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Wilson A, McCormick C. Reticulophagy and viral infection. Autophagy 2024. [PMID: 39394962 DOI: 10.1080/15548627.2024.2414424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 10/03/2024] [Accepted: 10/06/2024] [Indexed: 10/14/2024] Open
Abstract
All viruses are obligate intracellular parasites that use host machinery to synthesize viral proteins. In infected eukaryotes, viral secreted and transmembrane proteins are synthesized at the endoplasmic reticulum (ER). Many viruses refashion ER membranes into bespoke factories where viral products accumulate while evading host pattern recognition receptors. ER processes are tightly regulated to maintain cellular homeostasis, so viruses must either conform to ER regulatory mechanisms or subvert them to ensure efficient viral replication. Reticulophagy is a catabolic process that directs lysosomal degradation of ER components. There is accumulating evidence that reticulophagy serves as a form of antiviral defense; we call this defense "xERophagy" to acknowledge its relationship to xenophagy, the catabolic degradation of microorganisms by macroautophagy/autophagy. In turn, viruses can subvert reticulophagy to suppress host antiviral responses and support efficient viral replication. Here, we review the evidence for functional interplay between viruses and the host reticulophagy machinery.
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Affiliation(s)
- Alexa Wilson
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Craig McCormick
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
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2
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Zhang Y, Zhang X, Yang X, Lv L, Wang Q, Zeng S, Zhang Z, Dorf M, Li S, Zhao L, Fu B. AP3B1 facilitates PDIA3/ERP57 function to regulate rabies virus glycoprotein selective degradation and viral entry. Autophagy 2024:1-19. [PMID: 39128851 DOI: 10.1080/15548627.2024.2390814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 08/01/2024] [Accepted: 08/07/2024] [Indexed: 08/13/2024] Open
Abstract
Rabies virus causes an estimated 59,000 annual fatalities worldwide and promising therapeutic treatments are necessary to develop. In this study, affinity tag-purification mass spectrometry was employed to delineate RABV glycoprotein and host protein interactions, and PDIA3/ERP57 was identified as a potential inhibitor of RABV infection. PDIA3 restricted RABV infection with follow mechanisms: PDIA3 mediated the degradation of RABV G protein by targeting lysine 332 via the selective macroautophagy/autophagy pathway; The PDIA3 interactor, AP3B1 (adaptor related protein complex 3 subunit beta 1) was indispensable in PDIA3-triggered selective degradation of the G protein; Furthermore, PDIA3 competitively bound with NCAM1/NCAM (neural cell adhesion molecule 1) to block RABV G, hindering viral entry into host cells. PDIA3 190-199 aa residues bound to the RABV G protein were necessary and sufficient to defend against RABV. These results demonstrated the therapeutic potential of biologics that target PDIA3 or utilize PDIA3 190-199 aa peptide to treat clinical rabies.Abbreviation: aa: amino acids; ANXA2: annexin A2; AP-MS: affinity tag purification-mass spectrometry; AP3B1: adaptor related protein complex 3 subunit beta 1; ATP6V1A: ATPase H+ transporting V1 subunit A; ATP6V1H: ATPase H+ transporting V1 subunit H; BafA1: bafilomycin A1; CHX: cycloheximide; co-IP: co-immunoprecipitation; DDX17: DEAD-box helicase 17; DmERp60: drosophila melanogaster endoplasmic reticulum p60; EBOV: Zaire ebolavirus virus; EV: empty vector; GANAB: glucosidase II alpha subunit; G protein: glycoprotein; GRM2/mGluR2: glutamate metabotropic receptor 2; HsPDIA3: homo sapiens protein disulfide isomerase family A member 3; IAV: influenza virus; ILF2: interleukin enhancer binding factor 2; KO: knockout; MAGT1: magnesium transporter 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MmPDIA3: mus musculus protein disulfide isomerase associated 3; NCAM1/NCAM: neural cell adhesion molecule 1; NGFR/p75NTR: nerve growth factor receptor; NGLY1: N-glycanase 1; OTUD4: OTU deubiquitinase 4; PDI: protein disulfide isomerase; PPIs: protein-protein interactions; RABV: rabies virus; RUVBL2: RuvB like AAA ATPase 2; SCAMP3: secretory carrier membrane protein 3; ScPdi1: Saccharomyces cerevisiae s288c protein disulfide isomerase 1; SLC25A6: solute carrier family 25 member 6; SQSTM1/p62: sequestosome 1; VSV: vesicular stomatitis virus.
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Affiliation(s)
- Yuelan Zhang
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Xinyi Zhang
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Xue Yang
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Linyue Lv
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Qinyang Wang
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Shaowei Zeng
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Zhuyou Zhang
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Martin Dorf
- Department of Microbiology & Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Shitao Li
- Department of Microbiology and Immunology, Tulane University, New Orleans, LA, USA
| | - Ling Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Bishi Fu
- Department of Rheumatology and Immunology, State Key Laboratory of Virology, Zhongnan Hospital, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
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Sahragard I, Yaghobi R, Mohammadi A, Afshari A, Pakfetrat M, Hossein Karimi M, Reza Pourkarim M. Impact of BK Polyomavirus NCCR variations in post kidney transplant outcomes. Gene 2024; 913:148376. [PMID: 38490510 DOI: 10.1016/j.gene.2024.148376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/10/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
The human BK Polyomavirus (BKPyV) is a DNA virus that is prevalent in 80 % of the population. Infection with this virus may begin in childhood, followed by asymptomatic persistence in the urinary tract. However, in immunocompromised individuals, especially kidney transplant recipients (KTRs), heightened replication of BKPyV can lead to severe complications. The genome of this virus is divided into three parts; the early and late region, and the non-coding control region (NCCR). Mutations in the NCCR can change the archetype strain to the rearranged strain, and NCCR rearrangements play a significant in virus pathogenesis. Interestingly, diverse types of NCCR block rearrangement result in significant differences in conversion potential and host cell viability in the infected cells. A correlation has been detected between increased viral replication potential and pathogenesis in BKPyV-infected KTRs with specific NCCR rearrangements. The objective of this review study was to examine the disease-causing and clinical consequences of variations in the NCCR in BKPyV-infected KTRs such as virus-associated nephropathy (BKPyVAN).
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Affiliation(s)
- Ilnaz Sahragard
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Ramin Yaghobi
- Shiraz Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Ali Mohammadi
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Afsoon Afshari
- Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maryam Pakfetrat
- Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Mahmoud Reza Pourkarim
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Rega Institute for Medical Research, Laboratory for Clinical and Epidemiological Virology, Herestraat 49 BE-3000, Leuven, Belgium
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4
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Sarkar R, Chhabra S, Tanwar M, Agarwal N, Kalia M. Japanese encephalitis virus hijacks ER-associated degradation regulators for its replication. J Gen Virol 2024; 105. [PMID: 38787366 DOI: 10.1099/jgv.0.001995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
Abstract
Flaviviruses target their replication on membranous structures derived from the ER, where both viral and host proteins play crucial structural and functional roles. Here, we have characterized the involvement of the ER-associated degradation (ERAD) pathway core E3 ligase complex (SEL1L-HRD1) regulator proteins in the replication of Japanese encephalitis virus (JEV). Through high-resolution immunofluorescence imaging of JEV-infected HeLa cells, we observe that the virus replication complexes marked by NS1 strongly colocalize with the ERAD adapter SEL1L, lectin OS9, ER-membrane shuttle factor HERPUD1, E3 ubiquitin ligase HRD1 and rhomboid superfamily member DERLIN1. NS5 positive structures also show strong overlap with SEL1L. While these effectors show significant transcriptional upregulation, their protein levels remain largely stable in infected cells. siRNA mediated depletion of OS9, SEL1L, HERPUD1 and HRD1 significantly inhibit viral RNA replication and titres, with SEL1L depletion showing the maximum attenuation of replication. By performing protein translation arrest experiments, we show that SEL1L, and OS9 are stabilised upon JEV infection. Overall results from this study suggest that these ERAD effector proteins are crucial host-factors for JEV replication.
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Affiliation(s)
- Riya Sarkar
- Virology Research Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
- Centre for Tuberculosis Research, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, 121001, India
- Present address: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Simran Chhabra
- Virology Research Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
| | - Mukesh Tanwar
- Virology Research Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
| | - Nisheeth Agarwal
- Centre for Tuberculosis Research, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, 121001, India
| | - Manjula Kalia
- Virology Research Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
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5
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Christianson JC, Jarosch E, Sommer T. Mechanisms of substrate processing during ER-associated protein degradation. Nat Rev Mol Cell Biol 2023; 24:777-796. [PMID: 37528230 DOI: 10.1038/s41580-023-00633-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2023] [Indexed: 08/03/2023]
Abstract
Maintaining proteome integrity is essential for long-term viability of all organisms and is overseen by intrinsic quality control mechanisms. The secretory pathway of eukaryotes poses a challenge for such quality assurance as proteins destined for secretion enter the endoplasmic reticulum (ER) and become spatially segregated from the cytosolic machinery responsible for disposal of aberrant (misfolded or otherwise damaged) or superfluous polypeptides. The elegant solution provided by evolution is ER-membrane-bound ubiquitylation machinery that recognizes misfolded or surplus proteins or by-products of protein biosynthesis in the ER and delivers them to 26S proteasomes for degradation. ER-associated protein degradation (ERAD) collectively describes this specialized arm of protein quality control via the ubiquitin-proteasome system. But, instead of providing a single strategy to remove defective or unwanted proteins, ERAD represents a collection of independent processes that exhibit distinct yet overlapping selectivity for a wide range of substrates. Not surprisingly, ER-membrane-embedded ubiquitin ligases (ER-E3s) act as central hubs for each of these separate ERAD disposal routes. In these processes, ER-E3s cooperate with a plethora of specialized factors, coordinating recognition, transport and ubiquitylation of undesirable secretory, membrane and cytoplasmic proteins. In this Review, we focus on substrate processing during ERAD, highlighting common threads as well as differences between the many routes via ERAD.
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Affiliation(s)
- John C Christianson
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.
| | - Ernst Jarosch
- Max-Delbrück-Centrer for Molecular Medicine in Helmholtz Association, Berlin-Buch, Germany
| | - Thomas Sommer
- Max-Delbrück-Centrer for Molecular Medicine in Helmholtz Association, Berlin-Buch, Germany.
- Institute for Biology, Humboldt Universität zu Berlin, Berlin, Germany.
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6
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Pletan M, Liu X, Cha G, Chen YJ, Knupp J, Tsai B. The atlastin ER morphogenic proteins promote formation of a membrane penetration site during non-enveloped virus entry. J Virol 2023; 97:e0075623. [PMID: 37578227 PMCID: PMC10506488 DOI: 10.1128/jvi.00756-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/28/2023] [Indexed: 08/15/2023] Open
Abstract
During entry, non-enveloped viruses penetrate a host membrane to cause infection, although how this is accomplished remains enigmatic. Polyomaviruses (PyVs) are non-enveloped DNA viruses that penetrate the endoplasmic reticulum (ER) membrane to reach the cytosol en route to the nucleus for infection. To penetrate the ER membrane, the prototype PyV simian virus 40 (SV40) induces formation of ER-escape sites, called foci, composed of repeating units of multi-tubular ER junctions where the virus is thought to exit. How SV40 triggers formation of the ER-foci harboring these multi-tubular ER junctions is unclear. Here, we show that the ER morphogenic atlastin 2 (ATL2) and ATL3 membrane proteins play critical roles in SV40 infection. Mechanistically, ATL3 mobilizes to the ER-foci where it deploys its GTPase-dependent membrane fusion activity to promote formation of multi-tubular ER junctions within the ER-foci. ATL3 also engages an SV40-containing membrane penetration complex. By contrast, ATL2 does not reorganize to the ER-foci. Instead, it supports the reticular ER morphology critical for the integrity of the ATL3-dependent membrane complex. Our findings illuminate how two host factors play distinct roles in the formation of an essential membrane penetration site for a non-enveloped virus. IMPORTANCE Membrane penetration by non-enveloped viruses, a critical infection step, remains enigmatic. The non-enveloped PyV simian virus 40 (SV40) penetrates the endoplasmic reticulum (ER) membrane to reach the cytosol en route for infection. During ER-to-cytosol membrane penetration, SV40 triggers formation of ER-associated structures (called ER-foci) that function as the membrane penetration sites. Here, we discover a role of the ATL ER membrane proteins-known to shape the ER morphology-during SV40-induced ER-foci formation. These findings illuminate how a non-enveloped virus hijacks host components to construct a membrane penetration structure.
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Affiliation(s)
- Madison Pletan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Xiaofang Liu
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Grace Cha
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Yu-Jie Chen
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jeffrey Knupp
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Woo TT, Williams JM, Tsai B. How host ER membrane chaperones and morphogenic proteins support virus infection. J Cell Sci 2023; 136:jcs261121. [PMID: 37401530 PMCID: PMC10357032 DOI: 10.1242/jcs.261121] [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] [Indexed: 07/05/2023] Open
Abstract
The multi-functional endoplasmic reticulum (ER) is exploited by viruses to cause infection. Morphologically, this organelle is a highly interconnected membranous network consisting of sheets and tubules whose levels are dynamic, changing in response to cellular conditions. Functionally, the ER is responsible for protein synthesis, folding, secretion and degradation, as well as Ca2+ homeostasis and lipid biosynthesis, with each event catalyzed by defined ER factors. Strikingly, these ER host factors are hijacked by viruses to support different infection steps, including entry, translation, replication, assembly and egress. Although the full repertoire of these ER factors that are hijacked is unknown, recent studies have uncovered several ER membrane machineries that are exploited by viruses - ranging from polyomavirus to flavivirus and coronavirus - to facilitate different steps of their life cycle. These discoveries should provide better understanding of virus infection mechanisms, potentially leading to the development of more effective anti-viral therapies.
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Affiliation(s)
- Tai-Ting Woo
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109,USA
| | - Jeffrey M. Williams
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109,USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109,USA
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8
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Jassar O, Ghanim M. Association of endoplasmic reticulum associated degradation (ERAD) with the transmission of Liberibacter solanacearum by its psyllid vector. INSECT MOLECULAR BIOLOGY 2023. [PMID: 37060303 DOI: 10.1111/imb.12842] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Candidatus Liberibacter solanacearum (CLso) is a complex of gram negative plant pathogenic and fastidious bacterial haplotypes restricted to the phloem and transmitted by several psyllid species. In Israel, the carrot psyllid Bactericera trigonica transmits CLso haplotype D in a persistent and propagative manner and causes the carrot yellows disease, inflicting significant economic losses in many countries. Understanding the transmission of CLso is fundamental to devising sustainable management strategies. Persistent transmission of vector-borne pathogens involves the critical steps of adhesion, cell invasion and replication inside the insect gut cells before passage to the hemolymph. Using microscopy and expression analyses, we have previously confirmed a role for the endoplasmic reticulum (ER) in inducing immune responses and subsequent molecular pathways resulting in programmed cell death (apoptosis) upon CLso-infection in the midgut. In the current study, we confirm that the ER-associated degradation (ERAD) machinery and its associated marker genes were upregulated in CLso infected insects, including Derlin-1, Selenoprotein-1 and Ubiquitin Ligase RNF-185. Silencing Derlin-1, which acts on the ER membrane by regulating the degradation of unfolded proteins upon ER stress, revealed its role in CLso persistence and transmission. Molecular pathways initiated in the ER membrane upon bacterial infection are well documented in human, animal and insect systems, and this study confirms the role of the ER in CLso-psyllid interactions.
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Affiliation(s)
- Ola Jassar
- Department of Entomology, Volcani Institute, Rishon Lezion, Israel
- The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Murad Ghanim
- Department of Entomology, Volcani Institute, Rishon Lezion, Israel
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Winter SL, Chlanda P. The Art of Viral Membrane Fusion and Penetration. Subcell Biochem 2023; 106:113-152. [PMID: 38159225 DOI: 10.1007/978-3-031-40086-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
As obligate pathogens, viruses have developed diverse mechanisms to deliver their genome across host cell membranes to sites of virus replication. While enveloped viruses utilize viral fusion proteins to accomplish fusion of their envelope with the cellular membrane, non-enveloped viruses rely on machinery that causes local membrane ruptures and creates an opening through which the capsid or viral genome is released. Both membrane fusion and membrane penetration take place at the plasma membrane or in intracellular compartments, often involving the engagement of the cellular machinery and antagonism of host restriction factors. Enveloped and non-enveloped viruses have evolved intricate mechanisms to enable virus uncoating and modulation of membrane fusion in a spatiotemporally controlled manner. This chapter summarizes and discusses the current state of understanding of the mechanisms of viral membrane fusion and penetration. The focus is on the role of lipids, viral scaffold uncoating, viral membrane fusion inhibitors, and host restriction factors as physicochemical modulators. In addition, recent advances in visualizing and detecting viral membrane fusion and penetration using cryo-electron microscopy methods are presented.
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Affiliation(s)
- Sophie L Winter
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Petr Chlanda
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.
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10
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Spriggs CC, Cha G, Li J, Tsai B. Components of the LINC and NPC complexes coordinately target and translocate a virus into the nucleus to promote infection. PLoS Pathog 2022; 18:e1010824. [PMID: 36067270 PMCID: PMC9481172 DOI: 10.1371/journal.ppat.1010824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/16/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022] Open
Abstract
Nuclear entry represents the final and decisive infection step for most DNA viruses, although how this is accomplished by some viruses is unclear. Polyomavirus SV40 transports from the cell surface through the endosome, the endoplasmic reticulum, and the cytosol from where it enters the nucleus to cause infection. Here we elucidate the nuclear entry mechanism of SV40. Our results show that cytosol-localized SV40 is targeted to the nuclear envelope by directly engaging Nesprin-2 of the linker of nucleoskeleton and cytoskeleton (LINC) nuclear membrane complex. Additionally, we identify the NUP188 subunit of the nuclear pore complex (NPC) as a new Nesprin-2-interacting partner. This physical proximity positions the NPC to capture SV40 upon release from Nesprin-2, enabling the channel to facilitate nuclear translocation of the virus. Strikingly, SV40 disassembles during nuclear entry, generating a viral genome-VP1-VP3 subcomplex that efficiently crosses the NPC to enter the nucleus. Our results reveal how two major nuclear membrane protein complexes are exploited to promote targeting and translocation of a virus into the nucleus.
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Affiliation(s)
- Chelsey C. Spriggs
- Department of Cell and Developmental Biology, University of Michigan Medical School Ann Arbor, Michigan, United States of America
- * E-mail: (CCS); (BT)
| | - Grace Cha
- Department of Cell and Developmental Biology, University of Michigan Medical School Ann Arbor, Michigan, United States of America
| | - Jiaqian Li
- Department of Cell and Developmental Biology, University of Michigan Medical School Ann Arbor, Michigan, United States of America
- Department of Biological Chemistry, University of Michigan Medical School Ann Arbor, Michigan, United States of America
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School Ann Arbor, Michigan, United States of America
- * E-mail: (CCS); (BT)
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11
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Griffiths G, Gruenberg J, Marsh M, Wohlmann J, Jones AT, Parton RG. Nanoparticle entry into cells; the cell biology weak link. Adv Drug Deliv Rev 2022; 188:114403. [PMID: 35777667 DOI: 10.1016/j.addr.2022.114403] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 12/22/2022]
Abstract
Nanoparticles (NP) are attractive options for the therapeutic delivery of active pharmaceutical drugs, proteins and nucleic acids into cells, tissues and organs. Research into the development and application of NP most often starts with a diverse group of scientists, including chemists, bioengineers and material and pharmaceutical scientists, who design, fabricate and characterize NP in vitro (Stage 1). The next step (Stage 2) generally investigates cell toxicity as well as the processes by which NP bind, are internalized and deliver their cargo to appropriate model tissue culture cells. Subsequently, in Stage 3, selected NP are tested in animal systems, mostly mouse. Whereas the chemistry-based development and analysis in Stage 1 is increasingly sophisticated, the investigations in Stage 2 are not what could be regarded as 'state-of-the-art' for the cell biology field and the quality of research into NP interactions with cells is often sub-standard. In this review we describe our current understanding of the mechanisms by which particles gain entry into mammalian cells via endocytosis. We summarize the most important areas for concern, highlight some of the most common mis-conceptions, and identify areas where NP scientists could engage with trained cell biologists. Our survey of the different mechanisms of uptake into cells makes us suspect that claims for roles for caveolae, as well as macropinocytosis, in NP uptake into cells have been exaggerated, whereas phagocytosis has been under-appreciated.
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Affiliation(s)
- Gareth Griffiths
- Department Biosciences, University of Oslo, Blindernveien 31, PO Box 1041, 0316 Oslo, Norway.
| | - Jean Gruenberg
- Department of Biochemistry, University of Geneva, 30 quai E. Ansermet, 1211-Geneva-4, Switzerland
| | - Mark Marsh
- Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Jens Wohlmann
- Department Biosciences, University of Oslo, Blindernveien 31, PO Box 1041, 0316 Oslo, Norway
| | - Arwyn T Jones
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, Cardiff, Wales CF103NB, UK
| | - Robert G Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, The University of Queensland, Qld 4072, Australia
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12
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Viruses Hijack ERAD to Regulate Their Replication and Propagation. Int J Mol Sci 2022; 23:ijms23169398. [PMID: 36012666 PMCID: PMC9408921 DOI: 10.3390/ijms23169398] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/25/2022] Open
Abstract
Endoplasmic reticulum-associated degradation (ERAD) is highly conserved in yeast. Recent studies have shown that ERAD is also ubiquitous and highly conserved in eukaryotic cells, where it plays an essential role in maintaining endoplasmic reticulum (ER) homeostasis. Misfolded or unfolded proteins undergo ERAD. They are recognized in the ER, retrotranslocated into the cytoplasm, and degraded by proteasomes after polyubiquitin. This may consist of several main steps: recognition of ERAD substrates, retrotranslocation, and proteasome degradation. Replication and transmission of the virus in the host is a process of a “game” with the host. It can be assumed that the virus has evolved various mechanisms to use the host’s functions for its replication and transmission, including ERAD. However, until now, it is still unclear how the host uses ERAD to deal with virus infection and how the viruses hijack the function of ERAD to obtain a favorable niche or evade the immune clearance of the host. Recent studies have shown that viruses have also evolved mechanisms to use various processes of ERAD to promote their transmission. This review describes the occurrence of ERAD and how the viruses hijack the function of ERAD to spread by affecting the homeostasis and immune response of the host, and we will focus on the role of E3 ubiquitin ligase.
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Kler S, Zalk R, Upcher A, Kopatz I. Packaging of DNA origami in viral capsids: towards synthetic viruses. NANOSCALE 2022; 14:11535-11542. [PMID: 35861608 DOI: 10.1039/d2nr01316a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We report a new type of nanoparticle, consisting of a nucleic acid core (>7500 nt) folded into a 35 nm DNA origami sphere, encapsulated by a capsid composed of all three SV40 virus capsid proteins. Compared to the prototype reported previously, whose capsid consists of VP1 only, the new nanoparticle closely adopts the unique intracellular pathway of the native SV40, suggesting that the proteins of the synthetic capsid retain their native viral functionality. Some of the challenges in the design of such near-future composite drugs destined for gene delivery are discussed.
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Affiliation(s)
| | - Ran Zalk
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
| | - Alexander Upcher
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
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14
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Niu Y, Xue J, Wu X, Qu M, Wang L, Liang W, Li T. Clinical Significance of Serum Haptoglobin and Protein Disulfide-Isomerase A3 in the Screening, Diagnosis, and Staging of Colorectal Cancer. Front Pharmacol 2022; 13:935500. [PMID: 35860021 PMCID: PMC9290321 DOI: 10.3389/fphar.2022.935500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/06/2022] [Indexed: 12/19/2022] Open
Abstract
Objective: This study aims to explore the clinical significance of haptoglobin (HP) and protein disulfide-isomerase A3 (PDIA3) in human serum in the screening, diagnosis and staging of colorectal cancer (CRC), and to provide novel screening approaches featuring high specificity, sensitivity, and accuracy for early screening and diagnosis of clinical colorectal cancer. Methods: 88, 77, and 36 blood specimens were respectively harvested from colorectal cancer patients, colorectal polyp patients, and normal subjects (the health examination) who requested medical assistance from our hospital between Oct2019 and February 2022. The serum contents of HP and PDIA3 in each sample were determined through an enzyme linked immunosorbent assay (ELISA). This step was taken to analyze the differences among different specimen groups in terms of the serum contents of HP and PDIA3, to analyze the relationships between the expression levels of HP and PDIA3 and the pathological characteristics of colorectal cancer, and to explore the critical role of HP and PDIA3 in the screening, diagnosis, and staging of colorectal cancer. Results: Serum contents of HP and PDIA3 were higher in colorectal cancer patients, with statistical differences (p < 0.05), than those in the colonic polyp patients and healthy subjects. Receiver operating characteristic (ROC) curve demonstrated that the cut-offs of HP and PDIA3 serum contents indicating colorectal cancer were 149 ug/ml and 66 ng/ml respectively. The individually and jointly tested AUCs of HP (0.802) and PDIA3 (0.727) were higher than those of serum CEA and CA199, the sensitivity and specificity of HP were 64.8 and 91.2%, the sensitivity and specificity of PDIA3 were 65.9 and 71.7%. Moreover, the contents of HP and PDIA3 increased alongside disease progression, with differences (p < 0.05). Conclusion: Our research indicated that joint testing of HP and PDIA3 was of reference value for progressive stage and reliable biological indicators of colorectal cancer screening.
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Affiliation(s)
- Yajin Niu
- Graduate School, Hebei North University, Zhangjiakou, China
| | - Jun Xue
- Department of General Surgery, The First Affiliated Hospital of Hebei North University, Zhangjiakou, China
| | - Xueliang Wu
- Department of General Surgery, The First Affiliated Hospital of Hebei North University, Zhangjiakou, China
| | - Ming Qu
- Department of General Surgery, The First Affiliated Hospital of Hebei North University, Zhangjiakou, China
| | - Likun Wang
- Department of General Surgery, The First Affiliated Hospital of Hebei North University, Zhangjiakou, China
| | - Weizheng Liang
- Central Laboratory, The First Affiliated Hospital of Hebei North University, Zhangjiakou, China
| | - Tian Li
- School of Basic Medicine, Fourth Military Medical University, Xi’an, China
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15
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Pei D, Dalbey RE. Membrane Translocation of Folded Proteins. J Biol Chem 2022; 298:102107. [PMID: 35671825 PMCID: PMC9251779 DOI: 10.1016/j.jbc.2022.102107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 12/01/2022] Open
Abstract
An ever-increasing number of proteins have been shown to translocate across various membranes of bacterial as well as eukaryotic cells in their folded states as a part of physiological and/or pathophysiological processes. Herein we provide an overview of the systems/processes that are established or likely to involve the membrane translocation of folded proteins, such as protein export by the twin-arginine translocation (TAT) system in bacteria and chloroplasts, unconventional protein secretion (UPS) and protein import into the peroxisome in eukaryotes, and the cytosolic entry of proteins (e.g., bacterial toxins) and viruses into eukaryotes. We also discuss the various mechanistic models that have previously been proposed for the membrane translocation of folded proteins including pore/channel formation, local membrane disruption, membrane thinning, and transport by membrane vesicles. Finally, we introduce a newly discovered vesicular transport mechanism, vesicle budding and collapse (VBC), and present evidence that VBC may represent a unifying mechanism that drives some (and potentially all) of folded protein translocation processes.
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Affiliation(s)
- Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210.
| | - Ross E Dalbey
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210.
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16
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Gansemer ER, Rutkowski DT. Pathways Linking Nicotinamide Adenine Dinucleotide Phosphate Production to Endoplasmic Reticulum Protein Oxidation and Stress. Front Mol Biosci 2022; 9:858142. [PMID: 35601828 PMCID: PMC9114485 DOI: 10.3389/fmolb.2022.858142] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
The endoplasmic reticulum (ER) lumen is highly oxidizing compared to other subcellular compartments, and maintaining the appropriate levels of oxidizing and reducing equivalents is essential to ER function. Both protein oxidation itself and other essential ER processes, such as the degradation of misfolded proteins and the sequestration of cellular calcium, are tuned to the ER redox state. Simultaneously, nutrients are oxidized in the cytosol and mitochondria to power ATP generation, reductive biosynthesis, and defense against reactive oxygen species. These parallel needs for protein oxidation in the ER and nutrient oxidation in the cytosol and mitochondria raise the possibility that the two processes compete for electron acceptors, even though they occur in separate cellular compartments. A key molecule central to both processes is NADPH, which is produced by reduction of NADP+ during nutrient catabolism and which in turn drives the reduction of components such as glutathione and thioredoxin that influence the redox potential in the ER lumen. For this reason, NADPH might serve as a mediator linking metabolic activity to ER homeostasis and stress, and represent a novel form of mitochondria-to-ER communication. In this review, we discuss oxidative protein folding in the ER, NADPH generation by the major pathways that mediate it, and ER-localized systems that can link the two processes to connect ER function to metabolic activity.
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Affiliation(s)
- Erica R. Gansemer
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - D. Thomas Rutkowski
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
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17
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Tati S, Alisaraie L. Recruitment of dynein and kinesin to viral particles. FASEB J 2022; 36:e22311. [DOI: 10.1096/fj.202101900rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/14/2022] [Accepted: 03/29/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Sayi’Mone Tati
- School of Pharmacy Memorial University of Newfoundland St. John’s Newfoundland Canada
| | - Laleh Alisaraie
- School of Pharmacy Memorial University of Newfoundland St. John’s Newfoundland Canada
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18
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Bagchi P, Liu X, Cho WJ, Tsai B. Lunapark-dependent formation of a virus-induced ER exit site contains multi-tubular ER junctions that promote viral ER-to-cytosol escape. Cell Rep 2021; 37:110077. [PMID: 34879280 DOI: 10.1016/j.celrep.2021.110077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/16/2021] [Accepted: 11/09/2021] [Indexed: 10/19/2022] Open
Abstract
Viruses rearrange host membranes to support different entry steps. Polyomavirus simian virus 40 (SV40) reorganizes the endoplasmic reticulum (ER) membrane to generate focus structures that enable virus ER-to-cytosol escape, a decisive infection step. The molecular architecture of the ER exit site that might illuminate why it is ideally suited for membrane penetration is unknown. Here 3D focused ion beam scanning electron microscopy (FIB-SEM) reconstruction reveals that the ER focus structure consists of multi-tubular ER junctions where SV40 preferentially localizes, suggesting that tubular branch points are virus ER-to-cytosol penetration sites. Functional analysis demonstrates that lunapark-an ER membrane protein that typically stabilizes three-way ER junctions-relocates to the ER foci, where it supports focus formation, leading to SV40 ER escape and infection. Our results reveal how a virus repurposes the activity of an ER membrane protein to form a virus-induced ER substructure required for membrane escape and suggest that ER tubular junctions are vulnerable sites exploited by viruses for membrane penetration.
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Affiliation(s)
- Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA
| | - Xiaofang Liu
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA
| | - Woo Jung Cho
- Biomedical Research Core Facilities, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB, Ann Arbor, MI 48109, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, BSRB 3043, Ann Arbor, MI 48109, USA.
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19
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Mahmood F, Xu R, Awan MUN, Song Y, Han Q, Xia X, Zhang J. PDIA3: Structure, functions and its potential role in viral infections. Biomed Pharmacother 2021; 143:112110. [PMID: 34474345 DOI: 10.1016/j.biopha.2021.112110] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 02/08/2023] Open
Abstract
The catalysis of disulphide (SS) bonds is the most important characteristic of protein disulphide isomerase (PDI) family. Catalysis occurs in the endoplasmic reticulum, which contains many proteins, most of which are secretory in nature and that have at least one s-s bond. Protein disulphide isomerase A3 (PDIA3) is a member of the PDI family that acts as a chaperone. PDIA3 is highly expressed in response to cellular stress, and also intercept the apoptotic cellular death related to endoplasmic reticulum (ER) stress, and protein misfolding. PDIA3 expression is elevated in almost 70% of cancers and its expression has been linked with overall low cell invasiveness, survival and metastasis. Viral diseases present a significant public health threat. The presence of PDIA3 on the cell surface helps different viruses to enter the cells and also helps in replication. Therefore, inhibitors of PDIA3 have great potential to interfere with viral infections. In this review, we summarize what is known about the basic structure, functions and role of PDIA3 in viral infections. The review will inspire studies of pathogenic mechanisms and drug targeting to counter viral diseases.
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Affiliation(s)
- Faisal Mahmood
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China
| | - Ruixian Xu
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China
| | - Maher Un Nisa Awan
- Laboratory of Molecular Neurobiology, Medical Faculty, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China
| | - Yuzhu Song
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China
| | - Qinqin Han
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China
| | - Xueshan Xia
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China.
| | - Jinyang Zhang
- Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jingming South Road, Kunming 650500, China.
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20
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Newcastle Disease Virus Entry into Chicken Macrophages via a pH-Dependent, Dynamin and Caveola-Mediated Endocytic Pathway That Requires Rab5. J Virol 2021; 95:e0228820. [PMID: 33762417 DOI: 10.1128/jvi.02288-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The cellular entry pathways and the mechanisms of Newcastle disease virus (NDV) entry into cells are poorly characterized. In this study, we demonstrated that chicken interferon-induced transmembrane protein 1 (chIFITM1), which is located in the early endosomes, could limit the replication of NDV in chicken macrophage cell line HD11, suggesting the endocytic entry of NDV into chicken macrophages. Then, we presented a systematic study about the entry mechanism of NDV into chicken macrophages. First, we demonstrated that a low-pH condition and dynamin were required during NDV entry. However, NDV entry into chicken macrophages was independent of clathrin-mediated endocytosis. We also found that NDV entry was dependent on membrane cholesterol. The NDV entry and replication were significantly reduced by nystatin and phorbol 12-myristate 13-acetate treatment, overexpression of dominant-negative (DN) caveolin-1, or knockdown of caveolin-1, suggesting that NDV entry depends on caveola-mediated endocytosis. However, macropinocytosis did not play a role in NDV entry into chicken macrophages. In addition, we found that Rab5, rather than Rab7, was involved in the entry and traffic of NDV. The colocalization of NDV with Rab5 and early endosome suggested that NDV virion was transported to early endosomes in a Rab5-dependent manner after internalization. Of particular note, the caveola-mediated endocytosis was also utilized by NDV to enter primary chicken macrophages. Moreover, NDV entered different cell types using different pathways. Collectively, our findings demonstrate for the first time that NDV virion enters chicken macrophages via a pH-dependent, dynamin and caveola-mediated endocytosis pathway and that Rab5 is involved in the traffic and location of NDV. IMPORTANCE Although the pathogenesis of Newcastle disease virus (NDV) has been extensively studied, the detailed mechanism of NDV entry into host cells is largely unknown. Macrophages are the first-line defenders of host defense against infection of pathogens. Chicken macrophages are considered one of the main types of target cells during NDV infection. Here, we comprehensively investigated the entry mechanism of NDV in chicken macrophages. This is the first report to demonstrate that NDV enters chicken macrophages via a pH-dependent, dynamin and caveola-mediated endocytosis pathway that requires Rab5. The result is important for our understanding of the entry of NDV in chicken macrophages, which will further advance the knowledge of NDV pathogenesis and provide useful clues for the development of novel preventive or therapeutic strategies against NDV infection. In addition, this information will contribute to our further understanding of pathogenesis with regard to other members of the Avulavirus genus in the Paramyxoviridae family.
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21
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Abstract
My coworkers and I have used animal viruses and their interaction with host cells to investigate cellular processes difficult to study by other means. This approach has allowed us to branch out in many directions, including membrane protein characterization, endocytosis, secretion, protein folding, quality control, and glycobiology. At the same time, our aim has been to employ cell biological approaches to expand the fundamental understanding of animal viruses and their pathogenic lifestyles. We have studied mechanisms of host cell entry and the uncoating of incoming viruses as well as the synthesis, folding, maturation, and intracellular movement of viral proteins and molecular assemblies. I have had the privilege to work in institutions in four different countries. The early years in Finland (the University of Helsinki) were followed by 6 years in Germany (European Molecular Biology Laboratory), 16 years in the United States (Yale School of Medicine), and 16 years in Switzerland (ETH Zurich).
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Affiliation(s)
- Ari Helenius
- Institute of Biochemistry, ETH Zurich, Zurich 8093, Switzerland;
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22
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How DNA and RNA Viruses Exploit Host Chaperones to Promote Infection. Viruses 2021; 13:v13060958. [PMID: 34064125 PMCID: PMC8224278 DOI: 10.3390/v13060958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/18/2022] Open
Abstract
To initiate infection, a virus enters a host cell typically via receptor-dependent endocytosis. It then penetrates a subcellular membrane, reaching a destination that supports transcription, translation, and replication of the viral genome. These steps lead to assembly and morphogenesis of the new viral progeny. The mature virus finally exits the host cell to begin the next infection cycle. Strikingly, viruses hijack host molecular chaperones to accomplish these distinct entry steps. Here we highlight how DNA viruses, including polyomavirus and the human papillomavirus, exploit soluble and membrane-associated chaperones to enter a cell, penetrating and escaping an intracellular membrane en route for infection. We also describe the mechanism by which RNA viruses—including flavivirus and coronavirus—co-opt cytosolic and organelle-selective chaperones to promote viral endocytosis, protein biosynthesis, replication, and assembly. These examples underscore the importance of host chaperones during virus infection, potentially revealing novel antiviral strategies to combat virus-induced diseases.
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23
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Baccile JA, Voorhees PJ, Chillo AJ, Berry M, Morgenstern R, Schwertfeger TJ, Rossi FM, Nelson CDS. Site-Specific Small Molecule Labeling of an Internal Loop in JC Polyomavirus Pentamers Using the π-Clamp-Mediated Cysteine Conjugation. Chembiochem 2021; 22:3037-3041. [PMID: 34018291 DOI: 10.1002/cbic.202100188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/19/2021] [Indexed: 12/21/2022]
Abstract
The major capsid protein VP1 of JC Polyomavirus assembles into pentamers that serve as a model for studying viral entry of this potentially severe human pathogen. Previously, labeling of viral proteins utilized large fusion proteins or non-specific amine- or cysteine-functionalization with fluorescent dyes. Imaging of these sterically hindered fusion proteins or heterogeneously labeled virions limits reproducibility and could prevent the detection of subtle trafficking phenomena. Here we advance the π-clamp-mediated cysteine conjugation for site-selective fluorescent labeling of VP1-pentamers. We demonstrate a one-step synthesis of a probe consisting of a bio-orthogonal click chemistry handle bridged to a perfluoro-biphenyl π-clamp reactive electrophile by a polyethylene glycol linker. We expand the scope of the π-clamp conjugation by demonstrating selective labeling of an internal, surface exposed loop in VP1. Thus, the π-clamp conjugation offers a general method to selectively bioconjugate tags-of-interest to viral proteins without impeding their ability to bind and enter cells.
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Affiliation(s)
- Joshua A Baccile
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91106, USA
| | - Peter J Voorhees
- Department of Biological Sciences, SUNY Cortland, Cortland, NY, 13045, USA
| | - Anthony J Chillo
- Department of Biological Sciences, SUNY Cortland, Cortland, NY, 13045, USA
| | - Madeline Berry
- Department of Chemistry, SUNY Cortland, Cortland, NY, 13045, USA
| | | | | | - Francis M Rossi
- Department of Chemistry, SUNY Cortland, Cortland, NY, 13045, USA
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24
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Zapatero-Belinchón FJ, Carriquí-Madroñal B, Gerold G. Proximity labeling approaches to study protein complexes during virus infection. Adv Virus Res 2021; 109:63-104. [PMID: 33934830 DOI: 10.1016/bs.aivir.2021.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cellular compartmentalization of proteins and protein complex formation allow cells to tightly control biological processes. Therefore, understanding the subcellular localization and interactions of a specific protein is crucial to uncover its biological function. The advent of proximity labeling (PL) has reshaped cellular proteomics in infection biology. PL utilizes a genetically modified enzyme that generates a "labeling cloud" by covalently labeling proteins in close proximity to the enzyme. Fusion of a PL enzyme to a specific antibody or a "bait" protein of interest in combination with affinity enrichment mass spectrometry (AE-MS) enables the isolation and identification of the cellular proximity proteome, or proxisome. This powerful methodology has been paramount for the mapping of membrane or membraneless organelles as well as for the understanding of hard-to-purify protein complexes, such as those of transmembrane proteins. Unsurprisingly, more and more infection biology research groups have recognized the potential of PL for the identification of host-pathogen interactions. In this chapter, we introduce the enzymes commonly used for PL labeling as well as recent promising advancements and summarize the major achievements in organelle mapping and nucleic acid PL. Moreover, we comprehensively describe the research on host-pathogen interactions using PL, giving special attention to studies in the field of virology.
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Affiliation(s)
- Francisco José Zapatero-Belinchón
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany; Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture Between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden; Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden.
| | - Belén Carriquí-Madroñal
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany; Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture Between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Gisa Gerold
- Department of Biochemistry & Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany; Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture Between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany; Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden; Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden.
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25
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Intracellular Redox-Modulated Pathways as Targets for Effective Approaches in the Treatment of Viral Infection. Int J Mol Sci 2021; 22:ijms22073603. [PMID: 33808471 PMCID: PMC8036776 DOI: 10.3390/ijms22073603] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
Host-directed therapy using drugs that target cellular pathways required for virus lifecycle or its clearance might represent an effective approach for treating infectious diseases. Changes in redox homeostasis, including intracellular glutathione (GSH) depletion, are one of the key events that favor virus replication and contribute to the pathogenesis of virus-induced disease. Redox homeostasis has an important role in maintaining an appropriate Th1/Th2 balance, which is necessary to mount an effective immune response against viral infection and to avoid excessive inflammatory responses. It is known that excessive production of reactive oxygen species (ROS) induced by viral infection activates nuclear factor (NF)-kB, which orchestrates the expression of viral and host genes involved in the viral replication and inflammatory response. Moreover, redox-regulated protein disulfide isomerase (PDI) chaperones have an essential role in catalyzing formation of disulfide bonds in viral proteins. This review aims at describing the role of GSH in modulating redox sensitive pathways, in particular that mediated by NF-kB, and PDI activity. The second part of the review discusses the effectiveness of GSH-boosting molecules as broad-spectrum antivirals acting in a multifaceted way that includes the modulation of immune and inflammatory responses.
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26
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Wu Z, Graf FE, Hirsch HH. Antivirals against human polyomaviruses: Leaving no stone unturned. Rev Med Virol 2021; 31:e2220. [PMID: 33729628 DOI: 10.1002/rmv.2220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 12/20/2022]
Abstract
Human polyomaviruses (HPyVs) encompass more than 10 species infecting 30%-90% of the human population without significant illness. Proven HPyV diseases with documented histopathology affect primarily immunocompromised hosts with manifestations in brain, skin and renourinary tract such as polyomavirus-associated nephropathy (PyVAN), polyomavirus-associated haemorrhagic cystitis (PyVHC), polyomavirus-associated urothelial cancer (PyVUC), progressive multifocal leukoencephalopathy (PML), Merkel cell carcinoma (MCC), Trichodysplasia spinulosa (TS) and pruritic hyperproliferative keratinopathy. Although virus-specific immune control is the eventual goal of therapy and lasting cure, antiviral treatments are urgently needed in order to reduce or prevent HPyV diseases and thereby bridging the time needed to establish virus-specific immunity. However, the small dsDNA genome of only 5 kb of the non-enveloped HPyVs only encodes 5-7 viral proteins. Thus, HPyV replication relies heavily on host cell factors, thereby limiting both, number and type of specific virus-encoded antiviral targets. Lack of cost-effective high-throughput screening systems and relevant small animal models complicates the preclinical development. Current clinical studies are limited by small case numbers, poorly efficacious compounds and absence of proper randomized trial design. Here, we review preclinical and clinical studies that evaluated small molecules with presumed antiviral activity against HPyVs and provide an outlook regarding potential new antiviral strategies.
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Affiliation(s)
- Zongsong Wu
- Transplantation & Clinical Virology, Department Biomedicine, University of Basel, Basel, Switzerland
| | - Fabrice E Graf
- Transplantation & Clinical Virology, Department Biomedicine, University of Basel, Basel, Switzerland
| | - Hans H Hirsch
- Transplantation & Clinical Virology, Department Biomedicine, University of Basel, Basel, Switzerland.,Clinical Virology, Laboratory Medicine, University Hospital Basel, Basel, Switzerland.,Infectious Diseases & Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
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27
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Mayberry CL, Bond AC, Wilczek MP, Mehmood K, Maginnis MS. Sending mixed signals: polyomavirus entry and trafficking. Curr Opin Virol 2021; 47:95-105. [PMID: 33690104 DOI: 10.1016/j.coviro.2021.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/31/2022]
Abstract
Polyomaviruses are mostly non-pathogenic, yet some can cause human disease especially under conditions of immunosuppression, including JC, BK, and Merkel cell polyomaviruses. Direct interactions between viruses and the host early during infection dictate the outcome of disease, many of which remain enigmatic. However, significant work in recent years has contributed to our understanding of how this virus family establishes an infection, largely due to advances made for animal polyomaviruses murine and SV40. Here we summarize the major findings that have contributed to our understanding of polyomavirus entry, trafficking, disassembly, signaling, and immune evasion during the infectious process and highlight major unknowns in these processes that are open areas of study.
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Affiliation(s)
- Colleen L Mayberry
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Avery Cs Bond
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Michael P Wilczek
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Kashif Mehmood
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA
| | - Melissa S Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME, USA; Graduate School in Biomedical Sciences and Engineering, The University of Maine, Orono, ME, USA.
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28
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Spriggs CC, Badieyan S, Verhey KJ, Cianfrocco MA, Tsai B. Golgi-associated BICD adaptors couple ER membrane penetration and disassembly of a viral cargo. J Cell Biol 2021; 219:151622. [PMID: 32259203 PMCID: PMC7199864 DOI: 10.1083/jcb.201908099] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 12/04/2019] [Accepted: 02/21/2020] [Indexed: 12/22/2022] Open
Abstract
During entry, viruses must navigate through the host endomembrane system, penetrate cellular membranes, and undergo capsid disassembly to reach an intracellular destination that supports infection. How these events are coordinated is unclear. Here, we reveal an unexpected function of a cellular motor adaptor that coordinates virus membrane penetration and disassembly. Polyomavirus SV40 traffics to the endoplasmic reticulum (ER) and penetrates a virus-induced structure in the ER membrane called “focus” to reach the cytosol, where it disassembles before nuclear entry to promote infection. We now demonstrate that the ER focus is constructed proximal to the Golgi-associated BICD2 and BICDR1 dynein motor adaptors; this juxtaposition enables the adaptors to directly bind to and disassemble SV40 upon arrival to the cytosol. Our findings demonstrate that positioning of the virus membrane penetration site couples two decisive infection events, cytosol arrival and disassembly, and suggest cargo remodeling as a novel function of dynein adaptors.
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Affiliation(s)
- Chelsey C Spriggs
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Somayesadat Badieyan
- Department of Biological Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, MI
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Michael A Cianfrocco
- Department of Biological Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, MI
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
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29
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Jheng JR, Chen YS, Horng JT. Regulation of the proteostasis network during enterovirus infection: A feedforward mechanism for EV-A71 and EV-D68. Antiviral Res 2021; 188:105019. [PMID: 33484748 DOI: 10.1016/j.antiviral.2021.105019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/12/2021] [Accepted: 01/16/2021] [Indexed: 10/25/2022]
Abstract
The proteostasis network guarantees successful protein synthesis, folding, transportation, and degradation. Mounting evidence has revealed that this network maintains proteome integrity and is linked to cellular physiology, pathology, and virus infection. Human enterovirus A71 (EV-A71) and EV-D68 are suspected causative agents of acute flaccid myelitis, a severe poliomyelitis-like neurologic syndrome with no known cure. In this context, further clarification of the molecular mechanisms underlying EV-A71 and EV-D68 infection is paramount. Here, we summarize the components of the proteostasis network that are intercepted by EV-A71 and EV-D68, as well as antivirals that target this network and may help develop improved antiviral drugs.
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Affiliation(s)
- Jia-Rong Jheng
- Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - Yuan-Siao Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - Jim-Tong Horng
- Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan; Research Center for Industry of Human Ecology and Graduate Institute of Health Industry Technology, Chang Gung University of Science and Technology, Taoyuan, Taiwan; Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
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30
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ER functions are exploited by viruses to support distinct stages of their life cycle. Biochem Soc Trans 2020; 48:2173-2184. [PMID: 33119046 DOI: 10.1042/bst20200395] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum (ER), with its expansive membranous system and a vast network of chaperones, enzymes, sensors, and ion channels, orchestrates diverse cellular functions, ranging from protein synthesis, folding, secretion, and degradation to lipid biogenesis and calcium homeostasis. Strikingly, some of the functions of the ER are exploited by viruses to promote their life cycles. During entry, viruses must penetrate a host membrane and reach an intracellular destination to express and replicate their genomes. These events lead to the assembly of new viral progenies that exit the host cell, thereby initiating further rounds of infection. In this review, we highlight how three distinct viruses - polyomavirus, flavivirus, and coronavirus - co-opt key functions of the ER to cause infection. We anticipate that illuminating this virus-ER interplay will provide rational therapeutic approaches to combat the virus-induced diseases.
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31
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Uhlorn BL, Jackson R, Li S, Bratton SM, Van Doorslaer K, Campos SK. Vesicular trafficking permits evasion of cGAS/STING surveillance during initial human papillomavirus infection. PLoS Pathog 2020; 16:e1009028. [PMID: 33253291 PMCID: PMC7728285 DOI: 10.1371/journal.ppat.1009028] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 12/10/2020] [Accepted: 10/02/2020] [Indexed: 12/26/2022] Open
Abstract
Oncogenic human papillomaviruses (HPVs) replicate in differentiating epithelium, causing 5% of cancers worldwide. Like most other DNA viruses, HPV infection initiates after trafficking viral genome (vDNA) to host cell nuclei. Cells possess innate surveillance pathways to detect microbial components or physiological stresses often associated with microbial infections. One of these pathways, cGAS/STING, induces IRF3-dependent antiviral interferon (IFN) responses upon detection of cytosolic DNA. Virion-associated vDNA can activate cGAS/STING during initial viral entry and uncoating/trafficking, and thus cGAS/STING is an obstacle to many DNA viruses. HPV has a unique vesicular trafficking pathway compared to many other DNA viruses. As the capsid uncoats within acidic endosomal compartments, minor capsid protein L2 protrudes across vesicular membranes to facilitate transport of vDNA to the Golgi. L2/vDNA resides within the Golgi lumen until G2/M, whereupon vesicular L2/vDNA traffics along spindle microtubules, tethering to chromosomes to access daughter cell nuclei. L2/vDNA-containing vesicles likely remain intact until G1, following nuclear envelope reformation. We hypothesize that this unique vesicular trafficking protects HPV from cGAS/STING surveillance. Here, we investigate cGAS/STING responses to HPV infection. DNA transfection resulted in acute cGAS/STING activation and downstream IFN responses. In contrast, HPV infection elicited minimal cGAS/STING and IFN responses. To determine the role of vesicular trafficking in cGAS/STING evasion, we forced premature viral penetration of vesicular membranes with membrane-perturbing cationic lipids. Such treatment renders a non-infectious trafficking-defective mutant HPV infectious, yet susceptible to cGAS/STING detection. Overall, HPV evades cGAS/STING by its unique subcellular trafficking, a property that may contribute to establishment of infection.
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Affiliation(s)
- Brittany L. Uhlorn
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Robert Jackson
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
| | - Shuaizhi Li
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Shauna M. Bratton
- Department of Physiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Koenraad Van Doorslaer
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Genetics Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Samuel K. Campos
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Department of Molecular & Cellular Biology, The University of Arizona, Tucson, Arizona, United States of America
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32
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Schneider SM, Lee BH, Nicola AV. Viral entry and the ubiquitin-proteasome system. Cell Microbiol 2020; 23:e13276. [PMID: 33037857 DOI: 10.1111/cmi.13276] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 09/17/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023]
Abstract
Viruses confiscate cellular components of the ubiquitin-proteasome system (UPS) to facilitate many aspects of the infectious cycle. The 26S proteasome is an ATP-dependent, multisubunit proteolytic machine present in all eukaryotic cells. The proteasome executes the controlled degradation of functional proteins, as well as the hydrolysis of aberrantly folded polypeptides. There is growing evidence for the role of the UPS in viral entry. The UPS assists in several steps of the initiation of infection, including endosomal escape of the entering virion, intracellular transport of incoming nucleocapsids and uncoating of the viral genome. Inhibitors of proteasome activity, including MG132, epoxomicin, lactacystin and bortezomib have been integral to developments in this area. Here, we review the mechanistic details of UPS involvement in the entry process of viruses from a multitude of families. The possibility of proteasome inhibitors as therapeutic antiviral agents is highlighted.
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Affiliation(s)
- Seth M Schneider
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA.,School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Becky H Lee
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA.,School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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33
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Phosphoinositide 3'-Kinase γ Facilitates Polyomavirus Infection. Viruses 2020; 12:v12101190. [PMID: 33092168 PMCID: PMC7589550 DOI: 10.3390/v12101190] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 12/28/2022] Open
Abstract
Polyomaviruses are small, non-enveloped DNA tumor viruses that cause serious disease in immunosuppressed people, including progressive multifocal leukoencephalopathy (PML) in patients infected with JC polyomavirus, but the molecular events mediating polyomavirus entry are poorly understood. Through genetic knockdown approaches, we identified phosphoinositide 3′-kinase γ (PI3Kγ) and its regulatory subunit PIK3R5 as cellular proteins that facilitate infection of human SVG-A glial cells by JCPyV. PI3Kα appears less important for polyomavirus infection than PI3Kγ. CRISPR/Cas9-mediated knockout of PIK3R5 or PI3Kγ inhibited infection by authentic JCPyV and by JC pseudovirus. PI3Kγ knockout also inhibited infection by BK and Merkel Cell pseudoviruses, other pathogenic human polyomaviruses, and SV40, an important model polyomavirus. Reintroduction of the wild-type PI3Kγ gene into the PI3Kγ knock-out SVG-A cells rescued the JCPyV infection defect. Disruption of the PI3Kγ pathway did not block binding of JCPyV to cells or virus internalization, implying that PI3Kγ facilitates some intracellular step(s) of infection. These results imply that agents that inhibit PI3Kγ signaling may have a role in managing polyomavirus infections.
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34
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Mayberry CL, Maginnis MS. Taking the Scenic Route: Polyomaviruses Utilize Multiple Pathways to Reach the Same Destination. Viruses 2020; 12:v12101168. [PMID: 33076363 PMCID: PMC7602598 DOI: 10.3390/v12101168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/02/2023] Open
Abstract
Members of the Polyomaviridae family differ in their host range, pathogenesis, and disease severity. To date, some of the most studied polyomaviruses include human JC, BK, and Merkel cell polyomavirus and non-human subspecies murine and simian virus 40 (SV40) polyomavirus. Although dichotomies in host range and pathogenesis exist, overlapping features of the infectious cycle illuminate the similarities within this virus family. Of particular interest to human health, JC, BK, and Merkel cell polyomavirus have all been linked to critical, often fatal, illnesses, emphasizing the importance of understanding the underlying viral infections that result in the onset of these diseases. As there are significant overlaps in the capacity of polyomaviruses to cause disease in their respective hosts, recent advancements in characterizing the infectious life cycle of non-human murine and SV40 polyomaviruses are key to understanding diseases caused by their human counterparts. This review focuses on the molecular mechanisms by which different polyomaviruses hijack cellular processes to attach to host cells, internalize, traffic within the cytoplasm, and disassemble within the endoplasmic reticulum (ER), prior to delivery to the nucleus for viral replication. Unraveling the fundamental processes that facilitate polyomavirus infection provides deeper insight into the conserved mechanisms of the infectious process shared within this virus family, while also highlighting critical unique viral features.
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Affiliation(s)
- Colleen L. Mayberry
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04469, USA;
| | - Melissa S. Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04469, USA;
- Graduate School in Biomedical Sciences and Engineering, The University of Maine, Orono, ME 04469, USA
- Correspondence:
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35
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Lauver MD, Lukacher AE. JCPyV VP1 Mutations in Progressive MultifocalLeukoencephalopathy: Altering Tropismor Mediating Immune Evasion? Viruses 2020; 12:v12101156. [PMID: 33053912 PMCID: PMC7600905 DOI: 10.3390/v12101156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/15/2022] Open
Abstract
Polyomaviruses are ubiquitous human pathogens that cause lifelong, asymptomatic infections in healthy individuals. Although these viruses are restrained by an intact immune system, immunocompromised individuals are at risk for developing severe diseases driven by resurgent viral replication. In particular, loss of immune control over JC polyomavirus can lead to the development of the demyelinating brain disease progressive multifocal leukoencephalopathy (PML). Viral isolates from PML patients frequently carry point mutations in the major capsid protein, VP1, which mediates virion binding to cellular glycan receptors. Because polyomaviruses are non-enveloped, VP1 is also the target of the host's neutralizing antibody response. Thus, VP1 mutations could affect tropism and/or recognition by polyomavirus-specific antibodies. How these mutations predispose susceptible individuals to PML and other JCPyV-associated CNS diseases remains to be fully elucidated. Here, we review the current understanding of polyomavirus capsid mutations and their effects on viral tropism, immune evasion, and virulence.
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36
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SV40 Polyomavirus Activates the Ras-MAPK Signaling Pathway for Vacuolization, Cell Death, and Virus Release. Viruses 2020; 12:v12101128. [PMID: 33028008 PMCID: PMC7650553 DOI: 10.3390/v12101128] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
Polyomaviruses are a family of small, non-enveloped DNA viruses that can cause severe disease in immunosuppressed individuals. Studies with SV40, a well-studied model polyomavirus, have revealed the role of host proteins in polyomavirus entry and trafficking to the nucleus, in viral transcription and DNA replication, and in cell transformation. In contrast, little is known about host factors or cellular signaling pathways involved in the late steps of productive infection leading to release of progeny polyomaviruses. We previously showed that cytoplasmic vacuolization, a characteristic late cytopathic effect of SV40 infection, depends on the specific interaction between the major viral capsid protein VP1 and its cell surface ganglioside receptor GM1. Here, we show that, late during infection, SV40 activates a signaling cascade in permissive monkey CV-1 cells involving Ras, Rac1, MKK4, and JNK to stimulate SV40-specific cytoplasmic vacuolization and subsequent cell lysis and virus release. Inhibition of individual components of this signaling pathway inhibits vacuolization, lysis, and virus release, even though high-level intracellular virus replication occurs. Identification of this pathway for SV40-induced vacuolization and virus release provides new insights into the late steps of non-enveloped virus infection.
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37
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Structure of Merkel Cell Polyomavirus Capsid and Interaction with Its Glycosaminoglycan Attachment Receptor. J Virol 2020; 94:JVI.01664-19. [PMID: 32699083 PMCID: PMC7527053 DOI: 10.1128/jvi.01664-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 07/07/2020] [Indexed: 11/20/2022] Open
Abstract
The MCPyV genome was found to be clonally integrated in 80% of cases of Merkel cell carcinoma (MCC), a rare but aggressive form of human skin cancer, strongly suggesting that this virus is tumorigenic. In the metastasizing state, the course of the disease is often fatal, especially in immunocompromised individuals, as reflected by the high mortality rate of 33 to 46% and the low 5-year survival rate (<45%). The high seroprevalence of about 60% makes MCPyV a serious health care burden and illustrates the need for targeted treatments. In this study, we present the first high-resolution structural data for this human tumor virus and demonstrate that the full capsid is required for the essential interaction with its GAG receptor(s). Together, these data can be used as a basis for future strategies in drug development. Merkel cell polyomavirus (MCPyV) is a human double-stranded DNA tumor virus. MCPyV cell entry is unique among members of the polyomavirus family as it requires the engagement of two types of glycans, sialylated oligosaccharides and sulfated glycosaminoglycans (GAGs). Here, we present crystallographic and cryo-electron microscopic structures of the icosahedral MCPyV capsid and analysis of its glycan interactions via nuclear magnetic resonance (NMR) spectroscopy. While sialic acid binding is specific for α2-3-linked sialic acid and mediated by the exposed apical loops of the major capsid protein VP1, a broad range of GAG oligosaccharides bind to recessed regions between VP1 capsomers. Individual VP1 capsomers are tethered to one another by an extensive disulfide network that differs in architecture from previously described interactions for other PyVs. An unusual C-terminal extension in MCPyV VP1 projects from the recessed capsid regions. Mutagenesis experiments show that this extension is dispensable for receptor interactions. IMPORTANCE The MCPyV genome was found to be clonally integrated in 80% of cases of Merkel cell carcinoma (MCC), a rare but aggressive form of human skin cancer, strongly suggesting that this virus is tumorigenic. In the metastasizing state, the course of the disease is often fatal, especially in immunocompromised individuals, as reflected by the high mortality rate of 33 to 46% and the low 5-year survival rate (<45%). The high seroprevalence of about 60% makes MCPyV a serious health care burden and illustrates the need for targeted treatments. In this study, we present the first high-resolution structural data for this human tumor virus and demonstrate that the full capsid is required for the essential interaction with its GAG receptor(s). Together, these data can be used as a basis for future strategies in drug development.
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38
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Treasure T, Nelson CDS. Inhibition of JC polyomavirus infectivity by the retrograde transport inhibitor Retro-2.1. Microbiol Immunol 2020; 64:783-791. [PMID: 32965709 DOI: 10.1111/1348-0421.12851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 09/02/2020] [Accepted: 09/16/2020] [Indexed: 11/28/2022]
Abstract
JC polyomavirus (JCPyV) is a common human pathogen that results in a chronic asymptomatic infection in healthy adults. Under conditions of immunosuppression, JCPyV spreads to the central nervous system and can cause the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML), a disease for which there are no vaccines or antiviral therapies. Retro-2 is a previously identified small molecule inhibitor that was originally shown to block retrograde transport of toxins such as ricin toxin from endosomes to the Golgi apparatus and endoplasmic reticulum (ER), and Retro-2.1 is a chemical analog of Retro-2 that has been shown to inhibit ricin intoxication of cells at low nanomolar concentrations. Retro-2 has previously been shown to prevent retrograde transport of JCPyV virions to the ER, but the effect of Retro-2.1 on JCPyV infectivity is unknown. Here it is shown that Retro-2.1 inhibits JCPyV with an EC50 of 3.9 μM. This molecule inhibits JCPyV infection at dosages that are not toxic to human tissue culture cells. Retro-2.1 was also tested against two other polyomaviruses, the human BK polyomavirus and simian virus 40, and was also shown to inhibit infection at similar concentrations. Viral uncoating studies demonstrate that Retro-2.1 inhibits BKPyV infectivity in a manner similar to Retro-2. These studies demonstrate that improved analogs of Retro-2 can inhibit infection at lower dosages than Retro-2 and further optimization of these compounds may lead to effective treatment options for those suffering from JCPyV infection and PML.
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Affiliation(s)
- Tashania Treasure
- Department of Biological Sciences, State University of New York, Cortland, Cortland, New York
| | - Christian D S Nelson
- Department of Biological Sciences, State University of New York, Cortland, Cortland, New York
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39
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Chen YJ, Williams JM, Arvan P, Tsai B. Reticulon protects the integrity of the ER membrane during ER escape of large macromolecular protein complexes. J Cell Biol 2020; 219:133556. [PMID: 31895406 PMCID: PMC7041682 DOI: 10.1083/jcb.201908182] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/28/2019] [Accepted: 11/24/2019] [Indexed: 02/08/2023] Open
Abstract
Escape of large macromolecular complexes from the endoplasmic reticulum (ER), such as a viral particle or cellular aggregate, likely induces mechanical stress initiated on the luminal side of the ER membrane, which may threaten its integrity. How the ER responds to this threat remains unknown. Here we demonstrate that the cytosolic leaflet ER morphogenic protein reticulon (RTN) protects ER membrane integrity when polyomavirus SV40 escapes the ER to reach the cytosol en route to infection. SV40 coopts an intrinsic RTN function, as we also found that RTN prevents membrane damage during ER escape of a misfolded proinsulin aggregate destined for lysosomal degradation via ER-phagy. Our studies reveal that although ER membrane integrity may be threatened during ER escape of large macromolecular protein complexes, the action of RTN counters this, presumably by deploying its curvature-inducing activity to provide membrane flexibility and stability to limit mechanical stress imposed on the ER membrane.
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Affiliation(s)
- Yu-Jie Chen
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Jeffrey M Williams
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Peter Arvan
- Division of Metabolism Endocrinology and Diabetes, Comprehensive Diabetes Center, University of Michigan Medical School, Ann Arbor, MI
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
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40
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Bosso M, Prelli Bozzo C, Hotter D, Volcic M, Stürzel CM, Rammelt A, Ni Y, Urban S, Becker M, Schelhaas M, Wittmann S, Christensen MH, Schmidt FI, Gramberg T, Sparrer KMJ, Sauter D, Kirchhoff F. Nuclear PYHIN proteins target the host transcription factor Sp1 thereby restricting HIV-1 in human macrophages and CD4+ T cells. PLoS Pathog 2020; 16:e1008752. [PMID: 32760121 PMCID: PMC7433898 DOI: 10.1371/journal.ppat.1008752] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/18/2020] [Accepted: 06/26/2020] [Indexed: 02/02/2023] Open
Abstract
Members of the family of pyrin and HIN domain containing (PYHIN) proteins play an emerging role in innate immunity. While absent in melanoma 2 (AIM2) acts a cytosolic sensor of non-self DNA and plays a key role in inflammasome assembly, the γ-interferon-inducible protein 16 (IFI16) restricts retroviral gene expression by sequestering the transcription factor Sp1. Here, we show that the remaining two human PYHIN proteins, i.e. myeloid cell nuclear differentiation antigen (MNDA) and pyrin and HIN domain family member 1 (PYHIN1 or IFIX) share this antiretroviral function of IFI16. On average, knock-down of each of these three nuclear PYHIN proteins increased infectious HIV-1 yield from human macrophages by more than an order of magnitude. Similarly, knock-down of IFI16 strongly increased virus transcription and production in primary CD4+ T cells. The N-terminal pyrin domain (PYD) plus linker region containing a nuclear localization signal (NLS) were generally required and sufficient for Sp1 sequestration and anti-HIV-1 activity of IFI16, MNDA and PYHIN1. Replacement of the linker region of AIM2 by the NLS-containing linker of IFI16 resulted in a predominantly nuclear localization and conferred direct antiviral activity to AIM2 while attenuating its ability to form inflammasomes. The reverse change caused nuclear-to-cytoplasmic relocalization of IFI16 and impaired its antiretroviral activity but did not result in inflammasome assembly. We further show that the Zn-finger domain of Sp1 is critical for the interaction with IFI16 supporting that pyrin domains compete with DNA for Sp1 binding. Finally, we found that human PYHIN proteins also inhibit Hepatitis B virus and simian vacuolating virus 40 as well as the LINE-1 retrotransposon. Altogether, our data show that IFI16, PYHIN1 and MNDA restrict HIV-1 and other viral pathogens by interfering with Sp1-dependent gene expression and support an important role of nuclear PYHIN proteins in innate antiviral immunity.
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Affiliation(s)
- Matteo Bosso
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Meta Volcic
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Annika Rammelt
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Miriam Becker
- Institute of Cellular Virology, ZMBE, University of Münster, Münster, Germany
| | - Mario Schelhaas
- Institute of Cellular Virology, ZMBE, University of Münster, Münster, Germany
| | - Sabine Wittmann
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Thomas Gramberg
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
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41
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Wan Q, Song D, Li H, He ML. Stress proteins: the biological functions in virus infection, present and challenges for target-based antiviral drug development. Signal Transduct Target Ther 2020; 5:125. [PMID: 32661235 PMCID: PMC7356129 DOI: 10.1038/s41392-020-00233-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/26/2020] [Accepted: 06/13/2020] [Indexed: 02/06/2023] Open
Abstract
Stress proteins (SPs) including heat-shock proteins (HSPs), RNA chaperones, and ER associated stress proteins are molecular chaperones essential for cellular homeostasis. The major functions of HSPs include chaperoning misfolded or unfolded polypeptides, protecting cells from toxic stress, and presenting immune and inflammatory cytokines. Regarded as a double-edged sword, HSPs also cooperate with numerous viruses and cancer cells to promote their survival. RNA chaperones are a group of heterogeneous nuclear ribonucleoproteins (hnRNPs), which are essential factors for manipulating both the functions and metabolisms of pre-mRNAs/hnRNAs transcribed by RNA polymerase II. hnRNPs involve in a large number of cellular processes, including chromatin remodelling, transcription regulation, RNP assembly and stabilization, RNA export, virus replication, histone-like nucleoid structuring, and even intracellular immunity. Dysregulation of stress proteins is associated with many human diseases including human cancer, cardiovascular diseases, neurodegenerative diseases (e.g., Parkinson’s diseases, Alzheimer disease), stroke and infectious diseases. In this review, we summarized the biologic function of stress proteins, and current progress on their mechanisms related to virus reproduction and diseases caused by virus infections. As SPs also attract a great interest as potential antiviral targets (e.g., COVID-19), we also discuss the present progress and challenges in this area of HSP-based drug development, as well as with compounds already under clinical evaluation.
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Affiliation(s)
- Qianya Wan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Dan Song
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Huangcan Li
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Ming-Liang He
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China. .,CityU Shenzhen Research Institute, Shenzhen, China.
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Ubqln4 Facilitates Endoplasmic Reticulum-to-Cytosol Escape of a Nonenveloped Virus during Infection. J Virol 2020; 94:JVI.00103-20. [PMID: 32161173 DOI: 10.1128/jvi.00103-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/09/2020] [Indexed: 12/14/2022] Open
Abstract
The nonenveloped polyomavirus simian virus 40 (SV40) must penetrate the host endoplasmic reticulum (ER) membrane to enter the cytosol in order to promote infection. How this is accomplished is not entirely clear. Here, we demonstrate that the cytosolic chaperone Ubiquilin4 (Ubqln4) binds directly to the ER membrane J proteins B12 and B14. Strategically localized at the ER-cytosol interface, Ubqln4 captures SV40 emerging from the ER, thereby facilitating escape of the virus from the ER into the cytosol, which leads to infection. Strikingly, Ubqln4 engages the J proteins in a J-domain-independent manner, in contrast to the previously reported Hsc70-Hsp105-SGTA-Bag2 cytosolic complex that also mediates SV40 ER-to-cytosol transport. Our results also reveal that the H domain and STI1 motif (1-2) of Ubqln4 support J protein binding, essential for SV40 infection. Together, these data further clarify the molecular basis by which a nonenveloped virus escapes a host membrane during infectious entry.IMPORTANCE How a nonenveloped virus escapes from a host membrane to promote infection remains enigmatic. In the case of the nonenveloped polyomavirus SV40, penetration of the ER membrane to reach the cytosol is a decisive virus infection step. In this study, we found a new host factor called Ubqln4 that facilitates escape of SV40 from the ER into the cytosol, thereby providing a path for the virus to enter the nucleus to cause infection.
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43
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Dobson SJ, Mankouri J, Whitehouse A. Identification of potassium and calcium channel inhibitors as modulators of polyomavirus endosomal trafficking. Antiviral Res 2020; 179:104819. [PMID: 32389733 PMCID: PMC7205714 DOI: 10.1016/j.antiviral.2020.104819] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/02/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022]
Abstract
During virus entry, members of the Polyomaviridae transit the endolysosomal network en route to the endoplasmic reticulum (ER), from which degraded capsids escape into the cytoplasm and enter the nucleus. Emerging evidence suggests that viruses require both endosomal acidification and the correct ionic balance of K+ and Ca2+ ions in endosomes for correct virus trafficking and genome release. Here, using two polyomaviruses with different capsid architectures, namely Simian virus 40 (SV40) and Merkel cell polyomavirus (MCPyV), we describe methods to rapidly quantify virus infection using IncuCyte ZOOM imaging analysis, and use this system to investigate the role of both K+ and Ca2+ channels during the early stages of virus entry. Using broad spectrum blockers of both K+ and Ca2+ channels to specifically target host cell ion channel functionality, we show that MCPyV, but not SV40 can be inhibited by K+ channel modulators, whilst both viruses are restricted by the broad spectrum Ca2+ channel inhibitor verapamil. Using a panel of more specific Ca2+ blockers, we show that both MCPyV and SV40 are dependent on the activity of two-pore Ca2+ channels (TPCs), as the TPC-specific blocker tetrandrine prevented capsid disassembly and nuclear transport required for virus entry. We therefore reveal a novel target to restrict the entry of polyomaviruses, which given the known role of TPCs during endolysosomal-ER fusion, is likely to be applicable to other viruses that transit this pathway. We describe novel high-throughput assays to study SV40 and MCPyV infection. MCPyV, but not SV40, is sensitive to K+ channel inhibition. Verapamil inhibits MCPyV and SV40 infection. Tetrandrine is a potent inhibitor of MCPyV and SV40 infection. Two-pore channel 1/2 activity is essential for polyomavirus entry.
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Affiliation(s)
- Samuel J Dobson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, United Kingdom
| | - Jamel Mankouri
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, United Kingdom; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom.
| | - Adrian Whitehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, United Kingdom; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom.
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44
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Aviner R, Frydman J. Proteostasis in Viral Infection: Unfolding the Complex Virus-Chaperone Interplay. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a034090. [PMID: 30858229 DOI: 10.1101/cshperspect.a034090] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Viruses are obligate intracellular parasites that rely on their hosts for protein synthesis, genome replication, and viral particle production. As such, they have evolved mechanisms to divert host resources, including molecular chaperones, facilitate folding and assembly of viral proteins, stabilize complex structures under constant mutational pressure, and modulate signaling pathways to dampen antiviral responses and prevent premature host death. Biogenesis of viral proteins often presents unique challenges to the proteostasis network, as it requires the rapid and orchestrated production of high levels of a limited number of multifunctional, multidomain, and aggregation-prone proteins. To overcome such challenges, viruses interact with the folding machinery not only as clients but also as regulators of chaperone expression, function, and subcellular localization. In this review, we summarize the main types of interactions between viral proteins and chaperones during infection, examine evolutionary aspects of this relationship, and discuss the potential of using chaperone inhibitors as broad-spectrum antivirals.
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Affiliation(s)
- Ranen Aviner
- Department of Biology, Stanford University, Stanford, California 94305
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, California 94305.,Department of Genetics, Stanford University, Stanford, California 94305
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Selective EMC subunits act as molecular tethers of intracellular organelles exploited during viral entry. Nat Commun 2020; 11:1127. [PMID: 32111841 PMCID: PMC7048770 DOI: 10.1038/s41467-020-14967-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 02/10/2020] [Indexed: 12/22/2022] Open
Abstract
Although viruses must navigate the complex host endomembrane system to infect cells, the strategies used to achieve this is unclear. During entry, polyomavirus SV40 is sorted from the late endosome (LE) to the endoplasmic reticulum (ER) to cause infection, yet how this is accomplished remains enigmatic. Here we find that EMC4 and EMC7, two ER membrane protein complex (EMC) subunits, support SV40 infection by promoting LE-to-ER targeting of the virus. They do this by engaging LE-associated Rab7, presumably to stabilize contact between the LE and ER. These EMC subunits also bind to the ER-resident fusion machinery component syntaxin18, which is required for SV40-arrival to the ER. Our data suggest that EMC4 and EMC7 act as molecular tethers, inter-connecting two intracellular compartments to enable efficient transport of a virus between these compartments. As LE-to-ER transport of cellular cargos is unclear, our results have broad implications for illuminating inter-organelle cargo transport. The endoplasmic reticulum membrane protein complex (EMC) is known to play a role in SV40 viral infection but precise mechanisms are unclear. Here, the authors report that the EMC acts as tether of late endosome–endoplasmic reticulum interorganellar membrane contact sites to promote SV40 viral infection.
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46
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Comparative Transcriptome Analysis of Two Cucumber Cultivars with Different Sensitivity to Cucumber Mosaic Virus Infection. Pathogens 2020; 9:pathogens9020145. [PMID: 32098056 PMCID: PMC7168641 DOI: 10.3390/pathogens9020145] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 12/15/2022] Open
Abstract
Cucumber mosaic virus (CMV), with extremely broad host range including both monocots and dicots around the world, belongs to most important viral crop threats. Either natural or genetically constructed sources of resistance are being intensively investigated; for this purpose, exhaustive knowledge of molecular virus-host interaction during compatible and incompatible infection is required. New technologies and computer-based “omics” on various levels contribute markedly to this topic. In this work, two cucumber cultivars with different response to CMV challenge were tested, i.e., sensitive cv. Vanda and resistant cv. Heliana. The transcriptomes were prepared from both cultivars at 18 days after CMV or mock inoculation. Subsequently, four independent comparative analyses of obtained data were performed, viz. mock- and CMV-inoculated samples within each cultivar, samples from mock-inoculated cultivars to each other and samples from virus-inoculated cultivars to each other. A detailed picture of CMV-influenced genes, as well as constitutive differences in cultivar-specific gene expression was obtained. The compatible CMV infection of cv. Vanda caused downregulation of genes involved in photosynthesis, and induction of genes connected with protein production and modification, as well as components of signaling pathways. CMV challenge caused practically no change in the transcription profile of the cv. Heliana. The main differences between constitutive transcription activity of the two cultivars relied in the expression of genes responsible for methylation, phosphorylation, cell wall organization and carbohydrate metabolism (prevailing in cv. Heliana), or chromosome condensation and glucan biosynthesis (prevailing in cv. Vanda). Involvement of several genes in the resistant cucumber phenotype was predicted; this can be after biological confirmation potentially applied in breeding programs for virus-resistant crops.
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47
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Abstract
Influenza A virus (IAV) is an enveloped virus of the Orthomyxoviridae with a negative-sense single-stranded RNA genome. During virus cell entry, viral and cellular cues are delivered in a stepwise manner within two distinct cellular compartments-the endosomes and the cytosol. Endosome maturation primes the viral core for uncoating by cytosolic host proteins and host-mediated virus disaggregation is essential for genome import and replication in the nucleus. Recent evidence shows that two well-known cellular proteins-histone deacetylase 6 (HDAC6) and karyopherin-β2 (kapβ2)-uncoat influenza virus. HDAC6 is 1 of 11 HDACs and an X-linked, cytosolic lysine deacetylase. Under normal cellular conditions HDAC6 is the tubulin deacetylase. Under proteasomal stress HDAC6 binds unanchored ubiquitin, dynein and myosin II to sequester misfolded protein aggregates for autophagy. Kapβ2 is a member of the importin β family that transports RNA-binding proteins into the nucleus by binding to disordered nuclear localization signals (NLSs) known as PY-NLS. Kapβ2 is emerging as a universal uncoating factor for IAV and human immunodeficiency virus type 1 (HIV-1). Kapβ2 can also reverse liquid-liquid phase separation (LLPS) of RNA-binding proteins by promoting their disaggregation. Thus, it is becoming evident that key players in the management of cellular condensates and membraneless organelles are potent virus uncoating factors. This emerging concept reveals implications in viral pathogenesis, as well as, the promise for cell-targeted therapeutic strategies to block universal virus uncoating pathways hijacked by enveloped RNA viruses.
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Affiliation(s)
- Yohei Yamauchi
- School of Cellular & Molecular Medicine, University of Bristol, Bristol, United Kingdom.
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48
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Kane JR, Fong S, Shaul J, Frommlet A, Frank AO, Knapp M, Bussiere DE, Kim P, Ornelas E, Cuellar C, Hyrina A, Abend JR, Wartchow CA. A polyomavirus peptide binds to the capsid VP1 pore and has potent antiviral activity against BK and JC polyomaviruses. eLife 2020; 9:50722. [PMID: 31960795 PMCID: PMC6974358 DOI: 10.7554/elife.50722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/30/2019] [Indexed: 12/18/2022] Open
Abstract
In pursuit of therapeutics for human polyomaviruses, we identified a peptide derived from the BK polyomavirus (BKV) minor structural proteins VP2/3 that is a potent inhibitor of BKV infection with no observable cellular toxicity. The thirteen-residue peptide binds to major structural protein VP1 with single-digit nanomolar affinity. Alanine-scanning of the peptide identified three key residues, substitution of each of which results in ~1000 fold loss of binding affinity with a concomitant reduction in antiviral activity. Structural studies demonstrate specific binding of the peptide to the pore of pentameric VP1. Cell-based assays demonstrate nanomolar inhibition (EC50) of BKV infection and suggest that the peptide acts early in the viral entry pathway. Homologous peptide exhibits similar binding to JC polyomavirus VP1 and inhibits infection with similar potency to BKV in a model cell line. Lastly, these studies validate targeting the VP1 pore as a novel strategy for the development of anti-polyomavirus agents.
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Affiliation(s)
- Joshua R Kane
- Infectious Diseases, Novartis Institutes for BioMedical Research, Emeryville, United States.,Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Susan Fong
- Infectious Diseases, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Jacob Shaul
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Alexandra Frommlet
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Andreas O Frank
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Mark Knapp
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Dirksen E Bussiere
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Peter Kim
- Infectious Diseases, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Elizabeth Ornelas
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Carlos Cuellar
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Anastasia Hyrina
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Johanna R Abend
- Infectious Diseases, Novartis Institutes for BioMedical Research, Emeryville, United States
| | - Charles A Wartchow
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Emeryville, United States
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49
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Horníková L, Bruštíková K, Forstová J. Microtubules in Polyomavirus Infection. Viruses 2020; 12:E121. [PMID: 31963741 PMCID: PMC7019765 DOI: 10.3390/v12010121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/12/2022] Open
Abstract
Microtubules, part of the cytoskeleton, are indispensable for intracellular movement, cell division, and maintaining cell shape and polarity. In addition, microtubules play an important role in viral infection. In this review, we summarize the role of the microtubules' network during polyomavirus infection. Polyomaviruses usurp microtubules and their motors to travel via early and late acidic endosomes to the endoplasmic reticulum. As shown for SV40, kinesin-1 and microtubules are engaged in the release of partially disassembled virus from the endoplasmic reticulum to the cytosol, and dynein apparently assists in the further disassembly of virions prior to their translocation to the cell nucleus-the place of their replication. Polyomavirus gene products affect the regulation of microtubule dynamics. Early T antigens destabilize microtubules and cause aberrant mitosis. The role of these activities in tumorigenesis has been documented. However, its importance for productive infection remains elusive. On the other hand, in the late phase of infection, the major capsid protein, VP1, of the mouse polyomavirus, counteracts T-antigen-induced destabilization. It physically binds microtubules and stabilizes them. The interaction results in the G2/M block of the cell cycle and prolonged S phase, which is apparently required for successful completion of the viral replication cycle.
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Affiliation(s)
| | | | - Jitka Forstová
- Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, 25250 Vestec, Czech Republic; (L.H.); (K.B.)
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50
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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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