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Jafarzade M, Ramezani M, Hedayati F, Mokhtarzade Z, Zare B, Sabet MS, Norouzi P, Malboobi MA. Antibody-Mediated Resistance to Rhizomania Disease in Sugar Beet Hairy Roots. THE PLANT PATHOLOGY JOURNAL 2019; 35:692-697. [PMID: 31832049 PMCID: PMC6901245 DOI: 10.5423/ppj.oa.04.2018.0073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 08/31/2018] [Accepted: 10/01/2018] [Indexed: 06/10/2023]
Abstract
Agrobacterium rhizogenes-mediated transformation of sugar beet hairy roots expressing single-chain variable fragment (scFv) was exploited to evaluate the efficacy of four antibody-based constructs for interfering with the Beet necrotic yellow vein virus infection. The scFv specific to a major coat protein of virus, p21, was targeted to various cellular compartments including the cytosol (pIC and pICC constructs), apoplast (pIA), and mitochondrion (pIM). After mechanical virus inoculation, most of the hairy root clones expressing scFv in the cytosol displayed low virus titers while the majority of transgenic hairy root clones accumulated antibody in outer membrane of mitochondria or apoplast were infected. This hairy root system provided an efficient and rapid approach to initially investigating root disease resistance like rhizomania prior to transform whole recalcitrant plants such as sugar beet.
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Affiliation(s)
- M. Jafarzade
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
| | - M. Ramezani
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
| | - F. Hedayati
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
| | - Z. Mokhtarzade
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
| | - B. Zare
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
| | - M. S. Sabet
- Department of Agriculture, Tarbiat Modares University, Tehran 14115-336,
Iran
| | - P. Norouzi
- Sugar Beet Seed Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj 31585-4114,
Iran
| | - M. A. Malboobi
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran 14965-161,
Iran
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2
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Laufer M, Mohammad H, Christ DS, Riedel D, Maiss E, Varrelmann M, Liebe S. Fluorescent labelling of Beet necrotic yellow vein virus and Beet soil-borne mosaic virus for co- and superinfection experiments in Nicotiana benthamiana. J Gen Virol 2018; 99:1321-1330. [PMID: 30058995 DOI: 10.1099/jgv.0.001122] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
Infectious full-length clones of Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV), both genus Benyvirus, were used for fluorescent labelling with the objective to study their interaction in coinfection and superinfection experiments. Fluorescent labelling was achieved by replacing a part of the RNA2 encoded coat protein read-through domain with either GFP or mRFP fluorescent marker proteins. This resulted in a translational fusion comprising the coat and the fluorescent protein. The labelled viruses were infectious and moved systemically in Nicotiana benthamiana, producing wild-type-like symptoms. Virus particles could be observed by electron microscopy, demonstrating that the viral read-through domain is dispensable for particle formation. Coinfection experiments revealed a spatial separation of differentially labelled populations of both identical and different Benyvirus species after N. benthamiana agro-inoculation. Identical observations were obtained when Tobacco rattle virus (TRV) was differentially labelled and used for coinfection. In contrast, coinfections of BSBMV with Potato virus X (PVX) or TRV resulted in many co-infected cells lacking spatial separation. Micro-projectile co-bombardment of N. benthamiana leaves revealed that two differently labelled populations of the same virus co-infected only a few cells before starting to separate. In superinfection experiments with N. benthamiana, BSBMV and BNYVV were unable to establish a secondary infection in plants that were previously infected with BNYVV or BSBMV. Taken together, this is the first work to describe the interaction between two economically important Benyviruses using fluorescence-labelled full-length clones.
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Affiliation(s)
- Marlene Laufer
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Hamza Mohammad
- 2Department of Phytomedicine, Plant Virology, Institute of Horticultural Production Systems, Leibniz University, 30419 Hannover, Germany
| | - Daniela S Christ
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Dietmar Riedel
- 3Laboratory of Electron Microscopy, Max-Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Edgar Maiss
- 2Department of Phytomedicine, Plant Virology, Institute of Horticultural Production Systems, Leibniz University, 30419 Hannover, Germany
| | - Mark Varrelmann
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
| | - Sebastian Liebe
- 1Department of Phytopathology, Institute of Sugar Beet Research, 37079 Göttingen, Germany
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3
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Huang HJ, Liu CW, Zhou X, Zhang CX, Bao YY. A mitochondrial membrane protein is a target for rice ragged stunt virus in its insect vector. Virus Res 2016; 229:48-56. [PMID: 28034779 DOI: 10.1016/j.virusres.2016.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 10/20/2022]
Abstract
Rice ragged stunt virus (RRSV; Reoviridae) is exclusively transmitted by the brown planthopper Nilaparvata lugens in a persistent-propagative manner. It is understood that RNA viral proliferation is associated with the intracellular membranes of the insect host cells. However, the molecular mechanisms of the interaction between the RRSV proliferation and the intracellular membranes remain essentially unknown. It will be of great interest to determine whether RRSV protein(s) directly interact with intracellular membrane components of its host cells. In this study, we identified a RRSV nonstructural protein Pns10 interacting with a host oligomycin-sensitivity conferral protein (OSCP) using yeast two-hybrid system. The interaction between RRSV Pns10 and N. lugens OSCP was verified by a glutathione S-transferase pull-down assay. Confocal miscopy revealed colocalization of these two proteins in the cytoplasm of the salivary gland cells during the viral infection. The virions were further detected in the mitochondria under confocal miscopy and transmission electron microscopy combined with western blotting assay. This is the first observation that RRSV protein has a direct link with mitochondria. Suppressing OSCP gene expression by RNA interference notably decreased the viral loads in RRSV-infected insects. These findings revealed novel aspects of a viral protein in targeting the host mitochondrial membrane and provide insights concerning the mitochondrial membrane protein-based virus proliferation mode in the insect vector.
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Affiliation(s)
- Hai-Jian Huang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Cheng-Wen Liu
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Xiang Zhou
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Chuan-Xi Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Yan-Yuan Bao
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.
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4
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Yang J, Zhang F, Xie L, Song XJ, Li J, Chen JP, Zhang HM. Functional identification of two minor capsid proteins from Chinese wheat mosaic virus using its infectious full-length cDNA clones. J Gen Virol 2016; 97:2441-2450. [PMID: 27357465 DOI: 10.1099/jgv.0.000532] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Full-length cDNA clones of Chinese wheat mosaic virus (CWMV) RNA1 and RNA2 were produced from single reverse transcription PCR reactions and transcripts were shown to be infectious in both wheat and Nicotiana benthamiana. An efficient and reliable agro-infiltration method was then developed for reverse genetic assays in N. benthamiana. Inoculation of infectious cDNA clones resulted in obvious chlorotic symptoms, and CWMV viral genomic RNAs, capsid protein (CP)-related proteins, and typical rod-shaped particles were detectable on the inoculated and upper leaves, similar to those of WT virus. The optimal temperature for virus multiplication was 12 °C, but the optimum for systematic infection in plants was 17 °C. Mutant clones that abolished the N- or C-terminal extensions of the major CP did not inhibit systemic infection or the formation of rod-shaped particles but sometimes modified the symptoms in inoculated plants. These results suggest that the two minor CP-related proteins of CWMV are dispensable for viral infection, replication, systemic movement and virion assembly in plants.
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Affiliation(s)
- Jian Yang
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Fen Zhang
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
- College of Chemistry and Life Science, Zhejiang Normal University, Jinhua 321004, PR China
| | - Li Xie
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Xi-Jiao Song
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Jing Li
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Jian-Ping Chen
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Heng-Mu Zhang
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Key Laboratory of Plant Protection and Biotechnology, MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
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Dall'Ara M, Ratti C, Bouzoubaa SE, Gilmer D. Ins and Outs of Multipartite Positive-Strand RNA Plant Viruses: Packaging versus Systemic Spread. Viruses 2016; 8:E228. [PMID: 27548199 PMCID: PMC4997590 DOI: 10.3390/v8080228] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/29/2016] [Accepted: 08/09/2016] [Indexed: 11/16/2022] Open
Abstract
Viruses possessing a non-segmented genome require a specific recognition of their nucleic acid to ensure its protection in a capsid. A similar feature exists for viruses having a segmented genome, usually consisting of viral genomic segments joined together into one viral entity. While this appears as a rule for animal viruses, the majority of segmented plant viruses package their genomic segments individually. To ensure a productive infection, all viral particles and thereby all segments have to be present in the same cell. Progression of the virus within the plant requires as well a concerted genome preservation to avoid loss of function. In this review, we will discuss the "life aspects" of chosen phytoviruses and argue for the existence of RNA-RNA interactions that drive the preservation of viral genome integrity while the virus progresses in the plant.
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Affiliation(s)
- Mattia Dall'Ara
- Institut de Biologie Moléculaire des Plantes, Integrative Virology, CNRS UPR2367, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
- Dipartimento di Scienze Agrarie, Area Patologia Vegetale, Università di Bologna, Viale Fanin 40, 40127 Bologna, Italy.
| | - Claudio Ratti
- Dipartimento di Scienze Agrarie, Area Patologia Vegetale, Università di Bologna, Viale Fanin 40, 40127 Bologna, Italy.
| | - Salah E Bouzoubaa
- Institut de Biologie Moléculaire des Plantes, Integrative Virology, CNRS UPR2367, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
| | - David Gilmer
- Institut de Biologie Moléculaire des Plantes, Integrative Virology, CNRS UPR2367, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
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6
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Chiba S, Hleibieh K, Delbianco A, Klein E, Ratti C, Ziegler-Graff V, Bouzoubaa S, Gilmer D. The benyvirus RNA silencing suppressor is essential for long-distance movement, requires both zinc-finger and NoLS basic residues but not a nucleolar localization for its silencing-suppression activity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:168-81. [PMID: 23013437 DOI: 10.1094/mpmi-06-12-0142-r] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The RNA silencing-suppression properties of Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV) cysteine-rich p14 proteins have been investigated. Suppression of RNA silencing activities were made evident using viral infection of silenced Nicotiana benthamiana 16C, N. benthamiana agroinfiltrated with green fluorescent protein (GFP), and GF-FG hairpin triggers supplemented with viral suppressor of RNA silencing (VSR) constructs or using complementation of a silencing-suppressor-defective BNYVV virus in Chenopodium quinoa. Northern blot analyses of small-interfering RNAs (siRNAs) in agroinfiltration tests revealed reduced amounts of siRNA, especially secondary siRNA, suggesting that benyvirus VSR act downstream of the siRNA production. Using confocal laser-scanning microscopy imaging of infected protoplasts expressing functional p14 protein fused to an enhanced GFP reporter, we showed that benyvirus p14 accumulated in the nucleolus and the cytoplasm independently of other viral factors. Site-directed mutagenesis showed the importance of the nucleolar localization signal embedded in a C4 zinc-finger domain in the VSR function and intrinsic stability of the p14 protein. Conversely, RNA silencing suppression appeared independent of the nucleolar localization of the protein, and a correlation between BNYVV VSR expression and long-distance movement was established.
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Affiliation(s)
- Sotaro Chiba
- Institut de Biologie Moléculaire des Plantes, Laboratoire Propre du CNRS (UPR 2357) Conventionné avec l'Université de Strasbourg, 12 rue de Générale Zimmer, 67084 Strasbourg, France
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7
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Wei T, Miyazaki N, Uehara-Ichiki T, Hibino H, Shimizu T, Netsu O, Kikuchi A, Sasaya T, Iwasaki K, Omura T. Three-dimensional analysis of the association of viral particles with mitochondria during the replication of Rice gall dwarf virus. J Mol Biol 2011; 410:436-46. [PMID: 21635897 DOI: 10.1016/j.jmb.2011.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/28/2011] [Accepted: 05/10/2011] [Indexed: 10/18/2022]
Abstract
Examination of cultured insect vector cells that had been infected with Rice gall dwarf virus (RGDV), using transmission electron microscopy and confocal microscopy, revealed the presence of clusters of virus-coated mitochondria around viroplasms in which replication and assembly of RGDV occurred, suggesting a role for mitochondria in supplying the energy required for viral morphogenetic processes. Electron tomography revealed that RGDV particles on the surface of mitochondria are arrayed in an orderly but loose manner, unlike tightly packaged particles in vesicular compartments, suggesting the presence of counterpart molecules on the surface of mitochondria. The viral particles in close proximity to mitochondria were aligned along intermediate filaments, which might serve as scaffolds for the anchorage of these particles. RGDV has a putative mitochondrion-targeting sequence on the outer surface of the outer-capsid protein P8. The arrangement of RGDV particles around mitochondria suggests that the region of the P8 protein containing the mitochondrion-targeting sequence might attach to a molecule like a receptor on the outer mitochondrial membrane. Our analysis demonstrates the three-dimensional arrangement and molecular basis for the mitochondrial proximity of RGDV particles during viral replication.
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Affiliation(s)
- Taiyun Wei
- National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
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8
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Hui E, Xiang Y, Rochon D. Distinct regions at the N-terminus of the Cucumber necrosis virus coat protein target chloroplasts and mitochondria. Virus Res 2010; 153:8-19. [PMID: 20600385 DOI: 10.1016/j.virusres.2010.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Revised: 06/08/2010] [Accepted: 06/22/2010] [Indexed: 11/18/2022]
Abstract
Cucumber necrosis virus (CNV) is a spherical virus consisting of 180 identical coat protein (CP) subunits. The N-terminus of the CP subunit contains a 58aa RNA binding (R) domain and a 34aa arm that connects the R domain to the shell. These regions are known to play critical roles in virus assembly and disassembly. It has recently been shown that a region encompassing the arm can function as a chloroplast transit peptide (TP) in infected plants and that targeting may represent a means for virus particle disassembly. In this study, we further delineate the TP region and show that a 22aa sequence at the N-terminus of the shell enhances chloroplast targeting. We also demonstrate that R domain specifically co-localizes with mitochondria in agroinfiltrated plants. Deletion analyses show that the N-terminal 39 amino acids of the R domain are sufficient for mitochondrial targeting and that this region contains features typical of mitochondrial presequences. The R/arm region is found to be dually targeted to mitochondria and chloroplasts suggesting that this region of the CP plays a critical role in determining the fate of CP during the infection process.
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Affiliation(s)
- Elizabeth Hui
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
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9
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McGrann GRD, Grimmer MK, Mutasa-Göttgens ES, Stevens M. Progress towards the understanding and control of sugar beet rhizomania disease. MOLECULAR PLANT PATHOLOGY 2009; 10:129-41. [PMID: 19161359 PMCID: PMC6640442 DOI: 10.1111/j.1364-3703.2008.00514.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Rhizomania is a soil-borne disease that occurs throughout the major sugar beet growing regions of the world, causing severe yield losses in the absence of effective control measures. It is caused by Beet necrotic yellow vein virus (BNYVV), which is transmitted by the obligate root-infecting parasite Polymyxa betae. BNYVV has a multipartite RNA genome with all natural isolates containing four RNA species, although some isolates have a fifth RNA. The larger RNA1 and RNA2 contain the housekeeping genes of the virus and are always required for infection, whereas the smaller RNAs are involved in pathogenicity and vector transmission. RNA5-containing isolates are restricted to Asia and some parts of Europe, and these isolates tend to be more aggressive. With no acceptable pesticides available to restrict the vector, the control of rhizomania is now achieved almost exclusively through the use of resistant cultivars. A single dominant resistance gene, Rz1, has been used to manage the disease worldwide in recent years, although this gene confers only partial resistance. More recently, new variants of BNYVV have evolved (both with and without RNA5) that are able to cause significant yield penalties on resistant cultivars. These isolates are not yet widespread, but their appearance has resulted in accelerated searches for new sources of resistance to both the virus and the vector. Combined virus and vector resistance, achieved either by conventional or transgenic breeding, offers the sugar beet industry a new approach in its continuing struggle against rhizomania.
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Affiliation(s)
- Graham R D McGrann
- Broom's Barn Research Centre, Rothamsted Research, Department of Applied Crop Sciences, Higham, Bury St Edmunds, Suffolk IP28 6NP, UK
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10
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Hwang YT, McCartney AW, Gidda SK, Mullen RT. Localization of the Carnation Italian ringspot virus replication protein p36 to the mitochondrial outer membrane is mediated by an internal targeting signal and the TOM complex. BMC Cell Biol 2008; 9:54. [PMID: 18811953 PMCID: PMC2573885 DOI: 10.1186/1471-2121-9-54] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Accepted: 09/23/2008] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Carnation Italian ringspot virus (CIRV) is a positive-strand RNA virus that causes massive structural alterations of mitochondria in infected host cells, the most conspicuous being the formation of numerous internal vesicles/spherules that are derived from the mitochondrial outer membrane and serve as the sites for viral RNA replication. While the membrane-bound components of the CIRV replication complex, including a 36-kD RNA-binding protein (p36), are known to be essential for these changes in mitochondrial morphology and are relatively well characterized in terms of their roles in nascent viral RNA synthesis, how these proteins are specifically targeted and inserted into mitochondria is poorly defined. RESULTS Here we report on the molecular signal responsible for sorting p36 to the mitochondrial outer membrane. Using a combination of gain-of-function assays with portions of p36 fused to reporter proteins and domain-swapping assays with p36 and another closely-related viral RNA-binding protein, p33, that sorts specifically to the peroxisomal boundary membrane, we show that the mitochondrial targeting information in p36 resides within its two transmembrane domains (TMDs) and intervening hydrophilic loop sequence. Comprehensive mutational analysis of these regions in p36 revealed that the primary targeting determinants are the moderate hydrophobicity of both TMDs and the positively-charged face of an amphipathic helix within the intervening loop sequence. We show also using bimolecular fluorescence complementation (BiFC) that p36 interacts with certain components of the translocase complex in the mitochondrial outer membrane (TOM), but not with the sorting and assembly machinery (SAM). CONCLUSION Our results provide insight to how viruses, such as CIRV, exploit specific host-cell protein sorting pathways to facilitate their replication. The characterization of the targeting and insertion of p36 into the mitochondrial outer membrane also sheds light on the mechanisms involved in sorting of host-cell membrane proteins to mitochondria, a process that has been largely unexplored in plants.
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Affiliation(s)
- Yeen Ting Hwang
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Andrew W McCartney
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
- JD Irving, Limited, Woodlands Division, 1350 Regent Street, Fredericton, New Brunswick, E3C 2G6, Canada
| | - Satinder K Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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11
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Baboolal TG, Conroy MJ, Gill K, Ridley H, Visudtiphole V, Bullough PA, Lakey JH. Colicin N binds to the periphery of its receptor and translocator, outer membrane protein F. Structure 2008; 16:371-9. [PMID: 18334212 PMCID: PMC2581486 DOI: 10.1016/j.str.2007.12.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/20/2007] [Accepted: 12/21/2007] [Indexed: 11/24/2022]
Abstract
Colicins kill Escherichia coli after translocation across the outer membrane. Colicin N displays an unusually simple translocation pathway, using the outer membrane protein F (OmpF) as both receptor and translocator. Studies of this binary complex may therefore reveal a significant component of the translocation pathway. Here we show that, in 2D crystals, colicin is found outside the porin trimer, suggesting that translocation may occur at the protein-lipid interface. The major lipid of the outer leaflet interface is lipopolysaccharide (LPS). It is further shown that colicin N binding displaces OmpF-bound LPS. The N-terminal helix of the pore-forming domain, which is not required for pore formation, rearranges and binds to OmpF. Colicin N also binds artificial OmpF dimers, indicating that trimeric symmetry plays no part in the interaction. The data indicate that colicin is closely associated with the OmpF-lipid interface, providing evidence that this peripheral pathway may play a role in colicin transmembrane transport.
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Affiliation(s)
- Thomas G Baboolal
- The Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, United Kingdom
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12
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Mézeth KB, Nylund S, Henriksen H, Patel S, Nerland AH, Szilvay AM. RNA-dependent RNA polymerase from Atlantic halibut nodavirus contains two signals for localization to the mitochondria. Virus Res 2007; 130:43-52. [PMID: 17602779 DOI: 10.1016/j.virusres.2007.05.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 05/08/2007] [Accepted: 05/14/2007] [Indexed: 11/21/2022]
Abstract
Nodaviruses encode an RNA-dependent RNA polymerase called Protein A that is responsible for replication of the viral RNA segments. The intracellular localization of Protein A from a betanodavirus isolated from Atlantic halibut (AHNV) was studied in infected fish cells and in transfected mammalian cells expressing Myc-tagged wild type Protein A and mutants. In infected cells Protein A localized to cytoplasmic structures resembling mitochondria and in transfected mammalian cells the AHNV Protein A was found to co-localize with mitochondrial proteins. Two independent mitochondrial targeting signals, one N-terminal comprising residues 1-40 and one internal consisting of residues 225-246 were sufficient to target both Protein A deletion mutants and enhanced green fluorescent protein (EGFP) to the mitochondria. The N-terminal signal corresponds to the mitochondrial targeting sequence of the Flock House Virus (FHV) Protein A while the internal signal is similar to the single targeting signal previously found in Greasy Grouper Nervous Necrosis Virus (GGNNV) Protein A.
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13
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Lubicz JV, Rush CM, Payton M, Colberg T. Beet necrotic yellow vein virus accumulates inside resting spores and zoosporangia of its vector Polymyxa betae BNYVV infects P. betae. Virol J 2007; 4:37. [PMID: 17411435 PMCID: PMC1866226 DOI: 10.1186/1743-422x-4-37] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/05/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodiophorids and chytrids are zoosporic parasites of algae and land plant and are distributed worldwide. There are 35 species belonging to the order Plasmodiophorales and three species, Polymyxa betae, P. graminis, and Spongospora subterranea, are plant viral vectors. Plasmodiophorid transmitted viruses are positive strand RNA viruses belonging to five genera. Beet necrotic yellow vein virus (BNYVV) and its vector, P. betae, are the causal agents for rhizomania. RESULTS Evidence of BNYVV replication and movement proteins associating with P. betae resting spores was initially obtained using immunofluorescence labeling and well characterized antisera to each of the BNYVV proteins. Root cross sections were further examined using immunogold labeling and electron microscopy. BNYVV proteins translated from each of the four genomic and subgenomic RNAs accumulate inside P. betae resting spores and zoospores. Statistical analysis was used to determine if immunolabelling detected viral proteins in specific subcellular domains and at a level greater than in control samples. CONCLUSION Virus-like particles were detected in zoosporangia. Association of BNYVV replication and movement proteins with sporangial and sporogenic stages of P. betae suggest that BNYVV resides inside its vector during more than one life cycle stage. These data suggest that P. betae might be a host as well as a vector for BNYVV.
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Affiliation(s)
- Jeanmarie Verchot Lubicz
- Oklahoma State University, Department of Entomology and Plant Pathology, 127 Noble Research Center, Stillwater, OK 74078, USA
| | - Charles M Rush
- Texas Agricultural Experiment Station, 2301 Experiment Station Road, Bushland, TX 79012, USA
| | - Mark Payton
- Oklahoma State University, Department of Statistics, Stillwater, OK 74078, USA
| | - Terry Colberg
- Oklahoma State University, Electron and Confocal Microscopy Facility, Stillwater, OK 74078, USA
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D'Souza GGM, Boddapati SV, Weissig V. Gene therapy of the other genome: the challenges of treating mitochondrial DNA defects. Pharm Res 2006; 24:228-38. [PMID: 17180727 DOI: 10.1007/s11095-006-9150-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Accepted: 08/17/2006] [Indexed: 01/08/2023]
Abstract
Human mitochondrial DNA is a 16.5 kb circular DNA molecule located inside the mitochondrial matrix. Although accounting for only about 1% of total cellular DNA, defects in mitochondrial DNA have been found to have major effects on human health. A single mtDNA mutation may cause a bewildering variety of clinical symptoms mainly involving the neuromuscular system at any age of onset. Despite significant advances in the understanding of mitochondrial DNA defects at a molecular level, the clinical diagnosis of mtDNA diseases remains a significant challenge and effective therapies for such diseases are as yet unavailable. In contrast to gene therapy for chromosomal DNA defects, mitochondrial gene therapy is a field that is still in its infancy and attempts towards gene therapy of the mitochondrial genome are rare. In this review we outline what we believe are the unique challenges associated with the correction of mtDNA mutations and summarize current approaches to gene therapy for the "other genome".
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Affiliation(s)
- Gerard G M D'Souza
- Bouvé College of Health Sciences, Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Avenue, 211 Mugar Building, Boston, Massachusetts 02115, USA
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