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Shahgolzari M, Venkataraman S, Osano A, Akpa PA, Hefferon K. Plant Virus Nanoparticles Combat Cancer. Vaccines (Basel) 2023; 11:1278. [PMID: 37631846 PMCID: PMC10459942 DOI: 10.3390/vaccines11081278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 08/27/2023] Open
Abstract
Plant virus nanoparticles (PVNPs) have garnered considerable interest as a promising nanotechnology approach to combat cancer. Owing to their biocompatibility, stability, and adjustable surface functionality, PVNPs hold tremendous potential for both therapeutic and imaging applications. The versatility of PVNPs is evident from their ability to be tailored to transport a range of therapeutic agents, including chemotherapy drugs, siRNA, and immunomodulators, thereby facilitating targeted delivery to the tumor microenvironment (TME). Furthermore, PVNPs may be customized with targeting ligands to selectively bind to cancer cell receptors, reducing off-target effects. Additionally, PVNPs possess immunogenic properties and can be engineered to exhibit tumor-associated antigens, thereby stimulating anti-tumor immune responses. In conclusion, the potential of PVNPs as a versatile platform for fighting cancer is immense, and further research is required to fully explore their potential and translate them into clinical applications.
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Affiliation(s)
- Mehdi Shahgolzari
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 5166616471, Iran
| | - Srividhya Venkataraman
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Anne Osano
- Department of Natural Sciences, Bowie State University, Bowie, MD 20715, USA
| | - Paul Achile Akpa
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka 410001, Enugu State, Nigeria
| | - Kathleen Hefferon
- Department of Microbiology, Cornell University, Ithaca, NY 14850, USA
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2
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Bragard C, Baptista P, Chatzivassiliou E, Gonthier P, Jaques Miret JA, Justesen AF, MacLeod A, Magnusson CS, Milonas P, Navas‐Cortes JA, Parnell S, Potting R, Stefani E, Thulke H, Van der Werf W, Civera AV, Yuen J, Zappalà L, Streissl F, Carluccio AV, Chiumenti M, Di Serio F, Rubino L, Reignault PL. Pest categorisation of cowpea mosaic virus. EFSA J 2023; 21:e07847. [PMID: 36846393 PMCID: PMC9951085 DOI: 10.2903/j.efsa.2023.7847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
The EFSA Panel on Plant Health conducted a pest categorisation of cowpea mosaic virus (CPMV) for the EU territory. The identity of CPMV, a member of the genus Comovirus (family Secoviridae), is established and detection and identification methods are available. The pathogen is not included in the Commission Implementing Regulation (EU) 2019/2072. It has been reported from the Americas, and several countries in Africa and Asia and it is not known to be present in the EU in natural conditions. CPMV is considered a major pathogen of cowpea on which it causes symptoms ranging from mild to severe mosaic, chlorosis and necrosis. The virus has been reported sporadically on some other cultivated species of the family Fabaceae, including soybean and some common bean varieties. CPMV is transmitted by cowpea seeds, with uncertainty on the transmission rate. There is uncertainty on seed transmission by other Fabaceae host species due to lack of information. CPMV is also transmitted by several beetle species, one of which, Diabrotica virgifera virgifera, is present in the EU. Seeds for sowing of cowpea are identified as the major entry pathway. The cultivated area and production of cowpea in the EU territory are mainly limited to local varieties cultivated at a small scale in Mediterranean EU Member States. Should the pest establish in the EU, an impact is expected on cowpea crops at local scale. There is high uncertainty on the potential impact that CPMV would cause on other natural hosts cultivated in the EU due to the lack of information from the areas of CPMV's current distribution. Despite the uncertainty concerning the potential impact on bean and soybean crops in the EU, CPMV satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.
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3
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Villanova F, Marcatti R, Bertanhe M, Morais VDS, Milagres FADP, Brustulin R, Araújo ELL, Tahmasebi R, Witkin SS, Deng X, Delwart E, Sabino EC, Abreu-Junior CH, Leal É, da Costa AC. New Variants of Squash Mosaic Viruses Detected in Human Fecal Samples. Microorganisms 2021; 9:microorganisms9071349. [PMID: 34206387 PMCID: PMC8307838 DOI: 10.3390/microorganisms9071349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 11/16/2022] Open
Abstract
Squash mosaic virus (SqMV) is a phytovirus that infects great diversity of plants worldwide. In Brazil, the SqMV has been identified in the states of Ceará, Maranhão, Piauí, Rio Grande do Norte, and Tocantins. The presence of non-pathogenic viruses in animals, such as phytoviruses, may not be completely risk-free. Similarities in gene repertories between these viruses and viruses that affect animal species have been reported. The present study describes the fully sequenced genomes of SqMV found in human feces, collected in Tocantins, and analyzes the viral profile by metagenomics in the context of diarrhea symptomatology. The complete SqMV genome was obtained in 39 of 253 analyzed samples (15.5%); 97.4% of them belonged to children under 5 years old. There was no evidence that the observed symptoms were related to the presence of SqMV. Of the different virus species detected in these fecal samples, at least 4 (rotavirus, sapovirus, norovirus, parechovirus) are widely known to cause gastrointestinal symptoms. The presence of SqMV nucleic acid in fecal samples is likely due to recent dietary consumption and it is not evidence of viral replication in the human intestinal cells. Identifying the presence of SqMV in human feces and characterization of its genome is a relevant precursor to determining whether and how plant viruses interact with host cells or microorganisms in the human gastrointestinal tract.
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Affiliation(s)
- Fabiola Villanova
- Laboratório de Diversidade Viral, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belem 66075-000, PA, Brazil;
| | - Roberta Marcatti
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
| | - Mayara Bertanhe
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
- School of Veterinary Medicine and Animal Science, University of Sao Paulo, São Paulo 05508-270, SP, Brazil
| | - Vanessa dos Santos Morais
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
| | - Flavio Augusto de Padua Milagres
- Instituto de Ciências Biológicas, Universidade Federal do Tocantins, Palmas 77001-090, TO, Brazil; (F.A.d.P.M.); (R.B.)
- Public Health Laboratory of Tocantins State (LACEN/TO), Palmas 77016-330, TO, Brazil
| | - Rafael Brustulin
- Instituto de Ciências Biológicas, Universidade Federal do Tocantins, Palmas 77001-090, TO, Brazil; (F.A.d.P.M.); (R.B.)
- Public Health Laboratory of Tocantins State (LACEN/TO), Palmas 77016-330, TO, Brazil
| | - Emerson Luiz Lima Araújo
- General Coordination of Public Health, Laboratories of the Strategic Articulation, Department of the Health, Surveillance Secretariat, Ministry of Health (CGLAB/DAEVS/SVS-MS), Brasília 70719-040, DF, Brazil;
| | - Roozbeh Tahmasebi
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
| | - Steven S. Witkin
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Xutao Deng
- Vitalant Research Institute, 270 Masonic Avenue, San Francisco, CA 94143, USA; (X.D.); (E.D.)
- Department Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Eric Delwart
- Vitalant Research Institute, 270 Masonic Avenue, San Francisco, CA 94143, USA; (X.D.); (E.D.)
- Department Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ester Cerdeira Sabino
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
| | | | - Élcio Leal
- Laboratório de Diversidade Viral, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belem 66075-000, PA, Brazil;
- Correspondence:
| | - Antonio Charlys da Costa
- Departamento de Moléstias Infecciosas e Parasitárias and Instituto de Medicina Tropical da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-000, SP, Brazil; (R.M.); (M.B.); (V.d.S.M.); (R.T.); (S.S.W.); (E.C.S.); (A.C.d.C.)
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4
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Mann KS, Sanfaçon H. Expanding Repertoire of Plant Positive-Strand RNA Virus Proteases. Viruses 2019; 11:v11010066. [PMID: 30650571 PMCID: PMC6357015 DOI: 10.3390/v11010066] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 12/13/2022] Open
Abstract
Many plant viruses express their proteins through a polyprotein strategy, requiring the acquisition of protease domains to regulate the release of functional mature proteins and/or intermediate polyproteins. Positive-strand RNA viruses constitute the vast majority of plant viruses and they are diverse in their genomic organization and protein expression strategies. Until recently, proteases encoded by positive-strand RNA viruses were described as belonging to two categories: (1) chymotrypsin-like cysteine and serine proteases and (2) papain-like cysteine protease. However, the functional characterization of plant virus cysteine and serine proteases has highlighted their diversity in terms of biological activities, cleavage site specificities, regulatory mechanisms, and three-dimensional structures. The recent discovery of a plant picorna-like virus glutamic protease with possible structural similarities with fungal and bacterial glutamic proteases also revealed new unexpected sources of protease domains. We discuss the variety of plant positive-strand RNA virus protease domains. We also highlight possible evolution scenarios of these viral proteases, including evidence for the exchange of protease domains amongst unrelated viruses.
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Affiliation(s)
- Krin S Mann
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC V0H 1Z0, Canada.
| | - Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC V0H 1Z0, Canada.
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5
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Guo J, Han J, Lin J, Finer J, Dorrance A, Qu F. Functionally interchangeable cis-acting RNA elements in both genome segments of a picorna-like plant virus. Sci Rep 2017; 7:1017. [PMID: 28432346 PMCID: PMC5430698 DOI: 10.1038/s41598-017-01243-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/23/2017] [Indexed: 11/09/2022] Open
Abstract
Cis-acting RNA structures in the genomes of RNA viruses play critical roles in viral infection, yet their importance in the bipartite genomes of the picorna-like, plant-infecting comoviruses has not been carefully investigated. We previously characterized SLC, a stem-loop structure in the 5' untranslated region (UTR) of the bean pod mottle comovirus (BPMV) RNA2, and found it to be essential for RNA2 accumulation in infected cells. Here we report the identification of SL1, a similar cis-acting element in the other BPMV genome segment - RNA1. SL1 encompasses a portion of RNA1 5' UTR but extends into the coding sequence for nine nucleotides, thus was missed in the previous study. While the stems of SL1 and SLC share little sequence similarity, their end loops are of the same size and identical for 11 of 15 nucleotides. Importantly, SL1 and SLC are functionally interchangeable, and separate exchanges of the stem and loop portions were likewise well tolerated. By contrast, the conserved loop sequence tolerated minimal perturbations. Finally, stem-loop structures with similar configurations were identified in two other comoviruses. Therefore, SL1 and SLC are likely essential comoviral RNA structures that play a conserved function in viral infection cycles.
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Affiliation(s)
- Jiangbo Guo
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA.,School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou, China
| | - Junping Han
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA
| | - Junyan Lin
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA.,Joint Genome Institute, Department of Energy, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - John Finer
- Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA
| | - Anne Dorrance
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA
| | - Feng Qu
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA.
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6
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Fuchs M, Schmitt-Keichinger C, Sanfaçon H. A Renaissance in Nepovirus Research Provides New Insights Into Their Molecular Interface With Hosts and Vectors. Adv Virus Res 2016; 97:61-105. [PMID: 28057260 DOI: 10.1016/bs.aivir.2016.08.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Nepoviruses supplied seminal landmarks to the historical trail of plant virology. Among the first agriculturally relevant viruses recognized in the late 1920s and among the first plant viruses officially classified in the early 1970s, nepoviruses also comprise the first species for which a soil-borne ectoparasitic nematode vector was identified. Early research on nepoviruses shed light on the genome structure and expression, biological properties of the two genomic RNAs, and mode of transmission. In recent years, research on nepoviruses enjoyed an extraordinary renaissance. This resurgence provided new insights into the molecular interface between viruses and their plant hosts, and between viruses and dagger nematode vectors to advance our understanding of some of the major steps of the infectious cycle. Here we examine these recent findings, highlight ongoing work, and offer some perspectives for future research.
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Affiliation(s)
- M Fuchs
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, United States.
| | - C Schmitt-Keichinger
- Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, Strasbourg, France
| | - H Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada
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7
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Hiraguri A, Netsu O, Shimizu T, Uehara-Ichiki T, Omura T, Sasaki N, Nyunoya H, Sasaya T. The nonstructural protein pC6 of rice grassy stunt virus trans-complements the cell-to-cell spread of a movement-defective tomato mosaic virus. Arch Virol 2011; 156:911-6. [PMID: 21327784 DOI: 10.1007/s00705-011-0939-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/24/2011] [Indexed: 11/25/2022]
Abstract
The nonstructural protein pC6 encoded by rice grassy stunt virus is thought to correspond functionally to the nonstructural protein pC4 of rice stripe virus, which can support viral cell-to-cell movement. In a trans-complementation experiment with a movement-defective tomato mosaic virus, pC6 and pC4 facilitated intercellular transport of the virus. Transient expression of pC6, fused with green fluorescent protein, in epidermal cells was predominantly observed close to the cell wall as well as in a few punctate structures, presumably associated with plasmodesmata. These results suggest that pC6 has a role similar to that of pC4 in viral cell-to-cell movement.
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8
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Genovés A, Navarro JA, Pallás V. The Intra- and intercellular movement of Melon necrotic spot virus (MNSV) depends on an active secretory pathway. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:263-72. [PMID: 20121448 DOI: 10.1094/mpmi-23-3-0263] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Plant viruses hijack endogenous host transport machinery to aid their intracellular spread. Here, we study the localization of the p7B, the membrane-associated viral movement protein (MP) of the Melon necrotic spot virus (MNSV), and also the potential involvement of the secretory pathway on the p7B targeting and intra- and intercellular virus movements. p7B fused to fluorescent proteins was located throughout the endoplasmic reticulum (ER) at motile Golgi apparatus (GA) stacks that actively tracked the actin microfilaments, and at the plasmodesmata (PD). Hence, the secretory pathway inhibitor, Brefeldin A (BFA), and the overexpression of the GTPase-defective mutant of Sar1p, Sar1[H74L], fully retained the p7B within the ER, revealing that the protein is delivered to PD in a BFA-sensitive and COPII-dependent manner. Disruption of the actin cytoskeleton with latrunculin B led to the accumulation of p7B in the ER, which strongly suggests that p7B is also targeted to the cell periphery in an actin-dependent manner. Remarkably, the local spread of the viral infection was significantly restricted either with the presence of BFA or under the overexpression of Sar1[H74L], thus revealing the involvement of an active secretory pathway in the intracellular movement of MNSV. Overall, these findings support a novel route for the intracellular transport of a plant virus led by the GA.
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Affiliation(s)
- Ainhoa Genovés
- Instituto Biologia Molecular y Celular de Plantas, Universidad Politécnica, Universidad Politécnica de Valencia-CSIC, Avenida de los Naranjos s/n, 46022 Valencia, Spain
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9
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Sanfaçon H, Wellink J, Le Gall O, Karasev A, van der Vlugt R, Wetzel T. Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus. Arch Virol 2009; 154:899-907. [DOI: 10.1007/s00705-009-0367-z] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 03/16/2009] [Indexed: 11/24/2022]
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10
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Probing interactions between plant virus movement proteins and nucleic acids. Methods Mol Biol 2008. [PMID: 18370264 DOI: 10.1007/978-1-59745-102-4_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Most plant viruses move between plant cells with the help of their movement proteins (MPs). MPs are multifunctional proteins, and one of their functions is almost invariably binding to nucleic acids. Presumably, the MP-nucleic acid interaction is directly involved in formation of nucleoprotein complexes that function as intermediates in the cell-to-cell transport of many plant viruses. Thus, when studying a viral MP, it is important to determine whether or not it binds nucleic acids, and to characterize the hallmark parameters of such binding, i.e., preference for single- or double-stranded nucleic acids and binding cooperativity and sequence specificity. Here, we present two major experimental approaches, native gel mobility shift assay and ultra violet (UV) light cross-linking, for detection and characterization of MP binding to DNA and RNA molecules. We also describe protocols for purification of recombinant viral MPs over-expressed in bacteria and production of different DNA and RNA probes for these binding assays.
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11
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Abstract
Plant viruses spread from the initially infected cells to the rest of the plant in several distinct stages. First, the virus (in the form of virions or nucleic acid protein complexes) moves intracellularly from the sites of replication to plasmodesmata (PD, plant-specific intercellular membranous channels), the virus then transverses the PD to spread intercellularly (cell-to-cell movement). Long-distance movement of virus occurs through phloem sieve tubes. The processes of plant virus movement are controlled by specific viral movement proteins (MPs). No extensive sequence similarity has been found in MPs belonging to different plant virus taxonomic groups. Moreover, different MPs were shown to use different pathways and mechanisms for virus transport. Some viral transport systems require a single MP while others require additional virus-encoded proteins to transport viral genomes. In this review, we focus on the functions and properties of different classes of MPs encoded by RNA containing plant viruses.
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12
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Komatsu K, Hashimoto M, Maejima K, Ozeki J, Kagiwada S, Takahashi S, Yamaji Y, Namba S. Genome sequence of a Japanese isolate of Radish mosaic virus: the first complete nucleotide sequence of a crucifer-infecting comovirus. Arch Virol 2007; 152:1501-6. [PMID: 17533551 DOI: 10.1007/s00705-007-0993-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Accepted: 04/26/2007] [Indexed: 10/23/2022]
Abstract
The complete nucleotide sequences of RNA1 and RNA2 of a Japanese isolate of Radish mosaic virus (RaMV-J), a crucifer-infecting comovirus, were determined. RNA1 is 6064 nucleotides long and encodes a 210-kDa polyprotein containing conserved motifs that are required for replication. RNA2 is 4020 nucleotides long and encodes a 123-kDa polyprotein containing the putative movement protein and two coat proteins. Comparisons of the encoded proteins confirmed that RaMV-J and a Czech RaMV isolate are isolates of the same species in the genus Comovirus. A phylogenetic analysis of RaMV-J and other comoviruses revealed that legume-infecting comoviruses constitute a single branch to which RaMV is distantly related.
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Affiliation(s)
- K Komatsu
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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13
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Zhang G, Sanfaçon H. Characterization of membrane association domains within the Tomato ringspot nepovirus X2 protein, an endoplasmic reticulum-targeted polytopic membrane protein. J Virol 2006; 80:10847-57. [PMID: 16928745 PMCID: PMC1641798 DOI: 10.1128/jvi.00789-06] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 08/09/2006] [Indexed: 12/19/2022] Open
Abstract
Replication of nepoviruses (family Comoviridae) occurs in association with endoplasmic reticulum (ER)-derived membranes. We have previously shown that the putative nucleoside triphosphate-binding protein (NTB) of Tomato ringspot nepovirus is an integral membrane protein with two ER-targeting sequences and have suggested that it anchors the viral replication complex (VRC) to the membranes. A second highly hydrophobic protein domain (X2) is located immediately upstream of the NTB domain in the RNA1-encoded polyprotein. X2 shares conserved sequence motifs with the comovirus 32-kDa protein, an ER-targeted protein implicated in VRC assembly. In this study, we examined the ability of X2 to associate with intracellular membranes. The X2 protein was fused to the green fluorescent protein and expressed in Nicotiana benthamiana by agroinfiltration. Confocal microscopy and membrane flotation experiments suggested that X2 is targeted to ER membranes. Mutagenesis studies revealed that X2 contains multiple ER-targeting domains, including two C-terminal transmembrane helices and a less-well-defined domain further upstream. To investigate the topology of the protein in the membrane, in vitro glycosylation assays were conducted using X2 derivatives that contained N-glycosylation sites introduced at the N or C termini of the protein. The results led us to propose a topological model for X2 in which the protein traverses the membrane three times, with the N terminus oriented in the lumen and the C terminus exposed to the cytoplasmic face. Taken together, our results indicate that X2 is an ER-targeted polytopic membrane protein and raises the possibility that it acts as a second membrane anchor for the VRC.
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Affiliation(s)
- Guangzhi Zhang
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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14
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Gómez de Cedrón M, Osaba L, López L, García JA. Genetic analysis of the function of the plum pox virus CI RNA helicase in virus movement. Virus Res 2006; 116:136-45. [PMID: 16256236 DOI: 10.1016/j.virusres.2005.09.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 09/21/2005] [Accepted: 09/21/2005] [Indexed: 11/21/2022]
Abstract
The CI protein forms the cylindrical inclusions typical of potyviral infections and is involved in genome replication and virus movement. In this work, we have analyzed the effect of a series of point mutations at the N-terminal region of the CI protein of Plum pox virus (PPV) on the enzymatic activities and the self-interaction ability of the protein, and on virus replication and movement. DD3,4AA mutation, which had no apparent effects on ATPase and RNA helicase activities in vitro, and on virus replication in protoplasts, drastically impaired cell-to-cell spread of the virus. The effect of KK101,102AA mutation was host-specific. While no signals of virus infection were detected in Chenopodium foetidum inoculated with PPV KK101,102AA, the mutation caused a moderate effect on short distance movement in Nicotiana benthamiana and N. clevelandii, which resulted in a more drastic disturbance of systemic spread. None of the mutations analyzed abolished PPV CI self-interaction in the yeast Two-Hybrid system, but they caused a notable reduction in the binding strength, which appears to positively correlate with their effect on virus movement, suggesting that CI-CI interactions required for RNA replication and virus movement could be rather different.
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Affiliation(s)
- Marta Gómez de Cedrón
- Centro Nacional de Biotecnología-CSIC, Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain
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15
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Gu H, Ghabrial SA. The Bean pod mottle virus proteinase cofactor and putative helicase are symptom severity determinants. Virology 2005; 333:271-83. [PMID: 15721361 DOI: 10.1016/j.virol.2005.01.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Revised: 12/22/2004] [Accepted: 01/14/2005] [Indexed: 11/23/2022]
Abstract
Full-length infectious cDNA clones were constructed from the genomic RNAs of three distinct strains (K-G7, K-Ha1 and K-Ho1) of the comovirus Bean pod mottle virus (BPMV). Whereas K-G7, a subgroup I strain, and K-Ha1, a subgroup II strain produce mild mottling, the reassortant strain K-Ho1 (RNA1(I) + RNA2(II)) induces necrotic primary lesions on inoculated leaves of soybean and severe systemic leaf mottling and blistering. Pseudorecombinants of all possible combinations of transcripts were generated and tested for symptom production. Only soybean plants inoculated with combinations having RNA1 derived from the severe strain K-Ho1, regardless of the origin of RNA2, induced severe symptoms, indicating that symptom severity maps to RNA1. Experiments with chimeric RNA1 constructs indicated that the coding regions of the protease co-factor (Co-pro) and the C-terminal half of the putative helicase (Hel) are determinants of symptom severity. Symptom severity correlated well with higher accumulation of viral RNA, but neither the Co-pro nor Hel protein could be demonstrated as a suppressor of RNA silencing.
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Affiliation(s)
- Hongcang Gu
- Department of Plant Pathology, 201F Plant Science Building, 1405 Veterans Drive, University of Kentucky, Lexington, KY 40546-0312, USA
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16
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Pouwels J, van der Velden T, Willemse J, Borst JW, van Lent J, Bisseling T, Wellink J. Studies on the origin and structure of tubules made by the movement protein of Cowpea mosaic virus. J Gen Virol 2004; 85:3787-3796. [PMID: 15557252 DOI: 10.1099/vir.0.80497-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cowpea mosaic virus (CPMV) moves from cell to cell by transporting virus particles via tubules formed through plasmodesmata by the movement protein (MP). On the surface of protoplasts, a fusion between the MP and the green fluorescent protein forms similar tubules and peripheral punctate spots. Here it was shown by time-lapse microscopy that tubules can grow out from a subset of these peripheral punctate spots, which are dynamic structures that seem anchored to the plasma membrane. Fluorescence resonance energy transfer experiments showed that MP subunits interacted within the tubule, where they were virtually immobile, confirming that tubules consist of a highly organized MP multimer. Fluorescence recovery after photobleaching experiments with protoplasts, transiently expressing fluorescent plasma membrane-associated proteins of different sizes, indicated that tubules made by CPMV MP do not interact directly with the surrounding plasma membrane. These experiments indicated an indirect interaction between the tubule and the surrounding plasma membrane, possibly via a host plasma membrane protein.
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Affiliation(s)
- J Pouwels
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - T van der Velden
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - J Willemse
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - J W Borst
- MicroSpectroscopy Centre, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - J van Lent
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - T Bisseling
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - J Wellink
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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17
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Peremyslov VV, Pan YW, Dolja VV. Movement protein of a closterovirus is a type III integral transmembrane protein localized to the endoplasmic reticulum. J Virol 2004; 78:3704-9. [PMID: 15016890 PMCID: PMC371079 DOI: 10.1128/jvi.78.7.3704-3709.2004] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Accepted: 11/25/2003] [Indexed: 11/20/2022] Open
Abstract
Cell-to-cell movement of beet yellows closterovirus requires four structural proteins and a 6-kDa protein (p6) that is a conventional, nonstructural movement protein. Here we demonstrate that either virus infection or p6 overexpression results in association of p6 with the rough endoplasmic reticulum. The p6 protein possesses a single-span, transmembrane, N-terminal domain and a hydrophilic, C-terminal domain that is localized on the cytoplasmic face of the endoplasmic reticulum. In the infected cells, p6 forms a disulfide bridge via a cysteine residue located near the protein's N terminus. Mutagenic analyses indicated that each of the p6 domains, as well as protein dimerization, is essential for p6 function in virus movement.
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Affiliation(s)
- Valera V Peremyslov
- Department of Botany and Plant Pathology and Center for Gene Research and Biotechnology, Oregon State University, Corvallis, Oregon 97331, USA
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18
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Pouwels J, Kornet N, van Bers N, Guighelaar T, van Lent J, Bisseling T, Wellink J. Identification of distinct steps during tubule formation by the movement protein of Cowpea mosaic virus. J Gen Virol 2003; 84:3485-3494. [PMID: 14645930 DOI: 10.1099/vir.0.19553-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The movement protein (MP) of Cowpea mosaic virus (CPMV) forms tubules through plasmodesmata in infected plants thus enabling virus particles to move from cell to cell. Localization studies of mutant MPs fused to GFP in protoplasts and plants identified several functional domains within the MP that are involved in distinct steps during tubule formation. Coinoculation experiments and the observation that one of the C-terminal deletion mutants accumulated uniformly in the plasma membrane suggest that dimeric or multimeric MP is first targeted to the plasma membrane. At the plasma membrane the MP quickly accumulates in peripheral punctuate spots, from which tubule formation is initiated. One of the mutant MPs formed tubules containing virus particles on protoplasts, but could not support cell-to-cell movement in plants. The observations that this mutant MP accumulated to a higher level in the cell than wt MP and did not accumulate in the cell wall opposite infected cells suggest that breakdown or disassembly of tubules in neighbouring, uninfected cells is required for cell-to-cell movement.
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Affiliation(s)
- Jeroen Pouwels
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Noortje Kornet
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Nikkie van Bers
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Teun Guighelaar
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Jan van Lent
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - Ton Bisseling
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Joan Wellink
- Laboratory of Molecular Biology, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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19
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Carvalho CM, Wellink J, Ribeiro SG, Goldbach RW, van Lent JWM. The C-terminal region of the movement protein of Cowpea mosaic virus is involved in binding to the large but not to the small coat protein. J Gen Virol 2003; 84:2271-2277. [PMID: 12867661 DOI: 10.1099/vir.0.19101-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cowpea mosaic virus (CPMV) moves from cell to cell as virus particles which are translocated through a plasmodesmata-penetrating transport tubule made up of viral movement protein (MP) copies. To gain further insight into the roles of the viral MP and capsid proteins (CP) in virus movement, full-length and truncated forms of the MP were expressed in insect cells using the baculovirus expression system. Using ELISA and blot overlay assays, affinity purified MP was shown to bind specifically to intact CPMV virions and to the large CP, but not to the small CP. This binding was not observed with a C-terminal deletion mutant of the MP, although this mutant retained the capacity to bind to other MP molecules and to form tubules. These results suggest that the C-terminal 48 amino acids constitute the virion-binding domain of the MP.
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Affiliation(s)
- C M Carvalho
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - J Wellink
- Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - S G Ribeiro
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - R W Goldbach
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - J W M van Lent
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
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