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Guo X, Zhang M, Liu X, Zhang Y, Wang C, Guo Y. Attachment, Entry, and Intracellular Trafficking of Classical Swine Fever Virus. Viruses 2023; 15:1870. [PMID: 37766277 PMCID: PMC10534341 DOI: 10.3390/v15091870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Classical swine fever virus (CSFV), which is a positive-sense, single-stranded RNA virus with an envelope, is a member of the Pestivirus genus in the Flaviviridae family. CSFV causes a severe and highly contagious disease in pigs and is prevalent worldwide, threatening the pig farming industry. The detailed mechanisms of the CSFV life cycle have been reported, but are still limited. Some receptors and attachment factors of CSFV, including heparan sulfate (HS), laminin receptor (LamR), complement regulatory protein (CD46), MER tyrosine kinase (MERTK), disintegrin, and metalloproteinase domain-containing protein 17 (ADAM17), were identified. After attachment, CSFV internalizes via clathrin-mediated endocytosis (CME) and/or caveolae/raft-dependent endocytosis (CavME). After internalization, CSFV moves to early and late endosomes before uncoating. During this period, intracellular trafficking of CSFV relies on components of the endosomal sorting complex required for transport (ESCRT) and Rab proteins in the endosome dynamics, with a dependence on the cytoskeleton network. This review summarizes the data on the mechanisms of CSFV attachment, internalization pathways, and intracellular trafficking, and provides a general view of the early events in the CSFV life cycle.
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Affiliation(s)
| | | | | | | | | | - Yidi Guo
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130012, China
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2
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Riedel C, Aitkenhead H, El Omari K, Rümenapf T. Atypical Porcine Pestiviruses: Relationships and Conserved Structural Features. Viruses 2021; 13:v13050760. [PMID: 33926056 PMCID: PMC8146772 DOI: 10.3390/v13050760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/23/2021] [Accepted: 04/23/2021] [Indexed: 01/22/2023] Open
Abstract
For two decades, the genus pestivirus has been expanding and the host range now extends to rodents, bats and marine mammals. In this review, we focus on one of the most diverse pestiviruses, atypical porcine pestivirus or pestivirus K, comparing its special traits to what is already known at the structural and functional level from other pestiviruses.
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Affiliation(s)
- Christiane Riedel
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
- Correspondence:
| | - Hazel Aitkenhead
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (H.A.); (K.E.O.)
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, UK
| | - Kamel El Omari
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (H.A.); (K.E.O.)
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, UK
| | - Till Rümenapf
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
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3
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Zhang L, Jin M, Song M, Liu S, Wang T, Guo K, Zhang Y. ARFGAP1 binds to classical swine fever virus NS5A protein and enhances CSFV replication in PK-15 cells. Vet Microbiol 2021; 255:109034. [PMID: 33721634 DOI: 10.1016/j.vetmic.2021.109034] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/01/2021] [Indexed: 12/01/2022]
Abstract
Classical swine fever virus (CSFV), an enveloped virus belonging to the genus Pestivirus of the Flaviviridae family, utilizes cell host factors for its own replication. ARFGAP1, GTPase activating protein of ADP-ribosylation factor 1, regulates COP I vesicle formation and function in cells and is involved in the life cycle of several viruses. However, the effect of ARFGAP1 on the infection of CSFV has not been illustrated. Here we showed that inhibition of ARFGAP1 either by QS11 or by lentivirus-mediated silencing repressed CSFV replication. While, subsequent experiments revealed that CSFV production were increased in cells with sufficient ARFGAP1 expression. However, ARFGAP1 was not involved in CSFV binding, entry, access to cell vesicles, and RNA replication during the early stages of infection. Then, we showed that ARFGAP1 interacted with the viral protein of NS5A, measured by immunoprecipitation, GST-pulldown, and confocal microscopy assays. Furthermore, we revealed that ARFGAP1 could alleviated CSFV NS5A-induced endoplasmic reticulum stress (ERS). Altogether, these results demonstrate that ARFGAP1, a NS5A binding protein, is involved in CSFV replication.
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Affiliation(s)
- Liang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Mingxing Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Mengzhao Song
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Shanchuan Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tao Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Kangkang Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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4
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Zhang L, Zhao D, Jin M, Song M, Liu S, Guo K, Zhang Y. Rab18 binds to classical swine fever virus NS5A and mediates viral replication and assembly in swine umbilical vein endothelial cells. Virulence 2021; 11:489-501. [PMID: 32419589 PMCID: PMC7239025 DOI: 10.1080/21505594.2020.1767356] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Classical swine fever virus (CSFV), a positive-sense RNA virus, hijacks cell host proteins for its own replication. Rab18, a small Rab GTPase, regulates intracellular membrane-trafficking events between various compartments in cells and is involved in the life cycle of multiple viruses. However, the effect of Rab18 on the production of CSFV remains uncertain. In this study, we showed that knockdown of Rab18 by lentiviruses inhibited CSFV production, while overexpression of Rab18 by lentiviruses enhanced CSFV production. Subsequent experiments revealed that the negative-mutant Rab18-S22 N inhibited CSFV infection, while the positive-mutant Rab18-Q67 L enhanced CSFV infection. Furthermore, we showed that CSFV RNA replication and virion assembly, measured by real-time fluorescence quantitative PCR (RT-qPCR), indirect immunofluorescence assay (IFA), and confocal microscopy, were reduced in cells lacking Rab18 expression. In addition, co-immunoprecipitation, GST-pulldown, and confocal microscopy assays revealed that Rab18 bound to the viral protein NS5A. Further, NS5A was shown to be redistributed in Rab18 knockdown cells. Taken together, these findings demonstrate Rab18 as a novel host factor required for CSFV RNA replication and particle assembly by interaction with the viral protein NS5A.
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Affiliation(s)
- Liang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Di Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Mingxing Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Mengzhao Song
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Shanchuan Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Kangkang Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
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Ling S, Luo M, Jiang S, Liu J, Ding C, Zhang Q, Guo H, Gong W, Tu C, Sun J. Cellular Hsp27 interacts with classical swine fever virus NS5A protein and negatively regulates viral replication by the NF-κB signaling pathway. Virology 2018. [PMID: 29525670 DOI: 10.1016/j.virol.2018.02.020] [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] [Indexed: 12/16/2022]
Abstract
Classical swine fever virus (CSFV) nonstructural protein NS5A is a multifunctional protein functioning in regulation of viral genome replication, protein translation and assembly by interaction with viral or host proteins. Here, heat shock protein 27 (Hsp27) has been identified as a novel binding partner of NS5A by using His tag "pull down" coupled with shotgun LC-MS/MS, with interaction of both proteins further confirmed by co-immunoprecipitation and laser confocal assays. In PK-15 cells, silencing of Hsp27 expression by siRNA enhanced CSFV replication, and upregulation of Hsp27 inhibited viral proliferation. Additionally, we have shown that overexpression of Hsp27 increased NF-κB signaling induced by TNFα. Blocking NF-κB signaling in PK-15 cells overexpressing Hsp27 by ammonium pyrrolidinedithiocarbamate (PDTC) eliminated the inhibition of CSFV replication by Hsp27. These findings clearly demonstrate that the inhibition of CSFV replication by Hsp27 is mediated via the NF-κB signaling pathway.
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Affiliation(s)
- Shifeng Ling
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Mingyang Luo
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Shengnan Jiang
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Jiayu Liu
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Chunying Ding
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Qinghuan Zhang
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China
| | - Huancheng Guo
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, No. 666 Liuying West Road, Changchun 130122, PR China
| | - Wenjie Gong
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, No. 666 Liuying West Road, Changchun 130122, PR China
| | - Changchun Tu
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, No. 666 Liuying West Road, Changchun 130122, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonose, Yangzhou University, No. 48 Wenhui East Road, Yangzhou 225009, China.
| | - Jinfu Sun
- Institute of Biotechnology, College of Life and Health Sciences, Northeastern University, No. 195, Chuangxin Road, Shenyang 110000, PR China.
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6
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The eukaryotic translation initiation factor 3 subunit E binds to classical swine fever virus NS5A and facilitates viral replication. Virology 2018; 515:11-20. [DOI: 10.1016/j.virol.2017.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 01/12/2023]
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7
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Lin J, Wang C, Liang W, Zhang J, Zhang L, Lv H, Dong W, Zhang Y. Rab1A is required for assembly of classical swine fever virus particle. Virology 2017; 514:18-29. [PMID: 29128753 DOI: 10.1016/j.virol.2017.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/28/2017] [Accepted: 11/02/2017] [Indexed: 12/20/2022]
Abstract
Rab1A belongs to the small Rab GTPase family and is involved in the lifecycle of numerous viruses. Here, knockdown of Rab1A inhibited CSFV growth. Further study revealed that Rab1A depletion decreased intracellular and extracellular CSFV titers, but did not affect intracellular virus genome copies and E2 protein expression within a virus lifecycle, which suggested that Rab1A is required for CSFV particle assembly rather than for genome replication or virion release. This was proofed by blocking the spread of virus using neutralizing antibodies, through which the negative effects of Rab1A knockdown on multi-cycle replication of CSFV were eliminated. Moreover, co-immunoprecipitation and confocal microscopy assays showed that Rab1A bound to CSFV NS5A protein, indicating that Rab1A and viral NS5A proteins may work cooperatively during CSFV particle assembly. In conclusion, this study demonstrated for the first time that Rab1A is required for CSFV particle assembly and binds to viral particle assembly-related NS5A protein.
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Affiliation(s)
- Jihui Lin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Chengbao Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wulong Liang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jing Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Longxiang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Huifang Lv
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wang Dong
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China.
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Abstract
The Golgi apparatus and its resident proteins are utilized and regulated by viruses to facilitate their proliferation. In this study, we investigated Classical swine fever virus (CSFV) proliferation when the function of the Golgi was disturbed. Golgi function was disturbed using chemical inhibitors, namely, brefeldin A (BFA) and golgicide A (GCA), and RNA interfering targets, such as the Golgi-specific BFA-resistance guanine nucleotide exchange factor 1 (GBF1) and Rab2 GTPases. CSFV proliferation was significantly inhibited during RNA replication and viral particle generation after BFA and GCA treatment. CSFV multiplication dynamics were retarded in cells transfected with GBF1 and Rab2 shRNA. Furthermore, CSFV proliferation was promoted by GBF1 and Rab2 overexpression using a lentiviral system. Hence, Golgi function is important for CSFV multiplication, and GBF1 and Rab2 participate in CSFV proliferation. Further studies must investigate Golgi-resident proteins to elucidate the mechanism underlying CSFV replication.
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9
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The effect of classical swine fever virus NS5A and NS5A mutants on oxidative stress and inflammatory response in swine testicular cells. Res Vet Sci 2017; 112:89-96. [PMID: 28142057 DOI: 10.1016/j.rvsc.2017.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 01/06/2017] [Accepted: 01/12/2017] [Indexed: 12/22/2022]
Abstract
Infection with classical swine fever virus (CSFV) results in highly significant economic losses; this infection is characterized by being highly contagious and accompanied by hyperthermia and systemic bleeding. Oxidative stress (OS) plays a critical role in the pathological process of viral infection. The function of the nonstructural protein 5A (NS5A) in the pathogenesis of CSFV has not been completely understood. Here, OS and the inflammatory response were studied with NS5A and substitution mutants in swine testicular (ST) cells. ST cell lines stably expressing CSFV NS5A or substitution mutants were established. Reactive oxygen species (ROS) production, antioxidant protein expression and inflammatory response were analyzed by quantitative real-time PCR (qRT-PCR), ELISA and flow cytometry analysis. The results showed that CSFV NS5A did not increase ROS production or the antioxidant protein (Trx, HO-1 and PRDX-6) expression in ST cells. However, NS5A inhibited cyclooxygenase-2 (COX-2) expression, a pro-inflammatory protein related to OS. Further studies have shown that NS5A mutants S15A and S92A increased ROS production and inhibited antioxidant protein expression. S15A, S81A and T274A affected the inflammatory response. This study suggested that CSFV NS5A did not induce OS, and amino acids Ser15 and Ser92 of CSFV NS5A were essential for inhibiting OS. Additionally, Ser15, Ser81 and Thr274 played important roles in the inflammatory response in ST cells. These observations provided insight into the function of CSFV NS5A and the mechanism of CSFV persistent infection in ST cells.
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Identification of cleavage of NS5A of C-strain classical swine fever virus. Arch Virol 2016; 162:391-400. [PMID: 27766426 DOI: 10.1007/s00705-016-3117-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
NS5A is a multifunctional non-structural protein of classical swine fever virus (CSFV) that plays an important role in viral replication, but how it exerts its functions is unknown. Here, we report the cleavage of NS5A of the vaccine C-strain, resulting in two truncated forms (b and c). Further experiments using calpain- and caspase-family-specific inhibitors, followed by a caspase-6-specific shRNAs and inhibitor, showed that the cleavage of C-strain NS5A to produce truncated form c is mediated by caspase-6, mapping to 272DTTD275, while the cleavage producing truncated form b is probably mediated by another unknown protease. shRNA-mediated downregulation of caspase-6 and blocking of enzyme activity in ST cells significantly impaired genome replication and virus production, indicating that NS5A cleavage is required for CSFV replication.
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11
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Li H, Zhang C, Cui H, Guo K, Wang F, Zhao T, Liang W, Lv Q, Zhang Y. FKBP8 interact with classical swine fever virus NS5A protein and promote virus RNA replication. Virus Genes 2016; 52:99-106. [PMID: 26748656 DOI: 10.1007/s11262-015-1286-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 09/02/2015] [Indexed: 11/24/2022]
Abstract
The non-structural 5A (NS5A) protein of classical swine fever virus (CSFV) is proven to be involved in viral replication and can also modulate cellular signaling and host cellular responses via to its ability to interact with various cellular proteins. FKBP8 is also reported to promote virus replication. Here, we show that NS5A specifically interacts with FKBP8 through coimmunoprecipitation and GST-pulldown studies. Additionally, confocal microscopy study showed that NS5A and FKBP8 colocalized in the cytoplasm. Overexpression of FKBP8 via the eukaryotic expression plasmid pDsRED N1 significantly promoted viral RNA synthesis. The cells knockdown of FKBP8 by lentivirus-mediated shRNA markedly decreased the virus replication when infected with CSFV. These data suggest that FKBP8 plays a critical role in the viral life cycle, particularly during the virus RNA replication period. The investigation of FKBP8 protein functions may be beneficial for developing new strategies to treat CSFV infection.
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Affiliation(s)
- Helin Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Chengcheng Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Hongjie Cui
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Kangkang Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Fang Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Tianyue Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Wulong Liang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Qizhuang Lv
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
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Live Cell Reporter Systems for Positive-Sense Single Strand RNA Viruses. Appl Biochem Biotechnol 2016; 178:1567-85. [PMID: 26728654 PMCID: PMC7091396 DOI: 10.1007/s12010-015-1968-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/22/2015] [Indexed: 01/09/2023]
Abstract
Cell-based reporter systems have facilitated studies of viral replication and pathogenesis, virus detection, and drug susceptibility testing. There are three types of cell-based reporter systems that express certain reporter protein for positive-sense single strand RNA virus infections. The first type is classical reporter system, which relies on recombinant virus, reporter virus particle, or subgenomic replicon. During infection with the recombinant virus or reporter virus particle, the reporter protein is expressed and can be detected in real time in a dose-dependent manner. Using subgenomic replicon, which are genetically engineered viral RNA molecules that are capable of replication but incapable of producing virions, the translation and replication of the replicon could be tracked by the accumulation of reporter protein. The second type of reporter system involves genetically engineered cells bearing virus-specific protease cleavage sequences, which can sense the incoming viral protease. The third type is based on viral replicase, which can report the specific virus infection via detection of the incoming viral replicase. This review specifically focuses on the major technical breakthroughs in the design of cell-based reporter systems and the application of these systems to the further understanding and control of viruses over the past few decades.
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Abstract
Pestiviruses are among the economically most important pathogens of livestock. The biology of these viruses is characterized by unique and interesting features that are both crucial for their success as pathogens and challenging from a scientific point of view. Elucidation of these features at the molecular level has made striking progress during recent years. The analyses revealed that major aspects of pestivirus biology show significant similarity to the biology of human hepatitis C virus (HCV). The detailed molecular analyses conducted for pestiviruses and HCV supported and complemented each other during the last three decades resulting in elucidation of the functions of viral proteins and RNA elements in replication and virus-host interaction. For pestiviruses, the analyses also helped to shed light on the molecular basis of persistent infection, a special strategy these viruses have evolved to be maintained within their host population. The results of these investigations are summarized in this chapter.
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Affiliation(s)
- Norbert Tautz
- Institute for Virology and Cell Biology, University of Lübeck, Lübeck, Germany
| | - Birke Andrea Tews
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Gregor Meyers
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany.
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Zhang C, Kang K, Ning P, Peng Y, Lin Z, Cui H, Cao Z, Wang J, Zhang Y. Heat shock protein 70 is associated with CSFV NS5A protein and enhances viral RNA replication. Virology 2015; 482:9-18. [PMID: 25827528 DOI: 10.1016/j.virol.2015.02.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 12/17/2014] [Accepted: 02/09/2015] [Indexed: 01/13/2023]
Abstract
The non-structural 5A (NS5A) protein of classical swine fever virus (CSFV) is proven to be involved in viral replication and can also modulate cellular signaling via to its ability to interact with various cellular proteins. Here, HSP70/NS5A complex formation is confirmed by coimmunoprecipitation and GST-pulldown studies. Additionally, the N-terminal amino acids (29-240) of NS5A were identified as the interaction region through in vivo deletion analyses, and confocal microscopy showed that NS5A and HSP70 colocalized in the cytoplasm. Overexpression of HSP70 via the eukaryotic expression plasmid pDsRED N1 or lentivirus significantly promoted viral RNA synthesis. Whereas the knockdown of HSP70 by lentivirus-mediated shRNA or inhibition by quercetin markedly decreased the viral load. These data suggest that HSP70 plays a critical role in the viral life cycle, particularly during the virus RNA replication period. The investigation of HSP70 protein functions may be beneficial for developing new strategies to treat CSFV infection.
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Affiliation(s)
- Chengcheng Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Kai Kang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Pengbo Ning
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Yangxin Peng
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Zhi Lin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Hongjie Cui
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Zhi Cao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Jing Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China.
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15
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Sheng C, Kou S, Jiang Q, Zhou C, Xiao J, Li J, Chen B, Zhao Y, Wang Y, Xiao M. Characterization of the C-terminal sequence of NS5A necessary for the assembly and production of classical swine fever virus infectious particles. Res Vet Sci 2014; 97:449-54. [PMID: 25218811 DOI: 10.1016/j.rvsc.2014.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 07/11/2014] [Accepted: 07/25/2014] [Indexed: 11/16/2022]
Abstract
Recent studies show that classical swine fever virus (CSFV) NS5A is an essential replicase component, but it is not known how NS5A participates in viral particle production. In this study, deletion and substitution mutations were introduced into the C-terminus of CSFV NS5A. The efficiency of Core protein release and extracellular and intracellular infectivity levels were assessed and NS5A-Core interaction was investigated. These results suggested that CSFV NS5A was a key factor for the assembly of infectious CSFV particles. The C-terminal sequence from amino acids 478 to 487 and amino acids S481 and T482 were necessary for CSFV assembly and production. The effect of NS5A on CSFV assembly and production might be related to NS5A-Core interaction. T482 was found to be conserved in the C-terminus of NS5A proteins of pestiviruses and hepatitis C virus (HCV), therefore suggesting that it might be important for these virus assembly and production.
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Affiliation(s)
- Chun Sheng
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Shumeng Kou
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Qiuyue Jiang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chenhao Zhou
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jing Xiao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jing Li
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Bing Chen
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yu Zhao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yujing Wang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Ming Xiao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China.
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