1
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Arita M, Fuchino H. Characterization of Anti-Poliovirus Compounds Isolated from Edible Plants. Viruses 2023; 15:v15040903. [PMID: 37112883 PMCID: PMC10145814 DOI: 10.3390/v15040903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/29/2023] Open
Abstract
Poliovirus (PV) is the causative agent of poliomyelitis and is a target of the global eradication programs of the World Health Organization (WHO). After eradication of type 2 and 3 wild-type PVs, vaccine-derived PV remains a substantial threat against the eradication as well as type 1 wild-type PV. Antivirals could serve as an effective means to suppress the outbreak; however, no anti-PV drugs have been approved at present. Here, we screened for effective anti-PV compounds in a library of edible plant extracts (a total of 6032 extracts). We found anti-PV activity in the extracts of seven different plant species. We isolated chrysophanol and vanicoside B (VCB) as the identities of the anti-PV activities of the extracts of Rheum rhaponticum and Fallopia sachalinensis, respectively. VCB targeted the host PI4KB/OSBP pathway for its anti-PV activity (EC50 = 9.2 μM) with an inhibitory effect on in vitro PI4KB activity (IC50 = 5.0 μM). This work offers new insights into the anti-PV activity in edible plants that may serve as potent antivirals for PV infection.
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Affiliation(s)
- Minetaro Arita
- Department of Virology II, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama-shi 208-0011, Tokyo, Japan
| | - Hiroyuki Fuchino
- Research Center for Medicinal Plant Resources, National Institutes of Biomedical Innovation, Health and Nutrition, 1-2 Hachimandai, Tsukuba 305-0843, Ibaraki, Japan
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2
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Jackson T, Belsham GJ. Picornaviruses: A View from 3A. Viruses 2021; 13:v13030456. [PMID: 33799649 PMCID: PMC7999760 DOI: 10.3390/v13030456] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/14/2022] Open
Abstract
Picornaviruses are comprised of a positive-sense RNA genome surrounded by a protein shell (or capsid). They are ubiquitous in vertebrates and cause a wide range of important human and animal diseases. The genome encodes a single large polyprotein that is processed to structural (capsid) and non-structural proteins. The non-structural proteins have key functions within the viral replication complex. Some, such as 3Dpol (the RNA dependent RNA polymerase) have conserved functions and participate directly in replicating the viral genome, whereas others, such as 3A, have accessory roles. The 3A proteins are highly divergent across the Picornaviridae and have specific roles both within and outside of the replication complex, which differ between the different genera. These roles include subverting host proteins to generate replication organelles and inhibition of cellular functions (such as protein secretion) to influence virus replication efficiency and the host response to infection. In addition, 3A proteins are associated with the determination of host range. However, recent observations have challenged some of the roles assigned to 3A and suggest that other viral proteins may carry them out. In this review, we revisit the roles of 3A in the picornavirus life cycle. The 3AB precursor and mature 3A have distinct functions during viral replication and, therefore, we have also included discussion of some of the roles assigned to 3AB.
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Affiliation(s)
- Terry Jackson
- The Pirbright Institute, Pirbright, Woking, Surrey GU24 0NF, UK;
| | - Graham J. Belsham
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
- Correspondence:
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3
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Li X, Wang M, Cheng A, Wen X, Ou X, Mao S, Gao Q, Sun D, Jia R, Yang Q, Wu Y, Zhu D, Zhao X, Chen S, Liu M, Zhang S, Liu Y, Yu Y, Zhang L, Tian B, Pan L, Chen X. Enterovirus Replication Organelles and Inhibitors of Their Formation. Front Microbiol 2020; 11:1817. [PMID: 32973693 PMCID: PMC7468505 DOI: 10.3389/fmicb.2020.01817] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/10/2020] [Indexed: 12/23/2022] Open
Abstract
Enteroviral replication reorganizes the cellular membrane. Upon infection, viral proteins and hijacked host factors generate unique structures called replication organelles (ROs) to replicate their viral genomes. ROs promote efficient viral genome replication, coordinate the steps of the viral replication cycle, and protect viral RNA from host immune responses. More recent researches have focused on the ultrastructure structures, formation mechanism, and functions in the virus life cycle of ROs. Dynamic model of enterovirus ROs structure is proposed, and the secretory pathway, the autophagy pathway, and lipid metabolism are found to be associated in the formation of ROs. With deeper understanding of ROs, some compounds have been found to show inhibitory effects on viral replication by targeting key proteins in the process of ROs formation. Here, we review the recent findings concerning the role, morphology, biogenesis, formation mechanism, and inhibitors of enterovirus ROs.
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Affiliation(s)
- Xinhong Li
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xingjian Wen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Leichang Pan
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaoyue Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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4
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Laajala M, Reshamwala D, Marjomäki V. Therapeutic targets for enterovirus infections. Expert Opin Ther Targets 2020; 24:745-757. [DOI: 10.1080/14728222.2020.1784141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mira Laajala
- Department of Biological and Environmental Science/Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Dhanik Reshamwala
- Department of Biological and Environmental Science/Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Varpu Marjomäki
- Department of Biological and Environmental Science/Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
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5
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Martínez JL, Arias CF. Role of the Guanine Nucleotide Exchange Factor GBF1 in the Replication of RNA Viruses. Viruses 2020; 12:E682. [PMID: 32599855 PMCID: PMC7354614 DOI: 10.3390/v12060682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/06/2020] [Accepted: 04/06/2020] [Indexed: 12/12/2022] Open
Abstract
The guanine nucleotide exchange factor GBF1 is a well-known factor that can activate different ADP-ribosylation factor (Arf) proteins during the regulation of different cellular vesicular transport processes. In the last decade, it has become increasingly evident that GBF1 can also regulate different steps of the replication cycle of RNA viruses belonging to different virus families. GBF1 has been shown not only to facilitate the intracellular traffic of different viral and cellular elements during infection, but also to modulate the replication of viral RNA, the formation and maturation of viral replication complexes, and the processing of viral proteins through mechanisms that do not depend on its canonical role in intracellular transport. Here, we review the various roles that GBF1 plays during the replication of different RNA viruses.
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Affiliation(s)
| | - Carlos F. Arias
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 4510, Morelos, Mexico;
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6
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A Redundant Mechanism of Recruitment Underlies the Remarkable Plasticity of the Requirement of Poliovirus Replication for the Cellular ArfGEF GBF1. J Virol 2019; 93:JVI.00856-19. [PMID: 31375590 DOI: 10.1128/jvi.00856-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/26/2019] [Indexed: 12/24/2022] Open
Abstract
The replication of many positive-strand RNA viruses [(+)RNA viruses] depends on the cellular protein GBF1, but its role in the replication process is not clear. In uninfected cells, GBF1 activates small GTPases of the Arf family and coordinates multiple steps of membrane metabolism, including functioning of the cellular secretory pathway. The nonstructural protein 3A of poliovirus and related viruses has been shown to directly interact with GBF1, likely mediating its recruitment to the replication complexes. Surprisingly, viral mutants with a severely reduced level of 3A-GBF1 interaction demonstrate minimal replication defects in cell culture. Here, we systematically investigated the conserved elements of GBF1 to understand which determinants are important to support poliovirus replication. We demonstrate that multiple GBF1 mutants inactive in cellular metabolism could still be fully functional in the replication complexes. Our results show that the Arf-activating property, but not the primary structure of the Sec7 domain, is indispensable for viral replication. They also suggest a redundant mechanism of recruitment of GBF1 to the replication sites, which is dependent not only on direct interaction of the protein with the viral protein 3A but also on determinants located in the noncatalytic C-terminal domains of GBF1. Such a double-targeting mechanism explains the previous observations of the remarkable tolerance of different levels of GBF1-3A interaction by the virus and likely constitutes an important element of the resilience of viral replication.IMPORTANCE Enteroviruses are a vast group of viruses associated with diverse human diseases, but only two of them could be controlled with vaccines, and effective antiviral therapeutics are lacking. Here, we investigated in detail the contribution of a cellular protein, GBF1, in the replication of poliovirus, a representative enterovirus. GBF1 supports the functioning of cellular membrane metabolism and is recruited to viral replication complexes upon infection. Our results demonstrate that the virus requires a limited subset of the normal GBF1 functions and reveal the elements of GBF1 essential to support viral replication under different conditions. Since diverse viruses often rely on the same cellular proteins for replication, understanding the mechanisms by which these proteins support infection is essential for the development of broad-spectrum antiviral therapeutics.
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7
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Schögler A, Caliaro O, Brügger M, Oliveira Esteves BI, Nita I, Gazdhar A, Geiser T, Alves MP. Modulation of the unfolded protein response pathway as an antiviral approach in airway epithelial cells. Antiviral Res 2018; 162:44-50. [PMID: 30550797 DOI: 10.1016/j.antiviral.2018.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/07/2018] [Accepted: 12/10/2018] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Rhinovirus (RV) infection is a major cause of cystic fibrosis (CF) lung morbidity with limited therapeutic options. Various diseases involving chronic inflammatory response and infection are associated with endoplasmic reticulum (ER) stress and subsequent activation of the unfolded protein response (UPR), an adaptive response to maintain cellular homeostasis. Recent evidence suggests impaired ER stress response in CF airway epithelial cells, this might be a reason for recurrent viral infection in CF. Therefore, assuming that ER stress inducing drugs have antiviral properties, we evaluated the activation of the UPR by selected ER stress inducers as an approach to control virus replication in the CF bronchial epithelium. METHODS We assessed the levels of UPR markers, namely the glucose-regulated protein 78 (Grp78) and the C/EBP homologous protein (CHOP), in primary CF and control bronchial epithelial cells and in a CF and control bronchial epithelial cell line before and after infection with RV. The cells were also pretreated with ER stress-inducing drugs and RV replication and shedding was measured by quantitative RT-PCR and by a TCID50 assay, respectively. Cell death was assessed by a lactate dehydrogenate (LDH) activity test in supernatants. RESULTS We observed a significantly impaired induction of Grp78 and CHOP in CF compare to control cells following RV infection. The ER stress response could be significantly induced in CF cells by pharmacological ER stress inducers Brefeldin A, Tunicamycin, and Thapsigargin. The chemical induction of the UPR pathway prior to RV infection of CF and control cells reduced viral replication and shedding by up to two orders of magnitude and protected cells from RV-induced cell death. CONCLUSION RV infection causes an impaired activation of the UPR in CF cells. Rescue of the ER stress response by chemical ER stress inducers reduced significantly RV replication in CF cells. Thus, pharmacological modulation of the UPR might represent a strategy to control respiratory virus replication in the CF bronchial epithelium.
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Affiliation(s)
- Aline Schögler
- Division of Respiratory Medicine, Department of Paediatrics, University Hospital Bern, Bern, Switzerland
| | - Oliver Caliaro
- Division of Respiratory Medicine, Department of Paediatrics, University Hospital Bern, Bern, Switzerland
| | - Melanie Brügger
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland; Institute of Virology and Immunology, Bern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Blandina I Oliveira Esteves
- Institute of Virology and Immunology, Bern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Izabela Nita
- Department of Pulmonary Medicine, University Hospital Bern, Bern, Switzerland; Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Amiq Gazdhar
- Department of Pulmonary Medicine, University Hospital Bern, Bern, Switzerland; Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Thomas Geiser
- Department of Pulmonary Medicine, University Hospital Bern, Bern, Switzerland; Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Marco P Alves
- Division of Respiratory Medicine, Department of Paediatrics, University Hospital Bern, Bern, Switzerland; Institute of Virology and Immunology, Bern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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8
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Delorme-Axford E, Abernathy E, Lennemann NJ, Bernard A, Ariosa A, Coyne CB, Kirkegaard K, Klionsky DJ. The exoribonuclease Xrn1 is a post-transcriptional negative regulator of autophagy. Autophagy 2018; 14:898-912. [PMID: 29465287 DOI: 10.1080/15548627.2018.1441648] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Macroautophagy/autophagy is a conserved catabolic process that promotes survival during stress. Autophagic dysfunction is associated with pathologies such as cancer and neurodegenerative diseases. Thus, autophagy must be strictly modulated at multiple levels (transcriptional, post-transcriptional, translational and post-translational) to prevent deregulation. Relatively little is known about the post-transcriptional control of autophagy. Here we report that the exoribonuclease Xrn1/XRN1 functions as a negative autophagy factor in the yeast Saccharomyces cerevisiae and in mammalian cells. In yeast, chromosomal deletion of XRN1 enhances autophagy and the frequency of autophagosome formation. Loss of Xrn1 results in the upregulation of autophagy-related (ATG) transcripts under nutrient-replete conditions, and this effect is dependent on the ribonuclease activity of Xrn1. Xrn1 expression is regulated by the yeast transcription factor Ash1 in rich conditions. In mammalian cells, siRNA depletion of XRN1 enhances autophagy and the replication of 2 picornaviruses. This work provides insight into the role of the RNA decay factor Xrn1/XRN1 as a post-transcriptional regulator of autophagy.
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Affiliation(s)
| | - Emma Abernathy
- b Department of Genetics , Stanford University School of Medicine , Stanford , CA , USA
| | | | - Amélie Bernard
- a Life Sciences Institute, University of Michigan , Ann Arbor , MI , USA
| | - Aileen Ariosa
- a Life Sciences Institute, University of Michigan , Ann Arbor , MI , USA
| | - Carolyn B Coyne
- c Department of Pediatrics , University of Pittsburgh , Pittsburgh , PA , USA
| | - Karla Kirkegaard
- b Department of Genetics , Stanford University School of Medicine , Stanford , CA , USA
| | - Daniel J Klionsky
- a Life Sciences Institute, University of Michigan , Ann Arbor , MI , USA
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9
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Raekiansyah M, Mori M, Nonaka K, Agoh M, Shiomi K, Matsumoto A, Morita K. Identification of novel antiviral of fungus-derived brefeldin A against dengue viruses. Trop Med Health 2017; 45:32. [PMID: 29093640 PMCID: PMC5658972 DOI: 10.1186/s41182-017-0072-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/09/2017] [Indexed: 11/19/2022] Open
Abstract
Microbial natural products possess a wide range of biological and biochemical potential. Among them, fungal secondary metabolites are one of the most important sources for discovering new drugs or lead compounds. In the present study, we explored substances produced by the strain Penicillium sp. FKI-7127 for its antiviral activity. We identified brefeldin A as a novel antiviral agent against dengue viruses. The inhibitory effect of brefeldin A was confirmed by virus titer and immunofluorescence assay. Brefeldin A inhibited dengue viruses regardless of serotypes and other related viruses including Zika virus and Japanese encephalitis virus. Time-of-addition study showed that brefeldin A exerts its antiviral effect at an early stage of the dengue virus (DENV) life cycle. These studies demonstrate that (i) brefeldin A could be used as a lead compound for drug development of anti-DENV and other related viruses and (ii) fungal metabolites are a potential and valuable source for dengue virus drug discovery.
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Affiliation(s)
- Muhareva Raekiansyah
- Department of Virology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
| | - Mihoko Mori
- Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan.,Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan
| | - Kenichi Nonaka
- Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan.,Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan
| | - Masanobu Agoh
- Department of Virology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
| | - Kazuro Shiomi
- Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan.,Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan
| | - Atsuko Matsumoto
- Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan.,Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan
| | - Kouichi Morita
- Department of Virology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
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10
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Abstract
Various viral diseases, such as acquired immunodeficiency syndrome, influenza, and hepatitis, have emerged as leading causes of human death worldwide. Scientific endeavor since invention of DNA-dependent RNA polymerase of pox virus in 1967 resulted in better understanding of virus replication and development of various novel therapeutic strategies. Despite considerable advancement in every facet of drug discovery process, development of commercially viable, safe, and effective drugs for these viruses still remains a big challenge. Decades of intense research yielded a handful of natural and synthetic therapeutic options. But emergence of new viruses and drug-resistant viral strains had made new drug development process a never-ending battle. Small-molecule fungal metabolites due to their vast diversity, stereochemical complexity, and preapproved biocompatibility always remain an attractive source for new drug discovery. Though, exploration of therapeutic importance of fungal metabolites has started early with discovery of penicillin, recent prediction asserted that only a small percentage (5-10%) of fungal species have been identified and much less have been scientifically investigated. Therefore, exploration of new fungal metabolites, their bioassay, and subsequent mechanistic study bears huge importance in new drug discovery endeavors. Though no fungal metabolites so far approved for antiviral treatment, many of these exhibited high potential against various viral diseases. This review comprehensively discussed about antiviral activities of fungal metabolites of diverse origin against some important viral diseases. This also highlighted the mechanistic details of inhibition of viral replication along with structure-activity relationship of some common and important classes of fungal metabolites.
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Affiliation(s)
- Biswajit G Roy
- Department of Chemistry, Sikkim University, Gangtok, India
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11
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Zhou J, Wang SQ, Wei JC, Zhang XM, Gao ZC, Liu K, Ma ZY, Chen PY, Zhou B. Mx Is Not Responsible for the Antiviral Activity of Interferon-α against Japanese Encephalitis Virus. Viruses 2017; 9:v9010005. [PMID: 28075421 PMCID: PMC5294974 DOI: 10.3390/v9010005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 12/14/2016] [Accepted: 12/28/2016] [Indexed: 12/11/2022] Open
Abstract
Mx proteins are interferon (IFN)-induced dynamin-like GTPases that are present in all vertebrates and inhibit the replication of myriad viruses. However, the role Mx proteins play in IFN-mediated suppression of Japanese encephalitis virus (JEV) infection is unknown. In this study, we set out to investigate the effects of Mx1 and Mx2 expression on the interferon-α (IFNα) restriction of JEV replication. To evaluate whether the inhibitory activity of IFNα on JEV is dependent on Mx1 or Mx2, we knocked down Mx1 or Mx2 with siRNA in IFNα-treated PK-15 cells and BHK-21 cells, then challenged them with JEV; the production of progeny virus was assessed by plaque assay, RT-qPCR, and Western blotting. Our results demonstrated that depletion of Mx1 or Mx2 did not affect JEV restriction imposed by IFNα, although these two proteins were knocked down 66% and 79%, respectively. Accordingly, expression of exogenous Mx1 or Mx2 did not change the inhibitory activity of IFNα to JEV. In addition, even though virus-induced membranes were damaged by Brefeldin A (BFA), overexpressing porcine Mx1 or Mx2 did not inhibit JEV proliferation. We found that BFA inhibited JEV replication, not maturation, suggesting that BFA could be developed into a novel antiviral reagent. Collectively, our findings demonstrate that IFNα inhibits JEV infection by Mx-independent pathways.
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Affiliation(s)
- Jing Zhou
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Shi-Qi Wang
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jian-Chao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China.
| | - Xiao-Min Zhang
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Zhi-Can Gao
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China.
| | - Zhi-Yong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China.
| | - Pu-Yan Chen
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Bin Zhou
- Key Laboratory of Animal Diseases Diagnosis and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
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12
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Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly. Viruses 2016; 8:v8060160. [PMID: 27338443 PMCID: PMC4926180 DOI: 10.3390/v8060160] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles.
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13
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Vázquez-Calvo Á, Caridi F, González-Magaldi M, Saiz JC, Sobrino F, Martín-Acebes MA. The Amino Acid Substitution Q65H in the 2C Protein of Swine Vesicular Disease Virus Confers Resistance to Golgi Disrupting Drugs. Front Microbiol 2016; 7:612. [PMID: 27199941 PMCID: PMC4846857 DOI: 10.3389/fmicb.2016.00612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/13/2016] [Indexed: 11/13/2022] Open
Abstract
Swine vesicular disease virus (SVDV) is a porcine pathogen and a member of the species Enterovirus B within the Picornaviridae family. Brefeldin A (BFA) is an inhibitor of guanine nucleotide exchange factors of Arf proteins that induces Golgi complex disassembly and alters the cellular secretory pathway. Since BFA has been shown to inhibit the RNA replication of different enteroviruses, including SVDV, we have analyzed the effect of BFA and of golgicide A (GCA), another Golgi disrupting drug, on SVDV multiplication. BFA and GCA similarly inhibited SVDV production. To investigate the molecular basis of the antiviral effect of BFA, SVDV mutants with increased resistance to BFA were isolated. A single amino acid substitution, Q65H, in the non-structural protein 2C was found to be responsible for increased resistance to BFA. These results provide new insight into the relationship of enteroviruses with the components of the secretory pathway and on the role of SVDV 2C protein in this process.
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Affiliation(s)
- Ángela Vázquez-Calvo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM)Madrid, Spain; Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Madrid, Spain
| | - Flavia Caridi
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM) Madrid, Spain
| | | | - Juan-Carlos Saiz
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Madrid, Spain
| | | | - Miguel A Martín-Acebes
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM)Madrid, Spain; Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Madrid, Spain
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14
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BPIFB6 Regulates Secretory Pathway Trafficking and Enterovirus Replication. J Virol 2016; 90:5098-107. [PMID: 26962226 DOI: 10.1128/jvi.00170-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/06/2016] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Bactericidal/permeability-increasing protein (BPI) fold-containing family B, member 3 (BPIFB3) is an endoplasmic reticulum (ER)-localized host factor that negatively regulates coxsackievirus B (CVB) replication through its control of the autophagic pathway. Here, we show that another member of the BPIFB family, BPIFB6, functions as a positive regulator of CVB, and other enterovirus, replication by controlling secretory pathway trafficking and Golgi complex morphology. We show that similar to BPIFB3, BPIFB6 localizes exclusively to the ER, where it associates with other members of the BPIFB family. However, in contrast to our findings that RNA interference (RNAi)-mediated silencing of BPIFB3 greatly enhances CVB replication, we show that silencing of BPIFB6 expression dramatically suppresses enterovirus replication in a pan-viral manner. Mechanistically, we show that loss of BPIFB6 expression induces pronounced alterations in retrograde and anterograde trafficking, which correlate with dramatic fragmentation of the Golgi complex. Taken together, these data implicate BPIFB6 as a key regulator of secretory pathway trafficking and viral replication and suggest that members of the BPIFB family participate in diverse host cell functions to regulate virus infections. IMPORTANCE Enterovirus infections are associated with a number of severe pathologies, such as aseptic meningitis, dilated cardiomyopathy, type I diabetes, paralysis, and even death. These viruses, which include coxsackievirus B (CVB), poliovirus (PV), and enterovirus 71 (EV71), co-opt the host cell secretory pathway, which controls the transport of proteins from the endoplasmic reticulum to the Golgi complex, to facilitate their replication. Here we report on the identification of a novel regulator of the secretory pathway, bactericidal/permeability-increasing protein (BPI) fold-containing family B, member 6 (BPIFB6), whose expression is required for enterovirus replication. We show that loss of BPIFB6 expression correlates with pronounced defects in the secretory pathway and greatly reduces the replication of CVB, PV, and EV71. Our results thus identify a novel host cell therapeutic target whose function could be targeted to alter enterovirus replication.
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15
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Berryman S, Moffat K, Harak C, Lohmann V, Jackson T. Foot-and-mouth disease virus replicates independently of phosphatidylinositol 4-phosphate and type III phosphatidylinositol 4-kinases. J Gen Virol 2016; 97:1841-1852. [PMID: 27093462 PMCID: PMC5156328 DOI: 10.1099/jgv.0.000485] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Picornaviruses form replication complexes in association with membranes in structures called replication organelles. Common themes to emerge from studies of picornavirus replication are the need for cholesterol and phosphatidylinositol 4-phosphate (PI4P). In infected cells, type III phosphatidylinositol 4-kinases (PI4KIIIs) generate elevated levels of PI4P, which is then exchanged for cholesterol at replication organelles. For the enteroviruses, replication organelles form at Golgi membranes in a process that utilizes PI4KIIIβ. Other picornaviruses, for example the cardioviruses, are believed to initiate replication at the endoplasmic reticulum and subvert PI4KIIIα to generate PI4P. Here we investigated the role of PI4KIII in foot-and-mouth disease virus (FMDV) replication. Our results showed that, in contrast to the enteroviruses and the cardioviruses, FMDV replication does not require PI4KIII (PI4KIIIα and PI4KIIIβ), and PI4P levels do not increase in FMDV-infected cells and PI4P is not seen at replication organelles. These results point to a unique requirement towards lipids at the FMDV replication membranes.
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Affiliation(s)
- Stephen Berryman
- The Pirbright Institute, Ash Rd, Pirbright, Surrey, GU24 0NF, UK
| | - Katy Moffat
- The Pirbright Institute, Ash Rd, Pirbright, Surrey, GU24 0NF, UK
| | - Christian Harak
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Volker Lohmann
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Terry Jackson
- The Pirbright Institute, Ash Rd, Pirbright, Surrey, GU24 0NF, UK
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16
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Arita M. Mechanism of Poliovirus Resistance to Host Phosphatidylinositol-4 Kinase III β Inhibitor. ACS Infect Dis 2016; 2:140-8. [PMID: 27624965 DOI: 10.1021/acsinfecdis.5b00122] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Phosphatidylinositol-4 kinase III β (PI4KB) and oxysterol-binding protein (OSBP) family I have been identified as the major targets of anti-enterovirus drug candidates. Resistance mutations in poliovirus (PV) to these inhibitors have been identified in viral 3A protein, represented by a G5318A (3A-Ala70Thr) mutation, but the mechanism of viral resistance to host PI4KB/OSBP inhibitors remained unknown. In this study, we found that a G5318A mutation enhances the basal levels of phosphatidylinositol 4-phosphate (PI4P) and of the 3A protein and decreases the levels of the 3AB protein during PV replication. The 3A protein acted as a major effector responsible for the resistance to PI4KB inhibitor, but did not enhance the PI4KB activity in vitro in contrast to the 2C, 2BC, 3AB, and 3D proteins. The 3AB protein acted as the primary target of a G5318A mutation and also as an effector. We identified novel resistance mutations to a PI4KB inhibitor [C5151U (3A-T14M) and C5366U (3A-H86Y) mutations] and found that there is a positive correlation between the extent of the resistance phenotype and the levels of the 3A proteins. These results suggested that the 3A protein overproduced by enhanced processing of the 3AB protein with the resistance mutations overcomes the inhibitory effect of PI4KB inhibitor on PV replication independently of the hyperactivation of the PI4KB/OSBP pathway.
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Affiliation(s)
- Minetaro Arita
- Department
of Virology II, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama-shi, Tokyo 208-0011, Japan
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17
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de Armas-Rillo L, Valera MS, Marrero-Hernández S, Valenzuela-Fernández A. Membrane dynamics associated with viral infection. Rev Med Virol 2016; 26:146-60. [PMID: 26817660 PMCID: PMC5066672 DOI: 10.1002/rmv.1872] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 12/15/2022]
Abstract
Viral replication and spreading are fundamental events in the viral life cycle, accounting for the assembly and egression of nascent virions, events that are directly associated with viral pathogenesis in target hosts. These processes occur in cellular compartments that are modified by specialized viral proteins, causing a rearrangement of different cell membranes in infected cells and affecting the ER, mitochondria, Golgi apparatus, vesicles and endosomes, as well as processes such as autophagic membrane flux. In fact, the activation or inhibition of membrane trafficking and other related activities are fundamental to ensure the adequate replication and spreading of certain viruses. In this review, data will be presented that support the key role of membrane dynamics in the viral cycle, especially in terms of the assembly, egression and infection processes. By defining how viruses orchestrate these events it will be possible to understand how they successfully complete their route of infection, establishing viral pathogenesis and provoking disease. © 2015 The Authors Reviews in Medical Virology Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Laura de Armas-Rillo
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - María-Soledad Valera
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Sara Marrero-Hernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Tenerife, Spain
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18
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Reid CR, Airo AM, Hobman TC. The Virus-Host Interplay: Biogenesis of +RNA Replication Complexes. Viruses 2015; 7:4385-413. [PMID: 26287230 PMCID: PMC4576186 DOI: 10.3390/v7082825] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/21/2015] [Accepted: 07/24/2015] [Indexed: 12/22/2022] Open
Abstract
Positive-strand RNA (+RNA) viruses are an important group of human and animal pathogens that have significant global health and economic impacts. Notable members include West Nile virus, Dengue virus, Chikungunya, Severe acute respiratory syndrome (SARS) Coronavirus and enteroviruses of the Picornaviridae family.Unfortunately, prophylactic and therapeutic treatments against these pathogens are limited. +RNA viruses have limited coding capacity and thus rely extensively on host factors for successful infection and propagation. A common feature among these viruses is their ability to dramatically modify cellular membranes to serve as platforms for genome replication and assembly of new virions. These viral replication complexes (VRCs) serve two main functions: To increase replication efficiency by concentrating critical factors and to protect the viral genome from host anti-viral systems. This review summarizes current knowledge of critical host factors recruited to or demonstrated to be involved in the biogenesis and stabilization of +RNA virus VRCs.
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Affiliation(s)
- Colleen R Reid
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada.
| | - Adriana M Airo
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada.
| | - Tom C Hobman
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2E1, Canada.
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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19
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Albulescu L, Wubbolts R, van Kuppeveld FJM, Strating JRPM. Cholesterol shuttling is important for RNA replication of coxsackievirus B3 and encephalomyocarditis virus. Cell Microbiol 2015; 17:1144-56. [PMID: 25645595 DOI: 10.1111/cmi.12425] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 01/21/2015] [Accepted: 01/26/2015] [Indexed: 11/29/2022]
Abstract
Picornaviruses are a family of positive-strand RNA viruses that includes important human and animal pathogens. Upon infection, picornaviruses induce an extensive remodelling of host cell membranes into replication organelles (ROs), which is critical for replication. Membrane lipids and lipid remodelling processes are at the base of RO formation, yet their involvement remains largely obscure. Recently, phosphatidylinositol-4-phosphate was the first lipid discovered to be important for the replication of a number of picornaviruses. Here, we investigate the role of the lipid cholesterol in picornavirus replication. We show that two picornaviruses from distinct genera that rely on different host factors for replication, namely the enterovirus coxsackievirus B3 (CVB3) and the cardiovirus encephalomyocarditis virus (EMCV), both recruited cholesterol to their ROs. Although CVB3 and EMCV both required cholesterol for efficient genome replication, the viruses appeared to rely on different cellular cholesterol pools. Treatments that altered the distribution of endosomal cholesterol inhibited replication of both CVB3 and EMCV, showing the importance of endosomal cholesterol shuttling for the replication of these viruses. Summarizing, we here demonstrate the importance of cholesterol homeostasis for efficient replication of CVB3 and EMCV.
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Affiliation(s)
- Lucian Albulescu
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Richard Wubbolts
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Frank J M van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jeroen R P M Strating
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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20
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Harak C, Lohmann V. Ultrastructure of the replication sites of positive-strand RNA viruses. Virology 2015; 479-480:418-33. [PMID: 25746936 PMCID: PMC7111692 DOI: 10.1016/j.virol.2015.02.029] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/06/2015] [Accepted: 02/16/2015] [Indexed: 12/13/2022]
Abstract
Positive strand RNA viruses replicate in the cytoplasm of infected cells and induce intracellular membranous compartments harboring the sites of viral RNA synthesis. These replication factories are supposed to concentrate the components of the replicase and to shield replication intermediates from the host cell innate immune defense. Virus induced membrane alterations are often generated in coordination with host factors and can be grouped into different morphotypes. Recent advances in conventional and electron microscopy have contributed greatly to our understanding of their biogenesis, but still many questions remain how viral proteins capture membranes and subvert host factors for their need. In this review, we will discuss different representatives of positive strand RNA viruses and their ways of hijacking cellular membranes to establish replication complexes. We will further focus on host cell factors that are critically involved in formation of these membranes and how they contribute to viral replication.
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Affiliation(s)
- Christian Harak
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Im Neuenheimer Feld 345, D-69120 Heidelberg, Germany
| | - Volker Lohmann
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Im Neuenheimer Feld 345, D-69120 Heidelberg, Germany.
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21
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Cell-specific establishment of poliovirus resistance to an inhibitor targeting a cellular protein. J Virol 2015; 89:4372-86. [PMID: 25653442 DOI: 10.1128/jvi.00055-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED It is hypothesized that targeting stable cellular factors involved in viral replication instead of virus-specific proteins may raise the barrier for development of resistant mutants, which is especially important for highly adaptable small (+)RNA viruses. However, contrary to this assumption, the accumulated evidence shows that these viruses easily generate mutants resistant to the inhibitors of cellular proteins at least in some systems. We investigated here the development of poliovirus resistance to brefeldin A (BFA), an inhibitor of the cellular protein GBF1, a guanine nucleotide exchange factor for the small cellular GTPase Arf1. We found that while resistant viruses can be easily selected in HeLa cells, they do not emerge in Vero cells, in spite that in the absence of the drug both cultures support robust virus replication. Our data show that the viral replication is much more resilient to BFA than functioning of the cellular secretory pathway, suggesting that the role of GBF1 in the viral replication is independent of its Arf activating function. We demonstrate that the level of recruitment of GBF1 to the replication complexes limits the establishment and expression of a BFA resistance phenotype in both HeLa and Vero cells. Moreover, the BFA resistance phenotype of poliovirus mutants is also cell type dependent in different cells of human origin and results in a fitness loss in the form of reduced efficiency of RNA replication in the absence of the drug. Thus, a rational approach to the development of host-targeting antivirals may overcome the superior adaptability of (+)RNA viruses. IMPORTANCE Compared to the number of viral diseases, the number of available vaccines is miniscule. For some viruses vaccine development has not been successful after multiple attempts, and for many others vaccination is not a viable option. Antiviral drugs are needed for clinical practice and public health emergencies. However, viruses are highly adaptable and can easily generate mutants resistant to practically any compounds targeting viral proteins. An alternative approach is to target stable cellular factors recruited for the virus-specific functions. In the present study, we analyzed the factors permitting and restricting the establishment of the resistance of poliovirus, a small (+)RNA virus, to brefeldin A (BFA), a drug targeting a cellular component of the viral replication complex. We found that the emergence and replication potential of resistant mutants is cell type dependent and that BFA resistance reduces virus fitness. Our data provide a rational approach to the development of antiviral therapeutics targeting host factors.
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22
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Greninger AL. Picornavirus–Host Interactions to Construct Viral Secretory Membranes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 129:189-212. [DOI: 10.1016/bs.pmbts.2014.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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23
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Barroso-González J, García-Expósito L, Puigdomènech I, de Armas-Rillo L, Machado JD, Blanco J, Valenzuela-Fernández A. Viral infection. Commun Integr Biol 2014. [DOI: 10.4161/cib.16716] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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24
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Poliovirus-induced changes in cellular membranes throughout infection. Curr Opin Virol 2014; 9:67-73. [PMID: 25310497 DOI: 10.1016/j.coviro.2014.09.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/05/2014] [Accepted: 09/18/2014] [Indexed: 11/21/2022]
Abstract
The membrane landscape of a cell often changes drastically upon infection by a virus. In the case of the well-studied positive strand RNA virus poliovirus, the short infection cycle induces vesicles and tubular structures early in infection, and double-membraned vesicles late in infection. In this review, the current understanding of membrane changes in a PV-infected cell, the host and viral factors that facilitate these changes, and how these changes may promote virus replication will be discussed. Host factors involved in membrane rearrangement during infection include components of the COPI and COPII secretory pathways, lipid kinases, and the autophagy pathway. The roles of cellular membranes include acting as a scaffold for the RNA replication complex and roles in exit of mature virus. Finally, recent studies suggesting that not all picornaviruses are truly 'non-enveloped' are discussed in the context of the field, raising the possibility that cell-derived membranes play a role in delivering poliovirus particles to the extracellular space.
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25
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Abstract
UNLABELLED Few drugs targeting picornaviruses are available, making the discovery of antivirals a high priority. Here, we identified and characterized three compounds from a library of kinase inhibitors that block replication of poliovirus, coxsackievirus B3, and encephalomyocarditis virus. Using an in vitro translation-replication system, we showed that these drugs inhibit different stages of the poliovirus life cycle. A4(1) inhibited both the formation and functioning of the replication complexes, while E5(1) and E7(2) were most effective during the formation but not the functioning step. Neither of the compounds significantly inhibited VPg uridylylation. Poliovirus resistant to E7(2) had a G5318A mutation in the 3A protein. This mutation was previously found to confer resistance to enviroxime-like compounds, which target a phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ)-dependent step in viral replication. Analysis of host protein recruitment showed that E7(2) reduced the amount of GBF1 on the replication complexes; however, the level of PI4KIIIβ remained intact. E7(2) as well as another enviroxime-like compound, GW5074, interfered with viral polyprotein processing affecting both 3C- and 2A-dependent cleavages, and the resistant G5318A mutation partially rescued this defect. Moreover, E7(2) induced abnormal recruitment to membranes of the viral proteins; thus, enviroxime-like compounds likely severely compromise the interaction of the viral polyprotein with membranes. A4(1) demonstrated partial protection from paralysis in a murine model of poliomyelitis. Multiple attempts to isolate resistant mutants in the presence of A4(1) or E5(1) were unsuccessful, showing that effective broad-spectrum antivirals could be developed on the basis of these compounds. IMPORTANCE Diverse picornaviruses can trigger multiple human maladies, yet currently, only hepatitis A virus and poliovirus can be controlled with vaccination. The development of antipicornavirus therapeutics is also facing significant difficulties because these viruses readily generate resistance to compounds targeting either viral or cellular factors. Here, we describe three novel compounds that effectively block replication of distantly related picornaviruses with minimal toxicity to cells. The compounds prevent viral RNA replication after the synthesis of the uridylylated VPg primer. Importantly, two of the inhibitors are strongly refractory to the emergence of resistant mutants, making them promising candidates for further broad-spectrum therapeutic development. Evaluation of one of the compounds in an in vivo model of poliomyelitis demonstrated partial protection from the onset of paralysis.
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26
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Abstract
Viruses are obligatory intracellular parasites and utilize host elements to support key viral processes, including penetration of the plasma membrane, initiation of infection, replication, and suppression of the host's antiviral defenses. In this review, we focus on picornaviruses, a family of positive-strand RNA viruses, and discuss the mechanisms by which these viruses hijack the cellular machinery to form and operate membranous replication complexes. Studies aimed at revealing factors required for the establishment of viral replication structures identified several cellular-membrane-remodeling proteins and led to the development of models in which the virus used a preexisting cellular-membrane-shaping pathway "as is" for generating its replication organelles. However, as more data accumulate, this view is being increasingly questioned, and it is becoming clearer that viruses may utilize cellular factors in ways that are distinct from the normal functions of these proteins in uninfected cells. In addition, the proteincentric view is being supplemented by important new studies showing a previously unappreciated deep remodeling of lipid homeostasis, including extreme changes to phospholipid biosynthesis and cholesterol trafficking. The data on viral modifications of lipid biosynthetic pathways are still rudimentary, but it appears once again that the viruses may rewire existing pathways to generate novel functions. Despite remarkable progress, our understanding of how a handful of viral proteins can completely overrun the multilayered, complex mechanisms that control the membrane organization of a eukaryotic cell remains very limited.
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27
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Wang J, Du J, Jin Q. Class I ADP-ribosylation factors are involved in enterovirus 71 replication. PLoS One 2014; 9:e99768. [PMID: 24911624 PMCID: PMC4049829 DOI: 10.1371/journal.pone.0099768] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 05/16/2014] [Indexed: 12/16/2022] Open
Abstract
Enterovirus 71 is one of the major causative agents of hand, foot, and mouth disease in infants and children. Replication of enterovirus 71 depends on host cellular factors. The viral replication complex is formed in novel, cytoplasmic, vesicular compartments. It has not been elucidated which cellular pathways are hijacked by the virus to create these vesicles. Here, we investigated whether proteins associated with the cellular secretory pathway were involved in enterovirus 71 replication. We used a loss-of-function assay, based on small interfering RNA. We showed that enterovirus 71 RNA replication was dependent on the activity of Class I ADP-ribosylation factors. Simultaneous depletion of ADP-ribosylation factors 1 and 3, but not three others, inhibited viral replication in cells. We also demonstrated with various techniques that the brefeldin-A-sensitive guanidine nucleotide exchange factor, GBF1, was critically important for enterovirus 71 replication. Our results suggested that enterovirus 71 replication depended on GBF1-mediated activation of Class I ADP-ribosylation factors. These results revealed a connection between enterovirus 71 replication and the cellular secretory pathway; this pathway may represent a novel target for antiviral therapies.
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Affiliation(s)
- Jianmin Wang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Jiang Du
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Qi Jin
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
- * E-mail:
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28
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Carpp LN, Rogers RS, Moritz RL, Aitchison JD. Quantitative proteomic analysis of host-virus interactions reveals a role for Golgi brefeldin A resistance factor 1 (GBF1) in dengue infection. Mol Cell Proteomics 2014; 13:2836-54. [PMID: 24855065 DOI: 10.1074/mcp.m114.038984] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Dengue virus is considered to be the most important mosquito-borne virus worldwide and poses formidable economic and health care burdens on many tropical and subtropical countries. Dengue infection induces drastic rearrangement of host endoplasmic reticulum membranes into complex membranous structures housing replication complexes; the contribution(s) of host proteins and pathways to this process is poorly understood but is likely to be mediated by protein-protein interactions. We have developed an approach for obtaining high confidence protein-protein interaction data by employing affinity tags and quantitative proteomics, in the context of viral infection, followed by robust statistical analysis. Using this approach, we identified high confidence interactors of NS5, the viral polymerase, and NS3, the helicase/protease. Quantitative proteomics allowed us to exclude a large number of presumably nonspecific interactors from our data sets and imparted a high level of confidence to our resulting data sets. We identified 53 host proteins reproducibly associated with NS5 and 41 with NS3, with 13 of these candidates present in both data sets. The host factors identified have diverse functions, including retrograde Golgi-to-endoplasmic reticulum transport, biosynthesis of long-chain fatty-acyl-coenzyme As, and in the unfolded protein response. We selected GBF1, a guanine nucleotide exchange factor responsible for ARF activation, from the NS5 data set for follow up and functional validation. We show that GBF1 plays a critical role early in dengue infection that is independent of its role in the maintenance of Golgi structure. Importantly, the approach described here can be applied to virtually any organism/system as a tool for better understanding its molecular interactions.
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Affiliation(s)
- Lindsay N Carpp
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109
| | - Richard S Rogers
- ‖Institute for Systems Biology, 401 Terry Ave N, Seattle, WA 98109
| | - Robert L Moritz
- §Institute for Systems Biology, 401 Terry Ave N, Seattle, Washington 98109
| | - John D Aitchison
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109; §Institute for Systems Biology, 401 Terry Ave N, Seattle, Washington 98109, ‖Institute for Systems Biology, 401 Terry Ave N, Seattle, WA 98109.
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Abstract
Poliovirus (PV), a model for interactions of picornaviruses with host cells, replicates its genomic RNA in association with cellular membranes. The origin of PV replication membranes has not been determined. Hypotheses about the origin of replication membranes, based largely on localization of viral proteins, include modification of coat protein complex I (COPI) and/or COPII secretory pathway vesicles and subversion of autophagic membranes. Here, we use an antibody against double-stranded RNA (dsRNA) to identify replication complexes by detection of dsRNA replication intermediates. dsRNA signal is dependent on virus genome replication and colocalizes with the viral integral membrane protein 3A, which is part of the RNA replication complex. We show that early in infection, dsRNA does not colocalize with a marker for autophagic vesicles, making it unlikely that autophagosomes contribute to the generation of PV RNA replication membranes. We also find that dsRNA does not colocalize with a marker of the COPII coat, Sec31, and, in fact, we demonstrate proteasome-dependent loss of full-length Sec31 during PV infection. These data indicate that COPII vesicles are an unlikely source of PV replication membranes. We show that the Golgi resident G-protein Arf1 and its associated guanine nucleotide exchange factor (GEF), GBF1, transiently colocalize with dsRNA early in infection. In uninfected cells, Arf1 nucleates COPI coat formation, although during infection the COPI coat itself does not colocalize with dsRNA. Phosphatidylinositol-4-phosphate, which is associated with enterovirus-induced vesicles, tightly colocalizes with Arf1/GBF1 throughout infection. Our data point to a noncanonical role for some of the COPI-generating machinery in producing unique replication surfaces for PV RNA replication. IMPORTANCE Picornaviruses are a diverse and major cause of human disease, and their genomes replicate in association with intracellular membranes. There are multiple hypotheses to explain the nature and origin of these membranes, and a complete understanding of the host requirements for membrane rearrangement would provide novel drug targets essential for viral genome replication. Here, we study the model picornavirus, poliovirus, and show that some, but not all, components of the cellular machinery required for retrograde traffic from the Golgi apparatus to the endoplasmic reticulum are transiently present at the sites of viral RNA replication. We also show that the full-length Sec31 protein, which has been suggested to be present on PV RNA replication membranes, is lost during infection in a proteasome-dependent manner. This study helps to reconcile multiple hypotheses about the origin of poliovirus replication membranes and points to known host cell protein complexes that would make likely drug targets to inhibit picornavirus infections.
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30
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Midgley R, Moffat K, Berryman S, Hawes P, Simpson J, Fullen D, Stephens DJ, Burman A, Jackson T. A role for endoplasmic reticulum exit sites in foot-and-mouth disease virus infection. J Gen Virol 2013; 94:2636-2646. [PMID: 23963534 PMCID: PMC3836498 DOI: 10.1099/vir.0.055442-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Picornaviruses replicate their genomes in association with cellular membranes. While enteroviruses are believed to utilize membranes of the early secretory pathway, the origin of the membranes used by foot-and-mouth disease virus (FMDV) for replication are unknown. Secretory-vesicle traffic through the early secretory pathway is mediated by the sequential acquisition of two distinct membrane coat complexes, COPII and COPI, and requires the coordinated actions of Sar1, Arf1 and Rab proteins. Sar1 is essential for generating COPII vesicles at endoplasmic reticulum (ER) exit sites (ERESs), while Arf1 and Rab1 are required for subsequent vesicle transport by COPI vesicles. In the present study, we have provided evidence that FMDV requires pre-Golgi membranes of the early secretory pathway for infection. Small interfering RNA depletion of Sar1 or expression of a dominant-negative (DN) mutant of Sar1a inhibited FMDV infection. In contrast, a dominant-active mutant of Sar1a, which allowed COPII vesicle formation but inhibited the secretory pathway by stabilizing COPII coats, caused major disruption to the ER–Golgi intermediate compartment (ERGIC) but did not inhibit infection. Treatment of cells with brefeldin A, or expression of DN mutants of Arf1 and Rab1a, disrupted the Golgi and enhanced FMDV infection. These results show that reagents that block the early secretory pathway at ERESs have an inhibitory effect on FMDV infection, while reagents that block the early secretory pathway immediately after ER exit but before the ERGIC and Golgi make infection more favourable. Together, these observations argue for a role for Sar1 in FMDV infection and that initial virus replication takes place on membranes that are formed at ERESs.
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Affiliation(s)
| | - Katy Moffat
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | | | | | | | - Daniel Fullen
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, Medical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Alison Burman
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | - Terry Jackson
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
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31
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Seehafer K, Rominger F, Helmchen G, Langhans M, Robinson DG, Özata B, Brügger B, Strating JRPM, van Kuppeveld FJM, Klein CD. Synthesis and biological properties of novel brefeldin A analogues. J Med Chem 2013; 56:5872-84. [PMID: 23805957 DOI: 10.1021/jm400615g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
New brefeldin A (1) analogues were obtained by introducing a variety of substituents at C15. Most of the analogues exhibited significant biological activity. (15R)-Trifluoromethyl-nor-brefeldin A (3), (15R)-vinyl-nor-brefeldin A (5), their epimers 4 and 6 as well as (15S)-ethyl-nor-brefeldin A (2) were prepared from the key building blocks 12 or 24 by Julia-Kocienski olefination with tetrazolyl sulfones and subsequent macrolactonization. The vinyl derivative 5 allowed analogues to be synthesized by hydroboration and Suzuki-Miyaura coupling. The following biological properties were assessed: (a) inhibition of cell growth of human cancer cells (NCI), (b) induction of morphological changes of the Golgi apparatus of plant and mammalian cells, and (c) influence on the replication of the enterovirus CVB3. Furthermore, conformational aspects were studied by X-ray crystal structure analysis and molecular mechanics calculations, including docking of the analogues into the brefeldin A binding site of an Arf1/Sec7-complex.
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Affiliation(s)
- Kai Seehafer
- Institute of Organic Chemistry, University of Heidelberg , Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
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32
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Nchoutmboube JA, Viktorova EG, Scott AJ, Ford LA, Pei Z, Watkins PA, Ernst RK, Belov GA. Increased long chain acyl-Coa synthetase activity and fatty acid import is linked to membrane synthesis for development of picornavirus replication organelles. PLoS Pathog 2013; 9:e1003401. [PMID: 23762027 PMCID: PMC3675155 DOI: 10.1371/journal.ppat.1003401] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 04/19/2013] [Indexed: 12/20/2022] Open
Abstract
All positive strand (+RNA) viruses of eukaryotes replicate their genomes in association with membranes. The mechanisms of membrane remodeling in infected cells represent attractive targets for designing future therapeutics, but our understanding of this process is very limited. Elements of autophagy and/or the secretory pathway were proposed to be hijacked for building of picornavirus replication organelles. However, even closely related viruses differ significantly in their requirements for components of these pathways. We demonstrate here that infection with diverse picornaviruses rapidly activates import of long chain fatty acids. While in non-infected cells the imported fatty acids are channeled to lipid droplets, in infected cells the synthesis of neutral lipids is shut down and the fatty acids are utilized in highly up-regulated phosphatidylcholine synthesis. Thus the replication organelles are likely built from de novo synthesized membrane material, rather than from the remodeled pre-existing membranes. We show that activation of fatty acid import is linked to the up-regulation of cellular long chain acyl-CoA synthetase activity and identify the long chain acyl-CoA syntheatse3 (Acsl3) as a novel host factor required for polio replication. Poliovirus protein 2A is required to trigger the activation of import of fatty acids independent of its protease activity. Shift in fatty acid import preferences by infected cells results in synthesis of phosphatidylcholines different from those in uninfected cells, arguing that the viral replication organelles possess unique properties compared to the pre-existing membranes. Our data show how poliovirus can change the overall cellular membrane homeostasis by targeting one critical process. They explain earlier observations of increased phospholipid synthesis in infected cells and suggest a simple model of the structural development of the membranous scaffold of replication complexes of picorna-like viruses, that may be relevant for other (+)RNA viruses as well. Eukaryotic cells feature astonishing complexity of regulatory networks, yet control over this fine-tuned machinery is easily overrun by viruses with expression of just a handful of proteins. One of the striking examples of such hostile take-over is the rewiring of normal cellular membrane metabolism by (+)RNA viruses towards development of new membranous organelles harboring viral replication machinery. (+)RNA viruses of eukaryotes infect organisms from unicellular algae to humans. Many of them induce diseases resulting in significant economic losses, public health burden, human suffering and sometimes fatal consequences. We show how picornaviruses reorganize cellular lipid metabolism by targeting long chain acyl-CoA synthetase activity. This induces increased import of fatty acids in infected cells and up-regulation of phospholipid synthesis, resulting in formation of replication organelles different from the pre-existing cellular membranes. This mechanism is utilized by diverse viruses and may represent an attractive target for anti-viral interventions.
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Affiliation(s)
- Jules A. Nchoutmboube
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Ekaterina G. Viktorova
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Alison J. Scott
- University of Maryland, School of Dentistry, Baltimore, Maryland, United States of America
| | - Lauren A. Ford
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Zhengtong Pei
- Kennedy Krieger Institute and Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Paul A. Watkins
- Kennedy Krieger Institute and Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Robert K. Ernst
- University of Maryland, School of Dentistry, Baltimore, Maryland, United States of America
| | - George A. Belov
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
- * E-mail:
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33
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Oxysterol-binding protein family I is the target of minor enviroxime-like compounds. J Virol 2013; 87:4252-60. [PMID: 23365445 DOI: 10.1128/jvi.03546-12] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Enviroxime is an antipicornavirus compound that targets host phosphatidylinositol 4-kinase III beta (PI4KB) activity for its antipicornavirus activity. To date, several antipoliovirus (PV) compounds similar to enviroxime that are associated with a common resistance mutation in viral protein 3A (a G5318A [3A-Ala70Thr] mutation in PV) have been identified. Most of these compounds have a direct inhibitory effect on PI4KB activity, as well as enviroxime (designated major enviroxime-like compounds). However, one of the compounds, AN-12-H5, showed no inhibitory effect on PI4KB and was considered to belong to another group of enviroxime-like compounds (designated minor enviroxime-like compounds). In the present study, we performed a small interfering RNA (siRNA) sensitization assay targeting PI4KB-related genes and identified oxysterol-binding protein (OSBP) as a target of minor enviroxime-like compounds. Knockdown of OSBP and OSBP2 increased the anti-PV activities of AN-12-H5 and a newly identified minor enviroxime-like compound, T-00127-HEV2, and also to T-00127-HEV1 to a minor extent, in the cells. A ligand of OSBP, 25-hydroxycholesterol (25-HC), acted as a minor enviroxime-like compound. Minor enviroxime-like compounds induced relocalization of OSBP to the Golgi apparatus in cells. Treatment of the cells with major or minor enviroxime-like compounds suppressed the expression of genes (HMGCS1 and SQLE) in the SREBP/SCAP regulatory pathway and diminished endogenous phosphatidylinositol 4-phosphate (PI4P) at the Golgi apparatus. Our results suggested that minor enviroxime-like compounds are phenotypically identical to 25-HC and that major and minor enviroxime-like compounds suppress the production and/or accumulation of PI4P in PV-infected cells by targeting PI4KB and OSBP family I activities, respectively.
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34
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Richards AL, Jackson WT. Intracellular vesicle acidification promotes maturation of infectious poliovirus particles. PLoS Pathog 2012; 8:e1003046. [PMID: 23209416 PMCID: PMC3510256 DOI: 10.1371/journal.ppat.1003046] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 10/06/2012] [Indexed: 12/30/2022] Open
Abstract
The autophagic pathway acts as part of the immune response against a variety of pathogens. However, several pathogens subvert autophagic signaling to promote their own replication. In many cases it has been demonstrated that these pathogens inhibit or delay the degradative aspect of autophagy. Here, using poliovirus as a model virus, we report for the first time bona fide autophagic degradation occurring during infection with a virus whose replication is promoted by autophagy. We found that this degradation is not required to promote poliovirus replication. However, vesicular acidification, which in the case of autophagy precedes delivery of cargo to lysosomes, is required for normal levels of virus production. We show that blocking autophagosome formation inhibits viral RNA synthesis and subsequent steps in the virus cycle, while inhibiting vesicle acidification only inhibits the final maturation cleavage of virus particles. We suggest that particle assembly, genome encapsidation, and virion maturation may occur in a cellular compartment, and we propose the acidic mature autophagosome as a candidate vesicle. We discuss the implications of our findings in understanding the late stages of poliovirus replication, including the formation and maturation of virions and egress of infectious virus from cells. The autophagic degradation pathway is a well-known agent of innate immunity. Several pathogens, including poliovirus (PV), a model for several medically important RNA viruses, subvert this pathway for their own benefit. In doing so, pathogens often inhibit the degradative portion of the pathway, presumably to prevent their own destruction. We show here that, surprisingly, PV infection results in high levels of degradative autophagy. However, we find that autophagic degradation is dispensable for PV replication. Inhibiting the formation of autophagosomes inhibits virus RNA replication and subsequent steps in virus production. Inhibiting the acidification of vesicles, which in the case of autophagosomes precedes fusion with lysosomes and autophagic degradation, inhibits a much later step in virus production. Our data suggest an important role for an acidic compartment of the cell in the final maturation step, cleaving a capsid protein to generate infectious virus. Importantly, these data also call into question the long-standing hypothesis that all steps in the production of infectious poliovirus are cytosolic.
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Affiliation(s)
| | - William T. Jackson
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail:
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35
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Pliaka V, Kyriakopoulou Z, Markoulatos P. Risks associated with the use of live-attenuated vaccine poliovirus strains and the strategies for control and eradication of paralytic poliomyelitis. Expert Rev Vaccines 2012; 11:609-28. [PMID: 22827246 DOI: 10.1586/erv.12.28] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Global Polio Eradication Initiative was launched in 1988 with the aim to eliminate paralytic poliomyelitis. Two effective vaccines are available: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). Since 1964, OPV has been used instead of IPV in most countries due to several economic and biological advantages. However, in rare cases, the live-attenuated Sabin strains of OPV revert to neurovirulence and cause vaccine-associated paralytic poliomyelitis in vaccinees or lead to emergence of vaccine-derived poliovirus strains. Attenuating mutations and recombination events have been associated with the reversion of vaccine strains to neurovirulence. The substitution of OPV with an improved new-generation IPV and the availability of new specific drugs against polioviruses are considered as future strategies for outbreak control and the eradication of paralytic poliomyelitis worldwide.
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Affiliation(s)
- Vaia Pliaka
- University of Thessaly, School of Health Sciences, Department of Biochemistry and Biotechnology, Microbiology-Virology Laboratory, Larissa, Greece.
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36
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Abstract
Enterovirus 71 (EV71), a member of the Picornaviridae family, is found in Asian countries where it causes a wide range of human diseases. No effective therapy is available for the treatment of these infections. Picornaviruses undergo RNA replication in association with membranes of infected cells. COPI and COPII have been shown to be involved in the formation of picornavirus-induced vesicles. Replication of several picornaviruses, including poliovirus and Echovirus 11 (EV11), is dependent on COPI or COPII. Here, we report that COPI, but not COPII, is required for EV71 replication. Replication of EV71 was inhibited by brefeldin A and golgicide A, inhibitors of COPI activity. Furthermore, we found EV71 2C protein interacted with COPI subunits by co-immunoprecipitation and GST pull-down assay, indicating that COPI coatomer might be directed to the viral replication complex through viral 2C protein. Additionally, because the pathway is conserved among different species of enteroviruses, it may represent a novel target for antiviral therapies.
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37
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Valosin-containing protein (VCP/p97) is required for poliovirus replication and is involved in cellular protein secretion pathway in poliovirus infection. J Virol 2012; 86:5541-53. [PMID: 22379090 DOI: 10.1128/jvi.00114-12] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Poliovirus (PV) modifies membrane-trafficking machinery in host cells for its viral RNA replication. To date, ARF1, ACBD3, BIG1/BIG2, GBF1, RTN3, and PI4KB have been identified as host factors of enterovirus (EV), including PV, involved in membrane traffic. In this study, we performed small interfering RNA (siRNA) screening targeting membrane-trafficking genes for host factors required for PV replication. We identified valosin-containing protein (VCP/p97) as a host factor of PV replication required after viral protein synthesis, and its ATPase activity was essential for PV replication. VCP colocalized with viral proteins 2BC/2C and 3AB/3B in PV-infected cells and showed an interaction with 2BC and 3AB but not with 2C and 3A. Knockdown of VCP did not suppress the replication of coxsackievirus B3 or Aichi virus. A VCP-knockdown-resistant PV mutant had an A4881G (a mutation of E253G in 2C) mutation, which is known as a determinant of a secretion inhibition-negative phenotype. However, knockdown of VCP did not affect the inhibition of cellular protein secretion caused by overexpression of each individual viral protein. These results suggested that VCP is a host factor required for viral RNA replication of PV among membrane-trafficking proteins and provides a novel link between cellular protein secretion and viral RNA replication.
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38
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Chase AJ, Semler BL. Viral subversion of host functions for picornavirus translation and RNA replication. Future Virol 2012; 7:179-191. [PMID: 23293659 DOI: 10.2217/fvl.12.2] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Picornavirus infections lead to symptoms that can have serious health and economic implications. The viruses in this family (Picornaviridae) have a small genomic RNA and must rely on host proteins for efficient viral gene expression and RNA replication. To ensure their effectiveness as pathogens, picornaviruses have evolved to utilize and/or alter host proteins for the benefit of the virus life cycle. This review discusses the host proteins that are subverted during infection to aid in virus replication. It will also describe proteins and functions that are altered during infection for the benefit of the virus.
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Affiliation(s)
- Amanda J Chase
- Department of Microbiology & Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697, USA
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39
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Sanfaçon H. Investigating the role of viral integral membrane proteins in promoting the assembly of nepovirus and comovirus replication factories. FRONTIERS IN PLANT SCIENCE 2012; 3:313. [PMID: 23439982 PMCID: PMC3557413 DOI: 10.3389/fpls.2012.00313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 12/31/2012] [Indexed: 05/08/2023]
Abstract
Formation of plant virus membrane-associated replication factories requires the association of viral replication proteins and viral RNA with intracellular membranes, the recruitment of host factors and the modification of membranes to form novel structures that house the replication complex. Many viruses encode integral membrane proteins that act as anchors for the replication complex. These hydrophobic proteins contain transmembrane domains and/or amphipathic helices that associate with the membrane and modify its structure. The comovirus Co-Pro and NTP-binding (NTB, putative helicase) proteins and the cognate nepovirus X2 and NTB proteins are among the best characterized plant virus integral membrane replication proteins and are functionally related to the picornavirus 2B, 2C, and 3A membrane proteins. The identification of membrane association domains and analysis of the membrane topology of these proteins is discussed. The evidence suggesting that these proteins have the ability to induce membrane proliferation, alter the structure and integrity of intracellular membranes, and modulate the induction of symptoms in infected plants is also reviewed. Finally, areas of research that need further investigation are highlighted.
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Affiliation(s)
- Hélène Sanfaçon
- *Correspondence: Hélène Sanfaçon, Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, 4200 Highway 97, Summerland, BC, Canada V0H 1Z0. e-mail:
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40
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ACBD3-mediated recruitment of PI4KB to picornavirus RNA replication sites. EMBO J 2011; 31:754-66. [PMID: 22124328 DOI: 10.1038/emboj.2011.429] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 10/31/2011] [Indexed: 01/11/2023] Open
Abstract
Phosphatidylinositol 4-kinase IIIβ (PI4KB) is a host factor required for genome RNA replication of enteroviruses, small non-enveloped viruses belonging to the family Picornaviridae. Here, we demonstrated that PI4KB is also essential for genome replication of another picornavirus, Aichi virus (AiV), but is recruited to the genome replication sites by a different strategy from that utilized by enteroviruses. AiV non-structural proteins, 2B, 2BC, 2C, 3A, and 3AB, interacted with a Golgi protein, acyl-coenzyme A binding domain containing 3 (ACBD3). Furthermore, we identified previously unknown interaction between ACBD3 and PI4KB, which provides a novel manner of Golgi recruitment of PI4KB. Knockdown of ACBD3 or PI4KB suppressed AiV RNA replication. The viral proteins, ACBD3, PI4KB, and phophatidylinositol-4-phosphate (PI4P) localized to the viral RNA replication sites. AiV replication and recruitment of PI4KB to the RNA replication sites were not affected by brefeldin A, in contrast to those in enterovirus infection. These results indicate that a viral protein/ACBD3/PI4KB complex is formed to synthesize PI4P at the AiV RNA replication sites and plays an essential role in viral RNA replication.
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Abstract
Replication of all positive-strand RNA viruses is intimately associated with membranes. Here we utilize electron tomography and other methods to investigate the remodeling of membranes in poliovirus-infected cells. We found that the viral replication structures previously described as "vesicles" are in fact convoluted, branching chambers with complex and dynamic morphology. They are likely to originate from cis-Golgi membranes and are represented during the early stages of infection by single-walled connecting and branching tubular compartments. These early viral organelles gradually transform into double-membrane structures by extension of membranous walls and/or collapsing of the luminal cavity of the single-membrane structures. As the double-membrane regions develop, they enclose cytoplasmic material. At this stage, a continuous membranous structure may have double- and single-walled membrane morphology at adjacent cross-sections. In the late stages of the replication cycle, the structures are represented mostly by double-membrane vesicles. Viral replication proteins, double-stranded RNA species, and actively replicating RNA are associated with both double- and single-membrane structures. However, the exponential phase of viral RNA synthesis occurs when single-membrane formations are predominant in the cell. It has been shown previously that replication complexes of some other positive-strand RNA viruses form on membrane invaginations, which result from negative membrane curvature. Our data show that the remodeling of cellular membranes in poliovirus-infected cells produces structures with positive curvature of membranes. Thus, it is likely that there is a fundamental divergence in the requirements for the supporting cellular membrane-shaping machinery among different groups of positive-strand RNA viruses.
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The transformation of enterovirus replication structures: a three-dimensional study of single- and double-membrane compartments. mBio 2011; 2:mBio.00166-11. [PMID: 21972238 PMCID: PMC3187575 DOI: 10.1128/mbio.00166-11] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
All positive-strand RNA viruses induce membrane structures in their host cells which are thought to serve as suitable microenvironments for viral RNA synthesis. The structures induced by enteroviruses, which are members of the family Picornaviridae, have so far been described as either single- or double-membrane vesicles (DMVs). Aside from the number of delimiting membranes, their exact architecture has also remained elusive due to the limitations of conventional electron microscopy. In this study, we used electron tomography (ET) to solve the three-dimensional (3-D) ultrastructure of these compartments. At different time points postinfection, coxsackievirus B3-infected cells were high-pressure frozen and freeze-substituted for ET analysis. The tomograms showed that during the exponential phase of viral RNA synthesis, closed smooth single-membrane tubules constituted the predominant virus-induced membrane structure, with a minor proportion of DMVs that were either closed or connected to the cytosol in a vase-like configuration. As infection progressed, the DMV number steadily increased, while the tubular single-membrane structures gradually disappeared. Late in infection, complex multilamellar structures, previously unreported, became apparent in the cytoplasm. Serial tomography disclosed that their basic unit is a DMV, which is enwrapped by one or multiple cisternae. ET also revealed striking intermediate structures that strongly support the conversion of single-membrane tubules into double-membrane and multilamellar structures by a process of membrane apposition, enwrapping, and fusion. Collectively, our work unravels the sequential appearance of distinct enterovirus-induced replication structures, elucidates their detailed 3-D architecture, and provides the basis for a model for their transformation during the course of infection. Positive-strand RNA viruses hijack specific intracellular membranes and remodel them into special structures that support viral RNA synthesis. The ultrastructural characterization of these “replication structures” is key to understanding their precise role. Here, we resolved the three-dimensional architecture of enterovirus-induced membranous compartments and their transformation in time by applying electron tomography to cells infected with coxsackievirus B3 (CVB3). Our results show that closed single-membrane tubules are the predominant initial virus-induced structure, whereas double-membrane vesicles (DMVs) become increasingly abundant at the expense of these tubules as infection progresses. Additionally, more complex multilamellar structures appear late in infection. Based on compelling intermediate structures in our tomograms, we propose a model for transformation from the tubules to DMVs and multilamellar structures via enwrapping events. Our work provides an in-depth analysis of the development of an unsuspected variety of distinct replication structures during the course of CVB3 infection.
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Barroso-González J, García-Expósito L, Puigdomènech I, de Armas-Rillo L, Machado JD, Blanco J, Valenzuela-Fernández A. Viral infection: Moving through complex and dynamic cell-membrane structures. Commun Integr Biol 2011; 4:398-408. [PMID: 21966556 DOI: 10.4161/cib.4.4.16716] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 05/31/2011] [Indexed: 01/19/2023] Open
Abstract
Viruses have developed different survival strategies in host cells by crossing cell-membrane compartments, during different steps of their viral life cycle. In fact, the non-regenerative viral membrane of enveloped viruses needs to encounter the dynamic cell-host membrane, during early steps of the infection process, in which both membranes fuse, either at cell-surface or in an endocytic compartment, to promote viral entry and infection. Once inside the cell, many viruses accomplish their replication process through exploiting or modulating membrane traffic, and generating specialized compartments to assure viral replication, viral budding and spreading, which also serve to evade the immune responses against the pathogen. In this review, we have attempted to present some data that highlight the importance of membrane dynamics during viral entry and replicative processes, in order to understand how viruses use and move through different complex and dynamic cell-membrane structures and how they use them to persist.
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Affiliation(s)
- Jonathan Barroso-González
- Laboratorio de Inmunología Celular y Viral; Laboratorio de Neurosecreción; Unidad de Farmacología; Departamento de Medicina Física y Farmacología; Facultad de Medicina; Instituto de Tecnologías Biomédicas (ITB); Universidad de La Laguna (ULL)
| | - Laura García-Expósito
- Laboratorio de Inmunología Celular y Viral; Laboratorio de Neurosecreción; Unidad de Farmacología; Departamento de Medicina Física y Farmacología; Facultad de Medicina; Instituto de Tecnologías Biomédicas (ITB); Universidad de La Laguna (ULL)
| | - Isabel Puigdomènech
- Fundació irsiCaixa-HIVACAT; Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP); Hospital Germans Trias i Pujol; Universitat Autònoma de Barcelona; Barcelona, Catalonia Spain
| | - Laura de Armas-Rillo
- Laboratorio de Inmunología Celular y Viral; Laboratorio de Neurosecreción; Unidad de Farmacología; Departamento de Medicina Física y Farmacología; Facultad de Medicina; Instituto de Tecnologías Biomédicas (ITB); Universidad de La Laguna (ULL)
| | - José-David Machado
- Laboratorio de Inmunología Celular y Viral; Laboratorio de Neurosecreción; Unidad de Farmacología; Departamento de Medicina Física y Farmacología; Facultad de Medicina; Instituto de Tecnologías Biomédicas (ITB); Universidad de La Laguna (ULL)
| | - Julià Blanco
- Fundació irsiCaixa-HIVACAT; Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP); Hospital Germans Trias i Pujol; Universitat Autònoma de Barcelona; Barcelona, Catalonia Spain
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral; Laboratorio de Neurosecreción; Unidad de Farmacología; Departamento de Medicina Física y Farmacología; Facultad de Medicina; Instituto de Tecnologías Biomédicas (ITB); Universidad de La Laguna (ULL)
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Analysis of poliovirus protein 3A interactions with viral and cellular proteins in infected cells. J Virol 2011; 85:4284-96. [PMID: 21345960 DOI: 10.1128/jvi.02398-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Poliovirus proteins 3A and 3AB are small, membrane-binding proteins that play multiple roles in viral RNA replication complex formation and function. In the infected cell, these proteins associate with other viral and cellular proteins as part of a supramolecular complex whose structure and composition are unknown. We isolated viable viruses with three different epitope tags (FLAG, hemagglutinin [HA], and c-myc) inserted into the N-terminal region of protein 3A. These viruses exhibited growth properties and characteristics very similar to those of the wild-type, untagged virus. Extracts prepared from the infected cells were subjected to immunoaffinity purification of the tagged proteins by adsorption to commercial antibody-linked beads and examined after elution for cellular and other viral proteins that remained bound to 3A sequences during purification. Viral proteins 2C, 2BC, 3D, and 3CD were detected in all three immunopurified 3A samples. Among the cellular proteins previously reported to interact with 3A either directly or indirectly, neither LIS1 nor phosphoinositol-4 kinase (PI4K) were detected in any of the purified tagged 3A samples. However, the guanine nucleotide exchange factor GBF1, which is a key regulator of membrane trafficking in the cellular protein secretory pathway and which has been shown previously to bind enteroviral protein 3A and to be required for viral RNA replication, was readily recovered along with immunoaffinity-purified 3A-FLAG. Surprisingly, we failed to cocapture GBF1 with 3A-HA or 3A-myc proteins. A model for variable binding of these 3A mutant proteins to GBF1 based on amino acid sequence motifs and the resulting practical and functional consequences thereof are discussed.
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Phosphatidylinositol 4-kinase III beta is a target of enviroxime-like compounds for antipoliovirus activity. J Virol 2010; 85:2364-72. [PMID: 21177810 DOI: 10.1128/jvi.02249-10] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enviroxime is an antienterovirus compound that targets viral protein 3A and/or 3AB and suppresses a step in enterovirus replication by unknown mechanism. To date, four antienterovirus compounds, i.e., GW5074, Flt3 inhibitor II, TTP-8307, and AN-12-H5, are known to have similar mutations in the 3A protein-encoding region causing resistance to enviroxime (a G5318A [3A-Ala70Thr] mutation in poliovirus [PV]) and are considered enviroxime-like compounds. Recently, antienterovirus activity of a phosphatidylinositol 4-kinase III beta (PI4KB) inhibitor, PIK93, was reported, suggesting that PI4KB is an important host factor targetable by antienterovirus compounds (N. Y. Hsu et al., Cell 141:799-811, 2010). In this study, we analyzed the inhibitory effects of previously identified enviroxime-like compounds (GW5074 and AN-12-H5) and a newly identified antienterovirus compound, T-00127-HEV1, on phosphoinositide (PI) kinases. We found that T-00127-HEV1 inhibited PI4KB activity with a higher specificity for than other PI kinases, in contrast to GW5074, which had a broad specificity for PI kinases. In contrast, AN-12-H5 showed no inhibitory effect on PI4KB activity and only moderate inhibitory effects on PI 3-kinase activity. Small interfering RNA (siRNA) screening targeting PI kinases identified PI4KB is a target of GW5074 and T-00127-HEV1, but not of AN-12-H5, for anti-PV activity. Interestingly, T-00127-HEV1 and GW5074 did not inhibit hepatitis C virus (HCV) replication, in contrast to a strong inhibitory effect of AN-12-H5. These results suggested that PI4KB is an enterovirus-specific host factor required for the replication process and targeted by some enviroxime-like compounds (T-00127-HEV1 and GW5074) and that enviroxime-like compounds may have targets other than PI kinases for their antiviral effect.
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Belov GA, Kovtunovych G, Jackson CL, Ehrenfeld E. Poliovirus replication requires the N-terminus but not the catalytic Sec7 domain of ArfGEF GBF1. Cell Microbiol 2010; 12:1463-79. [PMID: 20497182 PMCID: PMC2945620 DOI: 10.1111/j.1462-5822.2010.01482.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Viruses are intracellular parasites whose reproduction relies on factors provided by the host. The cellular protein GBF1 is critical for poliovirus replication. Here we show that the contribution of GBF1 to virus replication is different from its known activities in uninfected cells. Normally GBF1 activates the ADP-ribosylation factor (Arf) GTPases necessary for formation of COPI transport vesicles. GBF1 function is modulated by p115 and Rab1b. However, in polio-infected cells, p115 is degraded and neither p115 nor Rab1b knock-down affects virus replication. Poliovirus infection is very sensitive to brefeldin A (BFA), an inhibitor of Arf activation by GBF1. BFA targets the catalytic Sec7 domain of GBF1. Nevertheless the BFA block of polio replication is rescued by expression of only the N-terminal region of GBF1 lacking the Sec7 domain. Replication of BFA-resistant poliovirus in the presence of BFA is uncoupled from Arf activation but is dependent on GBF1. Thus the function(s) of this protein essential for viral replication can be separated from those required for cellular metabolism.
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Affiliation(s)
- George A Belov
- National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
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Quiner CA, Jackson WT. Fragmentation of the Golgi apparatus provides replication membranes for human rhinovirus 1A. Virology 2010; 407:185-95. [PMID: 20825962 PMCID: PMC7111317 DOI: 10.1016/j.virol.2010.08.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 06/11/2010] [Accepted: 08/12/2010] [Indexed: 01/27/2023]
Abstract
All viruses with a positive-stranded RNA genome replicate their genomic RNA in association with membranes from the host cell. Here we demonstrate a novel organelle source of replication membranes for human rhinovirus 1A (HRV-1A). HRV-1A infection induces fragmentation of the Golgi apparatus, and Golgi membranes are rearranged into vesicles of approximately 250–500 nm diameter. The newly distributed Golgi membranes co-localize with viral RNA replication templates, strongly suggesting that the observed vesicles are the sites of viral RNA replication. Expression of the HRV-1A 3A protein induces alterations in the Golgi staining pattern similar to those seen during viral infection, and expressed 3A localizes to the Golgi-derived membranes. Taken together, these data show that in HRV-1A infection, the 3A protein plays a role in fragmenting the Golgi complex and generating vesicles that are used as the site of viral RNA replication.
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Affiliation(s)
- Claire A Quiner
- Department of Microbiology and Molecular Genetics and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
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Arita M, Takebe Y, Wakita T, Shimizu H. A bifunctional anti-enterovirus compound that inhibits replication and the early stage of enterovirus 71 infection. J Gen Virol 2010; 91:2734-44. [DOI: 10.1099/vir.0.023374-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Cameron CE, Oh HS, Moustafa IM. Expanding knowledge of P3 proteins in the poliovirus lifecycle. Future Microbiol 2010; 5:867-81. [PMID: 20521933 PMCID: PMC2904470 DOI: 10.2217/fmb.10.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Poliovirus is the most extensively studied member of the order Picornavirales, which contains numerous medical, veterinary and agricultural pathogens. The picornavirus genome encodes a single polyprotein that is divided into three regions: P1, P2 and P3. P3 proteins are known to participate more directly in genome replication, for example by containing the viral RNA-dependent RNA polymerase (RdRp or 3Dpol), among several other proteins and enzymes. We will review recent data that provide new insight into the structure, function and mechanism of P3 proteins and their complexes, which are required for initiation of genome replication. Replication of poliovirus genomes occurs within macromolecular complexes, containing viral RNA, viral proteins and host-cell membranes, collectively referred to as replication complexes. P2 proteins clearly contribute to interactions with the host cell that are required for virus multiplication, including formation of replication complexes. We will discuss recent data that suggest a role for P3 proteins in formation of replication complexes. Among the least understood steps of the poliovirus lifecycle is encapsidation of genomic RNA. We will also describe data that suggest a role for P3 proteins in this step.
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Affiliation(s)
- Craig E Cameron
- Department of Biochemistry & Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
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Role of cellular lipids in positive-sense RNA virus replication complex assembly and function. Viruses 2010; 2:1055-1068. [PMID: 21994671 PMCID: PMC3187604 DOI: 10.3390/v2051055] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Revised: 04/07/2010] [Accepted: 04/22/2010] [Indexed: 01/09/2023] Open
Abstract
Positive-sense RNA viruses are responsible for frequent and often devastating diseases in humans, animals, and plants. However, the development of effective vaccines and anti-viral therapies targeted towards these pathogens has been hindered by an incomplete understanding of the molecular mechanisms involved in viral replication. One common feature of all positive-sense RNA viruses is the manipulation of host intracellular membranes for the assembly of functional viral RNA replication complexes. This review will discuss the interplay between cellular membranes and positive-sense RNA virus replication, and will focus specifically on the potential structural and functional roles for cellular lipids in this process.
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