1
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Wąchalska M, Riepe C, Ślusarz MJ, Graul M, Borowski LS, Qiao W, Foltyńska M, Carette JE, Bieńkowska-Szewczyk K, Szczesny RJ, Kopito RR, Lipińska AD. The herpesvirus UL49.5 protein hijacks a cellular C-degron pathway to drive TAP transporter degradation. Proc Natl Acad Sci U S A 2024; 121:e2309841121. [PMID: 38442151 PMCID: PMC10945846 DOI: 10.1073/pnas.2309841121] [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: 06/12/2023] [Accepted: 12/29/2023] [Indexed: 03/07/2024] Open
Abstract
The transporter associated with antigen processing (TAP) is a key player in the major histocompatibility class I-restricted antigen presentation and an attractive target for immune evasion by viruses. Bovine herpesvirus 1 impairs TAP-dependent antigenic peptide transport through a two-pronged mechanism in which binding of the UL49.5 gene product to TAP both inhibits peptide transport and triggers its proteasomal degradation. How UL49.5 promotes TAP degradation has, so far, remained unknown. Here, we use high-content siRNA and genome-wide CRISPR-Cas9 screening to identify CLR2KLHDC3 as the E3 ligase responsible for UL49.5-triggered TAP disposal. We propose that the C terminus of UL49.5 mimics a C-end rule degron that recruits the E3 to TAP and engages the cullin-RING E3 ligase in endoplasmic reticulum-associated degradation.
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Affiliation(s)
- Magda Wąchalska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk80-307, Poland
- Department of Biology, Stanford University, Stanford, CA94305
| | - Celeste Riepe
- Department of Biology, Stanford University, Stanford, CA94305
| | - Magdalena J. Ślusarz
- Department of Theoretical Chemistry, Faculty of Chemistry, University of Gdańsk, Gdańsk80-308, Poland
| | - Małgorzata Graul
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk80-307, Poland
| | - Lukasz S. Borowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw02-106, Poland
| | - Wenjie Qiao
- Department of Microbiology and Immunology, Stanford University, Stanford, CA94305
| | - Michalina Foltyńska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk80-307, Poland
| | - Jan E. Carette
- Department of Microbiology and Immunology, Stanford University, Stanford, CA94305
| | - Krystyna Bieńkowska-Szewczyk
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk80-307, Poland
| | - Roman J. Szczesny
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw02-106, Poland
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA94305
| | - Andrea D. Lipińska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk80-307, Poland
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2
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Wąhalska M, Riepe C, Ślusarz MJ, Graul M, Borowski LS, Qiao W, Foltynska M, Carette JE, Bieńkowska-Szewczyk K, Szczesny RJ, Kopito RR, Lipińska AD. The herpesvirus UL49.5 protein hijacks a cellular C-degron pathway to drive TAP transporter degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559663. [PMID: 37808699 PMCID: PMC10557673 DOI: 10.1101/2023.09.27.559663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The transporter associated with antigen processing (TAP) is a key player in the MHC class I-restricted antigen presentation and an attractive target for immune evasion by viruses. Bovine herpesvirus 1 (BoHV-1) impairs TAP-dependent antigenic peptide transport through a two-pronged mechanism in which binding of the UL49.5 gene product to TAP both inhibits peptide transport and promotes its proteasomal degradation. How UL49.5 promotes TAP degradation is unknown. Here, we use high-content siRNA and genome-wide CRISPR-Cas9 screening to identify CLR2KLHDC3 as the E3 ligase responsible for UL49.5-triggered TAP disposal in human cells. We propose that the C-terminus of UL49.5 mimics a C-end rule degron that recruits the E3 to TAP and engages the CRL2 E3 in ER-associated degradation.
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Affiliation(s)
- Magda Wąhalska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdańsk, Poland
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Celeste Riepe
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Magdalena J. Ślusarz
- Department of Theoretical Chemistry, Faculty of Chemistry, University of Gdańsk, 80-308 Gdańsk, Poland
| | - Małgorzata Graul
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdańsk, Poland
| | - Lukasz S. Borowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
| | - Wenjie Qiao
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Michalina Foltynska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdańsk, Poland
| | - Jan E. Carette
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Krystyna Bieńkowska-Szewczyk
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdańsk, Poland
| | - Roman J. Szczesny
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Andrea D. Lipińska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdańsk, Poland
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3
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Kroemer G, Galassi C, Zitvogel L, Galluzzi L. Immunogenic cell stress and death. Nat Immunol 2022; 23:487-500. [PMID: 35145297 DOI: 10.1038/s41590-022-01132-2] [Citation(s) in RCA: 441] [Impact Index Per Article: 220.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/07/2022] [Indexed: 12/20/2022]
Abstract
Dying mammalian cells emit numerous signals that interact with the host to dictate the immunological correlates of cellular stress and death. In the absence of reactive antigenic determinants (which is generally the case for healthy cells), such signals may drive inflammation but cannot engage adaptive immunity. Conversely, when cells exhibit sufficient antigenicity, as in the case of infected or malignant cells, their death can culminate with adaptive immune responses that are executed by cytotoxic T lymphocytes and elicit immunological memory. Suggesting a key role for immunogenic cell death (ICD) in immunosurveillance, both pathogens and cancer cells evolved strategies to prevent the recognition of cell death as immunogenic. Intriguingly, normal cells succumbing to conditions that promote the formation of post-translational neoantigens (for example, oxidative stress) can also drive at least some degree of antigen-specific immunity, pointing to a novel implication of ICD in the etiology of non-infectious, non-malignant disorders linked to autoreactivity.
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Affiliation(s)
- Guido Kroemer
- Equipe labellisée par la Ligue contre le cancer, Centre de Recherche des Cordeliers, INSERM U1138, Sorbonne Université, Université de Paris, Institut Universitaire de France, Paris, France. .,Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, Villejuif, France. .,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
| | - Claudia Galassi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
| | - Laurence Zitvogel
- Gustave Roussy Comprehensive Cancer Institute, Villejuif, France.,Université Paris Saclay, Faculty of Medicine, Le Kremlin-Bicêtre, France.,INSERM U1015, Villejuif, France.,Equipe labellisée par la Ligue contre le cancer, Villejuif, France.,Center of Clinical Investigations in Biotherapies of Cancer (CICBT) BIOTHERIS, Villejuif, France
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA. .,Sandra and Edward Meyer Cancer Center, New York, NY, USA. .,Caryl and Israel Englander Institute for Precision Medicine, New York, NY, USA.
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4
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Wąchalska M, Graul M, Praest P, Luteijn RD, Babnis AW, Wiertz EJHJ, Bieńkowska-Szewczyk K, Lipińska AD. Fluorescent TAP as a Platform for Virus-Induced Degradation of the Antigenic Peptide Transporter. Cells 2019; 8:cells8121590. [PMID: 31817841 PMCID: PMC6952996 DOI: 10.3390/cells8121590] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 01/20/2023] Open
Abstract
Transporter associated with antigen processing (TAP), a key player in the major histocompatibility complex class I-restricted antigen presentation, makes an attractive target for viruses that aim to escape the immune system. Mechanisms of TAP inhibition vary among virus species. Bovine herpesvirus 1 (BoHV-1) is unique in its ability to target TAP for proteasomal degradation following conformational arrest by the UL49.5 gene product. The exact mechanism of TAP removal still requires elucidation. For this purpose, a TAP-GFP (green fluorescent protein) fusion protein is instrumental, yet GFP-tagging may affect UL49.5-induced degradation. Therefore, we constructed a series of TAP-GFP variants using various linkers to obtain an optimal cellular fluorescent TAP platform. Mel JuSo (MJS) cells with CRISPR/Cas9 TAP1 or TAP2 knockouts were reconstituted with TAP-GFP constructs. Our results point towards a critical role of GFP localization on fluorescent properties of the fusion proteins and, in concert with the type of a linker, on the susceptibility to virally-induced inhibition and degradation. The fluorescent TAP platform was also used to re-evaluate TAP stability in the presence of other known viral TAP inhibitors, among which only UL49.5 was able to reduce TAP levels. Finally, we provide evidence that BoHV-1 UL49.5-induced TAP removal is p97-dependent, which indicates its degradation via endoplasmic reticulum-associated degradation (ERAD).
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 2/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 2/metabolism
- ATP Binding Cassette Transporter, Subfamily B, Member 3/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 3/metabolism
- Acetanilides/pharmacology
- Animals
- Antigen Presentation/drug effects
- Antigen Presentation/genetics
- Benzothiazoles/pharmacology
- Cattle
- Cell Line
- Cell Line, Tumor
- Flow Cytometry
- Fluorescent Antibody Technique
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- HEK293 Cells
- Herpesvirus 1, Bovine/pathogenicity
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/metabolism
- Humans
- Immunoblotting
- Immunoprecipitation
- Plasmids/genetics
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Affiliation(s)
- Magda Wąchalska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Abrahama 58, 80–307 Gdańsk, Poland; (M.W.); (M.G.); (A.W.B.); (K.B.-S.)
| | - Małgorzata Graul
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Abrahama 58, 80–307 Gdańsk, Poland; (M.W.); (M.G.); (A.W.B.); (K.B.-S.)
| | - Patrique Praest
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands; (P.P.); (R.D.L.); (E.J.H.J.W.)
| | - Rutger D. Luteijn
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands; (P.P.); (R.D.L.); (E.J.H.J.W.)
| | - Aleksandra W. Babnis
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Abrahama 58, 80–307 Gdańsk, Poland; (M.W.); (M.G.); (A.W.B.); (K.B.-S.)
| | - Emmanuel J. H. J. Wiertz
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands; (P.P.); (R.D.L.); (E.J.H.J.W.)
| | - Krystyna Bieńkowska-Szewczyk
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Abrahama 58, 80–307 Gdańsk, Poland; (M.W.); (M.G.); (A.W.B.); (K.B.-S.)
| | - Andrea D. Lipińska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Abrahama 58, 80–307 Gdańsk, Poland; (M.W.); (M.G.); (A.W.B.); (K.B.-S.)
- Correspondence: ; Tel.: +48-585236383
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5
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Bagchi P. Endoplasmic reticulum in viral infection. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 350:265-284. [PMID: 32138901 DOI: 10.1016/bs.ircmb.2019.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Virus exploits host cellular machinery to replicate and form new viral progeny and endoplasmic reticulum (ER) plays central role in the interplay between virus and host cell. Here I will discuss how cellular functions of ER being utilized by viruses from different families during different stages of pathogenesis. Flow of knowledge related to this area of research based on interdisciplinary approach, using biochemical and cell biological assays coupled with advanced microscopy strategies, is pushing our understanding of the virus-ER interaction during infection to the next level.
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Affiliation(s)
- Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States.
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6
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Liu H, Mintern JD, Villadangos JA. MARCH ligases in immunity. Curr Opin Immunol 2019; 58:38-43. [PMID: 31063934 DOI: 10.1016/j.coi.2019.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/06/2019] [Indexed: 01/13/2023]
Abstract
Membrane associated RING-CH (MARCH) ubiquitin ligases control the stability, trafficking and function of important immunoreceptors, including MHC molecules and costimulatory molecule CD86. Regulation of the critical antigen presenting molecule MHC II by MARCH1 and the control of MARCH1 expression by inflammatory stimuli is a key step in the function of antigen presenting cells. MHC II ubiquitination by MARCH8 and CD83 plays a critical role in T cell thymic selection. Recent studies reveal new immune functions of MARCH ligases in innate immunity, regulation of FcγR expression and Treg development. In addition, we review the importance of MARCH in immunomodulation at the host-pathogen interface. Both bacterial and viral pathogens manipulate MARCH function, while MARCH ligases act as an important host anti-viral defence mechanism. Here, we review the role of membrane-bound MARCH ligases in immune function and provide an update on new substrates and concepts. Understanding the increasingly complex roles of MARCH E3 ligases will be vital to develop therapeutic strategies for their regulation.
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Affiliation(s)
- Haiyin Liu
- The Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Justine D Mintern
- The Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Jose A Villadangos
- The Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia; The Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Parkville, Victoria 3010, Australia.
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7
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Molluscum contagiosum virus MC80 sabotages MHC-I antigen presentation by targeting tapasin for ER-associated degradation. PLoS Pathog 2019; 15:e1007711. [PMID: 31034515 PMCID: PMC6508746 DOI: 10.1371/journal.ppat.1007711] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 05/09/2019] [Accepted: 03/18/2019] [Indexed: 11/19/2022] Open
Abstract
The human specific poxvirus molluscum contagiosum virus (MCV) produces skin lesions that can persist with minimal inflammation, suggesting that the virus has developed robust immune evasion strategies. However, investigations into the underlying mechanisms of MCV pathogenesis have been hindered by the lack of a model system to propagate the virus. Herein we demonstrate that MCV-encoded MC80 can disrupt MHC-I antigen presentation in human and mouse cells. MC80 shares moderate sequence-similarity with MHC-I and we find that it associates with components of the peptide-loading complex. Expression of MC80 results in ER-retention of host MHC-I and thereby reduced cell surface presentation. MC80 accomplishes this by engaging tapasin via its luminal domain, targeting it for ubiquitination and ER-associated degradation in a process dependent on the MC80 transmembrane region and cytoplasmic tail. Tapasin degradation is accompanied by a loss of TAP, which limits MHC-I access to cytosolic peptides. Our findings reveal a unique mechanism by which MCV undermines adaptive immune surveillance.
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8
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Wang X, Piersma SJ, Nelson CA, Dai YN, Christensen T, Lazear E, Yang L, Sluijter M, van Hall T, Hansen TH, Yokoyama WM, Fremont DH. A herpesvirus encoded Qa-1 mimic inhibits natural killer cell cytotoxicity through CD94/NKG2A receptor engagement. eLife 2018; 7:38667. [PMID: 30575523 PMCID: PMC6320069 DOI: 10.7554/elife.38667] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 12/20/2018] [Indexed: 11/13/2022] Open
Abstract
A recurrent theme in viral immune evasion is the sabotage of MHC-I antigen presentation, which brings virus the concomitant issue of ‘missing-self’ recognition by NK cells that use inhibitory receptors to detect surface MHC-I proteins. Here, we report that rodent herpesvirus Peru (RHVP) encodes a Qa-1 like protein (pQa-1) via RNA splicing to counteract NK activation. While pQa-1 surface expression is stabilized by the same canonical peptides presented by murine Qa-1, pQa-1 is GPI-anchored and resistant to the activity of RHVP pK3, a ubiquitin ligase that targets MHC-I for degradation. pQa-1 tetramer staining indicates that it recognizes CD94/NKG2A receptors. Consistently, pQa-1 selectively inhibits NKG2A+ NK cells and expression of pQa-1 can protect tumor cells from NK control in vivo. Collectively, these findings reveal an innovative NK evasion strategy wherein RHVP encodes a modified Qa-1 mimic refractory to MHC-I sabotage and capable of specifically engaging inhibitory receptors to circumvent NK activation.
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Affiliation(s)
- Xiaoli Wang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Sytse J Piersma
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, United States
| | - Christopher A Nelson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Ya-Nan Dai
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Ted Christensen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Eric Lazear
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Liping Yang
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, United States
| | - Marjolein Sluijter
- Department of Medical Oncology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Thorbald van Hall
- Department of Medical Oncology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Ted H Hansen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Wayne M Yokoyama
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States.,Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, United States
| | - Daved H Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, United States
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9
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Ravindran MS, Bagchi P, Cunningham CN, Tsai B. Opportunistic intruders: how viruses orchestrate ER functions to infect cells. Nat Rev Microbiol 2016; 14:407-420. [PMID: 27265768 PMCID: PMC5272919 DOI: 10.1038/nrmicro.2016.60] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Viruses exploit the functions of the endoplasmic reticulum (ER) to promote both early and later stages of their life cycle, including entry, translation, replication, assembly, morphogenesis and egress. This observation reveals a shared principle that underlies virus–host cell relationships. Viral entry often requires disassembly of the incoming virus particle. This is best exemplified in the case of polyomavirus entry, in which ER-associated machineries are hijacked to disassemble the virus and promote entry to the cytosol en route to the nucleus. Many enveloped viruses, such as HIV and influenza virus, co-opt the ER-associated protein biosynthetic machinery to translate their genome and produce structural proteins that are necessary for the formation of virus particles and non-structural proteins that are essential during genome replication. Replication of the viral genome, particularly for positive-sense RNA ((+)RNA) viruses including hepatitis C virus (HCV), dengue virus (DENV) and West Nile virus (WNV), occurs in virus-induced membranous structures that are most often derived from the ER. The formation of these structures requires morphological changes to the ER membrane, involving membrane rearrangements that are induced by viral non-structural proteins that are targeted to the ER. As virus assembly is often coupled to genome replication, the assembly process frequently relies on the ER membrane. This strategy is seen for both RNA and DNA viruses. Morphogenesis of assembled virus particles can also take advantage of the ER. This is best observed in the non-enveloped rotavirus, for which a transient enveloped intermediate is converted to the mature and infectious particle in the lumen of the ER. After maturation in the ER, progeny virus particles egress the host through the ER-dependent secretory pathway, which provides a physical conduit to the extracellular environment. The overall observations that the ER actively promotes all steps of viral infection have therapeutic implications. The development of chemical inhibitors of selective ER-associated components is emerging as a potential avenue of antiviral therapy, provided that these inhibitors have minimal toxicity to the host cell.
Many host structures are vital for viral infection and the endoplasmic reticulum (ER), in particular, is essential. In this Review, Tsai and colleagues highlight examples of subversion of the ER by diverse viruses to promote all stages of their life cycle, from entry to egress. Viruses subvert the functions of their host cells to replicate and form new viral progeny. The endoplasmic reticulum (ER) has been identified as a central organelle that governs the intracellular interplay between viruses and hosts. In this Review, we analyse how viruses from vastly different families converge on this unique intracellular organelle during infection, co-opting some of the endogenous functions of the ER to promote distinct steps of the viral life cycle from entry and replication to assembly and egress. The ER can act as the common denominator during infection for diverse virus families, thereby providing a shared principle that underlies the apparent complexity of relationships between viruses and host cells. As a plethora of information illuminating the molecular and cellular basis of virus–ER interactions has become available, these insights may lead to the development of crucial therapeutic agents.
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Affiliation(s)
- Madhu Sudhan Ravindran
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Corey Nathaniel Cunningham
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
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10
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Kaposi's sarcoma-associated herpesvirus K3 and K5 ubiquitin E3 ligases have stage-specific immune evasion roles during lytic replication. J Virol 2014; 88:9335-49. [PMID: 24899205 DOI: 10.1128/jvi.00873-14] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
UNLABELLED The downregulation of immune synapse components such as major histocompatibility complex class I (MHC-I) and ICAM-1 is a common viral immune evasion strategy that protects infected cells from targeted elimination by cytolytic effector functions of the immune system. Kaposi's sarcoma-associated herpesvirus (KSHV) encodes two membrane-bound ubiquitin E3 ligases, called K3 and K5, which share the ability to induce internalization and degradation of MHC-I molecules. Although individual functions of K3 and K5 outside the viral genome are well characterized, their roles during the KSHV life cycle are still unclear. In this study, we individually introduced the amino acid-coding sequences of K3 or K5 into a ΔK3 ΔK5 recombinant virus, at either original or interchanged genomic positions. Recombinants harboring coding sequences within the K5 locus showed higher K3 and K5 protein expression levels and more rapid surface receptor downregulation than cognate recombinants in which coding sequences were introduced into the K3 locus. To identify infected cells undergoing K3-mediated downregulation of MHC-I, we employed a novel reporter virus, called red-green-blue-BAC16 (RGB-BAC16), which was engineered to harbor three fluorescent protein expression cassettes: EF1α-monomeric red fluorescent protein 1 (mRFP1), polyadenylated nuclear RNA promoter (pPAN)-enhanced green fluorescent protein (EGFP), and pK8.1-monomeric blue fluorescent protein (tagBFP), marking latent, immediate early, and late viral gene expression, respectively. Analysis of RGB-derived K3 and K5 deletion mutants showed that while the K5-mediated downregulation of MHC-I was concomitant with pPAN induction, the reduction of MHC-I surface expression by K3 was evident in cells that were enriched for pPAN-driven EGFP(high) and pK8.1-driven blue fluorescent protein-positive (BFP(+)) populations. These data support the notion that immunoreceptor downregulation occurs by a sequential process wherein K5 is critical during the immediately early phase and K3 plays a significant role during later stages. IMPORTANCE Although the roles of K3 and K5 outside the viral genome are well characterized, the function of these proteins in the context of the KSHV life cycle has remained unclear, particularly in the case of K3. This study examined the relative contributions of K3 and K5 to the downregulation of MHC-I during the lytic replication of KSHV. We show that while K5 acts immediately upon entry into the lytic phase, K3-mediated downregulation of MHC-I was evident during later stages of lytic replication. The identification of distinctly timed K3 and K5 activities significantly advances our understanding of KSHV-mediated immune evasion. Crucial to this study was the development of a novel recombinant KSHV, called RGB-BAC16, which facilitated the delineation of stage-specific phenotypes.
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Calistri A, Munegato D, Carli I, Parolin C, Palù G. The ubiquitin-conjugating system: multiple roles in viral replication and infection. Cells 2014; 3:386-417. [PMID: 24805990 PMCID: PMC4092849 DOI: 10.3390/cells3020386] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 04/23/2014] [Accepted: 04/24/2014] [Indexed: 12/17/2022] Open
Abstract
Through the combined action of ubiquitinating and deubiquitinating enzymes, conjugation of ubiquitin to a target protein acts as a reversible post-translational modification functionally similar to phosphorylation. Indeed, ubiquitination is more and more recognized as a central process for the fine regulation of many cellular pathways. Due to their nature as obligate intracellular parasites, viruses rely on the most conserved host cell machineries for their own replication. Thus, it is not surprising that members from almost every viral family are challenged by ubiquitin mediated mechanisms in different steps of their life cycle and have evolved in order to by-pass or exploit the cellular ubiquitin conjugating system to maximize their chance to establish a successful infection. In this review we will present several examples of the complex interplay that links viruses and the ubiquitin conjugation machinery, with a special focus on the mechanisms evolved by the human immunodeficiency virus to escape from cellular restriction factors and to exit from infected cells.
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Affiliation(s)
- Arianna Calistri
- Department of Molecular Medicine, University of Padova, via Gabelli 63, Padova 35121, Italy.
| | - Denis Munegato
- Department of Molecular Medicine, University of Padova, via Gabelli 63, Padova 35121, Italy.
| | - Ilaria Carli
- Department of Molecular Medicine, University of Padova, via Gabelli 63, Padova 35121, Italy.
| | - Cristina Parolin
- Department of Molecular Medicine, University of Padova, via Gabelli 63, Padova 35121, Italy.
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padova, via Gabelli 63, Padova 35121, Italy.
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Abstract
Viruses have long been studied not only for their pathology and associated disease but also as model systems for understanding cellular and immunological processes. Rodent herpesvirus Peru (RHVP) is a recently characterized rhadinovirus related to murine gammaherpesvirus 68 (MHV68) and Kaposi's sarcoma-associated herpesvirus (KSHV) that establishes acute and latent infection in laboratory mice. RHVP encodes numerous unique proteins that we hypothesize might facilitate host immune evasion during infection. We report here that open reading frame (ORF) R17 encodes a high-affinity chemokine binding protein that broadly recognizes human and murine CC and C chemokines. The interaction of R17 with chemokines is generally characterized by rapid association kinetics, and in the case of CCL3, CCL4, CCL5, CCL24, and XCL1, extremely stable complexes are formed. Functionally, R17 potently inhibited CCL2-driven chemotaxis of the human monocytic cell line THP-1, CCL3-driven chemotaxis of peripheral blood mononuclear cells, and CCL2-mediated calcium flux. Our studies also reveal that R17 binds to glycosaminoglycans (GAGs) in a process dependent upon two BBXB motifs and that chemokine and GAG binding can occur simultaneously at distinct sites. Collectively, these studies suggest that R17 may play a role in RHVP immune evasion through the targeted sabotage of chemokine-mediated immune surveillance.
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Merulla J, Fasana E, Soldà T, Molinari M. Specificity and Regulation of the Endoplasmic Reticulum-Associated Degradation Machinery. Traffic 2013; 14:767-77. [DOI: 10.1111/tra.12068] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/18/2013] [Accepted: 03/23/2013] [Indexed: 02/05/2023]
Affiliation(s)
| | - Elisa Fasana
- Institute for Research in Biomedicine; Protein Folding and Quality Control; CH-6500; Bellinzona; Switzerland
| | - Tatiana Soldà
- Institute for Research in Biomedicine; Protein Folding and Quality Control; CH-6500; Bellinzona; Switzerland
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Using intein catalysis to probe the origin of major histocompatibility complex class I-presented peptides. Proc Natl Acad Sci U S A 2012; 109:16998-7003. [PMID: 23027972 DOI: 10.1073/pnas.1210271109] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
All vertebrate nucleated cells generate peptides from their expressed gene products and then display them at the cell surface bound to MHC class I molecules. This allows CD8(+) T cells to detect and eliminate abnormal cells that are synthesizing foreign proteins, e.g., from viruses or mutations. To permit the immune system to more uniformly monitor a cell's proteins, regardless of their half-life or location, it has been thought that the products of rapid degradation of the mistakes of protein synthesis (defective ribosomal products, DRiPs) preferentially contribute to the class I-presented peptides. However, using intein catalysis to generate peptide sequences exclusively by posttranslational splicing of mature proteins, we show here that presented peptides can be generated from fully folded and functional proteins. Remarkably, the presentation of peptides from two model mature proteins is just as efficient as from newly synthesized proteins subject to errors in translation or folding. These results indicate that for the constructs we have analyzed, DRiPs are not a more efficient source of class I peptides for antigen presentation than the turnover of mature functional proteins. Accordingly, our data suggest that one of the major ways the immune system evaluates the health of cells is by monitoring the breakdown products of the proteome.
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