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Chai M, Li L, Li Y, Yang Y, Wang Y, Jiang X, Luan Y, Li F, Cui H, Wang A, Xiang W, Wu X, Cheng X. The 6-kilodalton peptide 1 in plant viruses of the family Potyviridae is a viroporin. Proc Natl Acad Sci U S A 2024; 121:e2401748121. [PMID: 38739789 PMCID: PMC11127057 DOI: 10.1073/pnas.2401748121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Potyviridae, the largest family of plant RNA viruses, includes many important pathogens that significantly reduce the yields of many crops worldwide. In this study, we report that the 6-kilodalton peptide 1 (6K1), one of the least characterized potyviral proteins, is an endoplasmic reticulum-localized protein. AI-assisted structure modeling and biochemical assays suggest that 6K1 forms pentamers with a central hydrophobic tunnel, can increase the cell membrane permeability of Escherichia coli and Nicotiana benthamiana, and can conduct potassium in Saccharomyces cerevisiae. An infectivity assay showed that viral proliferation is inhibited by mutations that affect 6K1 multimerization. Moreover, the 6K1 or its homologous 7K proteins from other viruses of the Potyviridae family also have the ability to increase cell membrane permeability and transmembrane potassium conductance. Taken together, these data reveal that 6K1 and its homologous 7K proteins function as viroporins in viral infected cells.
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Affiliation(s)
- Mengzhu Chai
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Lei Li
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Yong Li
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Yingshuai Yang
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Yuting Wang
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Xue Jiang
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Yameng Luan
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China
| | - Hongguang Cui
- College of Plant Protection, Hainan University, Haikou570228, China
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ONN5V 4T3, Canada
| | - Wensheng Xiang
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Xiaoyun Wu
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
| | - Xiaofei Cheng
- College of Plant Protection, Northeast Agricultural University, Harbin, Heilongjiang150030, China
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Fang L, Geng C, Wei XY, Dong CC, Pang JP, Yan ZY, Jiang J, Tian YP, Li XD. Potato virus Y viral protein 6K1 inhibits the interaction between defense proteins during virus infection. PLANT PHYSIOLOGY 2024; 194:1447-1466. [PMID: 37962935 PMCID: PMC10904343 DOI: 10.1093/plphys/kiad612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 11/15/2023]
Abstract
14-3-3 proteins play vital roles in plant defense against various pathogen invasions. To date, how 14-3-3 affects virus infections in plants remains largely unclear. In this study, we found that Nicotiana benthamiana 14-3-3h interacts with TRANSLATIONALLY CONTROLLED TUMOR PROTEIN (TCTP), a susceptibility factor of potato virus Y (PVY). Silencing of Nb14-3-3h facilitates PVY accumulation, whereas overexpression of Nb14-3-3h inhibits PVY replication. The antiviral activities of 3 Nb14-3-3h dimerization defective mutants are significantly decreased, indicating that dimerization of Nb14-3-3h is indispensable for restricting PVY infection. Our results also showed that the mutant Nb14-3-3hE16A, which is capable of dimerizing but not interacting with NbTCTP, has reduced anti-PVY activity; the mutant NbTCTPI65A, which is unable to interact with Nb14-3-3h, facilitates PVY replication compared with the wild-type NbTCTP, indicating that dimeric Nb14-3-3h restricts PVY infection by interacting with NbTCTP and preventing its proviral function. As a counter-defense, PVY 6K1 interferes with the interaction between Nb14-3-3h and NbTCTP by competitively binding to Nb14-3-3h and rescues NbTCTP to promote PVY infection. Our results provide insights into the arms race between plants and potyviruses.
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Affiliation(s)
- Le Fang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, Shandong 250131, China
| | - Chao Geng
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Xin-Yu Wei
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Chen-Chen Dong
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Ju-Ping Pang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Zhi-Yong Yan
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Jun Jiang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Yan-Ping Tian
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Xiang-Dong Li
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, Shandong 250131, China
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Gong P, Shen Q, Zhang M, Qiao R, Jiang J, Su L, Zhao S, Fu S, Ma Y, Ge L, Wang Y, Lozano-Durán R, Wang A, Li F, Zhou X. Plant and animal positive-sense single-stranded RNA viruses encode small proteins important for viral infection in their negative-sense strand. MOLECULAR PLANT 2023; 16:1794-1810. [PMID: 37777826 DOI: 10.1016/j.molp.2023.09.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 07/03/2023] [Accepted: 09/26/2023] [Indexed: 10/02/2023]
Abstract
Positive-sense single-stranded RNA (+ssRNA) viruses, the most abundant viruses of eukaryotes in nature, require the synthesis of negative-sense RNA (-RNA) using their genomic (positive-sense) RNA (+RNA) as a template for replication. Based on current evidence, viral proteins are translated via viral +RNAs, whereas -RNA is considered to be a viral replication intermediate without coding capacity. Here, we report that plant and animal +ssRNA viruses contain small open reading frames (ORFs) in their -RNA (reverse ORFs [rORFs]). Using turnip mosaic virus (TuMV) as a model for plant +ssRNA viruses, we demonstrate that small proteins encoded by rORFs display specific subcellular localizations, and confirm the presence of rORF2 in infected cells through mass spectrometry analysis. The protein encoded by TuMV rORF2 forms punctuate granules that are localized in the perinuclear region and co-localized with viral replication complexes. The rORF2 protein can directly interact with the viral RNA-dependent RNA polymerase, and mutation of rORF2 completely abolishes virus infection, whereas ectopic expression of rORF2 rescues the mutant virus. Furthermore, we show that several rORFs in the -RNA of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have the ability to suppress type I interferon production and facilitate the infection of vesicular stomatitis virus. In addition, we provide evidence that TuMV might utilize internal ribosome entry sites to translate these small rORFs. Taken together, these findings indicate that the -RNA of +ssRNA viruses can also have the coding capacity and that small proteins encoded therein play critical roles in viral infection, revealing a viral proteome larger than previously thought.
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Affiliation(s)
- Pan Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qingtang Shen
- School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Mingzhen Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Rui Qiao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jing Jiang
- School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Lili Su
- School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Siwen Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shuai Fu
- State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yu Ma
- University of the Chinese Academy of Sciences, Beijing, China
| | - Linhao Ge
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Rosa Lozano-Durán
- Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), Eberhard Karls University, 72076 Tübingen, Germany
| | - Aiming Wang
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON, Canada
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
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4
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Soybean Mosaic Virus 6K1 Interactors Screening and GmPR4 and GmBI1 Function Characterization. Int J Mol Sci 2023; 24:ijms24065304. [PMID: 36982379 PMCID: PMC10049162 DOI: 10.3390/ijms24065304] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/27/2023] [Accepted: 03/04/2023] [Indexed: 03/12/2023] Open
Abstract
Host proteins are essential during virus infection, and viral factors must target numerous host factors to complete their infectious cycle. The mature 6K1 protein of potyviruses is required for viral replication in plants. However, the interaction between 6K1 and host factors is poorly understood. The present study aims to identify the host interacting proteins of 6K1. Here, the 6K1 of Soybean mosaic virus (SMV) was used as the bait to screen a soybean cDNA library to gain insights about the interaction between 6K1 and host proteins. One hundred and twenty-seven 6K1 interactors were preliminarily identified, and they were classified into six groups, including defense-related, transport-related, metabolism-related, DNA binding, unknown, and membrane-related proteins. Then, thirty-nine proteins were cloned and merged into a prey vector to verify the interaction with 6K1, and thirty-three of these proteins were confirmed to interact with 6K1 by yeast two-hybrid (Y2H) assay. Of the thirty-three proteins, soybean pathogenesis-related protein 4 (GmPR4) and Bax inhibitor 1 (GmBI1) were chosen for further study. Their interactions with 6K1 were also confirmed by bimolecular fluorescence complementation (BiFC) assay. Subcellular localization showed that GmPR4 was localized to the cytoplasm and endoplasmic reticulum (ER), and GmBI1 was located in the ER. Moreover, both GmPR4 and GmBI1 were induced by SMV infection, ethylene and ER stress. The transient overexpression of GmPR4 and GmBI1 reduced SMV accumulation in tobacco, suggesting their involvement in the resistance to SMV. These results would contribute to exploring the mode of action of 6K1 in viral replication and improve our knowledge of the role of PR4 and BI1 in SMV response.
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Bera S, Arena GD, Ray S, Flannigan S, Casteel CL. The Potyviral Protein 6K1 Reduces Plant Proteases Activity during Turnip mosaic virus Infection. Viruses 2022; 14:1341. [PMID: 35746814 PMCID: PMC9229136 DOI: 10.3390/v14061341] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/30/2022] [Accepted: 06/12/2022] [Indexed: 12/25/2022] Open
Abstract
Potyviral genomes encode just 11 major proteins and multifunctionality is associated with most of these proteins at different stages of the virus infection cycle. Some potyviral proteins modulate phytohormones and protein degradation pathways and have either pro- or anti-viral/insect vector functions. Our previous work demonstrated that the potyviral protein 6K1 has an antagonistic effect on vectors when expressed transiently in host plants, suggesting plant defenses are regulated. However, to our knowledge the mechanisms of how 6K1 alters plant defenses and how 6K1 functions are regulated are still limited. Here we show that the 6K1 from Turnip mosaic virus (TuMV) reduces the abundance of transcripts related to jasmonic acid biosynthesis and cysteine protease inhibitors when expressed in Nicotiana benthamiana relative to controls. 6K1 stability increased when cysteine protease activity was inhibited chemically, showing a mechanism to the rapid turnover of 6K1 when expressed in trans. Using RNAseq, qRT-PCR, and enzymatic assays, we demonstrate TuMV reprograms plant protein degradation pathways on the transcriptional level and increases 6K1 stability at later stages in the infection process. Moreover, we show 6K1 decreases plant protease activity in infected plants and increases TuMV accumulation in systemic leaves compared to controls. These results suggest 6K1 has a pro-viral function in addition to the anti-insect vector function we observed previously. Although the host targets of 6K1 and the impacts of 6K1-induced changes in protease activity on insect vectors are still unknown, this study enhances our understanding of the complex interactions occurring between plants, potyviruses, and vectors.
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Affiliation(s)
- Sayanta Bera
- School of Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14850, USA; (S.B.); (S.R.); (S.F.)
| | - Gabriella D. Arena
- Laboratório de Biologia Molecular Aplicada, Instituto Biológico de São Paulo, São Paulo 04014-002, Brazil;
| | - Swayamjit Ray
- School of Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14850, USA; (S.B.); (S.R.); (S.F.)
| | - Sydney Flannigan
- School of Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14850, USA; (S.B.); (S.R.); (S.F.)
| | - Clare L. Casteel
- School of Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14850, USA; (S.B.); (S.R.); (S.F.)
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6
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Yang X, Li Y, Wang A. Research Advances in Potyviruses: From the Laboratory Bench to the Field. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:1-29. [PMID: 33891829 DOI: 10.1146/annurev-phyto-020620-114550] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Potyviruses (viruses in the genus Potyvirus, family Potyviridae) constitute the largest group of known plant-infecting RNA viruses and include many agriculturally important viruses that cause devastating epidemics and significant yield losses in many crops worldwide. Several potyviruses are recognized as the most economically important viral pathogens. Therefore, potyviruses are more studied than other groups of plant viruses. In the past decade, a large amount of knowledge has been generated to better understand potyviruses and their infection process. In this review, we list the top 10 economically important potyviruses and present a brief profile of each. We highlight recent exciting findings on the novel genome expression strategy and the biological functions of potyviral proteins and discuss recent advances in molecular plant-potyvirus interactions, particularly regarding the coevolutionary arms race. Finally, we summarize current disease control strategies, with a focus on biotechnology-based genetic resistance, and point out future research directions.
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Affiliation(s)
- Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada;
| | - Yinzi Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada;
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada;
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7
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Kannan M, Zainal Z, Ismail I, Baharum SN, Bunawan H. Application of Reverse Genetics in Functional Genomics of Potyvirus. Viruses 2020; 12:v12080803. [PMID: 32722532 PMCID: PMC7472138 DOI: 10.3390/v12080803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/12/2020] [Accepted: 07/14/2020] [Indexed: 12/16/2022] Open
Abstract
Numerous potyvirus studies, including virus biology, transmission, viral protein function, as well as virus–host interaction, have greatly benefited from the utilization of reverse genetic techniques. Reverse genetics of RNA viruses refers to the manipulation of viral genomes, transfection of the modified cDNAs into cells, and the production of live infectious progenies, either wild-type or mutated. Reverse genetic technology provides an opportunity of developing potyviruses into vectors for improving agronomic traits in plants, as a reporter system for tracking virus infection in hosts or a production system for target proteins. Therefore, this review provides an overview on the breakthroughs achieved in potyvirus research through the implementation of reverse genetic systems.
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Affiliation(s)
- Maathavi Kannan
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (M.K.); (Z.Z.); (I.I.); (S.N.B.)
| | - Zamri Zainal
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (M.K.); (Z.Z.); (I.I.); (S.N.B.)
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, University Kebangsaan Malaysia, Bangi 43600, Malaysia
| | - Ismanizan Ismail
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (M.K.); (Z.Z.); (I.I.); (S.N.B.)
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, University Kebangsaan Malaysia, Bangi 43600, Malaysia
| | - Syarul Nataqain Baharum
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (M.K.); (Z.Z.); (I.I.); (S.N.B.)
| | - Hamidun Bunawan
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (M.K.); (Z.Z.); (I.I.); (S.N.B.)
- Correspondence: ; Tel.: +60-3-8921-4554
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Rodamilans B, Valli A, García JA. Molecular Plant-Plum Pox Virus Interactions. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:6-17. [PMID: 31454296 DOI: 10.1094/mpmi-07-19-0189-fi] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Plum pox virus, the agent that causes sharka disease, is among the most important plant viral pathogens, affecting Prunus trees across the globe. The fabric of interactions that the virus is able to establish with the plant regulates its life cycle, including RNA uncoating, translation, replication, virion assembly, and movement. In addition, plant-virus interactions are strongly conditioned by host specificities, which determine infection outcomes, including resistance. This review attempts to summarize the latest knowledge regarding Plum pox virus-host interactions, giving a comprehensive overview of their relevance for viral infection and plant survival, including the latest advances in genetic engineering of resistant species.
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Affiliation(s)
- Bernardo Rodamilans
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Adrián Valli
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Juan Antonio García
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Geng C, Yan ZY, Cheng DJ, Liu J, Tian YP, Zhu CX, Wang HY, Li XD. Tobacco vein banding mosaic virus 6K2 Protein Hijacks NbPsbO1 for Virus Replication. Sci Rep 2017; 7:43455. [PMID: 28230184 PMCID: PMC5322494 DOI: 10.1038/srep43455] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/23/2017] [Indexed: 01/18/2023] Open
Abstract
Chloroplast-bound vesicles are key components in viral replication complexes (VRCs) of potyviruses. The potyviral VRCs are induced by the second 6 kDa protein (6K2) and contain at least viral RNA and nuclear inclusion protein b. To date, no chloroplast protein has been identified to interact with 6K2 and involve in potyvirus replication. In this paper, we showed that the Photosystem II oxygen evolution complex protein of Nicotiana benthamiana (NbPsbO1) was a chloroplast protein interacting with 6K2 of Tobacco vein banding mosaic virus (TVBMV; genus Potyvirus) and present in the VRCs. The first 6 kDa protein (6K1) was recruited to VRCs by 6K2 but had no interaction with NbPSbO1. Knockdown of NbPsbO1 gene expression in N. benthamiana plants through virus-induced gene silencing significantly decreased the accumulation levels of TVBMV and another potyvirus Potato virus Y, but not Potato virus X of genus Potexvirus. Amino acid substitutions in 6K2 that disrupted its interaction with NbPsbO1 also affected the replication of TVBMV. NbPsbP1 and NbPsbQ1, two other components of the Photosystem II oxygen evolution complex had no interaction with 6K2 and no effect on TVBMV replication. To conclude, 6K2 recruits 6K1 to VRCs and hijacks chloroplast protein NbPsbO1 to regulate potyvirus replication.
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Affiliation(s)
- Chao Geng
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Zhi-Yong Yan
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - De-Jie Cheng
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Jin Liu
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Yan-Ping Tian
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Chang-Xiang Zhu
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
- Shandong Provincial Key laboratory for Agricultural Microbiology, Tai’an, Shandong, 271018, China
| | - Hong-Yan Wang
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Xiang-Dong Li
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
- Shandong Provincial Key laboratory for Agricultural Microbiology, Tai’an, Shandong, 271018, China
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10
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Cui H, Wang A. Plum Pox Virus 6K1 Protein Is Required for Viral Replication and Targets the Viral Replication Complex at the Early Stage of Infection. J Virol 2016; 90:5119-5131. [PMID: 26962227 PMCID: PMC4859702 DOI: 10.1128/jvi.00024-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/07/2016] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED The potyviral RNA genome encodes two polyproteins that are proteolytically processed by three viral protease domains into 11 mature proteins. Extensive molecular studies have identified functions for the majority of the viral proteins. For example, 6K2, one of the two smallest potyviral proteins, is an integral membrane protein and induces the endoplasmic reticulum (ER)-originated replication vesicles that target the chloroplast for robust viral replication. However, the functional role of 6K1, the other smallest protein, remains uncharacterized. In this study, we developed a series of recombinant full-length viral cDNA clones derived from a Canadian Plum pox virus (PPV) isolate. We found that deletion of any of the short motifs of 6K1 (each of which ranged from 5 to 13 amino acids), most of the 6K1 sequence (but with the conserved sequence of the cleavage sites being retained), or all of the 6K1 sequence in the PPV infectious clone abolished viral replication. The trans expression of 6K1 or the cis expression of a dislocated 6K1 failed to rescue the loss-of-replication phenotype, suggesting the temporal and spatial requirement of 6K1 for viral replication. Disruption of the N- or C-terminal cleavage site of 6K1, which prevented the release of 6K1 from the polyprotein, either partially or completely inhibited viral replication, suggesting the functional importance of the mature 6K1. We further found that green fluorescent protein-tagged 6K1 formed punctate inclusions at the viral early infection stage and colocalized with chloroplast-bound viral replicase elements 6K2 and NIb. Taken together, our results suggest that 6K1 is required for viral replication and is an important viral element of the viral replication complex at the early infection stage. IMPORTANCE Potyviruses account for more than 30% of known plant viruses and consist of many agriculturally important viruses. The genomes of potyviruses encode two polyproteins that are proteolytically processed into 11 mature proteins, with the majority of them having been at least partially functionally characterized. However, the functional role of a small protein named 6K1 remains obscure. In this study, we showed that deletion of 6K1 or a short motif/region of 6K1 in the full-length cDNA clones of plum pox virus abolishes viral replication and that mutation of the N- or C-terminal cleavage sites of 6K1 to prevent its release from the polyprotein greatly attenuates or completely inhibits viral replication, suggesting its important role in potyviral infection. We report that 6K1 forms punctate structures and targets the replication vesicles in PPV-infected plant leaf cells at the early infection stage. Our data reveal that 6K1 is an important viral protein of the potyviral replication complex.
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Affiliation(s)
- Hongguang Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
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11
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Abstract
Potyvirus is the largest genus of plant viruses causing significant losses in a wide range of crops. Potyviruses are aphid transmitted in a nonpersistent manner and some of them are also seed transmitted. As important pathogens, potyviruses are much more studied than other plant viruses belonging to other genera and their study covers many aspects of plant virology, such as functional characterization of viral proteins, molecular interaction with hosts and vectors, structure, taxonomy, evolution, epidemiology, and diagnosis. Biotechnological applications of potyviruses are also being explored. During this last decade, substantial advances have been made in the understanding of the molecular biology of these viruses and the functions of their various proteins. After a general presentation on the family Potyviridae and the potyviral proteins, we present an update of the knowledge on potyvirus multiplication, movement, and transmission and on potyvirus/plant compatible interactions including pathogenicity and symptom determinants. We end the review providing information on biotechnological applications of potyviruses.
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García JA, Glasa M, Cambra M, Candresse T. Plum pox virus and sharka: a model potyvirus and a major disease. MOLECULAR PLANT PATHOLOGY 2014; 15:226-41. [PMID: 24102673 PMCID: PMC6638681 DOI: 10.1111/mpp.12083] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
TAXONOMIC RELATIONSHIPS Plum pox virus (PPV) is a member of the genus Potyvirus in the family Potyviridae. PPV diversity is structured into at least eight monophyletic strains. GEOGRAPHICAL DISTRIBUTION First discovered in Bulgaria, PPV is nowadays present in most of continental Europe (with an endemic status in many central and southern European countries) and has progressively spread to many countries on other continents. GENOMIC STRUCTURE Typical of potyviruses, the PPV genome is a positive-sense single-stranded RNA (ssRNA), with a protein linked to its 5' end and a 3'-terminal poly A tail. It is encapsidated by a single type of capsid protein (CP) in flexuous rod particles and is translated into a large polyprotein which is proteolytically processed in at least 10 final products: P1, HCPro, P3, 6K1, CI, 6K2, VPg, NIapro, NIb and CP. In addition, P3N-PIPO is predicted to be produced by a translational frameshift. PATHOGENICITY FEATURES PPV causes sharka, the most damaging viral disease of stone fruit trees. It also infects wild and ornamental Prunus trees and has a large experimental host range in herbaceous species. PPV spreads over long distances by uncontrolled movement of plant material, and many species of aphid transmit the virus locally in a nonpersistent manner. SOURCES OF RESISTANCE A few natural sources of resistance to PPV have been found so far in Prunus species, which are being used in classical breeding programmes. Different genetic engineering approaches are being used to generate resistance to PPV, and a transgenic plum, 'HoneySweet', transformed with the viral CP gene, has demonstrated high resistance to PPV in field tests in several countries and has obtained regulatory approval in the USA.
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Affiliation(s)
- Juan Antonio García
- Departmento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain
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Calvo M, Malinowski T, García JA. Single amino acid changes in the 6K1-CI region can promote the alternative adaptation of Prunus- and Nicotiana-propagated Plum pox virus C isolates to either host. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:136-49. [PMID: 24200075 DOI: 10.1094/mpmi-08-13-0242-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plum pox virus (PPV) C is one of the less common PPV strains and specifically infects cherry trees in nature. Making use of two PPV-C isolates that display different pathogenicity features, i.e., SwCMp, which had been adapted to Nicotiana species, and BY101, which had been isolated from cherry rootstock L2 (Prunus lannesiana) and propagated only in cherry species, we have generated two infective full-length cDNA clones in order to determine which viral factors are involved in the adaptation to each host. According to our results, the C-P3(PIPO)/6K1/N-CI (cylindrical inclusion) region contains overlapping but not coincident viral determinants involved in symptoms development, local viral amplification, and systemic movement capacity. Amino acid changes in this region promoting the adaptation to N. benthamiana or P. avium have trade-off effects in the alternative host. In both cases, adaptation can be achieved through single amino acid changes in the NIapro protease recognition motif between 6K1 and CI or in nearby sequences. Thus, we hypothesize that the potyvirus polyprotein processing could depend on specific host factors and the adaptation of PPV-C isolates to particular hosts relies on a fine regulation of the proteolytic cleavage of the 6K1-CI junction.
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Sochor J, Babula P, Adam V, Krska B, Kizek R. Sharka: the past, the present and the future. Viruses 2012; 4:2853-901. [PMID: 23202508 PMCID: PMC3509676 DOI: 10.3390/v4112853] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 10/25/2012] [Accepted: 10/30/2012] [Indexed: 12/16/2022] Open
Abstract
Members the Potyviridae family belong to a group of plant viruses that are causing devastating plant diseases with a significant impact on agronomy and economics. Plum pox virus (PPV), as a causative agent of sharka disease, is widely discussed. The understanding of the molecular biology of potyviruses including PPV and the function of individual proteins as products of genome expression are quite necessary for the proposal the new antiviral strategies. This review brings to view the members of Potyviridae family with respect to plum pox virus. The genome of potyviruses is discussed with respect to protein products of its expression and their function. Plum pox virus distribution, genome organization, transmission and biochemical changes in infected plants are introduced. In addition, techniques used in PPV detection are accentuated and discussed, especially with respect to new modern techniques of nucleic acids isolation, based on the nanotechnological approach. Finally, perspectives on the future of possibilities for nanotechnology application in PPV determination/identification are outlined.
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Affiliation(s)
- Jiri Sochor
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; (J.S.); (P.B.); (V.A.); (R.K.)
- Department of Natural Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1-3, CZ-612 42, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Petr Babula
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; (J.S.); (P.B.); (V.A.); (R.K.)
- Department of Natural Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1-3, CZ-612 42, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; (J.S.); (P.B.); (V.A.); (R.K.)
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Boris Krska
- Department of Fruit Growing, Faculty of Horticulture, Mendel University in Brno, Valticka 337, CZ-691 44 Lednice, Czech Republic;
| | - Rene Kizek
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; (J.S.); (P.B.); (V.A.); (R.K.)
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
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Di Carli M, Benvenuto E, Donini M. Recent insights into plant-virus interactions through proteomic analysis. J Proteome Res 2012; 11:4765-80. [PMID: 22954327 DOI: 10.1021/pr300494e] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Plant viruses represent a major threat for a wide range of host species causing severe losses in agricultural practices. The full comprehension of mechanisms underlying events of virus-host plant interaction is crucial to devise novel plant resistance strategies. Until now, functional genomics studies in plant-virus interaction have been limited mainly on transcriptomic analysis. Only recently are proteomic approaches starting to provide important contributions to this area of research. Classical two-dimensional electrophoresis (2-DE) coupled to mass spectrometry (MS) is still the most widely used platform in plant proteome analysis, although in the last years the application of quantitative "second generation" proteomic techniques (such as differential in gel electrophoresis, DIGE, and gel-free protein separation methods) are emerging as more powerful analytical approaches. Apparently simple, plant-virus interactions reveal a really complex pathophysiological context, in which resistance, defense and susceptibility, and direct virus-induced reactions interplay to trigger expression responses of hundreds of genes. Given that, this review is specifically focused on comparative proteome-based studies on pathogenesis of several viral genera, including some of the most important and widespread plant viruses of the genus Tobamovirus, Sobemovirus, Cucumovirus and Potyvirus. In all, this overview reveals a widespread repression of proteins associated with the photosynthetic apparatus, while energy metabolism/protein synthesis and turnover are typically up-regulated, indicating a major redirection of cell metabolism. Other common features include the modulation of metabolisms concerning sugars, cell wall, and reactive oxigen species as well as pathogenesis-related (PR) proteins. The fine-tuning between plant development and antiviral defense mechanisms determines new patterns of regulation of common metabolic pathways. By offering a 360-degree view of protein modulation, all proteomic tools reveal the extraordinary intricacy of mechanisms with which a simple viral genome perturbs the plant cell molecular networks. This "omic" approach, while providing a global perspective and useful information to the understanding of the plant host-virus interactome, may possibly reveal protein targets/markers useful in the design of future diagnosis and/or plant protection strategies.
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Affiliation(s)
- Mariasole Di Carli
- ENEA, Laboratorio Biotecnologie, UT BIORAD-FARM, Casaccia Research Center, Via Anguillarese 301, I-00123 Rome, Italy
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Eiamtanasate S, Juricek M, Yap YK. C-terminal hydrophobic region leads PRSV P3 protein to endoplasmic reticulum. Virus Genes 2007; 35:611-7. [PMID: 17564824 DOI: 10.1007/s11262-007-0114-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 05/07/2007] [Indexed: 10/23/2022]
Abstract
P3 protein is one of the least characterized potyviral proteins in both functions and sub-cellular localization. In this study, we examined the sub-cellular localization of PRSV P3 and its intermediate, P3-6K1 by expressing their GFP fusion proteins in onion epidermal cells. Our results showed that both P3- and P3-6K1 GFP fusion proteins were localized at the endoplasmic reticulum. Deletion analysis indicated that C-terminal of P3 protein contained localization signal, and a 19 amino acids hydrophobic domain from this region was able to target the GFP fusion protein to endoplasmic reticulum. C-terminal of P3 proteins has been suggested to be involved in both viability and pathogenicity of the potyvirus. Therefore, our result suggests that localization of P3 protein at endoplasmic reticulum is essential for functionality of P3 protein.
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Affiliation(s)
- Sarasate Eiamtanasate
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya campus, 25/25 Phuttamonthon 4 Road, Salaya, Phuttamonthon, Nakhon Pathom 73170, Thailand
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Hong XY, Chen J, Shi YH, Chen JP. The '6K1' protein of a strain of Soybean mosaic virus localizes to the cell periphery. Arch Virol 2007; 152:1547-51. [PMID: 17458620 DOI: 10.1007/s00705-007-0972-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Accepted: 03/16/2007] [Indexed: 10/23/2022]
Abstract
The '6K1' protein of the Pinellia isolate of Soybean mosaic virus was cloned into a prokaryotic expression vector and a polyclonal antiserum raised to the expressed fusion protein. In immunogold labeling of thin sections of infected leaves of Pinellia ternata, specific labeling occurred at the cell periphery. This might suggest that the potyvirus '6K1' protein plays some role in viral cell-to-cell movement but the lack of transmembrane domains suggests that it does not conform to currently-recognized patterns of viral movement proteins.
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Affiliation(s)
- X-Y Hong
- Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, P.R. China
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