomic RNA of the virus. The accessory proteins found in these viruses are small proteins with immune modulatory roles. Besides functions of these proteins, solved X-ray and cryogenic electron microscopy structures related to the function of the proteins along with comparisons to other coronavirus homologs have been described in the article. Finally, the rate of mutation of SARS-CoV-2 residues of the proteome during the 2020 pandemic has been described. Some proteins are mutated more often than other proteins, but the significance of these mutation rates is not fully understood.
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Affiliation(s)
- Ritesh Gorkhali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | | | - Sadikshya Rijal
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Ashmita Mainali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Adesh Baral
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
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3
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Hopp MT, Domingo-Fernández D, Gadiya Y, Detzel MS, Graf R, Schmalohr BF, Kodamullil AT, Imhof D, Hofmann-Apitius M. Linking COVID-19 and Heme-Driven Pathophysiologies: A Combined Computational-Experimental Approach. Biomolecules 2021; 11:biom11050644. [PMID: 33925394 PMCID: PMC8147026 DOI: 10.3390/biom11050644] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 01/08/2023] Open
Abstract
The SARS-CoV-2 outbreak was declared a worldwide pandemic in 2020. Infection triggers the respiratory tract disease COVID-19, which is accompanied by serious changes in clinical biomarkers such as hemoglobin and interleukins. The same parameters are altered during hemolysis, which is characterized by an increase in labile heme. We present two computational–experimental approaches aimed at analyzing a potential link between heme-related and COVID-19 pathophysiologies. Herein, we performed a detailed analysis of the common pathways induced by heme and SARS-CoV-2 by superimposition of knowledge graphs covering heme biology and COVID-19 pathophysiology. Focus was laid on inflammatory pathways and distinct biomarkers as the linking elements. In a second approach, four COVID-19-related proteins, the host cell proteins ACE2 and TMPRSS2 as well as the viral proteins 7a and S protein were computationally analyzed as potential heme-binding proteins with an experimental validation. The results contribute to the understanding of the progression of COVID-19 infections in patients with different clinical backgrounds and may allow for a more individual diagnosis and therapy in the future.
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Affiliation(s)
- Marie-Thérèse Hopp
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; (M.-T.H.); (M.S.D.); (R.G.); (B.F.S.)
| | - Daniel Domingo-Fernández
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, D-53757 Sankt Augustin, Germany; (D.D.-F.); (Y.G.); (A.T.K.)
- Enveda Biosciences, Inc., San Francisco, CA 94080, USA
| | - Yojana Gadiya
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, D-53757 Sankt Augustin, Germany; (D.D.-F.); (Y.G.); (A.T.K.)
| | - Milena S. Detzel
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; (M.-T.H.); (M.S.D.); (R.G.); (B.F.S.)
| | - Regina Graf
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; (M.-T.H.); (M.S.D.); (R.G.); (B.F.S.)
| | - Benjamin F. Schmalohr
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; (M.-T.H.); (M.S.D.); (R.G.); (B.F.S.)
| | - Alpha T. Kodamullil
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, D-53757 Sankt Augustin, Germany; (D.D.-F.); (Y.G.); (A.T.K.)
- Causality Biomodels, Kinfra Hi-Tech Park, Kalamassery, Cochin, Kerala 683503, India
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; (M.-T.H.); (M.S.D.); (R.G.); (B.F.S.)
- Correspondence: (D.I.); (M.H.-A.)
| | - Martin Hofmann-Apitius
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, D-53757 Sankt Augustin, Germany; (D.D.-F.); (Y.G.); (A.T.K.)
- Correspondence: (D.I.); (M.H.-A.)
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4
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Gorgulla C, Padmanabha Das KM, Leigh KE, Cespugli M, Fischer PD, Wang ZF, Tesseyre G, Pandita S, Shnapir A, Calderaio A, Gechev M, Rose A, Lewis N, Hutcheson C, Yaffe E, Luxenburg R, Herce HD, Durmaz V, Halazonetis TD, Fackeldey K, Patten J, Chuprina A, Dziuba I, Plekhova A, Moroz Y, Radchenko D, Tarkhanova O, Yavnyuk I, Gruber C, Yust R, Payne D, Näär AM, Namchuk MN, Davey RA, Wagner G, Kinney J, Arthanari H. A multi-pronged approach targeting SARS-CoV-2 proteins using ultra-large virtual screening. iScience 2021; 24:102021. [PMID: 33426509 PMCID: PMC7783459 DOI: 10.1016/j.isci.2020.102021] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/28/2020] [Accepted: 12/29/2020] [Indexed: 02/07/2023] Open
Abstract
The unparalleled global effort to combat the continuing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic over the last year has resulted in promising prophylactic measures. However, a need still exists for cheap, effective therapeutics, and targeting multiple points in the viral life cycle could help tackle the current, as well as future, coronaviruses. Here, we leverage our recently developed, ultra-large-scale in silico screening platform, VirtualFlow, to search for inhibitors that target SARS-CoV-2. In this unprecedented structure-based virtual campaign, we screened roughly 1 billion molecules against each of 40 different target sites on 17 different potential viral and host targets. In addition to targeting the active sites of viral enzymes, we also targeted critical auxiliary sites such as functionally important protein-protein interactions.
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Affiliation(s)
- Christoph Gorgulla
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- Department of Physics, Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Krishna M. Padmanabha Das
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Kendra E. Leigh
- Max Planck Institute of Biophysics, Frankfurt am Main, Hessen 60438, Germany
| | | | - Patrick D. Fischer
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University, Saarbrücken, Saarland 66123, Germany
| | - Zi-Fu Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
| | | | | | | | - Anthony Calderaio
- VirtualFlow Organization, https://virtual-flow.org/, Boston, MA 02115, USA
| | | | - Alexander Rose
- Mol∗ Consortium, https://molstar.org, San Diego, CA 92109, USA
| | | | | | | | | | - Henry D. Herce
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | | | | | - Konstantin Fackeldey
- Zuse Institute Berlin (ZIB), Berlin 14195, Germany
- Institute of Mathematics, Technical University Berlin, Berlin 10587, Germany
| | - J.J. Patten
- Department of Microbiology, Boston University Medical School, Boston University, Boston, MA 02118, USA
| | | | | | | | - Yurii Moroz
- Chemspace, Kyiv 02094, Ukraine
- Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
| | - Dmytro Radchenko
- Enamine, Kyiv 02094, Ukraine
- Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
| | | | | | - Christian Gruber
- Innophore GmbH, Graz 8010, Austria
- Institute of Molecular Biosciences, University of Graz, Graz 8010, Austria
| | - Ryan Yust
- Google, Mountain View, CA 94043, USA
| | | | - Anders M. Näär
- Department of Nutritional Sciences & Toxicology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Mark N. Namchuk
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
| | - Robert A. Davey
- Department of Microbiology, Boston University Medical School, Boston University, Boston, MA 02118, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
| | | | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
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5
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Gorgulla C, Padmanabha Das KM, Leigh KE, Cespugli M, Fischer PD, Wang ZF, Tesseyre G, Pandita S, Shnapir A, Calderaio A, Gechev M, Rose A, Lewis N, Hutcheson C, Yaffe E, Luxenburg R, Herce HD, Durmaz V, Halazonetis TD, Fackeldey K, Patten JJ, Chuprina A, Dziuba I, Plekhova A, Moroz Y, Radchenko D, Tarkhanova O, Yavnyuk I, Gruber C, Yust R, Payne D, Näär AM, Namchuk MN, Davey RA, Wagner G, Kinney J, Arthanari H. A Multi-Pronged Approach Targeting SARS-CoV-2 Proteins Using Ultra-Large Virtual Screening. CHEMRXIV : THE PREPRINT SERVER FOR CHEMISTRY 2020:12682316. [PMID: 33200116 PMCID: PMC7668741 DOI: 10.26434/chemrxiv.12682316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 07/24/2020] [Indexed: 11/23/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), previously known as 2019 novel coronavirus (2019-nCoV), has spread rapidly across the globe, creating an unparalleled global health burden and spurring a deepening economic crisis. As of July 7th, 2020, almost seven months into the outbreak, there are no approved vaccines and few treatments available. Developing drugs that target multiple points in the viral life cycle could serve as a strategy to tackle the current as well as future coronavirus pandemics. Here we leverage the power of our recently developed in silico screening platform, VirtualFlow, to identify inhibitors that target SARS-CoV-2. VirtualFlow is able to efficiently harness the power of computing clusters and cloud-based computing platforms to carry out ultra-large scale virtual screens. In this unprecedented structure-based multi-target virtual screening campaign, we have used VirtualFlow to screen an average of approximately 1 billion molecules against each of 40 different target sites on 17 different potential viral and host targets in the cloud. In addition to targeting the active sites of viral enzymes, we also target critical auxiliary sites such as functionally important protein-protein interaction interfaces. This multi-target approach not only increases the likelihood of finding a potent inhibitor, but could also help identify a collection of anti-coronavirus drugs that would retain efficacy in the face of viral mutation. Drugs belonging to different regimen classes could be combined to develop possible combination therapies, and top hits that bind at highly conserved sites would be potential candidates for further development as coronavirus drugs. Here, we present the top 200 in silico hits for each target site. While in-house experimental validation of some of these compounds is currently underway, we want to make this array of potential inhibitor candidates available to researchers worldwide in consideration of the pressing need for fast-tracked drug development.
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Affiliation(s)
- Christoph Gorgulla
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
- Department of Physics, Faculty of Arts and Sciences, Harvard University, Cambridge, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, USA
| | - Krishna M. Padmanabha Das
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, USA
| | | | | | - Patrick D. Fischer
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, USA
- Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University, Saarbrücken, Germany
| | - Zi-Fu Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
| | | | | | | | | | | | | | | | | | | | | | - Henry D. Herce
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, USA
| | | | | | - Konstantin Fackeldey
- Zuse Institute Berlin (ZIB), Berlin, Germany
- Institute of Mathematics, Technical University Berlin, Berlin, Germany
| | - Justin J. Patten
- Department of Microbiology, Boston University Medical School, Boston University, Boston, USA
| | | | | | | | - Yurii Moroz
- Chemspace, Kyiv, Ukraine
- Taras Shevchenko National University of Kyiv, Ukraine
| | - Dmytro Radchenko
- Enamine, Kyiv, Ukraine
- Taras Shevchenko National University of Kyiv, Ukraine
| | | | | | - Christian Gruber
- Innophore GmbH, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Austria
| | | | | | - Anders M. Näär
- Department of Nutritional Sciences & Toxicology, University of California Berkeley, USA
| | - Mark N. Namchuk
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
| | - Robert A. Davey
- Department of Microbiology, Boston University Medical School, Boston University, Boston, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
| | | | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, USA
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6
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Benarroch R, Austin JM, Ahmed F, Isaacson RL. The roles of cytosolic quality control proteins, SGTA and the BAG6 complex, in disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 114:265-313. [PMID: 30635083 PMCID: PMC7102839 DOI: 10.1016/bs.apcsb.2018.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SGTA is a co-chaperone that, in collaboration with the complex of BAG6/UBL4A/TRC35, facilitates the biogenesis and quality control of hydrophobic proteins, protecting them from the aqueous cytosolic environment. This work includes targeting tail-anchored proteins to their resident membranes, sorting of membrane and secretory proteins that mislocalize to the cytoplasm and endoplasmic reticulum-associated degradation of misfolded proteins. Since these functions are all vital for the cell's continued proteostasis, their disruption poses a threat to the cell, with a particular risk of protein aggregation, a phenomenon that underpins many diseases. Although the specific disease implications of machinery involved in quality control of hydrophobic substrates are poorly understood, here we summarize much of the available information on this topic.
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Affiliation(s)
- Rashi Benarroch
- Department of Chemistry, King's College London, London, United Kingdom
| | - Jennifer M Austin
- Department of Chemistry, King's College London, London, United Kingdom
| | - Fahmeda Ahmed
- Department of Chemistry, King's College London, London, United Kingdom
| | - Rivka L Isaacson
- Department of Chemistry, King's College London, London, United Kingdom.
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7
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How Polyomaviruses Exploit the ERAD Machinery to Cause Infection. Viruses 2016; 8:v8090242. [PMID: 27589785 PMCID: PMC5035956 DOI: 10.3390/v8090242] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/18/2016] [Accepted: 08/23/2016] [Indexed: 12/18/2022] Open
Abstract
To infect cells, polyomavirus (PyV) traffics from the cell surface to the endoplasmic reticulum (ER) where it hijacks elements of the ER-associated degradation (ERAD) machinery to penetrate the ER membrane and reach the cytosol. From the cytosol, the virus transports to the nucleus, enabling transcription and replication of the viral genome that leads to lytic infection or cellular transformation. How PyV exploits the ERAD machinery to cross the ER membrane and access the cytosol, a decisive infection step, remains enigmatic. However, recent studies have slowly unraveled many aspects of this process. These emerging insights should advance our efforts to develop more effective therapies against PyV-induced human diseases.
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8
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Philp LK, Day TK, Butler MS, Laven-Law G, Jindal S, Hickey TE, Scher HI, Butler LM, Tilley WD. Small Glutamine-Rich Tetratricopeptide Repeat-Containing Protein Alpha (SGTA) Ablation Limits Offspring Viability and Growth in Mice. Sci Rep 2016; 6:28950. [PMID: 27358191 PMCID: PMC4928056 DOI: 10.1038/srep28950] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/07/2016] [Indexed: 01/26/2023] Open
Abstract
Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) has been implicated as a co-chaperone and regulator of androgen and growth hormone receptor (AR, GHR) signalling. We investigated the functional consequences of partial and full Sgta ablation in vivo using Cre-lox Sgta-null mice. Sgta(+/-) breeders generated viable Sgta(-/-) offspring, but at less than Mendelian expectancy. Sgta(-/-) breeders were subfertile with small litters and higher neonatal death (P < 0.02). Body size was significantly and proportionately smaller in male and female Sgta(-/-) (vs WT, Sgta(+/-) P < 0.001) from d19. Serum IGF-1 levels were genotype- and sex-dependent. Food intake, muscle and bone mass and adiposity were unchanged in Sgta(-/-). Vital and sex organs had normal relative weight, morphology and histology, although certain androgen-sensitive measures such as penis and preputial size, and testis descent, were greater in Sgta(-/-). Expression of AR and its targets remained largely unchanged, although AR localisation was genotype- and tissue-dependent. Generally expression of other TPR-containing proteins was unchanged. In conclusion, this thorough investigation of SGTA-null mutation reports a mild phenotype of reduced body size. The model's full potential likely will be realised by genetic crosses with other models to interrogate the role of SGTA in the many diseases in which it has been implicated.
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Affiliation(s)
- Lisa K. Philp
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Tanya K. Day
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Miriam S. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Geraldine Laven-Law
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Shalini Jindal
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Theresa E. Hickey
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | | | - Lisa M. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
- Freemason’s Foundation Centre for Men’s Health, School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Wayne D. Tilley
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
- Freemason’s Foundation Centre for Men’s Health, School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
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9
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The Vpu-interacting Protein SGTA Regulates Expression of a Non-glycosylated Tetherin Species. Sci Rep 2016; 6:24934. [PMID: 27103333 PMCID: PMC4840321 DOI: 10.1038/srep24934] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 04/07/2016] [Indexed: 01/02/2023] Open
Abstract
The HIV-1 accessory protein Vpu enhances virus release by counteracting the host restriction factor tetherin. To further understand the role of host cell proteins in Vpu function, we carried out yeast two-hybrid screening and identified a previously reported Vpu-interacting host factor, small glutamine-rich tetratricopeptide repeat-containing protein (SGTA). While RNAi-mediated depletion of SGTA did not significantly affect levels of tetherin or virus release efficiency, we observed that overexpression of SGTA inhibited HIV-1 release in a Vpu- and tetherin-independent manner. Overexpression of SGTA in the presence of Vpu, but not in its absence, resulted in a marked stabilization and cytosolic relocalization of a 23-kDa, non-glycosylated tetherin species. Coimmunoprecipitation studies indicated that non-glycosylated tetherin is stabilized through the formation of a ternary SGTA/Vpu/tetherin complex. This accumulation of non-glycosylated tetherin is due to inhibition of its degradation, independent of the ER-associated degradation (ERAD) pathway. Because the SGTA-stabilized tetherin species is partially localized to the cytosol, we propose that overexpression of SGTA in the presence of Vpu blocks the translocation of tetherin across the ER membrane, resulting in cytosolic accumulation of a non-glycosylated tetherin species. Although our results do not provide support for a physiological function of SGTA in HIV-1 replication, they demonstrate that SGTA overexpression regulates tetherin expression and stability, thus providing insights into the function of SGTA in ER translocation and protein degradation.
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10
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Roberts JD, Thapaliya A, Martínez-Lumbreras S, Krysztofinska EM, Isaacson RL. Structural and Functional Insights into Small, Glutamine-Rich, Tetratricopeptide Repeat Protein Alpha. Front Mol Biosci 2015; 2:71. [PMID: 26734616 PMCID: PMC4683186 DOI: 10.3389/fmolb.2015.00071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/29/2015] [Indexed: 11/21/2022] Open
Abstract
The small glutamine-rich, tetratricopeptide repeat-containing protein alpha (SGTA) is an emerging player in the quality control of secretory and membrane proteins mislocalized to the cytosol, with established roles in tail-anchored (TA) membrane protein biogenesis. SGTA consists of three structural domains with individual functions, an N-terminal dimerization domain that assists protein sorting pathways, a central tetratricopeptide repeat (TPR) domain that mediates interactions with heat-shock proteins, proteasomal, and hormonal receptors, and viral proteins, and a C-terminal glutamine rich region that binds hydrophobic substrates. SGTA has been linked to viral lifecycles and hormone receptor signaling, with implications in the pathogenesis of various disease states. Thus far, a range of biophysical techniques have been employed to characterize SGTA structure in some detail, and to investigate its interactions with binding partners in different biological contexts. A complete description of SGTA structure, together with further investigation into its function as a co-chaperone involved quality control, could provide us with useful insights into its role in maintaining cellular proteostasis, and broaden our understanding of mechanisms underlying associated pathologies. This review describes how some structural features of SGTA have been elucidated, and what this has uncovered about its cellular functions. A brief background on the structure and function of SGTA is given, highlighting its importance to biomedicine and related fields. The current level of knowledge and what remains to be understood about the structure and function of SGTA is summarized, discussing the potential direction of future research.
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11
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Leznicki P, Korac-Prlic J, Kliza K, Husnjak K, Nyathi Y, Dikic I, High S. Binding of SGTA to Rpn13 selectively modulates protein quality control. J Cell Sci 2015; 128:3187-96. [PMID: 26169395 PMCID: PMC4582187 DOI: 10.1242/jcs.165209] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 07/03/2015] [Indexed: 12/16/2022] Open
Abstract
Rpn13 is an intrinsic ubiquitin receptor of the 26S proteasome regulatory subunit that facilitates substrate capture prior to degradation. Here we show that the C-terminal region of Rpn13 binds to the tetratricopeptide repeat (TPR) domain of SGTA, a cytosolic factor implicated in the quality control of mislocalised membrane proteins (MLPs). The overexpression of SGTA results in a substantial increase in steady-state MLP levels, consistent with an effect on proteasomal degradation. However, this effect is strongly dependent upon the interaction of SGTA with the proteasomal component Rpn13. Hence, overexpression of the SGTA-binding region of Rpn13 or point mutations within the SGTA TPR domain both inhibit SGTA binding to the proteasome and substantially reduce MLP levels. These findings suggest that SGTA can regulate the access of MLPs to the proteolytic core of the proteasome, implying that a protein quality control cycle that involves SGTA and the BAG6 complex can operate at the 19S regulatory particle. We speculate that the binding of SGTA to Rpn13 enables specific polypeptides to escape proteasomal degradation and/or selectively modulates substrate degradation. Highlighted Article: Binding of SGTA to the proteasome delays substrate degradation, thereby providing a mechanism for potentially viable proteins to be rescued for reuse.
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Affiliation(s)
- Pawel Leznicki
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Jelena Korac-Prlic
- Department of Immunology and Medical Genetics, School of Medicine, University of Split, Soltanska 2, Split 21000, Croatia
| | - Katarzyna Kliza
- Institute of Biochemistry II, School of Medicine, Goethe University, Theodor-Stern-Kai 7, Frankfurt (Main) 60590, Germany
| | - Koraljka Husnjak
- Institute of Biochemistry II, School of Medicine, Goethe University, Theodor-Stern-Kai 7, Frankfurt (Main) 60590, Germany
| | - Yvonne Nyathi
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Ivan Dikic
- Department of Immunology and Medical Genetics, School of Medicine, University of Split, Soltanska 2, Split 21000, Croatia Institute of Biochemistry II, School of Medicine, Goethe University, Theodor-Stern-Kai 7, Frankfurt (Main) 60590, Germany Buchmann Institute for Molecular Life Sciences, School of Medicine, Goethe University, Theodor-Stern-Kai 7, Frankfurt (Main) 60590, Germany
| | - Stephen High
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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12
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Maier HJ, Bickerton E, Britton P, Jones LM, Neveu G, Roussarie JP, Rottier PJM, Tangy F, de Haan CAM. A field-proven yeast two-hybrid protocol used to identify coronavirus-host protein-protein interactions. Methods Mol Biol 2014; 1282:213-29. [PMID: 25720483 PMCID: PMC7121825 DOI: 10.1007/978-1-4939-2438-7_18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Over the last 2 decades, yeast two-hybrid became an invaluable technique to decipher protein-protein interaction networks. In the field of virology, it has proven instrumental to identify virus-host interactions that are involved in viral embezzlement of cellular functions and inhibition of immune mechanisms. Here, we present a yeast two-hybrid protocol that has been used in our laboratory since 2006 to search for cellular partners of more than 300 viral proteins. Our aim was to develop a robust and straightforward pipeline, which minimizes false-positive interactions with a decent coverage of target cDNA libraries, and only requires a minimum of equipment. We also discuss reasons that motivated our technical choices and compromises that had to be made. This protocol has been used to screen most non-structural proteins of murine hepatitis virus (MHV), a member of betacoronavirus genus, against a mouse brain cDNA library. Typical results were obtained and are presented in this report.
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Affiliation(s)
- Helena Jane Maier
- grid.63622.330000000403887540The Pirbright Institute, Compton, United Kingdom
| | - Erica Bickerton
- grid.63622.330000000403887540The Pirbright Institute, Compton, United Kingdom
| | - Paul Britton
- grid.63622.330000000403887540The Pirbright Institute, Compton, United Kingdom
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13
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Liu DX, Fung TS, Chong KKL, Shukla A, Hilgenfeld R. Accessory proteins of SARS-CoV and other coronaviruses. Antiviral Res 2014; 109:97-109. [PMID: 24995382 PMCID: PMC7113789 DOI: 10.1016/j.antiviral.2014.06.013] [Citation(s) in RCA: 298] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/17/2014] [Accepted: 06/23/2014] [Indexed: 01/21/2023]
Abstract
The huge RNA genome of SARS coronavirus comprises a number of open reading frames that code for a total of eight accessory proteins. Although none of these are essential for virus replication, some appear to have a role in virus pathogenesis. Notably, some SARS-CoV accessory proteins have been shown to modulate the interferon signaling pathways and the production of pro-inflammatory cytokines. The structural information on these proteins is also limited, with only two (p7a and p9b) having their structures determined by X-ray crystallography. This review makes an attempt to summarize the published knowledge on SARS-CoV accessory proteins, with an emphasis on their involvement in virus-host interaction. The accessory proteins of other coronaviruses are also briefly discussed. This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses" (see Introduction by Hilgenfeld and Peiris (2013)).
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Affiliation(s)
- Ding Xiang Liu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - To Sing Fung
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Kelvin Kian-Long Chong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Aditi Shukla
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; German Center for Infection Research (DZIF), University of Lübeck, Germany
| | - Rolf Hilgenfeld
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; German Center for Infection Research (DZIF), University of Lübeck, Germany
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14
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Xue Q, Lv L, Wan C, Chen B, Li M, Ni T, Liu Y, Liu Y, Cong X, Zhou Y, Ni R, Mao G. Expression and clinical role of small glutamine-rich tetratricopeptide repeat (TPR)-containing protein alpha (SGTA) as a novel cell cycle protein in NSCLC. J Cancer Res Clin Oncol 2013; 139:1539-49. [PMID: 23857189 DOI: 10.1007/s00432-013-1474-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 07/04/2013] [Indexed: 11/24/2022]
Abstract
PURPOSE A small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a 35 kDa protein involved in a number of biological processes. However, the role of SGTA in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. The purpose of this study was to determine whether SGTA could serve as a biomarker for stratification and prediction of prognosis in NSCLC. METHODS Small glutamine-rich tetratricopeptide repeat-containing protein alpha expression was evaluated by Western blot in 8 paired fresh lung cancer tissues and immunohistochemistry on 83 paraffin-embedded sections. The effect of SGTA was assessed by RNA interference in A549 cells. Serum starvation and refeeding, flow cytometry, CCK-8, and tunnel assays were performed. RESULTS Small glutamine-rich tetratricopeptide repeat-containing protein alpha was highly expressed in NSCLC and significantly correlated with NSCLC histological differentiation, clinical stage, and Ki-67. Multivariate analysis indicated that SGTA was an independent prognostic factor for NSCLC patients' survival. The present investigation demonstrated that suppression of SGTA expression resulted in a significant decline of proliferation in A549 cells. Besides, SGTA could abolish the toxicity of cisplatin in A549 cells. CONCLUSIONS These findings suggested that SGTA might play an important role in promoting the tumorigenesis of NSCLC, and thus be a promising therapeutic target to prevent NSCLC progression.
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Affiliation(s)
- Qun Xue
- Department of Cardiothoracic Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, China
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15
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Philp LK, Butler MS, Hickey TE, Butler LM, Tilley WD, Day TK. SGTA: a new player in the molecular co-chaperone game. Discov Oncol 2013; 4:343-57. [PMID: 23818240 PMCID: PMC7091355 DOI: 10.1007/s12672-013-0151-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/12/2013] [Indexed: 12/25/2022] Open
Abstract
Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) is a steroid receptor molecular co-chaperone that may substantially influence hormone action and, consequently, hormone-mediated carcinogenesis. To date, published studies describe SGTA as a protein that is potentially critical in a range of biological processes, including viral infection, cell division, mitosis, and cell cycle checkpoint activation. SGTA interacts with the molecular chaperones, heat shock protein 70 (HSP70) and HSP90, and with steroid receptor complexes, including those containing the androgen receptor. Steroid receptors are critical for maintaining cell growth and differentiation in hormonally regulated tissues, such as male and female reproductive tissues, and also play a role in disease states involving these tissues. There is growing evidence that, through its interactions with chaperones and steroid receptors, SGTA may be a key player in the pathogenesis of hormonally influenced disease states, including prostate cancer and polycystic ovary syndrome. Research into the function of SGTA has been conducted in several model organisms and cell types, with these studies showing that SGTA functionality is cell-specific and tissue-specific. However, very few studies have been replicated in multiple cell types or experimental systems. Although a broad range of functions have been attributed to SGTA, there is a serious lack of mechanistic information to describe how SGTA acts. In this review, published evidence linking SGTA with hormonally regulated disease states is summarized and discussed, highlighting the need for future research to more clearly define the biological function(s) of this potentially important co-chaperone.
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Affiliation(s)
- Lisa K. Philp
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
| | - Miriam S. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
| | - Theresa E. Hickey
- Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
| | - Lisa M. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
| | - Wayne D. Tilley
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
| | - Tanya K. Day
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, Faculty of Health Sciences, The University of Adelaide, Level 4, Hanson Institute Building, DX Number 650 801, Adelaide, South Australia 5000 Australia
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16
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McBride R, Fielding BC. The role of severe acute respiratory syndrome (SARS)-coronavirus accessory proteins in virus pathogenesis. Viruses 2012. [PMID: 23202509 PMCID: PMC3509677 DOI: 10.3390/v4112902] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
A respiratory disease caused by a novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), was first reported in China in late 2002. The subsequent efficient human-to-human transmission of this virus eventually affected more than 30 countries worldwide, resulting in a mortality rate of ~10% of infected individuals. The spread of the virus was ultimately controlled by isolation of infected individuals and there has been no infections reported since April 2004. However, the natural reservoir of the virus was never identified and it is not known if this virus will re-emerge and, therefore, research on this virus continues. The SARS-CoV genome is about 30 kb in length and is predicted to contain 14 functional open reading frames (ORFs). The genome encodes for proteins that are homologous to known coronavirus proteins, such as the replicase proteins (ORFs 1a and 1b) and the four major structural proteins: nucleocapsid (N), spike (S), membrane (M) and envelope (E). SARS-CoV also encodes for eight unique proteins, called accessory proteins, with no known homologues. This review will summarize the current knowledge on SARS-CoV accessory proteins and will include: (i) expression and processing; (ii) the effects on cellular processes; and (iii) functional studies.
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Affiliation(s)
- Ruth McBride
- Anatomy Cluster, Department of Medical Biosciences, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Modderdam Road, Bellville, Western Cape, 7535, South Africa;
| | - Burtram C. Fielding
- Molecular Biology and Virology Laboratory, Department of Medical Biosciences, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Modderdam Road, Bellville, Western Cape, 7535, South Africa
- Author to whom correspondence should be addressed; ; Tel.: +27-21-959-3620; Fax: +27-21-959-3125
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17
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Abstract
Coronaviruses infect many species of animals including humans, causing acute and chronic diseases. This review focuses primarily on the pathogenesis of murine coronavirus mouse hepatitis virus (MHV) and severe acute respiratory coronavirus (SARS-CoV). MHV is a collection of strains, which provide models systems for the study of viral tropism and pathogenesis in several organs systems, including the central nervous system, the liver, and the lung, and has been cited as providing one of the few animal models for the study of chronic demyelinating diseases such as multiple sclerosis. SARS-CoV emerged in the human population in China in 2002, causing a worldwide epidemic with severe morbidity and high mortality rates, particularly in older individuals. We review the pathogenesis of both viruses and the several reverse genetics systems that made much of these studies possible. We also review the functions of coronavirus proteins, structural, enzymatic, and accessory, with an emphasis on roles in pathogenesis. Structural proteins in addition to their roles in virion structure and morphogenesis also contribute significantly to viral spread in vivo and in antagonizing host cell responses. Nonstructural proteins include the small accessory proteins that are not at all conserved between MHV and SARS-CoV and the 16 conserved proteins encoded in the replicase locus, many of which have enzymatic activities in RNA metabolism or protein processing in addition to functions in antagonizing host response.
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Affiliation(s)
- Susan R Weiss
- Department of Microbiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, USA
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18
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Chartron JW, Gonzalez GM, Clemons WM. A structural model of the Sgt2 protein and its interactions with chaperones and the Get4/Get5 complex. J Biol Chem 2011; 286:34325-34. [PMID: 21832041 PMCID: PMC3190793 DOI: 10.1074/jbc.m111.277798] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/18/2011] [Indexed: 11/06/2022] Open
Abstract
The insertion of tail-anchored transmembrane (TA) proteins into the appropriate membrane is a post-translational event that requires stabilization of the transmembrane domain and targeting to the proper destination. Sgt2 is a heat-shock protein cognate (HSC) co-chaperone that preferentially binds endoplasmic reticulum-destined TA proteins and directs them to the GET pathway via Get4 and Get5. Here, we present the crystal structure from a fungal Sgt2 homolog of the tetratrico-repeat (TPR) domain and part of the linker that connects to the C-terminal domain. The linker extends into the two-carboxylate clamp of the TPR domain from a symmetry-related molecule mimicking the binding to HSCs. Based on this structure, we provide biochemical evidence that the Sgt2 TPR domain has the ability to directly bind multiple HSC family members. The structure allows us to propose features involved in this lower specificity relative to other TPR containing co-chaperones. We further show that a dimer of Sgt2 binds a single Get5 and use small angle x-ray scattering to characterize the domain arrangement of Sgt2 in solution. These results allow us to present a structural model of the Sgt2-Get4/Get5-HSC complex.
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Affiliation(s)
- Justin W. Chartron
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Grecia M. Gonzalez
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - William M. Clemons
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
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19
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Abstract
Coronaviruses infect many species of animals including humans, causing acute and chronic diseases. This review focuses primarily on the pathogenesis of murine coronavirus mouse hepatitis virus (MHV) and severe acute respiratory coronavirus (SARS-CoV). MHV is a collection of strains, which provide models systems for the study of viral tropism and pathogenesis in several organs systems, including the central nervous system, the liver, and the lung, and has been cited as providing one of the few animal models for the study of chronic demyelinating diseases such as multiple sclerosis. SARS-CoV emerged in the human population in China in 2002, causing a worldwide epidemic with severe morbidity and high mortality rates, particularly in older individuals. We review the pathogenesis of both viruses and the several reverse genetics systems that made much of these studies possible. We also review the functions of coronavirus proteins, structural, enzymatic, and accessory, with an emphasis on roles in pathogenesis. Structural proteins in addition to their roles in virion structure and morphogenesis also contribute significantly to viral spread in vivo and in antagonizing host cell responses. Nonstructural proteins include the small accessory proteins that are not at all conserved between MHV and SARS-CoV and the 16 conserved proteins encoded in the replicase locus, many of which have enzymatic activities in RNA metabolism or protein processing in addition to functions in antagonizing host response.
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Affiliation(s)
- Susan R Weiss
- Department of Microbiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, USA
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20
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Cox MB, Johnson JL. The role of p23, Hop, immunophilins, and other co-chaperones in regulating Hsp90 function. Methods Mol Biol 2011; 787:45-66. [PMID: 21898226 DOI: 10.1007/978-1-61779-295-3_4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Molecular chaperones are a diverse group of highly conserved proteins that transiently interact with partially folded polypeptide chains during normal cellular processes, such as protein translation, translocation, and disassembly of protein complexes (1). Prior to folding or after denaturation, hydrophobic residues that are normally sequestered within a folded protein are exposed to the aqueous environment and are prone to aggregation or misfolding. Multiple classes of molecular chaperones, such as Hsp70s and Hsp40s, recognize and transiently bind polypeptides with exposed hydrophobic stretches in order to prevent misfolding. Other types of chaperones, such as Hsp90, have more specialized functions in that they appear to interact with only a subset of cellular proteins. This chapter focuses on the role of Hsp90 and partner co-chaperones in promoting the folding and activation of a diverse group of proteins with critical roles in cellular signaling and function.
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Affiliation(s)
- Marc B Cox
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
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21
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Vasilenko N, Moshynskyy I, Zakhartchouk A. SARS coronavirus protein 7a interacts with human Ap4A-hydrolase. Virol J 2010; 7:31. [PMID: 20144233 PMCID: PMC2831879 DOI: 10.1186/1743-422x-7-31] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 02/09/2010] [Indexed: 12/12/2022] Open
Abstract
The SARS coronavirus (SARS-CoV) open reading frame 7a (ORF 7a) encodes a 122 amino acid accessory protein. It has no significant sequence homology with any other known proteins. The 7a protein is present in the virus particle and has been shown to interact with several host proteins; thereby implicating it as being involved in several pathogenic processes including apoptosis, inhibition of cellular protein synthesis, and activation of p38 mitogen activated protein kinase. In this study we present data demonstrating that the SARS-CoV 7a protein interacts with human Ap4A-hydrolase (asymmetrical diadenosine tetraphosphate hydrolase, EC 3.6.1.17). Ap4A-hydrolase is responsible for metabolizing the "allarmone" nucleotide Ap4A and therefore likely involved in regulation of cell proliferation, DNA replication, RNA processing, apoptosis and DNA repair. The interaction between 7a and Ap4A-hydrolase was identified using yeast two-hybrid screening. The interaction was confirmed by co-immunoprecipitation from cultured human cells transiently expressing V5-His tagged 7a and HA tagged Ap4A-hydrolase. Human tissue culture cells transiently expressing 7a and Ap4A-hydrolase tagged with EGFP and Ds-Red2 respectively show these proteins co-localize in the cytoplasm.
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Affiliation(s)
- Natalia Vasilenko
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK S7N5E3, Canada
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22
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Abstract
Coronavirus genomes are single-stranded positive-sense RNA that are transcribed into a nested set of 3′ coterminal subgenomic RNAs for gene expression. Members of the Coronaviridae express canonical polymerase genes, as well as structural genes, including S, E, M, and N, but also express a highly divergent set of accessory genes whose open reading frames are interspersed among the structural genes within the 3′ one-third of the viral genome. The accessory genes are thought to contain “luxury” functions that are often not required for in-vitro virus replication. The severe acute respiratory syndrome coronavirus (SARS-CoV) expresses eight such accessory genes (ORF3a, -3b, -6, -7a, -7b, -8a, -8b, and -9b), the most of any known coronavirus. This chapter will review our current knowledge of expression, structure, and function of each of the SARS-CoV accessory genes.
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Affiliation(s)
- Sunil K. Lal
- Engineering & Biotechnology, International Centre for Genetic, Aruna Asaf Ali Marg, New Delhi, 110067 India
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23
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Pan J, Peng X, Gao Y, Li Z, Lu X, Chen Y, Ishaq M, Liu D, DeDiego ML, Enjuanes L, Guo D. Genome-wide analysis of protein-protein interactions and involvement of viral proteins in SARS-CoV replication. PLoS One 2008; 3:e3299. [PMID: 18827877 PMCID: PMC2553179 DOI: 10.1371/journal.pone.0003299] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 09/09/2008] [Indexed: 02/05/2023] Open
Abstract
Analyses of viral protein-protein interactions are an important step to understand viral protein functions and their underlying molecular mechanisms. In this study, we adopted a mammalian two-hybrid system to screen the genome-wide intraviral protein-protein interactions of SARS coronavirus (SARS-CoV) and therefrom revealed a number of novel interactions which could be partly confirmed by in vitro biochemical assays. Three pairs of the interactions identified were detected in both directions: non-structural protein (nsp) 10 and nsp14, nsp10 and nsp16, and nsp7 and nsp8. The interactions between the multifunctional nsp10 and nsp14 or nsp16, which are the unique proteins found in the members of Nidovirales with large RNA genomes including coronaviruses and toroviruses, may have important implication for the mechanisms of replication/transcription complex assembly and functions of these viruses. Using a SARS-CoV replicon expressing a luciferase reporter under the control of a transcription regulating sequence, it has been shown that several viral proteins (N, X and SUD domains of nsp3, and nsp12) provided in trans stimulated the replicon reporter activity, indicating that these proteins may regulate coronavirus replication and transcription. Collectively, our findings provide a basis and platform for further characterization of the functions and mechanisms of coronavirus proteins.
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Affiliation(s)
- Ji'An Pan
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Xiaoxue Peng
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Yajing Gao
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Zhilin Li
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Xiaolu Lu
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Yingzhao Chen
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Musarat Ishaq
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Dan Liu
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
| | - Marta L. DeDiego
- Centro Nacional de Biotecnología, CSIC, Department of Molecular and Cell Biology, Campus Universidad Autónoma, Madrid, Spain
| | - Luis Enjuanes
- Centro Nacional de Biotecnología, CSIC, Department of Molecular and Cell Biology, Campus Universidad Autónoma, Madrid, Spain
| | - Deyin Guo
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China
- * E-mail:
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24
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Dutta S, Tan YJ. Structural and functional characterization of human SGT and its interaction with Vpu of the human immunodeficiency virus type 1. Biochemistry 2008; 47:10123-31. [PMID: 18759457 DOI: 10.1021/bi800758a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The small glutamine-rich tetratricopeptide repeat protein (SGT) belongs to a family of cochaperones that interacts with both Hsp70 and Hsp90 via the so-called TPR domain. Here, we present the crystal structure of the TPR domain of human SGT (SGT-TPR), which shows that it contains typical features found in the structures of other TPR domains. Previous studies show that full-length SGT can bind to both Vpu and Gag of human immunodeficiency virus type 1 (HIV-1) and the overexpression of SGT in cells reduces the efficiency of HIV-1 particle release. We show that SGT-TPR can bind Vpu and reduce the amount of HIV-1 p24, which is the viral capsid, secreted from cells transfected with the HIV-1 proviral construct, albeit at a lower efficiency than full-length SGT. This indicates that the TPR domain of SGT is sufficient for the inhibition of HIV-1 particle release but the N- and/or C-terminus also have some contributions. The SGT binding site in Vpu was also identified by using peptide array and confirmed by GST pull-down assay.
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Affiliation(s)
- Sujit Dutta
- Collaborative Antiviral Research Group, Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 61 Biopolis Drive, Singapore 138673
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25
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Dutta S, Kotaka M, Tan YJ. Expression, purification and preliminary crystallographic analysis of recombinant human small glutamine-rich tetratricopeptide-repeat protein. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:602-4. [PMID: 18607086 DOI: 10.1107/s1744309108009299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 04/06/2008] [Indexed: 11/11/2022]
Abstract
Human small glutamine-rich tetratricopeptide-repeat protein (hSGT) is a 35 kDa protein implicated in a number of biological processes that include apoptosis, cell division and intracellular cell transport. The tetratricopeptide-repeat (TPR) domain of hSGT has been cloned and expressed in Escherichia coli and purified. Here, the crystallization and preliminary diffraction analysis of the TPR domain of hSGT is reported. X-ray diffraction data were processed to a resolution of 2.4 A. Crystals belong to space group P2(1)2(1)2, with unit-cell parameters a = 67.82, b = 81.93, c = 55.92 A, alpha = beta = gamma = 90 degrees .
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Affiliation(s)
- Sujit Dutta
- Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Singapore 138673, Singapore
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26
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Worrall LJ, Wear MA, Page AP, Walkinshaw MD. Cloning, purification and characterization of the Caenorhabditis elegans small glutamine-rich tetratricopeptide repeat-containing protein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:496-503. [DOI: 10.1016/j.bbapap.2007.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 11/27/2007] [Accepted: 12/10/2007] [Indexed: 11/15/2022]
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27
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Buchanan G, Ricciardelli C, Harris JM, Prescott J, Yu ZCL, Jia L, Butler LM, Marshall VR, Scher HI, Gerald WL, Coetzee GA, Tilley WD. Control of androgen receptor signaling in prostate cancer by the cochaperone small glutamine rich tetratricopeptide repeat containing protein alpha. Cancer Res 2007; 67:10087-96. [PMID: 17942943 DOI: 10.1158/0008-5472.can-07-1646] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the androgen receptor (AR) is accepted as the major determinant of prostate cancer cell survival throughout disease progression, it is currently unclear how the receptor sustains genomic signaling under conditions of systemic androgen ablation. Here, we show that the evolutionarily conserved Hsp70/Hsp90 cochaperone, small glutamine-rich tetratricopeptide repeat containing protein alpha (alphaSGT), interacts with the hinge region of the human AR in yeast and mammalian cells. Overexpression and RNA interference revealed that alphaSGT acts to (a) promote cytoplasmic compartmentalization of the AR, thereby silencing the receptors basal/ligand-independent transcriptional activity, (b) regulate the sensitivity of receptor signaling by androgens, and (c) limit the capacity of noncanonical ligands to induce AR agonist activity. Immunofluorescence, coactivator, and chromatin immunoprecipitation analyses strongly suggest that these effects of alphaSGT on AR function are mediated by interaction in the cytoplasm and are distinct from the receptors response to classic coregulators. Quantitative immunohistochemical analysis of alphaSGT and AR levels in a cohort of 32 primary and 64 metastatic human prostate cancers revealed dysregulation in the level of both proteins during disease progression. The significantly higher AR/alphaSGT ratio in metastatic samples is consistent with the sensitization of prostate tumor cells to androgen signaling with disease progression, particularly in a low-hormone environment. These findings implicate alphaSGT as a molecular rheostat of in vivo signaling competence by the AR, and provide new insight into the determinants of androgen sensitivity during prostate cancer progression.
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Affiliation(s)
- Grant Buchanan
- Dame Roma Mitchell Cancer Research Laboratories, School of Medicine, The University of Adelaide/Hanson Institute, Adelaide, South Australia, Australia.
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28
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Narayanan K, Huang C, Makino S. SARS coronavirus accessory proteins. Virus Res 2007; 133:113-21. [PMID: 18045721 PMCID: PMC2720074 DOI: 10.1016/j.virusres.2007.10.009] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 09/12/2007] [Accepted: 10/10/2007] [Indexed: 12/19/2022]
Abstract
The emergence of the severe acute respiratory syndrome coronavirus (SARS-CoV) has led to a renewed interest in studying the role of accessory proteins in regulating coronavirus infections in the natural host. A significant body of evidence has accumulated in the area of SARS-CoV and host interactions that indicate that the accessory proteins might play an important role in modulating the host response to virus infection and thereby, contribute to pathogenesis. In this review, we have compiled the current knowledge about SARS-CoV accessory proteins, obtained from studies in cell culture systems, reverse genetics and animal models, to shed some light into the possible role of these proteins in the propagation and virulence of SARS-CoV in its natural host. We conclude by providing some questions for future studies that will greatly advance our knowledge about the biological significance and contributions of the accessory proteins in the development of SARS in humans.
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Affiliation(s)
- Krishna Narayanan
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555-1019, United States.
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29
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Severe acute respiratory syndrome coronavirus as an agent of emerging and reemerging infection. Clin Microbiol Rev 2007; 20:660-94. [PMID: 17934078 DOI: 10.1128/cmr.00023-07] [Citation(s) in RCA: 657] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Before the emergence of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) in 2003, only 12 other animal or human coronaviruses were known. The discovery of this virus was soon followed by the discovery of the civet and bat SARS-CoV and the human coronaviruses NL63 and HKU1. Surveillance of coronaviruses in many animal species has increased the number on the list of coronaviruses to at least 36. The explosive nature of the first SARS epidemic, the high mortality, its transient reemergence a year later, and economic disruptions led to a rush on research of the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the virus and the disease. This research resulted in over 4,000 publications, only some of the most representative works of which could be reviewed in this article. The marked increase in the understanding of the virus and the disease within such a short time has allowed the development of diagnostic tests, animal models, antivirals, vaccines, and epidemiological and infection control measures, which could prove to be useful in randomized control trials if SARS should return. The findings that horseshoe bats are the natural reservoir for SARS-CoV-like virus and that civets are the amplification host highlight the importance of wildlife and biosecurity in farms and wet markets, which can serve as the source and amplification centers for emerging infections.
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30
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Severe acute respiratory syndrome coronavirus gene 7 products contribute to virus-induced apoptosis. J Virol 2007. [PMID: 17686858 DOI: 10.1128/jvi.01266‐07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The proteins encoded by gene 7 of the severe acute respiratory syndrome coronavirus (SARS-CoV) have been demonstrated to have proapoptotic activity when expressed from cDNA but appear to be dispensable for virus replication. Recombinant SARS-CoVs bearing deletions in gene 7 were used to assess the contribution of gene 7 to virus replication and apoptosis in several transformed cell lines, as well as to replication and pathogenesis in golden Syrian hamsters. Deletion of gene 7 had no effect on SARS-CoV replication in transformed cell lines, nor did it alter the induction of early apoptosis markers such as annexin V binding and activation of caspase 3. However, viruses with gene 7 disruptions were not as efficient as wild-type virus in inducing DNA fragmentation, as judged by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining, indicating that the gene 7 products do contribute to virus-induced apoptosis. Disruption of gene 7 did not affect virus replication or morbidity in golden Syrian hamsters, suggesting that the gene 7 products are not required for acute infection in vivo. The data indicate that open reading frames 7a and 7b contribute to but are not solely responsible for the apoptosis seen in SARS-CoV-infected cells.
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31
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Schaecher SR, Touchette E, Schriewer J, Buller RM, Pekosz A. Severe acute respiratory syndrome coronavirus gene 7 products contribute to virus-induced apoptosis. J Virol 2007; 81:11054-68. [PMID: 17686858 PMCID: PMC2045523 DOI: 10.1128/jvi.01266-07] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The proteins encoded by gene 7 of the severe acute respiratory syndrome coronavirus (SARS-CoV) have been demonstrated to have proapoptotic activity when expressed from cDNA but appear to be dispensable for virus replication. Recombinant SARS-CoVs bearing deletions in gene 7 were used to assess the contribution of gene 7 to virus replication and apoptosis in several transformed cell lines, as well as to replication and pathogenesis in golden Syrian hamsters. Deletion of gene 7 had no effect on SARS-CoV replication in transformed cell lines, nor did it alter the induction of early apoptosis markers such as annexin V binding and activation of caspase 3. However, viruses with gene 7 disruptions were not as efficient as wild-type virus in inducing DNA fragmentation, as judged by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining, indicating that the gene 7 products do contribute to virus-induced apoptosis. Disruption of gene 7 did not affect virus replication or morbidity in golden Syrian hamsters, suggesting that the gene 7 products are not required for acute infection in vivo. The data indicate that open reading frames 7a and 7b contribute to but are not solely responsible for the apoptosis seen in SARS-CoV-infected cells.
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Affiliation(s)
- Scott R Schaecher
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., Campus Box 8230, St. Louis, Missouri 63110, USA
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32
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Chan CM, Ma CW, Chan WY, Chan HYE. The SARS-Coronavirus Membrane protein induces apoptosis through modulating the Akt survival pathway. Arch Biochem Biophys 2007; 459:197-207. [PMID: 17306213 PMCID: PMC7094499 DOI: 10.1016/j.abb.2007.01.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 12/20/2006] [Accepted: 01/05/2007] [Indexed: 01/12/2023]
Abstract
A number of viral gene products are capable of triggering apoptotic cell death through interfering with cellular signaling cascades, including the Akt kinase pathway. In this study, the pro-apoptotic role of the SARS-CoV Membrane (M) structural protein is described. We found that the SARS-CoV M protein induced apoptosis in both HEK293T cells and transgenic Drosophila. We further showed that M protein-induced apoptosis involved mitochondrial release of cytochrome c protein, and could be suppressed by caspase inhibitors. Over-expression of M caused a dominant rough-eye phenotype in adult Drosophila. By performing a forward genetic modifier screen, we identified phosphoinositide-dependent kinase-1 (PDK-1) as a dominant suppressor of M-induced apoptotic cell death. Both PDK-1 and Akt kinases play essential roles in the cell survival signaling pathway. Altogether, our data show that SARS-CoV M protein induces apoptosis through the modulation of the cellular Akt pro-survival pathway and mitochondrial cytochrome c release.
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Affiliation(s)
- Chak-Ming Chan
- Laboratory of Drosophila Research, Department of Biochemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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33
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Hänel K, Willbold D. SARS-CoV accessory protein 7a directly interacts with human LFA-1. Biol Chem 2007; 388:1325-32. [DOI: 10.1515/bc.2007.157] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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34
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Kanzawa N, Nishigaki K, Hayashi T, Ishii Y, Furukawa S, Niiro A, Yasui F, Kohara M, Morita K, Matsushima K, Le MQ, Masuda T, Kannagi M. Augmentation of chemokine production by severe acute respiratory syndrome coronavirus 3a/X1 and 7a/X4 proteins through NF-kappaB activation. FEBS Lett 2006; 580:6807-12. [PMID: 17141229 PMCID: PMC7094718 DOI: 10.1016/j.febslet.2006.11.046] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 11/06/2006] [Accepted: 11/16/2006] [Indexed: 01/20/2023]
Abstract
Severe acute respiratory syndrome (SARS) is characterized by rapidly progressing respiratory failure resembling acute/adult respiratory distress syndrome (ARDS) associated with uncontrolled inflammatory responses. Here, we demonstrated that, among five accessory proteins of SARS coronavirus (SARS-CoV) tested, 3a/X1 and 7a/X4 were capable of activating nuclear factor kappa B (NF-kappaB) and c-Jun N-terminal kinase (JNK), and significantly enhanced interleukin 8 (IL-8) promoter activity. Furthermore, 3a/X1 and 7a/X4 expression in A549 cells enhanced production of inflammatory chemokines that were known to be up-regulated in SARS-CoV infection. Our results suggest potential involvement of 3a/X1 and 7a/X4 proteins in the pathological inflammatory responses in SARS.
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Affiliation(s)
- Noriyuki Kanzawa
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Kazuo Nishigaki
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Takaya Hayashi
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Yuichi Ishii
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Souichi Furukawa
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Ayako Niiro
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Fumihiko Yasui
- Department of Microbiology and Cell Biology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan
| | - Michinori Kohara
- Department of Microbiology and Cell Biology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan
| | - Kouichi Morita
- Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Kouji Matsushima
- Department of Molecular Preventive Medicine, School of Medicine, The University of Tokyo, 113-0033, Japan
| | - Mai Quynh Le
- Department of Virology, National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam
| | - Takao Masuda
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Mari Kannagi
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
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35
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Tan YJ, Lim SG, Hong W. Understanding the accessory viral proteins unique to the severe acute respiratory syndrome (SARS) coronavirus. Antiviral Res 2006; 72:78-88. [PMID: 16820226 PMCID: PMC7114237 DOI: 10.1016/j.antiviral.2006.05.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 04/29/2006] [Accepted: 05/15/2006] [Indexed: 12/14/2022]
Abstract
A novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), infected humans in Guangdong, China, in November 2002 and the subsequent efficient human-to-human transmissions of this virus caused profound disturbances in over 30 countries worldwide in 2003. Eventually, this epidemic was controlled by isolation and there has been no human infection reported since January 2004. However, research on different aspects of the SARS-CoV is not waning, as it is not known if this virus will re-emerge, especially since its origins and potential reservoir(s) are unresolved. The SARS-CoV genome is nearly 30 kb in length and contains 14 potential open reading frames (ORFs). Some of these ORFs encode for genes that are homologous to proteins found in all known coronaviruses, namely the replicase genes (ORFs 1a and 1b) and the four structural proteins: nucleocapsid, spike, membrane and envelope, and these proteins are expected to be essential for the replication of the virus. The remaining eight ORFs encodes for accessory proteins, varying in length from 39 to 274 amino acids, which are unique to SARS-CoV. This review will summarize the expeditious research on these accessory viral proteins in three major areas: (i) the detection of antibodies against accessory proteins in the serum of infected patients, (ii) the expression, processing and cellular localization of the accessory proteins, and (iii) the effects of the accessory proteins on cellular functions. These in-depth molecular and biochemical characterizations of the SARS-CoV accessory proteins, which have no homologues in other coronaviruses, may offer clues as to why the SARS-CoV causes such a severe and rapid attack in humans, while other coronaviruses that infect humans seem to be more forgiving.
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Affiliation(s)
- Yee-Joo Tan
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore.
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