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Tang Q, Tang J, Chen C, Zhu F, Yu Q, Chen H, Chen L, Ma S, Chen K, Li G. Bombyx mori RPL13 participates in UV-induced DNA damage repair of B. mori nucleopolyhedrovirus through interaction with Bm65. INSECT MOLECULAR BIOLOGY 2024; 33:638-649. [PMID: 38801334 DOI: 10.1111/imb.12928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 05/01/2024] [Indexed: 05/29/2024]
Abstract
Ribosomal protein L13 (RPL13) is highly conserved in evolution. At present, the properties and functions of RPL13 have not been characterised in insects. In this study, Bombyx mori RPL13 (BmRPL13) was first found to be specifically recruited to the sites of ultraviolet (UV)-induced DNA damage and contributed to UV damage repair. Escherichia coli expressing BmRPL13 showed better resistance to UV radiation. After knocking down the expression of BmRPL13 in BmN cells, the repair speed of UV-damaged DNA slowed down. The further results showed that BmRPL13 interacted with B. mori nucleopolyhedrovirus (BmNPV) ORF65 (Bm65) protein to locate at the UV-induced DNA damage sites of BmNPV and helped repair UV-damaged viral DNA.
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Affiliation(s)
- Qi Tang
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Jingjing Tang
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Ceru Chen
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Feifei Zhu
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Qian Yu
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Huiqing Chen
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Liang Chen
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Shangshang Ma
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Keping Chen
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Guohui Li
- Department of Biological Sciences, School of Life Sciences, Jiangsu University, Zhenjiang, China
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2
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Pollari ME, Aspelin WWE, Wang L, Mäkinen KM. The Molecular Maze of Potyviral and Host Protein Interactions. Annu Rev Virol 2024; 11:147-170. [PMID: 38848589 DOI: 10.1146/annurev-virology-100422-034124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
The negative effects of potyvirus diseases on the agricultural industry are extensive and global. Understanding how protein-protein interactions contribute to potyviral infections is imperative to developing resistant varieties that help counter the threat potyviruses pose. While many protein-protein interactions have been reported, only a fraction are essential for potyviral infection. Accumulating evidence demonstrates that potyviral infection processes are interconnected. For instance, the interaction between the eukaryotic initiation factor 4E (eIF4E) and viral protein genome-linked (VPg) is crucial for both viral translation and protecting viral RNA (vRNA). Additionally, recent evidence for open reading frames on the reverse-sense vRNA and for nonequimolar expression of viral proteins has challenged the previous polyprotein expression model. These discoveries will surely reveal more about the potyviral protein interactome. In this review, we present a synthesis of the potyviral infection cycle and discuss influential past discoveries and recent work on protein-protein interactions in various infection processes.
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Affiliation(s)
- Maija E Pollari
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland;
| | - William W E Aspelin
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland;
| | - Linping Wang
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland;
| | - Kristiina M Mäkinen
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland;
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Kwon J, Hu R, Penicks AK, Zhang C, Wang Y, Lohry D, Fernandez EJ, Domier LL, Hajimorad MR. Replacement of P1 of soybean mosaic virus with P1 of clover yellow vein virus has no impact on virus viability and host specificity. Arch Virol 2024; 169:143. [PMID: 38864946 DOI: 10.1007/s00705-024-06071-x] [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: 03/15/2024] [Accepted: 05/02/2024] [Indexed: 06/13/2024]
Abstract
Potyvirus genomes are expressed as polyproteins that are autocatalytically cleaved to produce 10 to 12 multifunctional proteins, among which P1 is the most variable. It has long been hypothesized that P1 plays role(s) in host adaptation and host specificity. We tested this hypothesis using two phylogenetically distinct potyviruses: soybean mosaic virus (SMV), with a narrow host range, and clover yellow vein virus (ClYVV), with a broader host range. When the full-length P1 cistron of SMV-N was replaced with P1 from ClYVV-No.30, the chimera systemically infected only SMV-N-permissive hosts. Hence, there were no changes in the host range or host specificity of the chimeric viruses. Despite sharing only 20.3% amino acid sequence identity, predicted molecular models of P1 proteins from SMV-N and ClYVV-No.30 showed analogous topologies. These observations suggest that P1 of ClYVV-No.30 can functionally replace P1 of SMV-N. However, the P1 proteins of these two potyviruses are not determinants of host specificity and host range.
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Affiliation(s)
- Joon Kwon
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA
- International Research Center for Agricultural & Environmental Biology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Rongbin Hu
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA
- Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA, 92521, USA
| | - Amanda K Penicks
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Chunyu Zhang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, Jilin, China
| | - Yongzhi Wang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, Jilin, China
| | - David Lohry
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 39316, USA
| | - Elias J Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 39316, USA
| | - Leslie L Domier
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, USDA-ARS, Urbana, IL, 61801, USA
| | - M R Hajimorad
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA.
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Manasseh R, Sathuvalli V, Pappu HR. Transcriptional and functional predictors of potato virus Y-induced tuber necrosis in potato ( Solanum tuberosum). FRONTIERS IN PLANT SCIENCE 2024; 15:1369846. [PMID: 38638354 PMCID: PMC11024271 DOI: 10.3389/fpls.2024.1369846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 02/26/2024] [Indexed: 04/20/2024]
Abstract
Introduction Potato (Solanum tuberosum L.), the fourth most important food crop in the world, is affected by several viral pathogens with potato virus Y (PVY) having the greatest economic impact. At least nine biologically distinct variants of PVY are known to infect potato. These include the relatively new recombinant types named PVY-NTN and PVYN-Wi, which induce tuber necrosis in susceptible cultivars. To date, the molecular plant-virus interactions underlying this pathogenicity have not been fully characterized. We hypothesized that this necrotic behavior is supported by transcriptional and functional signatures that are unique to PVY-NTN and PVYN-Wi. Methods To test this hypothesis, transcriptional responses of cv. Russet Burbank, a PVY susceptible cultivar, to three PVY strains PVY-O, PVY-NTN, and PVYN-Wi were studied using mRNA-Seq. A haploid-resolved genome assembly for tetraploid potato was used for bioinformatics analysis. Results The study revealed 36 GO terms and nine KEGG 24 pathways that overlapped across the three PVY strains, making them generic features of PVY susceptibility in potato. Ten GO terms and three KEGG pathways enriched for PVY-NTN and PVYN-Wi only, which made them candidate functional signatures associated with PVY-induced tuber necrosis in potato. In addition, five other pathways were enriched for PVYNTN or PVYN-Wi. One carbon pool by folate was enriched exclusively in response to PVY-NTN infection; PVYN-Wi infection specifically impacted cutin, suberine and wax biosynthesis, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and monoterpenoid biosynthesis. Discussion Results suggest that PVYN-Wi-induced necrosis may be mechanistically distinguishable from that of PVY-NTN. Our study provides a basis for understanding the mechanism underlying the development of PVY-induced tuber necrosis in potato.
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Affiliation(s)
- Richard Manasseh
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Vidyasagar Sathuvalli
- Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston, OR, United States
| | - Hanu R. Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
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Deng S, Tian X, Belshaw R, Zhou J, Zhang S, Yang Y, Huang C, Chen W, Qiu H, Choo SW. An RNA-Seq analysis of coronavirus in the skin of the Pangolin. Sci Rep 2024; 14:910. [PMID: 38195813 PMCID: PMC10776870 DOI: 10.1038/s41598-024-51261-x] [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: 10/26/2023] [Accepted: 01/02/2024] [Indexed: 01/11/2024] Open
Abstract
Protection of the Critically Endangered East Asian Pangolin species is hampered by the vulnerability of captive individuals to infection. Studies have previously shown the pangolin to have a unique pseudogenisation of many immunity genes (including IFNE, IFIH1, cGAS, STING, TLR5, and TLR11), and we suspected that these losses could account for this vulnerability. Here we used RNA-Seq data to show the effect of these gene losses on the transcriptional response to a viral skin infection in a deceased pangolin. This virus is very closely related to the one causing the current COVID-19 pandemic in the human population (SARS-CoV2), and we found the most upregulated pathway was the same one previously identified in the lungs of SARS-CoV2-infected humans. As predicted, we found that the pathways downstream of the lost genes were not upregulated. For example, the pseudogenised interferon epsilon (IFNE) is known to be particularly important in epithelial immunity, and we show that interferon-related responses were not upregulated in the infected pangolin skin. We suggest that the pangolin's innate gene pseudogenisation is indeed likely to be responsible for the animal's vulnerability to infection.
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Affiliation(s)
- Siwei Deng
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Xuechen Tian
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
- Zhejiang Bioinformatics International Science and Technology Cooperation Centre, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
- Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Robert Belshaw
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Jinfeng Zhou
- China Biodiversity Conservation and Green Development Foundation (CBCGDF), Empark International Apartment, No. 69, Banding Road, Haidian District, Beijing, China
| | - Siyuan Zhang
- China Biodiversity Conservation and Green Development Foundation (CBCGDF), Empark International Apartment, No. 69, Banding Road, Haidian District, Beijing, China
| | - Yixin Yang
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
- Zhejiang Bioinformatics International Science and Technology Cooperation Centre, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
- Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
- Dorothy and George Hennings College of Science, Mathematics and Technology, Kean University, 1000 Morris Ave, Union, NJ, 07083, USA
| | - Chang Huang
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Weikang Chen
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Hailu Qiu
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China
| | - Siew Woh Choo
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China.
- Zhejiang Bioinformatics International Science and Technology Cooperation Centre, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China.
- Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang, 325060, China.
- Dorothy and George Hennings College of Science, Mathematics and Technology, Kean University, 1000 Morris Ave, Union, NJ, 07083, USA.
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Gomaa AE, El Mounadi K, Parperides E, Garcia-Ruiz H. Cell Fractionation and the Identification of Host Proteins Involved in Plant-Virus Interactions. Pathogens 2024; 13:53. [PMID: 38251360 PMCID: PMC10819628 DOI: 10.3390/pathogens13010053] [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: 12/08/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Plant viruses depend on host cellular factors for their replication and movement. There are cellular proteins that change their localization and/or expression and have a proviral role or antiviral activity and interact with or target viral proteins. Identification of those proteins and their roles during infection is crucial for understanding plant-virus interactions and to design antiviral resistance in crops. Important host proteins have been identified using approaches such as tag-dependent immunoprecipitation or yeast two hybridization that require cloning individual proteins or the entire virus. However, the number of possible interactions between host and viral proteins is immense. Therefore, an alternative method is needed for proteome-wide identification of host proteins involved in host-virus interactions. Here, we present cell fractionation coupled with mass spectrometry as an option to identify protein-protein interactions between viruses and their hosts. This approach involves separating subcellular organelles using differential and/or gradient centrifugation from virus-free and virus-infected cells (1) followed by comparative analysis of the proteomic profiles obtained for each subcellular organelle via mass spectrometry (2). After biological validation, prospect host proteins with proviral or antiviral roles can be subject to fundamental studies in the context of basic biology to shed light on both virus replication and cellular processes. They can also be targeted via gene editing to develop virus-resistant crops.
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Affiliation(s)
- Amany E. Gomaa
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA (E.P.)
- Department of Botany, Faculty of Science, Mansoura University, Mansoura 35516, Egypt
| | - Kaoutar El Mounadi
- Department of Biology, Kutztown University of Pennsylvania, Kutztown, PA 19530, USA
| | - Eric Parperides
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA (E.P.)
| | - Hernan Garcia-Ruiz
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA (E.P.)
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7
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Mäkinen K, Aspelin W, Pollari M, Wang L. How do they do it? The infection biology of potyviruses. Adv Virus Res 2023; 117:1-79. [PMID: 37832990 DOI: 10.1016/bs.aivir.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Affiliation(s)
- Kristiina Mäkinen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
| | - William Aspelin
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Maija Pollari
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Linping Wang
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
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Bello EO, Yang Y, Fang Y, Chai M, Jiang X, Luan Y, Wang Y, Guo Y, Wu XY, Cheng X, Wu XX. P1 of turnip mosaic virus interacts with NOD19 for vigorous infection. Front Microbiol 2023; 14:1216950. [PMID: 37426031 PMCID: PMC10326430 DOI: 10.3389/fmicb.2023.1216950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/02/2023] [Indexed: 07/11/2023] Open
Abstract
P1 protein, the most divergent protein of virus members in the genus Potyvirus of the family Potyviridae, is required for robust infection and host adaptation. However, how P1 affects viral proliferation is still largely elusive. In this work, a total number of eight potential P1-interacting Arabidopsis proteins were identified by the yeast-two-hybrid screening using the turnip mosaic virus (TuMV)-encoded P1 protein as the bait. Among which, the stress upregulated NODULIN 19 (NOD19) was selected for further characterization. The bimolecular fluorescent complementation assay confirmed the interaction between TuMV P1 and NOD19. Expression profile, structure, and subcellular localization analyses showed that NOD19 is a membrane-associated protein expressed mainly in plant aerial parts. Viral infectivity assay showed that the infection of turnip mosaic virus and soybean mosaic virus was attenuated in the null mutant of Arabidopsis NOD19 and NOD19-knockdown soybean seedlings, respectively. Together, these data indicate that NOD19 is a P1-interacting host factor required for robust infection.
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Affiliation(s)
- Esther O. Bello
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
- College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yingshuai Yang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yue Fang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Mengzhu Chai
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Xue Jiang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yameng Luan
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yuting Wang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yating Guo
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Xiao-Yun Wu
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Xiaofei Cheng
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of the Ministry of Education, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Xiao-Xia Wu
- College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang, China
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A Zinc Finger Motif in the P1 N Terminus, Highly Conserved in a Subset of Potyviruses, Is Associated with the Host Range and Fitness of Telosma Mosaic Virus. J Virol 2023; 97:e0144422. [PMID: 36688651 PMCID: PMC9972955 DOI: 10.1128/jvi.01444-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
P1 is the first protein translated from the genomes of most viruses in the family Potyviridae, and it contains a C-terminal serine-protease domain that cis-cleaves the junction between P1 and HCPro in most cases. Intriguingly, P1 is the most divergent among all mature viral factors, and its roles during viral infection are still far from understood. In this study, we found that telosma mosaic virus (TelMV, genus Potyvirus) in passion fruit, unlike TelMV isolates present in other hosts, has two stretches at the P1 N terminus, named N1 and N2, with N1 harboring a Zn finger motif. Further analysis revealed that at least 14 different potyviruses, mostly belonging to the bean common mosaic virus subgroup, encode a domain equivalent to N1. Using the newly developed TelMV infectious cDNA clones from passion fruit, we demonstrated that N1, but not N2, is crucial for viral infection in both Nicotiana benthamiana and passion fruit. The regulatory effects of N1 domain on P1 cis cleavage, as well as the accumulation and RNA silencing suppression (RSS) activity of its cognate HCPro, were comprehensively investigated. We found that N1 deletion decreases HCPro abundance at the posttranslational level, likely by impairing P1 cis cleavage, thus reducing HCPro-mediated RSS activity. Remarkably, disruption of the Zn finger motif in N1 did not impair P1 cis cleavage and HCPro accumulation but severely debilitated TelMV fitness. Therefore, our results suggest that the Zn finger motif in P1s plays a critical role in viral infection that is independent of P1 protease activity and self-release, as well as HCPro accumulation and silencing suppression. IMPORTANCE Viruses belonging to the family Potyviridae represent the largest group of plant-infecting RNA viruses, including a variety of agriculturally and economically important viral pathogens. Like all picorna-like viruses, potyvirids employ polyprotein processing as the gene expression strategy. P1, the first protein translated from most potyvirid genomes, is the most variable viral factor and has attracted great scientific interest. Here, we defined a Zn finger motif-encompassing domain (N1) at the N terminus of P1 among diverse potyviruses phylogenetically related to bean common mosaic virus. Using TelMV as a model virus, we demonstrated that the N1 domain is key for viral infection, as it is involved both in regulating the abundance of its cognate HCPro and in an as-yet-undefined key function unrelated to protease processing and RNA silencing suppression. These results advance our knowledge of the hypervariable potyvirid P1s and highlight the importance for infection of a previously unstudied Zn finger domain at the P1 N terminus.
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10
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A binary interaction map between turnip mosaic virus and Arabidopsis thaliana proteomes. Commun Biol 2023; 6:28. [PMID: 36631662 PMCID: PMC9834402 DOI: 10.1038/s42003-023-04427-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/05/2023] [Indexed: 01/13/2023] Open
Abstract
Viruses are obligate intracellular parasites that have co-evolved with their hosts to establish an intricate network of protein-protein interactions. Here, we followed a high-throughput yeast two-hybrid screening to identify 378 novel protein-protein interactions between turnip mosaic virus (TuMV) and its natural host Arabidopsis thaliana. We identified the RNA-dependent RNA polymerase NIb as the viral protein with the largest number of contacts, including key salicylic acid-dependent transcription regulators. We verified a subset of 25 interactions in planta by bimolecular fluorescence complementation assays. We then constructed and analyzed a network comprising 399 TuMV-A. thaliana interactions together with intravirus and intrahost connections. In particular, we found that the host proteins targeted by TuMV are enriched in different aspects of plant responses to infections, are more connected and have an increased capacity to spread information throughout the cell proteome, display higher expression levels, and have been subject to stronger purifying selection than expected by chance. The proviral or antiviral role of ten host proteins was validated by characterizing the infection dynamics in the corresponding mutant plants, supporting a proviral role for the transcriptional regulator TGA1. Comparison with similar studies with animal viruses, highlights shared fundamental features in their mode of action.
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11
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Bakshi A, Moin M, Gayatri MB, Reddy ABM, Datla R, Madhav MS, Kirti PB. Involvement of Target of Rapamycin (TOR) Signaling in the Regulation of Crosstalk between Ribosomal Protein Small Subunit 6 Kinase-1 (RPS6K-1) and Ribosomal Proteins. PLANTS (BASEL, SWITZERLAND) 2023; 12:176. [PMID: 36616305 PMCID: PMC9824793 DOI: 10.3390/plants12010176] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The target of rapamycin (TOR) protein phosphorylates its downstream effector p70kDa ribosomal protein S6 kinases (S6K1) for ribosome biogenesis and translation initiation in eukaryotes. However, the molecular mechanism of TOR-S6K1-ribosomal protein (RP) signaling is not well understood in plants. In the present study, we report the transcriptional upregulation of ribosomal protein large and small subunit (RPL and RPS) genes in the previously established TOR overexpressing transgenic lines of rice (in Oryza sativa ssp. indica, variety BPT-5204, TR-2.24 and TR-15.1) and of Arabidopsis thaliana (in Col 0 ecotype, ATR-1.4.27 and ATR-3.7.32). The mRNA levels of RP genes from this study were compared with those previously available in transcriptomic datasets on the expression of RPs in relation to TOR inhibitor and in the TOR-RNAi lines of Arabidopsis thaliana. We further analyzed TOR activity, i.e., S6K1 phosphorylation in SALK lines of Arabidopsis with mutation in rpl6, rpl18, rpl23, rpl24 and rps28C, where the rpl18 mutant showed inactivation of S6K1 phosphorylation. We also predicted similar putative Ser/Thr phosphorylation sites for ribosomal S6 kinases (RSKs) in the RPs of Oryza sativa ssp. indica and Arabidopsis thaliana. The findings of this study indicate that the TOR pathway is possibly interlinked in a cyclic manner via the phosphorylation of S6K1 as a modulatory step for the regulation of RP function to switch 'on'/'off' the translational regulation for balanced plant growth.
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Affiliation(s)
- Achala Bakshi
- Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India
- Global Institute for Food Security, Saskatoon, SK S7N 0W9, Canada
| | - Mazahar Moin
- Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India
- Agri Biotech Foundation, PJTS Agricultural University Campus, Rajendranagar, Hyderabad 500030, Telangana, India
| | - Meher B. Gayatri
- Department of Animal Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Aramati B. M. Reddy
- Department of Animal Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Raju Datla
- Global Institute for Food Security, Saskatoon, SK S7N 0W9, Canada
| | - Maganti S. Madhav
- Indian Institute of Rice Research, Rajendranagar, Hyderabad 500030, Telangana, India
- Central Tobacco Research Institute, Rajahmundry 533105, Andhra Pradesh, India
| | - Pulugurtha B. Kirti
- Agri Biotech Foundation, PJTS Agricultural University Campus, Rajendranagar, Hyderabad 500030, Telangana, India
- Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, Telangana, India
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12
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Sasaki J, Kawakubo S, Kim H, Kim OK, Yamashita K, Shimura H, Masuta C. Leek Yellow Stripe Virus Can Adjust for Host Adaptation by Trimming the N-Terminal Domain to Allow the P1 Protein to Function as an RNA Silencing Suppressor. THE PLANT PATHOLOGY JOURNAL 2022; 38:383-394. [PMID: 35953058 PMCID: PMC9372110 DOI: 10.5423/ppj.ft.06.2022.0077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
In Japan, the P1 protein (S-type) encoded by leek yellow stripe virus (LYSV) isolates detected in Honshu and southward is shorter than the P1 (N-type) of LYSV isolates from garlic grown in Hokkaido due to a large deletion in the N-terminal half. In garlic fields in Hokkaido, two types of LYSV isolate with N- and S-type P1s are sometimes found in mixed infections. In this study, we confirmed that N- and S-type P1 sequences were present in the same plant and that they belong to different evolutionary phylogenetic groups. To investigate how LYSV with S-type P1 (LYSV-S) could have invaded LYSV with N-type P1 (LYSV-N)-infected garlic, we examined wild Allium spp. plants in Hokkaido and found that LYSV was almost undetectable. On the other hand, in Honshu, LYSV-S was detected at a high frequency in Allium spp. other than garlic, suggesting that the LYSV-S can infect a wider host range of Allium spp. compared to LYSV-N. Because P1 proteins of potyviruses have been reported to promote RNA silencing suppressor (RSS) activity of HC-Pro proteins, we analyzed whether the same was true for P1 of LYSV. In onion, contrary to expectation, the P1 protein itself had RSS activity. Moreover, the RSS activity of S-type P1 was considerably stronger than that of N-type P1, suggesting that LYSV P1 may be able to enhance its RSS activity when the deletion is in the N-terminal half and that acquiring S-type P1 may have enabled LYSV to expand its host range.
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Affiliation(s)
- Jun Sasaki
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589,
Japan
- Ornamental Plants and Vegetables Research Center, Takikawa 073-0026,
Japan
| | - Shusuke Kawakubo
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589,
Japan
| | - Hangil Kim
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589,
Japan
| | - Ok-Kyung Kim
- Department of Agriculture, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi 243-0034,
Japan
| | - Kazuo Yamashita
- Department of Agriculture, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi 243-0034,
Japan
- Fukuchi Garlic R&S, Nambu-Chou, Aomori 039-0815,
Japan
| | - Hanako Shimura
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589,
Japan
| | - Chikara Masuta
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589,
Japan
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13
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Zhao L, Che X, Wang Z, Zhou X, Xie Y. Functional Characterization of Replication-Associated Proteins Encoded by Alphasatellites Identified in Yunnan Province, China. Viruses 2022; 14:222. [PMID: 35215816 PMCID: PMC8875141 DOI: 10.3390/v14020222] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 12/20/2022] Open
Abstract
Alphasatellites, which encode only a replication-associated protein (alpha-Rep), are frequently found to be non-essential satellite components associated with begomovirus/betasatellite complexes, and their presence can modulate disease symptoms and/or viral DNA accumulation during infection. Our previous study has shown that there are three types of alphasatellites associated with begomovirus/betasatellite complexes in Yunnan province in China and they encode three corresponding types of alpha-Rep proteins. However, the biological functions of alpha-Reps remain poorly understood. In this study, we investigated the biological functions of alpha-Reps in post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) using 16c and 16-TGS transgenic Nicotiana benthamiana plants. Results showed that all the three types of alpha-Rep proteins were capable of suppressing the PTGS and reversing the TGS. Among them, the alpha-Rep of Y10DNA1 has the strongest PTGS and TGS suppressor activities. We also found that the alpha-Rep proteins were able to increase the accumulation of their helper virus during coinfection. These results suggest that the alpha-Reps may have a role in overcoming host defense, which provides a possible explanation for the selective advantage provided by the association of alphasatellites with begomovirus/betasatellite complexes.
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Affiliation(s)
- Liling Zhao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
- Biotechnology and Germplasm Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650223, China
| | - Xuan Che
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
| | - Zhanqi Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China;
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
- Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
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14
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Pasin F, Daròs JA, Tzanetakis IE. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6534904. [PMID: 35195244 PMCID: PMC9249622 DOI: 10.1093/femsre/fuac011] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022] Open
Abstract
Potyviridae, the largest family of known RNA viruses (realm Riboviria), belongs to the picorna-like supergroup and has important agricultural and ecological impacts. Potyvirid genomes are translated into polyproteins, which are in turn hydrolyzed to release mature products. Recent sequencing efforts revealed an unprecedented number of potyvirids with a rich variability in gene content and genomic layouts. Here, we review the heterogeneity of non-core modules that expand the structural and functional diversity of the potyvirid proteomes. We provide a family-wide classification of P1 proteinases into the functional Types A and B, and discuss pretty interesting sweet potato potyviral ORF (PISPO), putative zinc fingers, and alkylation B (AlkB)—non-core modules found within P1 cistrons. The atypical inosine triphosphate pyrophosphatase (ITPase/HAM1), as well as the pseudo tobacco mosaic virus-like coat protein (TMV-like CP) are discussed alongside homologs of unrelated virus taxa. Family-wide abundance of the multitasking helper component proteinase (HC-pro) is revised. Functional connections between non-core modules are highlighted to support host niche adaptation and immune evasion as main drivers of the Potyviridae evolutionary radiation. Potential biotechnological and synthetic biology applications of potyvirid leader proteinases and non-core modules are finally explored.
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Affiliation(s)
- Fabio Pasin
- Corresponding author: Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), UPV Building 8E, Ingeniero Fausto Elio, 46011 Valencia, Spain. E-mail:
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), 46011 Valencia, Spain
| | - Ioannis E Tzanetakis
- Department of Entomology and Plant Pathology, Division of Agriculture, University of Arkansas System, 72701 Fayetteville, AR, USA
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15
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García B, Bedoya L, García JA, Rodamilans B. An Importin-β-like Protein from Nicotiana benthamiana Interacts with the RNA Silencing Suppressor P1b of the Cucumber Vein Yellowing Virus, Modulating Its Activity. Viruses 2021; 13:2406. [PMID: 34960675 PMCID: PMC8706682 DOI: 10.3390/v13122406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 11/26/2022] Open
Abstract
During a plant viral infection, host-pathogen interactions are critical for successful replication and propagation of the virus through the plant. RNA silencing suppressors (RSSs) are key players of this interplay, and they often interact with different host proteins, developing multiple functions. In the Potyviridae family, viruses produce two main RSSs, HCPro and type B P1 proteins. We focused our efforts on the less known P1b of cucumber vein yellowing virus (CVYV), a type B P1 protein, to try to identify possible factors that could play a relevant role during viral infection. We used a chimeric expression system based on plum pox virus (PPV) encoding a tagged CVYV P1b in place of the canonical HCPro. We used that tag to purify P1b in Nicotiana-benthamiana-infected plants and identified by mass spectrometry an importin-β-like protein similar to importin 7 of Arabidopsis thaliana. We further confirmed the interaction by bimolecular fluorescence complementation assays and defined its nuclear localization in the cell. Further analyses showed a possible role of this N. benthamiana homolog of Importin 7 as a modulator of the RNA silencing suppression activity of P1b.
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Affiliation(s)
| | | | | | - Bernardo Rodamilans
- Centro Nacional de Biotecnología CNB, Consejo Superior de Investigaciones Científicas CSIC, 28049 Madrid, Spain; (B.G.); (L.B.); (J.A.G.)
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16
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Investigating the Viral Suppressor HC-Pro Inhibiting Small RNA Methylation through Functional Comparison of HEN1 in Angiosperm and Bryophyte. Viruses 2021; 13:v13091837. [PMID: 34578418 PMCID: PMC8473176 DOI: 10.3390/v13091837] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 12/27/2022] Open
Abstract
In plants, HEN1-facilitated methylation at 3′ end ribose is a critical step of small-RNA (sRNA) biogenesis. A mutant of well-studied Arabidopsis HEN1 (AtHEN1), hen1-1, showed a defective developmental phenotype, indicating the importance of sRNA methylation. Moreover, Marchantia polymorpha has been identified to have a HEN1 ortholog gene (MpHEN1); however, its function remained unfathomed. Our in vivo and in vitro data have shown MpHEN1 activity being comparable with AtHEN1, and their substrate specificity towards duplex microRNA (miRNA) remained consistent. Furthermore, the phylogenetic tree and multiple alignment highlighted the conserved molecular evolution of the HEN1 family in plants. The P1/HC-Pro of the turnip mosaic virus (TuMV) is a known RNA silencing suppressor and inhibits HEN1 methylation of sRNAs. Here, we report that the HC-Pro physically binds with AtHEN1 through FRNK motif, inhibiting HEN1’s methylation activity. Moreover, the in vitro EMSA data indicates GST-HC-Pro of TuMV lacks sRNA duplex-binding ability. Surprisingly, the HC-Pro also inhibits MpHEN1 activity in a dosage-dependent manner, suggesting the possibility of interaction between HC-Pro and MpHEN1 as well. Further investigations on understanding interaction mechanisms of HEN1 and various HC-Pros can advance the knowledge of viral suppressors.
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17
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Cheng DJ, Xu XJ, Yan ZY, Tettey CK, Fang L, Yang GL, Geng C, Tian YP, Li XD. The chloroplast ribosomal protein large subunit 1 interacts with viral polymerase and promotes virus infection. PLANT PHYSIOLOGY 2021; 187:174-186. [PMID: 34618134 PMCID: PMC8418413 DOI: 10.1093/plphys/kiab249] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/06/2021] [Indexed: 05/18/2023]
Abstract
Chloroplasts play an indispensable role in the arms race between plant viruses and hosts. Chloroplast proteins are often recruited by plant viruses to support viral replication and movement. However, the mechanism by which chloroplast proteins regulate potyvirus infection remains largely unknown. In this study, we observed that Nicotiana benthamiana ribosomal protein large subunit 1 (NbRPL1), a chloroplast ribosomal protein, localized to the chloroplasts via its N-terminal 61 amino acids (transit peptide), and interacted with tobacco vein banding mosaic virus (TVBMV) nuclear inclusion protein b (NIb), an RNA-dependent RNA polymerase. Upon TVBMV infection, NbRPL1 was recruited into the 6K2-induced viral replication complexes in chloroplasts. Silencing of NbRPL1 expression reduced TVBMV replication. NbRPL1 competed with NbBeclin1 to bind NIb, and reduced the NbBeclin1-mediated degradation of NIb. Therefore, our results suggest that NbRPL1 interacts with NIb in the chloroplasts, reduces NbBeclin1-mediated NIb degradation, and enhances TVBMV infection.
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Affiliation(s)
- De-Jie Cheng
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Xiao-Jie Xu
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, 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, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Carlos Kwesi Tettey
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Le Fang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Guang-Ling Yang
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Chao Geng
- Shandong Provincial Key Laboratory of Agricultural Microbiology, Laboratory of Plant Virology, 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, Laboratory of Plant Virology, 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, Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018, China
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18
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P1 of Sweet Potato Feathery Mottle Virus Shows Strong Adaptation Capacity, Replacing P1-HCPro in a Chimeric Plum Pox Virus. J Virol 2021; 95:e0015021. [PMID: 33952634 DOI: 10.1128/jvi.00150-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Potyviridae is the largest family of plant RNA viruses. Their genomes are expressed through long polyproteins that are usually headed by the leader endopeptidase P1. This protein can be classified as type A or type B based on host proteolytic requirements and RNA silencing suppression (RSS) capacity. The main Potyviridae genus is Potyvirus, and a group of potyviruses infecting sweet potato presents an enlarged P1 protein with a polymerase slippage motif that produces an extra product termed P1N-PISPO. These two proteins display some RSS activity and are expressed followed by HCPro, which appears to be the main RNA silencing suppressor in these viruses. Here, we studied the behavior of the P1 protein of Sweet potato feathery mottle virus (SPFMV) using a viral system based on a canonical potyvirus, Plum pox virus (PPV), and discovered that this protein is able to replace both PPV P1 and HCPro. We also found that P1N-PISPO, produced after polymerase slippage, provides extra RNA silencing suppression capacity to SPFMV P1 in this viral context. In addition, the results showed that presence of two type A P1 proteins was detrimental for viral viability. The ample recombination spectrum that we found in the recovered viruses supports the strong adaptation capacity of P1 proteins and signals the N-terminal part of SPFMV P1 as essential for RSS activity. Further analyses provided data to add extra layers to the evolutionary history of sweet potato-infecting potyvirids. IMPORTANCE Plant viruses represent a major challenge for agriculture worldwide and Potyviridae, being the largest family of plant RNA viruses, is one of the primary players. P1, the leader endopeptidase, is a multifunctional protein that contributes to the successful spread of these viruses over a wide host range. Understanding how P1 proteins work, their dynamic interplay during viral infection, and their evolutionary path is critical for the development of strategic tools to fight the multiple diseases these viruses cause. We focused our efforts on the P1 protein of Sweet potato feathery mottle virus, which is coresponsible for the most devastating disease in sweet potato. The significance of our research is in understanding the capacity of this protein to perform several independent functions, using this knowledge to learn more about P1 proteins in general and the potyvirids infecting this host.
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19
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Domingo-Calap ML, Chase O, Estapé M, Moreno AB, López-Moya JJ. The P1 Protein of Watermelon mosaic virus Compromises the Activity as RNA Silencing Suppressor of the P25 Protein of Cucurbit yellow stunting disorder virus. Front Microbiol 2021; 12:645530. [PMID: 33828542 PMCID: PMC8019732 DOI: 10.3389/fmicb.2021.645530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/02/2021] [Indexed: 11/17/2022] Open
Abstract
Mixed viral infections in plants involving a potyvirus and other unrelated virus often result in synergistic effects, with significant increases in accumulation of the non-potyvirus partner, as in the case of melon plants infected by the potyvirus Watermelon mosaic virus (WMV) and the crinivirus Cucurbit yellow stunting disorder virus (CYSDV). To further explore the synergistic interaction between these two viruses, the activity of RNA silencing suppressors (RSSs) was addressed in transiently co-expressed combinations of heterologous viral products in Nicotiana benthamiana leaves. While the strong RSS activity of WMV Helper Component Proteinase (HCPro) was unaltered, including no evident additive effects observed when co-expressed with the weaker CYSDV P25, an unexpected negative effect of WMV P1 was found on the RSS activity of P25. Analysis of protein expression during the assays showed that the amount of P25 was not reduced when co-expressed with P1. The detrimental action of P1 on the activity of P25 was dose-dependent, and the subcellular localization of fluorescently labeled variants of P1 and P25 when transiently co-expressed showed coincidences both in nucleus and cytoplasm. Also, immunoprecipitation experiments showed interaction of tagged versions of the two proteins. This novel interaction, not previously described in other combinations of potyviruses and criniviruses, might play a role in modulating the complexities of the response to multiple viral infections in susceptible plants.
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Affiliation(s)
- Maria Luisa Domingo-Calap
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain.,Instituto Valencia de Investigaciones Agrarias, IVIA, Valencia, Spain
| | - Ornela Chase
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain
| | - Mariona Estapé
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain.,Universitair Medisch Centrum, UMC, Utrecht, Netherlands
| | - Ana Beatriz Moreno
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain
| | - Juan José López-Moya
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain.,Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
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20
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A Newly Identified Virus in the Family Potyviridae Encodes Two Leader Cysteine Proteases in Tandem That Evolved Contrasting RNA Silencing Suppression Functions. J Virol 2020; 95:JVI.01414-20. [PMID: 33055249 DOI: 10.1128/jvi.01414-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
Potyviridae is the largest family of plant-infecting RNA viruses and includes many agriculturally and economically important viral pathogens. The viruses in the family, known as potyvirids, possess single-stranded, positive-sense RNA genomes with polyprotein processing as a gene expression strategy. The N-terminal regions of potyvirid polyproteins vary greatly in sequence. Previously, we identified a novel virus species within the family, Areca palm necrotic spindle-spot virus (ANSSV), which was predicted to encode two cysteine proteases, HCPro1 and HCPro2, in tandem at the N-terminal region. Here, we present evidence showing self-cleavage activity of these two proteins and define their cis-cleavage sites. We demonstrate that HCPro2 is a viral suppressor of RNA silencing (VSR), and both the variable N-terminal and conserved C-terminal (protease domain) moieties have antisilencing activity. Intriguingly, the N-terminal region of HCPro1 also has RNA silencing suppression activity, which is, however, suppressed by its C-terminal protease domain, leading to the functional divergence of HCPro1 and HCPro2 in RNA silencing suppression. Moreover, the deletion of HCPro1 or HCPro2 in a newly created infectious clone abolishes viral infection, and the deletion mutants cannot be rescued by addition of corresponding counterparts of a potyvirus. Altogether, these data suggest that the two closely related leader proteases of ANSSV have evolved differential and essential functions to concertedly maintain viral viability.IMPORTANCE The Potyviridae represent the largest group of known plant RNA viruses and account for more than half of the viral crop damage worldwide. The leader proteases of viruses within the family vary greatly in size and arrangement and play key roles during the infection. Here, we experimentally demonstrate the presence of a distinct pattern of leader proteases, HCPro1 and HCPro2 in tandem, in a newly identified member within the family. Moreover, HCPro1 and HCPro2, which are closely related and typically characterized with a short size, have evolved contrasting RNA silencing suppression activity and seem to function in a coordinated manner to maintain viral infectivity. Altogether, the new knowledge fills a missing piece in the evolutionary relationship history of potyvirids and improves our understanding of the diversification of potyvirid genomes.
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21
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Pasin F, Shan H, García B, Müller M, San León D, Ludman M, Fresno DH, Fátyol K, Munné-Bosch S, Rodrigo G, García JA. Abscisic Acid Connects Phytohormone Signaling with RNA Metabolic Pathways and Promotes an Antiviral Response that Is Evaded by a Self-Controlled RNA Virus. PLANT COMMUNICATIONS 2020; 1:100099. [PMID: 32984814 PMCID: PMC7518510 DOI: 10.1016/j.xplc.2020.100099] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 05/13/2023]
Abstract
A complex network of cellular receptors, RNA targeting pathways, and small-molecule signaling provides robust plant immunity and tolerance to viruses. To maximize their fitness, viruses must evolve control mechanisms to balance host immune evasion and plant-damaging effects. The genus Potyvirus comprises plant viruses characterized by RNA genomes that encode large polyproteins led by the P1 protease. A P1 autoinhibitory domain controls polyprotein processing, the release of a downstream functional RNA-silencing suppressor, and viral replication. Here, we show that P1Pro, a plum pox virus clone that lacks the P1 autoinhibitory domain, triggers complex reprogramming of the host transcriptome and high levels of abscisic acid (ABA) accumulation. A meta-analysis highlighted ABA connections with host pathways known to control RNA stability, turnover, maturation, and translation. Transcriptomic changes triggered by P1Pro infection or ABA showed similarities in host RNA abundance and diversity. Genetic and hormone treatment assays showed that ABA promotes plant resistance to potyviral infection. Finally, quantitative mathematical modeling of viral replication in the presence of defense pathways supported self-control of polyprotein processing kinetics as a viral mechanism that attenuates the magnitude of the host antiviral response. Overall, our findings indicate that ABA is an active player in plant antiviral immunity, which is nonetheless evaded by a self-controlled RNA virus.
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Affiliation(s)
- Fabio Pasin
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
- Agricultural Biotechnology Research Center, Academia Sinica, 11529 Taipei, Taiwan
| | - Hongying Shan
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Beatriz García
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Maren Müller
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - David San León
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Márta Ludman
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, 2100 Gödöllő, Hungary
| | - David H. Fresno
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - Károly Fátyol
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, 2100 Gödöllő, Hungary
| | - Sergi Munné-Bosch
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - Guillermo Rodrigo
- Institute for Integrative Systems Biology (I2SysBio), CSIC-University of Valencia, 46980 Paterna, Spain
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22
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Hu SF, Wei WL, Hong SF, Fang RY, Wu HY, Lin PC, Sanobar N, Wang HP, Sulistio M, Wu CT, Lo HF, Lin SS. Investigation of the effects of P1 on HC-pro-mediated gene silencing suppression through genetics and omics approaches. BOTANICAL STUDIES 2020; 61:22. [PMID: 32748085 PMCID: PMC7399735 DOI: 10.1186/s40529-020-00299-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/16/2020] [Indexed: 05/15/2023]
Abstract
BACKGROUND Posttranscriptional gene silencing (PTGS) is one of the most important mechanisms for plants during viral infection. However, viruses have also developed viral suppressors to negatively control PTGS by inhibiting microRNA (miRNA) and short-interfering RNA (siRNA) regulation in plants. The first identified viral suppressor, P1/HC-Pro, is a fusion protein that was translated from potyviral RNA. Upon infecting plants, the P1 protein itself is released from HC-Pro by the self-cleaving activity of P1. P1 has an unknown function in enhancing HC-Pro-mediated PTGS suppression. We performed proteomics to identify P1-interacting proteins. We also performed transcriptomics that were generated from Col-0 and various P1/HC-Pro-related transgenic plants to identify novel genes. The results showed several novel genes were identified through the comparative network analysis that might be involved in P1/HC-Pro-mediated PTGS suppression. RESULTS First, we demonstrated that P1 enhances HC-Pro function and that the mechanism might work through P1 binding to VERNALIZATION INDEPENDENCE 3/SUPERKILLER 8 (VIP3/SKI8), a subunit of the exosome, to interfere with the 5'-fragment of the PTGS-cleaved RNA degradation product. Second, the AGO1 was specifically posttranslationally degraded in transgenic Arabidopsis expressing P1/HC-Pro of turnip mosaic virus (TuMV) (P1/HCTu plant). Third, the comparative network highlighted potentially critical genes in PTGS, including miRNA targets, calcium signaling, hormone (JA, ET, and ABA) signaling, and defense response. CONCLUSION Through these genetic and omics approaches, we revealed an overall perspective to identify many critical genes involved in PTGS. These new findings significantly impact in our understanding of P1/HC-Pro-mediated PTGS suppression.
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Affiliation(s)
- Sin-Fen Hu
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Wei-Lun Wei
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Syuan-Fei Hong
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Ru-Ying Fang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Hsin-Yi Wu
- Instrumentation Center, National Taiwan University, Taipei, 106, Taiwan
| | - Pin-Chun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Neda Sanobar
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Hsin-Ping Wang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Margo Sulistio
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Chun-Ta Wu
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Hsiao-Feng Lo
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan.
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan.
- Center of Biotechnology, National Taiwan University, Taipei, 106, Taiwan.
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Proteomic Changes during MCMV Infection Revealed by iTRAQ Quantitative Proteomic Analysis in Maize. Int J Mol Sci 2019; 21:ijms21010035. [PMID: 31861651 PMCID: PMC6981863 DOI: 10.3390/ijms21010035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/04/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Maize chlorotic mottle virus (MCMV) has been occurring frequently worldwide and causes severe yield losses in maize (Zea mays). To better investigate the destructive effects of MCMV infection on maize plants, isobaric tagging for relative and absolute quantitation (iTRAQ)-based comparative proteomic analysis was performed on MCMV infected maize cv. B73. A total of 972 differentially abundant proteins (DAPs), including 661 proteins with increased abundance and 311 proteins with reduced abundance, were identified in response to MCMV infection. Functional annotations of DAPs and measurement of photosynthetic activity revealed that photosynthesis was decreased, while the abundance of ribosomal proteins, proteins related to stress responses, oxidation-reduction and redox homeostasis was altered significantly during MCMV infection. Two DAPs, disulfide isomerases like protein ZmPDIL-1 and peroxiredoxin family protein ZmPrx5, were further analyzed for their roles during MCMV infection through cucumber mosaic virus-based virus-induced gene silencing (CMV-VIGS). The accumulation of MCMV was suppressed in ZmPDIL-1-silenced or ZmPrx5-silenced B73 maize, suggesting ZmPDIL-1 and ZmPrx5 might enhance host susceptibility to MCMV infection.
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24
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Li S. Regulation of Ribosomal Proteins on Viral Infection. Cells 2019; 8:E508. [PMID: 31137833 PMCID: PMC6562653 DOI: 10.3390/cells8050508] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/20/2022] Open
Abstract
Ribosomal proteins (RPs), in conjunction with rRNA, are major components of ribosomes involved in the cellular process of protein biosynthesis, known as "translation". The viruses, as the small infectious pathogens with limited genomes, must recruit a variety of host factors to survive and propagate, including RPs. At present, more and more information is available on the functional relationship between RPs and virus infection. This review focuses on advancements in my own understanding of critical roles of RPs in the life cycle of viruses. Various RPs interact with viral mRNA and proteins to participate in viral protein biosynthesis and regulate the replication and infection of virus in host cells. Most interactions are essential for viral translation and replication, which promote viral infection and accumulation, whereas the minority represents the defense signaling of host cells by activating immune pathway against virus. RPs provide a new platform for antiviral therapy development, however, at present, antiviral therapeutics with RPs involving in virus infection as targets is limited, and exploring antiviral strategy based on RPs will be the guides for further study.
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Affiliation(s)
- Shuo Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
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25
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Eskelin K, Varjosalo M, Ravantti J, Mäkinen K. Ribosome profiles and riboproteomes of healthy and Potato virus A- and Agrobacterium-infected Nicotiana benthamiana plants. MOLECULAR PLANT PATHOLOGY 2019; 20:392-409. [PMID: 30375150 PMCID: PMC6637900 DOI: 10.1111/mpp.12764] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nicotiana benthamiana is an important model plant for plant-microbe interaction studies. Here, we compared ribosome profiles and riboproteomes of healthy and infected N. benthamiana plants. We affinity purified ribosomes from transgenic leaves expressing a FLAG-tagged ribosomal large subunit protein RPL18B of Arabidopsis thaliana. Purifications were prepared from healthy plants and plants that had been infiltrated with Agrobacterium tumefaciens carrying infectious cDNA of Potato virus A (PVA) or firefly luciferase gene, referred to here as PVA- or Agrobacterium-infected plants, respectively. Plants encode a number of paralogous ribosomal proteins (r-proteins). The N. benthamiana riboproteome revealed approximately 6600 r-protein hits representing 424 distinct r-proteins that were members of 71 of the expected 81 r-protein families. Data are available via ProteomeXchange with identifier PXD011602. The data indicated that N. benthamiana ribosomes are heterogeneous in their r-protein composition. In PVA-infected plants, the number of identified r-protein paralogues was lower than in Agrobacterium-infected or healthy plants. A. tumefaciens proteins did not associate with ribosomes, whereas ribosomes from PVA-infected plants co-purified with viral cylindrical inclusion protein and helper component proteinase, reinforcing their possible role in protein synthesis during virus infection. In addition, viral NIa protease-VPg, RNA polymerase NIb and coat protein were occasionally detected. Infection did not affect the proportions of ribosomal subunits or the monosome to polysome ratio, suggesting that no overall alteration in translational activity took place on infection with these pathogens. The riboproteomic data of healthy and pathogen-infected N. benthamiana will be useful for studies on the specific use of r-protein paralogues to control translation in infected plants.
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Affiliation(s)
- Katri Eskelin
- Department of Microbiology, Faculty of Agriculture and ForestryUniversity of HelsinkiPO Box 56FI‐00014Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiPO Box 56FI‐00014Finland
| | - Markku Varjosalo
- Institute of BiotechnologyUniversity of HelsinkiPO Box 65FI‐00014Finland
| | - Janne Ravantti
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiPO Box 56FI‐00014Finland
| | - Kristiina Mäkinen
- Department of Microbiology, Faculty of Agriculture and ForestryUniversity of HelsinkiPO Box 56FI‐00014Finland
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26
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Rose H, Döring I, Vetten HJ, Menzel W, Richert-Pöggeler KR, Maiss E. Complete genome sequence and construction of an infectious full-length cDNA clone of celery latent virus - an unusual member of a putative new genus within the Potyviridae. J Gen Virol 2019; 100:308-320. [PMID: 30667354 DOI: 10.1099/jgv.0.001207] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Celery latent virus (CeLV) is an incompletely described plant virus known to be sap and seed transmissible and to possess flexuous filamentous particles measuring about 900 nm in length, suggesting it as a possible member of the family Potyviridae. Here, an Italian isolate of CeLV was transmitted by sap to a number of host plants and shown to have a single-stranded and monopartite RNA genome being 11 519 nucleotides (nts) in size and possessing some unusual features. The RNA contains a large open reading frame (ORF) that is flanked by a short 5' untranslated region (UTR) of 13 nt and a 3' UTR consisting of 586 nt that is not polyadenylated. CeLV RNA shares nt sequence identity of only about 40 % with other members of the Potyviridae (potyvirids). The CeLV polyprotein is notable in that it starts with a signal peptide, has a putative P3N-PIPO ORF and shares low aa sequence identity (about 18 %) with other potyvirids. Although potential cleavage sites were not identified for the N-terminal two-thirds of the polyprotein, the latter possesses a number of sequence motifs, the identity and position of which are characteristic of other potyvirids. Attempts at constructing an infectious full-length cDNA clone of CeLV were successful following Rhizobium radiobacter infiltration of Nicotiana benthamiana and Apium graveolens. CeLV appears to have the largest genome of all known potyvirids and some unique genome features that may warrant the creation of a new genus, for which we propose the name 'celavirus'.
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Affiliation(s)
- Hanna Rose
- 1Department Phytomedicine, Leibniz University Hannover, Institute of Horticultural Production Systems, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | - Ines Döring
- 1Department Phytomedicine, Leibniz University Hannover, Institute of Horticultural Production Systems, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | | | - Wulf Menzel
- 3Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7 B, 38124 Braunschweig, Germany
| | - Katja R Richert-Pöggeler
- 4Julius Kühn Institut JKI, Federal Research Centre for Cultivated Plants, Institute of Epidemiology and Pathogen Diagnostics, Messeweg 11-12, 38104 Braunschweig, Germany
| | - Edgar Maiss
- 1Department Phytomedicine, Leibniz University Hannover, Institute of Horticultural Production Systems, Herrenhäuser Str. 2, 30419, Hannover, Germany
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27
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Rodamilans B, Valli A, Mingot A, San León D, López-Moya JJ, García JA. An atypical RNA silencing suppression strategy provides a snapshot of the evolution of sweet potato-infecting potyviruses. Sci Rep 2018; 8:15937. [PMID: 30374036 PMCID: PMC6206096 DOI: 10.1038/s41598-018-34358-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022] Open
Abstract
Plant viruses usually encode proteins with RNA silencing suppression (RSS) activity to counteract plant defenses. In Potyvirus, the largest genus in the family Potyviridae, this role is taken over by the multifunctional HCPro, also involved in aphid transmission, polyprotein processing and virion formation. Recently, the large P1 of Sweet potato feathery mottle virus (SPFMV) was characterized finding an extra ORF produced after polymerase slippage, which originates the product P1N-PISPO. Transient expression assays showed that SPFMV P1 and P1N-PISPO presented RSS activity, while HCPro did not. In this work, we analyze possible differences between HCPro of SPFMV and other potyviruses, testing HCPro RSS activity in a transient expression assay, and using a Plum pox virus-based system to test the ability of SPFMV P1N-PISPO and HCPro to serve as RNA silencing suppressors in the context of a viral infection. Our results indicate that not only P1 and P1N-PISPO, but also HCPro display RSS activity when expressed in a suitable context, stressing the importance of the selected experimental system for testing anti-silencing capacity of proteins. The presence of multiple viral silencing suppressors in SPFMV adds complexity to an already intricate RSS system, and provides insight into the hypothetical evolution of sweet potato-infecting potyvirids.
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Affiliation(s)
| | - Adrián Valli
- Centro Nacional de Biotecnología CNB, CSIC, Madrid, Spain
| | - Ares Mingot
- Center for Research in Agricultural Genomics CRAG, CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Cerdanyola del Vallès, Barcelona, Spain
| | - David San León
- Centro Nacional de Biotecnología CNB, CSIC, Madrid, Spain
| | - Juan José López-Moya
- Center for Research in Agricultural Genomics CRAG, CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Cerdanyola del Vallès, Barcelona, Spain
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28
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Rodamilans B, Shan H, Pasin F, García JA. Plant Viral Proteases: Beyond the Role of Peptide Cutters. FRONTIERS IN PLANT SCIENCE 2018; 9:666. [PMID: 29868107 PMCID: PMC5967125 DOI: 10.3389/fpls.2018.00666] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/30/2018] [Indexed: 05/23/2023]
Abstract
Almost half of known plant viral species rely on proteolytic cleavages as key co- and post-translational modifications throughout their infection cycle. Most of these viruses encode their own endopeptidases, proteases with high substrate specificity that internally cleave large polyprotein precursors for the release of functional sub-units. Processing of the polyprotein, however, is not an all-or-nothing process in which endopeptidases act as simple peptide cutters. On the contrary, spatial-temporal modulation of these polyprotein cleavage events is crucial for a successful viral infection. In this way, the processing of the polyprotein coordinates viral replication, assembly and movement, and has significant impact on pathogen fitness and virulence. In this mini-review, we give an overview of plant viral proteases emphasizing their importance during viral infections and the varied functionalities that result from their proteolytic activities.
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Affiliation(s)
- Bernardo Rodamilans
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Hongying Shan
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Fabio Pasin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Juan Antonio García
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
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29
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Brewer HC, Hird DL, Bailey AM, Seal SE, Foster GD. A guide to the contained use of plant virus infectious clones. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:832-843. [PMID: 29271098 PMCID: PMC5867029 DOI: 10.1111/pbi.12876] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/08/2017] [Accepted: 12/17/2017] [Indexed: 05/18/2023]
Abstract
Plant virus infectious clones are important tools with wide-ranging applications in different areas of biology and medicine. Their uses in plant pathology include the study of plant-virus interactions, and screening of germplasm as part of prebreeding programmes for virus resistance. They can also be modified to induce transient plant gene silencing (Virus Induced Gene Silencing - VIGS) and as expression vectors for plant or exogenous proteins, with applications in both plant pathology and more generally for the study of plant gene function. Plant viruses are also increasingly being investigated as expression vectors for in planta production of pharmaceutical products, known as molecular farming. However, plant virus infectious clones may pose a risk to the environment due to their ability to reconstitute fully functional, transmissible viruses. These risks arise from both their inherent pathogenicity and the effect of any introduced genetic modifications. Effective containment measures are therefore required. There has been no single comprehensive review of the biosafety considerations for the contained use of genetically modified plant viruses, despite their increasing importance across many biological fields. This review therefore explores the biosafety considerations for working with genetically modified plant viruses in contained environments, with focus on plant growth facilities. It includes regulatory frameworks, risk assessment, assignment of biosafety levels, facility features and working practices. The review is based on international guidance together with information provided by plant virus researchers.
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Affiliation(s)
| | - Diane L. Hird
- School of Biological SciencesUniversity of BristolBristolUK
| | - Andy M. Bailey
- School of Biological SciencesUniversity of BristolBristolUK
| | - Susan E. Seal
- Natural Resources InstituteUniversity of GreenwichChatham MaritimeKentUK
| | - Gary D. Foster
- School of Biological SciencesUniversity of BristolBristolUK
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30
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Rajamäki ML, Xi D, Sikorskaite-Gudziuniene S, Valkonen JPT, Whitham SA. Differential Requirement of the Ribosomal Protein S6 and Ribosomal Protein S6 Kinase for Plant-Virus Accumulation and Interaction of S6 Kinase with Potyviral VPg. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:374-384. [PMID: 28437137 DOI: 10.1094/mpmi-06-16-0122-r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Ribosomal protein S6 (RPS6) is an indispensable plant protein regulated, in part, by ribosomal protein S6 kinase (S6K) which, in turn, is a key regulator of plant responses to stresses and developmental cues. Increased expression of RPS6 was detected in Nicotiana benthamiana during infection by diverse plant viruses. Silencing of the RPS6 and S6K genes in N. benthamiana affected accumulation of Cucumber mosaic virus, Turnip mosaic virus (TuMV), and Potato virus A (PVA) in contrast to Turnip crinkle virus and Tobacco mosaic virus. In addition, the viral genome-linked protein (VPg) of TuMV and PVA interacted with S6K in plant cells, as detected by bimolecular fluorescence complementation assay. The VPg-S6K interaction was detected in cytoplasm, nucleus, and nucleolus, whereas the green fluorescent protein-tagged S6K alone showed cytoplasmic localization only. These results demonstrate that the requirement for RPS6 and S6K differs for diverse plant viruses with different translation initiation strategies and suggest that potyviral VPg-S6K interaction may affect S6K functions in both the cytoplasm and the nucleus.
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Affiliation(s)
- Minna-Liisa Rajamäki
- 1 Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Helsinki, Finland
| | - Dehui Xi
- 2 College of Life Science, Sichuan University, Chengdu, 610064, China; and
| | | | - Jari P T Valkonen
- 1 Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Helsinki, Finland
| | - Steven A Whitham
- 3 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
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31
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Cheng X, Xiong R, Li Y, Li F, Zhou X, Wang A. Sumoylation of Turnip mosaic virus RNA Polymerase Promotes Viral Infection by Counteracting the Host NPR1-Mediated Immune Response. THE PLANT CELL 2017; 29:508-525. [PMID: 28223439 PMCID: PMC5385955 DOI: 10.1105/tpc.16.00774] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/27/2017] [Accepted: 02/17/2017] [Indexed: 05/14/2023]
Abstract
Sumoylation is a transient, reversible dynamic posttranslational modification that regulates diverse cellular processes including plant-pathogen interactions. Sumoylation of NPR1, a master regulator of basal and systemic acquired resistance to a broad spectrum of plant pathogens, activates the defense response. Here, we report that NIb, the only RNA-dependent RNA polymerase of Turnip mosaic virus (TuMV) that targets the nucleus upon translation, interacts exclusively with and is sumoylated by SUMO3 (SMALL UBIQUITIN-LIKE MODIFIER3), but not the three other Arabidopsis thaliana SUMO paralogs. TuMV infection upregulates SUMO3 expression, and the sumoylation of NIb by SUMO3 regulates the nuclear-cytoplasmic partitioning of NIb. We identified the SUMO-interacting motif in NIb that is essential for its sumoylation and found that knockout or overexpression of SUMO3 suppresses TuMV replication and attenuates viral symptoms, suggesting that SUMO3 plays dual roles as a host factor of TuMV and as an antiviral defender. Sumoylation of NIb by SUMO3 is crucial for its role in suppressing the host immune response. Taken together, our findings reveal that sumoylation of NIb promotes TuMV infection by retargeting NIb from the nucleus to the cytoplasm where viral replication takes place and by suppressing host antiviral responses through counteracting the TuMV infection-induced, SUMO3-activated, NPR1-mediated resistance pathway.
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Affiliation(s)
- Xiaofei Cheng
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada
| | - Ruyi Xiong
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Yinzi Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
| | - Fangfang Li
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
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32
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Charon J, Theil S, Nicaise V, Michon T. Protein intrinsic disorder within the Potyvirus genus: from proteome-wide analysis to functional annotation. MOLECULAR BIOSYSTEMS 2016; 12:634-52. [PMID: 26699268 DOI: 10.1039/c5mb00677e] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Within proteins, intrinsically disordered regions (IDRs) are devoid of stable secondary and tertiary structures under physiological conditions and rather exist as dynamic ensembles of inter-converting conformers. Although ubiquitous in all domains of life, the intrinsic disorder content is highly variable in viral genomes. Over the years, functional annotations of disordered regions at the scale of the whole proteome have been conducted for several animal viruses. But to date, similar studies applied to plant viruses are still missing. Based on disorder prediction tools combined with annotation programs and evolutionary studies, we analyzed the intrinsic disorder content in Potyvirus, using a 10-species dataset representative of this genus diversity. In this paper, we revealed that: (i) the Potyvirus proteome displays high disorder content, (ii) disorder is conserved during Potyvirus evolution, suggesting a functional advantage of IDRs, (iii) IDRs evolve faster than ordered regions, and (iv) IDRs may be associated with major biological functions required for the Potyvirus cycle. Notably, the proteins P1, Coat protein (CP) and Viral genome-linked protein (VPg) display a high content of conserved disorder, enriched in specific motifs mimicking eukaryotic functional modules and suggesting strategies of host machinery hijacking. In these three proteins, IDRs are particularly conserved despite their high amino acid polymorphism, indicating a link to adaptive processes. Through this comprehensive study, we further investigate the biological relevance of intrinsic disorder in Potyvirus biology and we propose a functional annotation of potyviral proteome IDRs.
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Affiliation(s)
- Justine Charon
- UMR Biologie du Fruit et Pathologie, INRA, Villenave d'Ornon cedex, France. and UMR Biologie du Fruit et Pathologie, Université de Bordeaux, Villenave d'Ornon cedex, France
| | - Sébastien Theil
- UMR Biologie du Fruit et Pathologie, INRA, Villenave d'Ornon cedex, France. and UMR Biologie du Fruit et Pathologie, Université de Bordeaux, Villenave d'Ornon cedex, France
| | - Valérie Nicaise
- UMR Biologie du Fruit et Pathologie, INRA, Villenave d'Ornon cedex, France. and UMR Biologie du Fruit et Pathologie, Université de Bordeaux, Villenave d'Ornon cedex, France
| | - Thierry Michon
- UMR Biologie du Fruit et Pathologie, INRA, Villenave d'Ornon cedex, France. and UMR Biologie du Fruit et Pathologie, Université de Bordeaux, Villenave d'Ornon cedex, France
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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: 55] [Impact Index Per Article: 6.9] [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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Martínez F, Rodrigo G, Aragonés V, Ruiz M, Lodewijk I, Fernández U, Elena SF, Daròs JA. Interaction network of tobacco etch potyvirus NIa protein with the host proteome during infection. BMC Genomics 2016; 17:87. [PMID: 26830344 PMCID: PMC4735970 DOI: 10.1186/s12864-016-2394-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 01/14/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The genomes of plant viruses have limited coding capacity, and to complete their infectious cycles, viral factors must target, direct or indirectly, many host elements. However, the interaction networks between viruses and host factors are poorly understood. The genus Potyvirus is the largest group of plus-strand RNA viruses infecting plants. Potyviral nuclear inclusion a (NIa) plays many roles during infection. NIa is a polyprotein consisting of two domains, viral protein genome-linked (VPg) and protease (NIaPro), separated by an inefficiently utilized self-proteolytic site. To gain insights about the interaction between potyviral NIa and the host cell during infection, we constructed Tobacco etch virus (TEV, genus Potyvirus) infectious clones in which the VPg or the NIaPro domains of NIa were tagged with the affinity polypeptide Twin-Strep-tag and identified the host proteins targeted by the viral proteins by affinity purification followed by mass spectrometry analysis (AP-MS). RESULTS We identified 232 different Arabidopsis thaliana proteins forming part of complexes in which TEV NIa products were also involved. VPg and NIaPro specifically targeted 89 and 76 of these proteins, respectively, whereas 67 proteins were targeted by both domains and considered full-length NIa targets. Taking advantage of the currently known A. thaliana interactome, we constructed a protein interaction network between TEV NIa domains and 516 host proteins. The most connected elements specifically targeted by VPg were G-box regulating factor 6 and mitochondrial ATP synthase δ subunit; those specifically targeted by NIaPro were plasma membrane aquaporin PIP2;7 and actin 7, whereas those targeted by full-length NIa were heat shock protein 70-1 and photosystem protein LHCA3. Moreover, a contextualization in the global A. thaliana interactome showed that NIa targets are not more connected with other host proteins than expected by chance, but are in a position that allows them to connect with other host proteins in shorter paths. Further analysis of NIa-targeted host proteins revealed that they are mainly involved in response to stress, metabolism, photosynthesis, and localization. Many of these proteins are connected with the phytohormone ethylene. CONCLUSIONS Potyviral NIa targets many host elements during infection, establishing a network in which information is efficiently transmitted.
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Affiliation(s)
- Fernando Martínez
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Guillermo Rodrigo
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Verónica Aragonés
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Marta Ruiz
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Iris Lodewijk
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Unai Fernández
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
| | - Santiago F Elena
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
- The Santa Fe Institute, Santa Fe, NM, USA.
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas - Universidad Politécnica de Valencia), Avenida de los Naranjos s/n, 46022, Valencia, Spain.
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Mingot A, Valli A, Rodamilans B, San León D, Baulcombe DC, García JA, López-Moya JJ. The P1N-PISPO trans-Frame Gene of Sweet Potato Feathery Mottle Potyvirus Is Produced during Virus Infection and Functions as an RNA Silencing Suppressor. J Virol 2016; 90:3543-57. [PMID: 26792740 PMCID: PMC4794657 DOI: 10.1128/jvi.02360-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/07/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED The positive-sense RNA genome of Sweet potato feathery mottle virus (SPFMV) (genus Potyvirus, family Potyviridae) contains a large open reading frame (ORF) of 3,494 codons translatable as a polyprotein and two embedded shorter ORFs in the -1 frame: PISPO, of 230 codons, and PIPO, of 66 codons, located in the P1 and P3 regions, respectively. PISPO is specific to some sweet potato-infecting potyviruses, while PIPO is present in all potyvirids. In SPFMV these two extra ORFs are preceded by conserved G2A6 motifs. We have shown recently that a polymerase slippage mechanism at these sites could produce transcripts bringing these ORFs in frame with the upstream polyprotein, thus leading to P1N-PISPO and P3N-PIPO products (B. Rodamilans, A. Valli, A. Mingot, D. San Leon, D. B. Baulcombe, J. J. Lopez-Moya, and J.A. Garcia, J Virol 89:6965-6967, 2015, doi:10.1128/JVI.00337-15). Here, we demonstrate by liquid chromatography coupled to mass spectrometry that both P1 and P1N-PISPO are produced during viral infection and coexist in SPFMV-infected Ipomoea batatas plants. Interestingly, transient expression of SPFMV gene products coagroinfiltrated with a reporter gene in Nicotiana benthamiana revealed that P1N-PISPO acts as an RNA silencing suppressor, a role normally associated with HCPro in other potyviruses. Moreover, mutation of WG/GW motifs present in P1N-PISPO abolished its silencing suppression activity, suggesting that the function might require interaction with Argonaute components of the silencing machinery, as was shown for other viral suppressors. Altogether, our results reveal a further layer of complexity of the RNA silencing suppression activity within the Potyviridae family. IMPORTANCE Gene products of potyviruses include P1, HCPro, P3, 6K1, CI, 6K2, VPg/NIaPro, NIb, and CP, all derived from the proteolytic processing of a large polyprotein, and an additional P3N-PIPO product, with the PIPO segment encoded in a different frame within the P3 cistron. In sweet potato feathery mottle virus (SPFMV), another out-of-frame element (PISPO) was predicted within the P1 region. We have shown recently that a polymerase slippage mechanism can generate the transcript variants with extra nucleotides that could be translated into P1N-PISPO and P3N-PIPO. Now, we demonstrate by mass spectrometry analysis that P1N-PISPO is indeed produced in SPFMV-infected plants, in addition to P1. Interestingly, while in other potyviruses the suppressor of RNA silencing is HCPro, we show here that P1N-PISPO exhibited this activity in SPFMV, revealing how the complexity of the gene content could contribute to supply this essential function in members of the Potyviridae family.
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Affiliation(s)
- Ares Mingot
- Center for Research in Agricultural Genomics, CSIC-IRTA-UAB-UB, Cerdanyola del Vallès, Barcelona, Spain
| | - Adrián Valli
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | | | - David San León
- Centro Nacional de Biotecnología CNB, CSIC, Madrid, Spain
| | - David C Baulcombe
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | | | - Juan José López-Moya
- Center for Research in Agricultural Genomics, CSIC-IRTA-UAB-UB, Cerdanyola del Vallès, Barcelona, Spain
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Ivanov KI, Eskelin K, Bašić M, De S, Lõhmus A, Varjosalo M, Mäkinen K. Molecular insights into the function of the viral RNA silencing suppressor HCPro. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:30-45. [PMID: 26611351 DOI: 10.1111/tpj.13088] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 05/23/2023]
Abstract
Potyviral helper component proteinase (HCPro) is a well-characterized suppressor of antiviral RNA silencing, but its mechanism of action is not yet fully understood. In this study, we used affinity purification coupled with mass spectrometry to identify binding partners of HCPro in potyvirus-infected plant cells. This approach led to identification of various HCPro interactors, including two key enzymes of the methionine cycle, S-adenosyl-L-methionine synthase and S-adenosyl-L-homocysteine hydrolase. This finding, together with the results of enzymatic activity and gene knockdown experiments, suggests a mechanism in which HCPro complexes containing viral and host proteins act to suppress antiviral RNA silencing through local disruption of the methionine cycle. Another group of HCPro interactors identified in this study comprised ribosomal proteins. Immunoaffinity purification of ribosomes demonstrated that HCPro is associated with ribosomes in virus-infected cells. Furthermore, we show that HCPro and ARGONAUTE1 (AGO1), the core component of the RNA-induced silencing complex (RISC), interact with each other and are both associated with ribosomes in planta. These results, together with the fact that AGO1 association with ribosomes is a hallmark of RISC-mediated translational repression, suggest a second mechanism of HCPro action, whereby ribosome-associated multiprotein complexes containing HCPro relieve viral RNA translational repression through interaction with AGO1.
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Affiliation(s)
- Konstantin I Ivanov
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
| | - Katri Eskelin
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
| | - Marta Bašić
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
| | - Swarnalok De
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
| | - Andres Lõhmus
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
| | - Kristiina Mäkinen
- Department of Food and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, 00014, Finland
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Zheng L, Du Z, Lin C, Mao Q, Wu K, Wu J, Wei T, Wu Z, Xie L. Rice stripe tenuivirus p2 may recruit or manipulate nucleolar functions through an interaction with fibrillarin to promote virus systemic movement. MOLECULAR PLANT PATHOLOGY 2015; 16:921-30. [PMID: 25431002 PMCID: PMC6638460 DOI: 10.1111/mpp.12220] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Rice stripe virus (RSV) is the type species of the genus Tenuivirus and represents a major viral pathogen affecting rice production in East Asia. In this study, RSV p2 was fused to yellow fluorescent protein (p2-YFP) and expressed in epidermal cells of Nicotiana benthamiana. p2-YFP fluorescence was found to move to the nucleolus initially, but to leave the nucleolus for the cytoplasm forming numerous distinct bright spots there at later time points. A bimolecular fluorescence complementation (BiFC) assay showed that p2 interacted with fibrillarin and that the interaction occurred in the nucleus. Both the nucleolar localization and cytoplasmic distribution of p2-YFP fluorescence were affected in fibrillarin-silenced N. benthamiana. Fibrillarin depletion abolished the systemic movement of RSV, but not that of Tobacco mosaic virus (TMV) and Potato virus X (PVX). A Tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) method was used to diminish RSV NS2 (encoding p2) or NS3 (encoding p3) during RSV infection. Silencing of NS3 alleviated symptom severity and reduced RSV accumulation, but had no obvious effects on virus movement and the timing of symptom development. However, silencing of NS2 abolished the systemic movement of RSV. The possibility that RSV p2 may recruit or manipulate nucleolar functions to promote virus systemic infection is discussed.
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Affiliation(s)
- Luping Zheng
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenguo Du
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, GAAS, Guangzhou, 510640, China
| | - Chen Lin
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Bayuquan Entry-Exit Inspection and Quarantine Bureau, Yingkou, 115007, China
| | - Qianzhuo Mao
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Kangcheng Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianguo Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Taiyun Wei
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zujian Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lianhui Xie
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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38
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Majer E, Navarro JA, Daròs JA. A potyvirus vector efficiently targets recombinant proteins to chloroplasts, mitochondria and nuclei in plant cells when expressed at the amino terminus of the polyprotein. Biotechnol J 2015; 10:1792-802. [PMID: 26147811 DOI: 10.1002/biot.201500042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 05/11/2015] [Accepted: 07/03/2015] [Indexed: 01/29/2023]
Abstract
Plant virus-based expression systems allow quick and efficient production of recombinant proteins in plant biofactories. Among them, a system derived from tobacco etch virus (TEV; genus potyvirus) permits coexpression of equimolar amounts of several recombinant proteins. This work analyzed how to target recombinant proteins to different subcellular localizations in the plant cell using this system. We constructed TEV clones in which green fluorescent protein (GFP), with a chloroplast transit peptide (cTP), a nuclear localization signal (NLS) or a mitochondrial targeting peptide (mTP) was expressed either as the most amino-terminal product or embedded in the viral polyprotein. Results showed that cTP and mTP mediated efficient translocation of GFP to the corresponding organelle only when present at the amino terminus of the viral polyprotein. In contrast, the NLS worked efficiently at both positions. Viruses expressing GFP in the amino terminus of the viral polyprotein produced milder symptoms. Untagged GFPs and cTP and NLS tagged amino-terminal GFPs accumulated to higher amounts in infected tissues. Finally, viral progeny from clones with internal GFPs maintained the extra gene better. These observations will help in the design of potyvirus-based vectors able to coexpress several proteins while targeting different subcellular localizations, as required in plant metabolic engineering.
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Affiliation(s)
- Eszter Majer
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia, Spain
| | - José-Antonio Navarro
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia, Spain
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia, Spain.
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39
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Cuevas JM, Willemsen A, Hillung J, Zwart MP, Elena SF. Temporal dynamics of intrahost molecular evolution for a plant RNA virus. Mol Biol Evol 2015; 32:1132-47. [PMID: 25660377 DOI: 10.1093/molbev/msv028] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Populations of plant RNA viruses are highly polymorphic in infected plants, which may allow rapid within-host evolution. To understand tobacco etch potyvirus (TEV) evolution, longitudinal samples from experimentally evolved populations in the natural host tobacco and from the alternative host pepper were phenotypically characterized and genetically analyzed. Temporal and compartmental variabilities of TEV populations were quantified using high throughput Illumina sequencing and population genetic approaches. Of the two viral phenotypic traits measured, virulence increased in the novel host but decreased in the original one, and viral load decreased in both hosts, though to a lesser extent in the novel one. Dynamics of population genetic diversity were also markedly different among hosts. Population heterozygosity increased in the ancestral host, with a dominance of synonymous mutations fixed, whereas it did not change or even decreased in the new host, with an excess of nonsynonymous mutations. All together, these observations suggest that directional selection is the dominant evolutionary force in TEV populations evolving in a novel host whereas either diversifying selection or random genetic drift may play a fundamental role in the natural host. To better understand these evolutionary dynamics, we developed a computer simulation model that incorporates the effects of mutation, selection, and drift. Upon parameterization with empirical data from previous studies, model predictions matched the observed patterns, thus reinforcing our idea that the empirical patterns of mutation accumulation represent adaptive evolution.
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Affiliation(s)
- José M Cuevas
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, València, Spain
| | - Anouk Willemsen
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, València, Spain
| | - Julia Hillung
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, València, Spain
| | - Mark P Zwart
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, València, Spain
| | - Santiago F Elena
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, València, Spain The Santa Fe Institute, Santa Fe, NM
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Shan H, Pasin F, Valli A, Castillo C, Rajulu C, Carbonell A, Simón-Mateo C, García JA, Rodamilans B. The Potyviridae P1a leader protease contributes to host range specificity. Virology 2015; 476:264-270. [PMID: 25562450 DOI: 10.1016/j.virol.2014.12.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/24/2014] [Accepted: 12/07/2014] [Indexed: 11/24/2022]
Abstract
The P1a protein of the ipomovirus Cucumber vein yellowing virus is one of the self-cleavage serine proteases present in Potyviridae family members. P1a is located at the N-terminal end of the viral polyprotein, and is closely related to potyviral P1 protease. For its proteolytic activity, P1a requires a still unknown host factor; this might be linked to involvement in host specificity. Here we built a series of constructs and chimeric viruses to help elucidate the role of P1a cleavage in host range definition. We demonstrate that host-dependent separation of P1a from the remainder of the polyprotein is essential for suppressing RNA silencing defenses and for efficient viral infection. These findings support the role of viral proteases as important determinants in host adaptation.
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Affiliation(s)
- Hongying Shan
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Fabio Pasin
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain.
| | - Adrián Valli
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Carla Castillo
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Charukesi Rajulu
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Alberto Carbonell
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Carmen Simón-Mateo
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Juan Antonio García
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain.
| | - Bernardo Rodamilans
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain.
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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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Worrall EA, Wamonje FO, Mukeshimana G, Harvey JJ, Carr JP, Mitter N. Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus: Relationships, Biology, and Prospects for Control. Adv Virus Res 2015; 93:1-46. [PMID: 26111585 DOI: 10.1016/bs.aivir.2015.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The closely related potyviruses Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) are major constraints on common bean (Phaseolus vulgaris) production. Crop losses caused by BCMV and BCMNV impact severely not only on commercial scale cultivation of this high-value crop but also on production by smallholder farmers in the developing world, where bean serves as a key source of dietary protein and mineral nutrition. In many parts of the world, progress has been made in combating BCMV through breeding bean varieties possessing the I gene, a dominant gene conferring resistance to most BCMV strains. However, in Africa, and in particular in Central and East Africa, BCMNV is endemic and this presents a serious problem for deployment of the I gene because this virus triggers systemic necrosis (black root disease) in plants possessing this resistance gene. Information on these two important viruses is scattered throughout the literature from 1917 onward, and although reviews on resistance to BCMV and BCMNV exist, there is currently no comprehensive review on the biology and taxonomy of BCMV and BCMNV. In this chapter, we discuss the current state of our knowledge of these two potyviruses including fundamental aspects of classification and phylogeny, molecular biology, host interactions, transmission through seed and by aphid vectors, geographic distribution, as well as current and future prospects for the control of these important viruses.
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