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Kamal H, Zafar MM, Razzaq A, Parvaiz A, Ercisli S, Qiao F, Jiang X. Functional role of geminivirus encoded proteins in the host: Past and present. Biotechnol J 2024; 19:e2300736. [PMID: 38900041 DOI: 10.1002/biot.202300736] [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: 12/26/2023] [Revised: 03/19/2024] [Accepted: 04/16/2024] [Indexed: 06/21/2024]
Abstract
During plant-pathogen interaction, plant exhibits a strong defense system utilizing diverse groups of proteins to suppress the infection and subsequent establishment of the pathogen. However, in response, pathogens trigger an anti-silencing mechanism to overcome the host defense machinery. Among plant viruses, geminiviruses are the second largest virus family with a worldwide distribution and continue to be production constraints to food, feed, and fiber crops. These viruses are spread by a diverse group of insects, predominantly by whiteflies, and are characterized by a single-stranded DNA (ssDNA) genome coding for four to eight proteins that facilitate viral infection. The most effective means to managing these viruses is through an integrated disease management strategy that includes virus-resistant cultivars, vector management, and cultural practices. Dynamic changes in this virus family enable the species to manipulate their genome organization to respond to external changes in the environment. Therefore, the evolutionary nature of geminiviruses leads to new and novel approaches for developing virus-resistant cultivars and it is essential to study molecular ecology and evolution of geminiviruses. This review summarizes the multifunctionality of each geminivirus-encoded protein. These protein-based interactions trigger the abrupt changes in the host methyl cycle and signaling pathways that turn over protein normal production and impair the plant antiviral defense system. Studying these geminivirus interactions localized at cytoplasm-nucleus could reveal a more clear picture of host-pathogen relation. Data collected from this antagonistic relationship among geminivirus, vector, and its host, will provide extensive knowledge on their virulence mode and diversity with climate change.
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Affiliation(s)
- Hira Kamal
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA
| | - Muhammad Mubashar Zafar
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
| | - Abdul Razzaq
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Aqsa Parvaiz
- Department of Biochemistry and Biotechnology, The Women University Multan, Multan, Pakistan
| | - Sezai Ercisli
- Department of Horticulture, Faculty of Agriculture, Ataturk University, Erzurum, Turkey
| | - Fei Qiao
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
| | - Xuefei Jiang
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
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Wei Y, Xie H, Xu L, Cheng X, Zhu B, Zeng H, Shi H. Coat protein of cassava common mosaic virus targets RAV1 and RAV2 transcription factors to subvert immunity in cassava. PLANT PHYSIOLOGY 2024; 194:1218-1232. [PMID: 37874769 DOI: 10.1093/plphys/kiad569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/26/2023] [Accepted: 10/03/2023] [Indexed: 10/26/2023]
Abstract
Cassava common mosaic virus (CsCMV, genus Potexvirus) is a prevalent virus associated with cassava mosaic disease, so it is essential to elucidate the underlying molecular mechanisms of the coevolutionary arms race between viral pathogenesis and the cassava (Manihot esculenta Crantz) defense response. However, the molecular mechanism underlying CsCMV infection is largely unclear. Here, we revealed that coat protein (CP) acts as a major pathogenicity determinant of CsCMV via a mutant infectious clone. Moreover, we identified the target proteins of CP-related to abscisic acid insensitive3 (ABI3)/viviparous1 (VP1) (MeRAV1) and MeRAV2 transcription factors, which positively regulated disease resistance against CsCMV via transcriptional activation of melatonin biosynthetic genes (tryptophan decarboxylase 2 (MeTDC2), tryptamine 5-hydroxylase (MeT5H), N-aceylserotonin O-methyltransferase 1 (MeASMT1)) and MeCatalase6 (MeCAT6) and MeCAT7. Notably, the interaction between CP, MeRAV1, and MeRAV2 interfered with the protein phosphorylation of MeRAV1 and MeRAV2 individually at Ser45 and Ser44 by the protein kinase, thereby weakening the transcriptional activation activity of MeRAV1 and MeRAV2 on melatonin biosynthetic genes, MeCAT6 and MeCAT7 dependent on the protein phosphorylation of MeRAV1 and MeRAV2. Taken together, the identification of the CP-MeRAV1 and CP-MeRAV2 interaction module not only illustrates a molecular mechanism by which CsCMV orchestrates the host defense system to benefit its infection and development but also provides a gene network with potential value for the genetic improvement of cassava disease resistance.
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Affiliation(s)
- Yunxie Wei
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Haoqi Xie
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Lulu Xu
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Xiao Cheng
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Binbin Zhu
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Hongqiu Zeng
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
| | - Haitao Shi
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biotechnology of Salt Tolerant Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Sanya, Hainan Province 572025, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan Province 572025, China
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3
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Fetters AM, Ashman TL. The pollen virome: A review of pollen-associated viruses and consequences for plants and their interactions with pollinators. AMERICAN JOURNAL OF BOTANY 2023:e16144. [PMID: 36924316 DOI: 10.1002/ajb2.16144] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 06/18/2023]
Abstract
The movement of pollen grains from anthers to stigmas, often by insect pollinator vectors, is essential for plant reproduction. However, pollen is also a unique vehicle for viral spread. Pollen-associated plant viruses reside on the outside or inside of pollen grains, infect susceptible individuals through vertical or horizontal infection pathways, and can decrease plant fitness. These viruses are transferred with pollen between plants by pollinator vectors as they forage for floral resources; thus, pollen-associated viral spread is mediated by floral and pollen grain phenotypes and pollinator traits, much like pollination. Most of what is currently known about pollen-associated viruses was discovered through infection and transmission experiments in controlled settings, usually involving one virus and one plant species of agricultural or horticultural interest. In this review, we first provide an updated, comprehensive list of the recognized pollen-associated viruses. Then, we summarize virus, plant, pollinator vector, and landscape traits that can affect pollen-associated virus transmission, infection, and distribution. Next, we highlight the consequences of plant-pollinator-virus interactions that emerge in complex communities of co-flowering plants and pollinator vectors, such as pollen-associated virus spread between plant species and viral jumps from plant to pollinator hosts. We conclude by emphasizing the need for collaborative research that bridges pollen biology, virology, and pollination biology.
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Affiliation(s)
- Andrea M Fetters
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA, 15260, USA
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 318 W. 12th Avenue, Columbus, OH, 43210, USA
| | - Tia-Lynn Ashman
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA, 15260, USA
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Zhang C, Wang D, Li W, Zhang B, Abdel-Fattah Ouf GM, Su X, Li J. The coat protein p25 from maize chlorotic mottle virus involved in symptom development and systemic movement of tobacco mosaic virus hybrids. Front Microbiol 2022; 13:951479. [PMID: 35992724 PMCID: PMC9389212 DOI: 10.3389/fmicb.2022.951479] [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: 05/24/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Viral coat protein (CP) has numerous critical functions in plant infection, but little is known about p25, the CP of maize chlorotic mottle virus (MCMV; Machlomovirus), which causes severe yield losses in maize worldwide. Here, we investigated the roles of p25 in pathogenicity and systemic movement, as well as potential interactions with host plants, using a hybrid tobacco mosaic virus (TMV)-based expression system. Highly conserved protein p25 is predicted to contain a membrane-anchored nuclear localization signal (NLS) sequence and an extracellular sequence. In transgenic Nicotiana benthamiana plants containing the movement protein (MP) of TMV (TMV-MP), p25 induced severe symptoms, including dwarf and foliar necrosis, and was detected in inoculated and non-inoculated leaves. After the deletion of NLS from nuclear-located p25, the protein was found throughout the host cell, and plant stunting and starch granule deformity were reduced. Systemic movement and pathogenicity were significantly impaired when the C-terminal regions of p25 were absent. Using virus-induced gene silencing (VIGS), the transcript level of heat shock protein HSP90 was distinctly lower in host plants in association with the absence of leaf necrosis induced by TMV-p25. Our results revealed crucial roles for MCMV p25 in viral pathogenicity, long-distance movement, and interactions with N. benthamiana.
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Affiliation(s)
- Chao Zhang
- State Key Laboratory of North China Crop Improvement and Regulation, College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Di Wang
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China
| | - Weimin Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baolong Zhang
- Excellence and Innovation Center, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Gamal M. Abdel-Fattah Ouf
- Department of Botany and Applied Microbiology, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun Li
- State Key Laboratory of North China Crop Improvement and Regulation, College of Life Sciences, Hebei Agricultural University, Baoding, China
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Wu Z, Yang W, Hou S, Xie D, Yang J, Liu L, Yang S. In vivo antiviral activity and disassembly mechanism of novel 1-phenyl-5-amine-4-pyrazole thioether derivatives against Tobacco mosaic virus. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 173:104771. [PMID: 33771249 DOI: 10.1016/j.pestbp.2021.104771] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/31/2020] [Accepted: 01/03/2021] [Indexed: 06/12/2023]
Abstract
A series of novel 1-phenyl-5-amine-4-pyrazole thioether derivatives containing a 1,3,4-oxadiazole moiety was designed and synthesised. In vivo antiviral bioassay results showed that most of the target compounds exhibited excellent inactivation activity against Tobacco mosaic virus (TMV). The EC50 values of the inactivation activities for T2, T7, T9, T24, T25 and T27 were 15.7, 15.7, 15.5, 11.9, 12.5 and 16.5 μg/mL, respectively, which were remarkably superior over that of the commercialised antiviral agent ningnanmycin (40.3 μg/mL). Morphological study using AFM and TEM of TMV treated with T24 showed that T24 could significantly shorten the polymerization length of TMV particles and formed a distinct break on the rod-shaped TMV. Investigations for virus infection efficiency on tobacco leaves demonstrated that infectivity of virion had been reduced obviously upon T24 treatment. Subsequently, a strong interaction between T24 and TMV-CP (Kd = 3.8 μM, score 6.11) was observed through MST experiments. Molecular docking study further revealed that target compounds interact with amino acid residue Glu50 in TMV CP, causing disassembly of virion, shorting the length of the virion and reducing the infectivity of virion, and resulting in high inactivating activity of target compounds. This study provides a new insight for discovery of antiviral compounds through a new action mechanism with a new binding site.
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Affiliation(s)
- Zhibing Wu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China.
| | - Wenqing Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China
| | - Shuaitao Hou
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China
| | - Dewen Xie
- College of Pharmacy, Guizhou University, Guiyang 550025, PR China
| | - Jingxin Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China
| | - Liwei Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China
| | - Song Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, PR China.
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6
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Yang G, Zheng H, Shao W, Liu L, Wu Z. Study of the in vivo antiviral activity against TMV treated with novel 1-(t-butyl)-5-amino-4-pyrazole derivatives containing a 1,3,4-oxadiazole sulfide moiety. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 171:104740. [PMID: 33357562 DOI: 10.1016/j.pestbp.2020.104740] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/02/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
A series of new 1-tert-butyl-5-amino-4-pyrazole bioxadiazole sulfide derivatives containing a 1,3,4-oxadiazole moiety were designed and synthesized. The bioactivity results showed that some title compounds exhibited excellent protective activity against TMV and certain insecticidal activity. Among the tested compounds, the EC50 values of 5d, 5j, 5k and 5l were 165.8, 163.2, 159.7 and 193.1 mg/L, respectively, which are better than the EC50 value of ningnanmycin (271.3 mg/L). The chlorophyll contents and the defense enzyme activities of the tobacco leaves after treatment with 5j were significantly increased, which indicated that this series of title compounds may induce the systemic acquired resistance of host to defend against diseases. Further in vivo protective activity research on 5j using TMV with a GFP gene tag found that it can effectively inhibit the spread of TMV in inoculated tobacco. A morphological study with TEM revealed that title compound 5h can cause a distinct break of the rod-shaped TMV. Moreover, the insecticidal activity revealed that the fatality rates of 5a, 5b and 5m against aphidoidea were 85%, 83% and 87%, respectively, which indicated that the title compounds can effectively block the common carrier of plant viruses, thereby effectively reducing the TMV infection risk of tobacco. This series of synergistic effects provide key information for the research and development of antiviral agents.
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Affiliation(s)
- Guangqian Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R & D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Huanlin Zheng
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R & D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Wubin Shao
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R & D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Liwei Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R & D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Zhibing Wu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R & D of Fine Chemicals of Guizhou University, Guiyang 550025, China.
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7
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Zhou Y, Ghidey MR, Pruett G, Kearney CM. The use of functionally deficient viral vectors as visualization tools to reveal complementation patterns between plant viruses and the silencing suppressor p19. J Virol Methods 2020; 286:113980. [PMID: 33010375 DOI: 10.1016/j.jviromet.2020.113980] [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: 11/02/2019] [Revised: 08/10/2020] [Accepted: 09/24/2020] [Indexed: 10/23/2022]
Abstract
Plant virus transport complementation is classically observed as a helper virus allowing another virus to regain cell-to-cell or systemic movement through a restrictive host plant (Malyshenko et al., 1989). The complementation effect is usually studied by observing virus infection after co-infection or super-inoculation of the helper virus. We herein demonstrate the utility of functionally deficient viral vectors as tools to determine the contribution of individual viral genes to plant viral transport complementation. Two functionally deficient viral vectors were engineered that derive from foxtail mosaic potexvirus and sunn-hemp mosaic tobamovirus, namely FECT (FoMV Eliminate CP and TGB, (Liu and Kearney, 2010)) and SHEC (SHMV Eliminate CP gene, (Liu and Kearney, 2010)), respectively. FECT had all the ORFs removed except for the replicase and thus is defective for both long-distance and cell-to-cell movement. SHEC lacked only the coat protein ORF and retained the movement protein (MP) and is functional for cell-to-cell movement. When FECT and SHEC vectors were inoculated with the silencing suppressor p19 in different zones of the same leaf, FECT was enabled to express its reporter gene beyond the original inoculation zone. When FECT, SHEC, and p19 were individually inoculated in separate zones, both FECT and SHEC reporter gene expression was observed within the p19 zone, distant from the original virus inoculation points. These observations indicate that SHEC movement protein could create a trafficking network to allow viral RNAs of FECT and SHEC and p19/p19 transcript to move from cell to cell. This system provides a tool to visually monitor the movement of viruses and silencing suppressors as well as to identify the effects of individual viral components on virus movement.
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Affiliation(s)
- Yiyang Zhou
- Institute of Biomedical Studies, Baylor University, Waco, TX, USA
| | - Meron R Ghidey
- Institute of Biomedical Studies, Baylor University, Waco, TX, USA
| | - Grace Pruett
- Department of Biology, Baylor University, Waco, TX, USA
| | - Christopher M Kearney
- Institute of Biomedical Studies, Baylor University, Waco, TX, USA; Department of Biology, Baylor University, Waco, TX, USA.
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Yang H, Zu G, Liu Y, Xie D, Gan X, Song B. Tomato Chlorosis Virus Minor Coat Protein as a Novel Target To Screen Antiviral Drugs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3425-3433. [PMID: 32091891 DOI: 10.1021/acs.jafc.9b08215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Minor coat protein (mCP), an important component of tomato chlorosis virus (ToCV), plays a significant role in the process of virus assembly and movement and is directly related to the virus-insect transmission. Therefore, ToCV mCP could be considered as a potent target for anti-ToCV drugs. In this study, ToCV mCP was first cloned, expressed, purified, and a novel target to screen the antiviral agents. The results showed that some antiviral compounds bound to ToCV mCP with strongly affinities in vitro, including quinazoline derivatives 4a and 4b, Ningnanmycin, and Ribavirin. Subsequently, three-dimensional-quantitative structure-activity relationship (3D-QSAR) analysis was performed based on the binding affinities, and the model indicated that 4a and 4b had indeed stronger binding effects on ToCV mCP than other quinazoline derivatives. Finally, the anti-ToCV activities of compounds 4a and 4b were evaluated by quantitative real-time polymerase chain reaction in vivo. Compounds 4a and 4b inhibited infection of ToCV in the host and as well as reduced the level of ToCV mCP gene expression. Thus, ToCV mCP can be used as a novel drug target for screening anti-ToCV agents, and the ligand-based 3D-QSAR analysis of quinazoline derivatives provided new insights into the design and optimization of novel anti-ToCV drug molecules based on ToCV mCP.
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Affiliation(s)
- Huanyu Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Guangcheng Zu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Yuewen Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Dandan Xie
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xiuhai Gan
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
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Lezzhov AA, Atabekova AK, Tolstyko EA, Lazareva EA, Solovyev AG. RNA phloem transport mediated by pre-miRNA and viral tRNA-like structures. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 284:99-107. [PMID: 31084885 DOI: 10.1016/j.plantsci.2019.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 06/09/2023]
Abstract
Phloem-mobile mRNAs are assumed to contain sequence elements directing RNA to the phloem translocation pathway. One of such elements is represented by tRNA sequences embedded in untranslated regions of many mRNAs, including those proved to be mobile. Genomic RNAs of a number of plant viruses possess a 3'-terminal tRNA-like structures (TLSs) only distantly related to genuine tRNAs, but nevertheless aminoacylated and capable of interaction with some tRNA-binding proteins. Here, we elaborated an experimental system for analysis of RNA phloem transport based on an engineered RNA of Potato virus X capable of replication, but not encapsidation and movement in plants. The TLSs of Brome mosaic virus, Tobacco mosaic virus and Turnip yellow mosaic virus were demonstrated to enable the phloem transport of foreign RNA. A miRNA precursor, pre-miR390b, was also found to render RNA competent for the phloem transport. In line with this, sequences of miRNA precursors were identified in a Cucurbita maxima phloem transcriptome, supporting the hypothesis that, at least in some cases, miRNA phloem signaling can involve miRNA precursors. Collectively, the data presented here suggest that RNA molecules can be directed into the phloem translocation pathway by structured RNA elements such as those of viral TLSs and miRNA precursors.
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Affiliation(s)
- Alexander A Lezzhov
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow 119991, Russia
| | - Anastasia K Atabekova
- Department of Virology, Biological Faculty, Moscow State University, Moscow 119234, Russia
| | - Eugeny A Tolstyko
- Department of Virology, Biological Faculty, Moscow State University, Moscow 119234, Russia
| | - Ekaterina A Lazareva
- Department of Virology, Biological Faculty, Moscow State University, Moscow 119234, Russia
| | - Andrey G Solovyev
- Department of Virology, Biological Faculty, Moscow State University, Moscow 119234, Russia; Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119992, Russia; Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Moscow 119991, Russia.
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Röder J, Dickmeis C, Commandeur U. Small, Smaller, Nano: New Applications for Potato Virus X in Nanotechnology. FRONTIERS IN PLANT SCIENCE 2019; 10:158. [PMID: 30838013 PMCID: PMC6390637 DOI: 10.3389/fpls.2019.00158] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 01/29/2019] [Indexed: 05/08/2023]
Abstract
Nanotechnology is an expanding interdisciplinary field concerning the development and application of nanostructured materials derived from inorganic compounds or organic polymers and peptides. Among these latter materials, proteinaceous plant virus nanoparticles have emerged as a key platform for the introduction of tailored functionalities by genetic engineering and conjugation chemistry. Tobacco mosaic virus and Cowpea mosaic virus have already been developed for bioimaging, vaccination and electronics applications, but the flexible and filamentous Potato virus X (PVX) has received comparatively little attention. The filamentous structure of PVX particles allows them to carry large payloads, which are advantageous for applications such as biomedical imaging in which multi-functional scaffolds with a high aspect ratio are required. In this context, PVX achieves superior tumor homing and retention properties compared to spherical nanoparticles. Because PVX is a protein-based nanoparticle, its unique functional properties are combined with enhanced biocompatibility, making it much more suitable for biomedical applications than synthetic nanomaterials. Moreover, PVX nanoparticles have very low toxicity in vivo, and superior pharmacokinetic profiles. This review focuses on the production of PVX nanoparticles engineered using chemical and/or biological techniques, and describes current and future opportunities and challenges for the application of PVX nanoparticles in medicine, diagnostics, materials science, and biocatalysis.
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Affiliation(s)
| | | | - Ulrich Commandeur
- Institute for Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
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Röder J, Dickmeis C, Fischer R, Commandeur U. Systemic Infection of Nicotiana benthamiana with Potato virus X Nanoparticles Presenting a Fluorescent iLOV Polypeptide Fused Directly to the Coat Protein. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9328671. [PMID: 29662905 PMCID: PMC5831704 DOI: 10.1155/2018/9328671] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/25/2017] [Indexed: 02/01/2023]
Abstract
Plant virus-based nanoparticles can be produced in plants on a large scale and are easily modified to introduce new functions, making them suitable for applications such as vaccination and drug delivery, tissue engineering, and in vivo imaging. The latter is often achieved using green fluorescent protein and its derivatives, but the monovalent fluorescent protein iLOV is smaller and more robust. Here, we fused the iLOV polypeptide to the N-terminus of the Potato virus X (PVX) coat protein, directly or via the Foot-and-mouth disease virus 2A sequence, for expression in Nicotiana benthamiana. Direct fusion of the iLOV polypeptide did not prevent the assembly or systemic spread of the virus and we verified the presence of fusion proteins and iLOV hybrid virus particles in leaf extracts. Compared to wild-type PVX virions, the PVX particles displaying the iLOV peptide showed an atypical, intertwined morphology. Our results confirm that a direct fusion of the iLOV fluorescent protein to filamentous PVX nanoparticles offers a promising tool for imaging applications.
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Affiliation(s)
- Juliane Röder
- Institute for Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52072 Aachen, Germany
| | - Christina Dickmeis
- Institute for Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52072 Aachen, Germany
| | - Rainer Fischer
- Institute for Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52072 Aachen, Germany
| | - Ulrich Commandeur
- Institute for Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52072 Aachen, Germany
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12
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Lazareva EA, Lezzhov AA, Komarova TV, Morozov SY, Heinlein M, Solovyev AG. A novel block of plant virus movement genes. MOLECULAR PLANT PATHOLOGY 2017; 18:611-624. [PMID: 27118327 PMCID: PMC6638293 DOI: 10.1111/mpp.12418] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/14/2016] [Accepted: 04/21/2016] [Indexed: 05/10/2023]
Abstract
Hibiscus green spot virus (HGSV) is a recently discovered and so far poorly characterized bacilliform plant virus with a positive-stranded RNA genome consisting of three RNA species. Here, we demonstrate that the proteins encoded by the ORF2 and ORF3 in HGSV RNA2 are necessary and sufficient to mediate cell-to-cell movement of transport-deficient Potato virus X in Nicotiana benthamiana. These two genes represent a specialized transport module called a 'binary movement block' (BMB), and ORF2 and ORF3 are termed BMB1 and BMB2 genes. In agroinfiltrated epidermal cells of N. benthamiana, green fluorescent protein (GFP)-BMB1 fusion protein was distributed diffusely in the cytoplasm and the nucleus. However, in the presence of BMB2, GFP-BMB1 was directed to cell wall-adjacent elongated bodies at the cell periphery, to cell wall-embedded punctate structures co-localizing with callose deposits at plasmodesmata, and to cells adjacent to the initially transformed cell. Thus, BMB2 can mediate the transport of BMB1 to and through plasmodesmata. In general, our observations support the idea that cell-to-cell trafficking of movement proteins involves an initial delivery to membrane compartments adjacent to plasmodesmata, subsequent entry of the plasmodesmata cavity and, finally, transport to adjacent cells. This process, as an alternative to tubule-based transport, has most likely evolved independently in triple gene block (TGB), double gene block (DGB), BMB and the single gene-coded transport system.
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Affiliation(s)
| | - Alexander A. Lezzhov
- Department of Virology, Biological FacultyMoscow State UniversityMoscow119234Russia
| | - Tatiana V. Komarova
- A. N. Belozersky Institute of Physico‐Chemical Biology, Moscow State UniversityMoscow119992Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of ScienceMoscow119991Russia
| | - Sergey Y. Morozov
- Department of Virology, Biological FacultyMoscow State UniversityMoscow119234Russia
- A. N. Belozersky Institute of Physico‐Chemical Biology, Moscow State UniversityMoscow119992Russia
| | - Manfred Heinlein
- Centre National de la Recherche ScientifiqueInstitut de Biologie Moléculaire des Plantes (IBMP)Strasbourg67084France
| | - Andrey G. Solovyev
- A. N. Belozersky Institute of Physico‐Chemical Biology, Moscow State UniversityMoscow119992Russia
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Meng M, Lee CC. Function and Structural Organization of the Replication Protein of Bamboo mosaic virus. Front Microbiol 2017; 8:522. [PMID: 28400766 PMCID: PMC5368238 DOI: 10.3389/fmicb.2017.00522] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/13/2017] [Indexed: 12/17/2022] Open
Abstract
The genus Potexvirus is one of the eight genera belonging to the family Alphaflexiviridae according to the Virus Taxonomy 2015 released by International Committee on Taxonomy of Viruses (www.ictvonline.org/index.asp). Currently, the genus contains 35 known species including many agricultural important viruses, e.g., Potato virus X (PVX). Members of this genus are characterized by flexuous, filamentous virions of 13 nm in diameter and 470-580 nm in length. A potexvirus has a monopartite positive-strand RNA genome, encoding five open-reading frames (ORFs), with a cap structure at the 5' end and a poly(A) tail at the 3' end. Besides PVX, Bamboo mosaic virus (BaMV) is another potexvirus that has received intensive attention due to the wealth of knowledge on the molecular biology of the virus. In this review, we discuss the enzymatic activities associated with each of the functional domains of the BaMV replication protein, a 155-kDa polypeptide encoded by ORF1. The unique cap formation mechanism, which may be conserved across the alphavirus superfamily, is particularly addressed. The recently identified interactions between the replication protein and the plant host factors are also described.
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Affiliation(s)
- Menghsiao Meng
- Graduate Institute of Biotechnology, National Chung Hsing University Taichung, Taiwan
| | - Cheng-Cheng Lee
- Graduate Institute of Biotechnology, National Chung Hsing University Taichung, Taiwan
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14
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Makarov VV, Kalinina NO. Structure and Noncanonical Activities of Coat Proteins of Helical Plant Viruses. BIOCHEMISTRY (MOSCOW) 2016; 81:1-18. [PMID: 26885578 DOI: 10.1134/s0006297916010016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The main function of virus coat protein is formation of the capsid that protects the virus genome against degradation. However, besides the structural function, coat proteins have many additional important activities in the infection cycle of the virus and in the defense response of host plants to viral infection. This review focuses on noncanonical functions of coat proteins of helical RNA-containing plant viruses with positive genome polarity. Analysis of data on the structural organization of coat proteins of helical viruses has demonstrated that the presence of intrinsically disordered regions within the protein structure plays an important role in implementation of nonstructural functions and largely determines the multifunctionality of coat proteins.
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Affiliation(s)
- V V Makarov
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, 119991, Russia.
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15
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Solovyev AG, Makarov VV. Helical capsids of plant viruses: architecture with structural lability. J Gen Virol 2016; 97:1739-1754. [DOI: 10.1099/jgv.0.000524] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- A. G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - V. V. Makarov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
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16
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Choi H, Cho WK, Kim KH. Two homologous host proteins interact with potato virus X RNAs and CPs and affect viral replication and movement. Sci Rep 2016; 6:28743. [PMID: 27353522 PMCID: PMC4926161 DOI: 10.1038/srep28743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/08/2016] [Indexed: 11/30/2022] Open
Abstract
Because viruses encode only a small number of proteins, all steps of virus infection rely on specific interactions between viruses and hosts. We previously screened several Nicotiana benthamiana (Nb) proteins that interact with the stem-loop 1 (SL1) RNA structure located at the 5' end of the potato virus X (PVX) genome. In this study, we characterized two of these proteins (NbCPIP2a and NbCPIP2b), which are homologous and are induced upon PVX infection. Electrophoretic mobility shift assay confirmed that both proteins bind to either SL1(+) or SL1(-) RNAs of PVX. The two proteins also interact with the PVX capsid protein (CP) in planta. Overexpression of NbCPIP2a positively regulated systemic movement of PVX in N. benthamiana, whereas NbCPIP2b overexpression did not affect systemic movement of PVX. Transient overexpression and silencing experiments demonstrated that NbCPIP2a and NbCPIP2b are positive regulators of PVX replication and that the effect on replication was greater for NbCPIP2a than for NbCPIP2b. Although these two host proteins are associated with plasma membranes, PVX infection did not affect their subcellular localization. Taken together, these results indicate that NbCPIP2a and NbCPIP2b specifically bind to PVX SL1 RNAs as well as to CP and enhance PVX replication and movement.
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Affiliation(s)
- Hoseong Choi
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, Korea
| | - Won Kyong Cho
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Kook-Hyung Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, Korea
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Geng C, Cong QQ, Li XD, Mou AL, Gao R, Liu JL, Tian YP. DEVELOPMENTALLY REGULATED PLASMA MEMBRANE PROTEIN of Nicotiana benthamiana contributes to potyvirus movement and transports to plasmodesmata via the early secretory pathway and the actomyosin system. PLANT PHYSIOLOGY 2015; 167:394-410. [PMID: 25540331 PMCID: PMC4326756 DOI: 10.1104/pp.114.252734] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/23/2014] [Indexed: 05/09/2023]
Abstract
The intercellular movement of plant viruses requires both viral and host proteins. Previous studies have demonstrated that the frame-shift protein P3N-PIPO (for the protein encoded by the open reading frame [ORF] containing 5'-terminus of P3 and a +2 frame-shift ORF called Pretty Interesting Potyviridae ORF and embedded in the P3) and CYLINDRICAL INCLUSION (CI) proteins were required for potyvirus cell-to-cell movement. Here, we provide genetic evidence showing that a Tobacco vein banding mosaic virus (TVBMV; genus Potyvirus) mutant carrying a truncated PIPO domain of 58 amino acid residues could move between cells and induce systemic infection in Nicotiana benthamiana plants; mutants carrying a PIPO domain of seven, 20, or 43 amino acid residues failed to move between cells and cause systemic infection in this host plant. Interestingly, the movement-defective mutants produced progeny that eliminated the previously introduced stop codons and thus restored their systemic movement ability. We also present evidence showing that a developmentally regulated plasma membrane protein of N. benthamiana (referred to as NbDREPP) interacted with both P3N-PIPO and CI of the movement-competent TVBMV. The knockdown of NbDREPP gene expression in N. benthamiana impeded the cell-to-cell movement of TVBMV. NbDREPP was shown to colocalize with TVBMV P3N-PIPO and CI at plasmodesmata (PD) and traffic to PD via the early secretory pathway and the actomyosin motility system. We also show that myosin XI-2 is specially required for transporting NbDREPP to PD. In conclusion, NbDREPP is a key host protein within the early secretory pathway and the actomyosin motility system that interacts with two movement proteins and influences virus movement.
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Affiliation(s)
- Chao Geng
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Qian-Qian Cong
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Xiang-Dong Li
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - An-Li Mou
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Rui Gao
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Jin-Liang Liu
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Yan-Ping Tian
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
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18
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Abstract
The symplastic communication network established by plasmodesmata (PD) and connected phloem provides an essential pathway for spatiotemporal intercellular signaling in plant development but is also exploited by viruses for moving their genomes between cells in order to infect plants systemically. Virus movement depends on virus-encoded movement proteins (MPs) that target PD and therefore represent important keys to the cellular mechanisms underlying the intercellular trafficking of viruses and other macromolecules. Viruses and their MPs have evolved different mechanisms for intracellular transport and interaction with PD. Some viruses move from cell to cell by interacting with cellular mechanisms that control the size exclusion limit of PD whereas other viruses alter the PD architecture through assembly of specialized transport structures within the channel. Some viruses move between cells in the form of assembled virus particles whereas other viruses may interact with nucleic acid transport mechanisms to move their genomes in a non-encapsidated form. Moreover, whereas several viruses rely on the secretory pathway to target PD, other viruses interact with the cortical endoplasmic reticulum and associated cytoskeleton to spread infection. This chapter provides an introduction into viruses and their role in studying the diverse cellular mechanisms involved in intercellular PD-mediated macromolecular trafficking.
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Affiliation(s)
- Manfred Heinlein
- Institut de Biologie Moléculaire des Plantes (IBMP), Centre National de la Recherche Scientifique (CNRS), 12 rue du Général Zimmer, 67084, Strasbourg, France,
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19
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Kumar D, Kumar R, Hyun TK, Kim JY. Cell-to-cell movement of viruses via plasmodesmata. JOURNAL OF PLANT RESEARCH 2015; 128:37-47. [PMID: 25527904 DOI: 10.1007/s10265-014-0683-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/14/2014] [Indexed: 05/03/2023]
Abstract
Plant viruses utilize plasmodesmata (PD), unique membrane-lined cytoplasmic nanobridges in plants, to spread infection cell-to-cell and long-distance. Such invasion involves a range of regulatory mechanisms to target and modify PD. Exciting discoveries in this field suggest that these mechanisms are executed by the interaction between plant cellular components and viral movement proteins (MPs) or other virus-encoded factors. Striking working analogies exist among endogenous non-cell-autonomous proteins and viral MPs, in which not only do they all use PD to traffic, but also they exploit same regulatory components to exert their functions. Thus, this review discusses on the viral strategies to move via PD and the PD-regulatory mechanisms involved in viral pathogenesis.
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Affiliation(s)
- Dhinesh Kumar
- Division of Applied Life Science (BK21plus), Department of Biochemistry, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, 27-306, 501 Jinju-Daero, Jinju, 660-701, Korea
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20
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Hung CJ, Huang YW, Liou MR, Lee YC, Lin NS, Meng M, Tsai CH, Hu CC, Hsu YH. Phosphorylation of coat protein by protein kinase CK2 regulates cell-to-cell movement of Bamboo mosaic virus through modulating RNA binding. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1211-25. [PMID: 25025779 DOI: 10.1094/mpmi-04-14-0112-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In this study, we investigated the fine regulation of cell-to-cell movement of Bamboo mosaic virus (BaMV). We report that the coat protein (CP) of BaMV is phosphorylated in planta at position serine 241 (S241), in a process involving Nicotiana benthamiana casein kinase 2α (NbCK2α). BaMV CP and NbCK2α colocalize at the plasmodesmata, suggesting that phosphorylation of BaMV may be involved in its movement. S241 was mutated to examine the effects of temporal and spatial dysregulation of phosphorylation on i) the interactions between CP and viral RNA and ii) the regulation of cell-to-cell movement. Replacement of S241 with alanine did not affect RNA binding affinity but moderately impaired cell-to-cell movement. A negative charge at position 241 reduced the ability of CP to bind RNA and severely interfered with cell-to-cell movement. Deletion of residues 240 to 242 increased the affinity of CP to viral RNA and dramatically impaired cell-to-cell movement. A threonine at position 241 changed the binding preference of CP toward genomic RNA and inhibited cell-to-cell movement. Together, these results reveal a fine regulatory mechanism for the cell-to-cell movement of BaMV, which involves the modulation of RNA binding affinity through appropriate phosphorylation of CP by NbCK2α.
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21
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Development of new potato virus X-based vectors for gene over-expression and gene silencing assay. Virus Res 2014; 191:62-9. [DOI: 10.1016/j.virusres.2014.07.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/16/2014] [Accepted: 07/20/2014] [Indexed: 11/19/2022]
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Park MR, Seo JK, Kim KH. Viral and nonviral elements in potexvirus replication and movement and in antiviral responses. Adv Virus Res 2013; 87:75-112. [PMID: 23809921 DOI: 10.1016/b978-0-12-407698-3.00003-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In Potato virus X, a member of the genus Potexvirus, special sequences and structures at the 5' and 3' ends of the nontranslated region function as cis-acting elements for viral replication. These elements greatly affect interactions between viral RNAs and those between viral RNAs and host factors. The potexvirus genome encodes five open-reading frames. Viral replicase, which is required for the synthesis of viral RNA, binds viral RNA elements and host factors to form a viral replication complex at the host cellular membrane. The coat protein (CP) and three viral movement proteins (TGB1, TGB2, and TGB3) have critical roles in mediating cell-to-cell viral movement through plasmodesmata by virion formation or by nonvirion ribonucleoprotein (RNP) complex formation with viral movement proteins (TGBs). The RNP complex, like TGB1-CP-viral RNA, is associated with viral replicase and used for immediate reinitiation of viral replication in newly invaded cells. Higher plants have defense mechanisms against potexviruses such as Rx-mediated resistance and RNA silencing. The CP acts as an avirulence effector for plant defense mechanisms, while TGB1 functions as a viral suppressor of RNA silencing, which is the mechanism of innate immune resistance. Here, we describe recent findings concerning the involvement of viral and host factors in potexvirus replication and in antiviral responses to potexvirus infection.
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Affiliation(s)
- Mi-Ri Park
- Department of Agricultural Biotechnology, Plant Genomics and Breeding Institute, Seoul National University, Seoul, Republic of Korea
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23
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Mann K, Meng B. The triple gene block movement proteins of a grape virus in the genus Foveavirus confer limited cell-to-cell spread of a mutant Potato virus X. Virus Genes 2013; 47:93-104. [PMID: 23543158 DOI: 10.1007/s11262-013-0908-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 03/18/2013] [Indexed: 11/29/2022]
Abstract
Grapevine rupestris stem pitting-associated virus (GRSPaV) is a member of the genus Foveavirus in the family Betaflexiviridae. The genome of GRSPaV encodes five proteins, among which are three movement proteins designated the triple gene block (TGB) proteins. The TGB proteins of GRSPaV are highly similar to their counterparts in Potato virus X (PVX), as reflected in size, modular structure, conservation of critical amino acid sequence motifs, as well as similar cellular localization. Based on these similarities, we predicted that the TGB proteins of these two viruses would be interchangeable. To test this hypothesis, we replaced the entire or partial sequence of PVX TGB with the corresponding regions from GRSPaV, creating chimeric viruses that contain the PVX backbone and different sequences from GRSPaV TGB. These chimeric constructs were delivered into plants of Nicotiana benthamiana through agro-infiltration to test whether they were capable of cell-to-cell and systemic movement. To our surprise, viruses derived from pPVX.GFP(CH3) bearing GRSPaV TGB in place of PVX TGB lost the ability to move either cell-to-cell or systemically. Interestingly, another chimeric virus resulting from pPVX.GFP(HY2) containing four TGB genes (TGB1 from PVX and TGB1-3 from GRSPaV), exhibited limited cell-to-cell, but not systemic, movement. Our data question the notion that analogous movement proteins encoded by even distantly related viruses are functionally interchangeable and can be replaced by each other. These data suggest that other factors, besides the TGB proteins, may be required for successful intercellular and/or systemic movement of progeny viruses. This is the first experimental demonstration that the GRSPaV TGB function as movement proteins in the context of a chimeric virus and that four TGB genes were required to support the intercellular movement of the chimeric virus.
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Affiliation(s)
- Krinpreet Mann
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road, Guelph, ON N1G 2W1, Canada
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24
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Tilsner J, Linnik O, Louveaux M, Roberts IM, Chapman SN, Oparka KJ. Replication and trafficking of a plant virus are coupled at the entrances of plasmodesmata. J Cell Biol 2013; 201:981-95. [PMID: 23798728 PMCID: PMC3691464 DOI: 10.1083/jcb.201304003] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 05/16/2013] [Indexed: 02/04/2023] Open
Abstract
Plant viruses use movement proteins (MPs) to modify intercellular pores called plasmodesmata (PD) to cross the plant cell wall. Many viruses encode a conserved set of three MPs, known as the triple gene block (TGB), typified by Potato virus X (PVX). In this paper, using live-cell imaging of viral RNA (vRNA) and virus-encoded proteins, we show that the TGB proteins have distinct functions during movement. TGB2 and TGB3 established endoplasmic reticulum-derived membranous caps at PD orifices. These caps harbored the PVX replicase and nonencapsidated vRNA and represented PD-anchored viral replication sites. TGB1 mediated insertion of the viral coat protein into PD, probably by its interaction with the 5' end of nascent virions, and was recruited to PD by the TGB2/3 complex. We propose a new model of plant virus movement, which we term coreplicational insertion, in which MPs function to compartmentalize replication complexes at PD for localized RNA synthesis and directional trafficking of the virus between cells.
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Affiliation(s)
- Jens Tilsner
- Biomedical Sciences Research Complex, University of St Andrews, Fife KY16 9ST, Scotland, UK.
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25
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Nazim Uddin M, Kim JY. Intercellular and systemic spread of RNA and RNAi in plants. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:279-93. [PMID: 23536229 DOI: 10.1002/wrna.1160] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Plants possess dynamic networks of intercellular communication that are crucial for plant development and physiology. In plants, intercellular communication involves a combination of ligand-receptor-based apoplasmic signaling, and plasmodesmata and phloem-mediated symplasmic signaling. The intercellular trafficking of macromolecules, including RNAs and proteins, has emerged as a novel mechanism of intercellular communication in plants. Various forms of regulatory RNAs move over distinct cellular boundaries through plasmodesmata and phloem. This plant-specific, non-cell-autonomous RNA trafficking network is also involved in development, nutrient homeostasis, gene silencing, pathogen defense, and many other physiological processes. However, the mechanism underlying macromolecular trafficking in plants remains poorly understood. Current progress made in RNA trafficking research and its biological relevance to plant development will be summarized. Diverse plant regulatory mechanisms of cell-to-cell and systemic long-distance transport of RNAs, including mRNAs, viral RNAs, and small RNAs, will also be discussed.
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Affiliation(s)
- Mohammad Nazim Uddin
- Division of Applied Life Science (BK21-WCU Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, South Korea
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Cerovska N, Hoffmeisterova H, Moravec T, Plchova H, Folwarczna J, Synkova H, Ryslava H, Ludvikova V, Smahel M. Transient expression of Human papillomavirus type 16 L2 epitope fused to N- and C-terminus of coat protein of Potato virus X in plants. J Biosci 2012; 37:125-33. [PMID: 22357210 DOI: 10.1007/s12038-011-9177-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 12/13/2011] [Indexed: 01/29/2023]
Abstract
Transient expression of foreign genes based on plant viral vectors is a suitable system for the production of relevant immunogens that can be used for the development of a new generation of vaccines against a variety of infectious diseases. In the present study the epitope derived from HPV-16 L2 minor capsid protein (amino acids 108-120) was expressed from Potato virus X (PVX)-based vector pGR106 as N- or C-terminal fusion with the PVX coat protein (PVX CP) in transgenic Nicotiana benthamiana plants. The fusion protein L2 108-120-PVX CP was successfully expressed in plants at a level of 170 mg/kg of fresh leaf tissue. The C-terminal fusion protein PVX CP- L2 108-120 was expressed using mutated vector sequence to avoid homologous recombination at a level of 8 mg/kg of fresh leaf tissue. Immunogenicity of L2 108-120-PVX CP virus-like particles was tested after immunization of mice by subcutaneous injection or tattoo administration. In animal sera the antibodies against the PVX CP and the L2 108-120 epitope were found after both methods of vaccine delivery.
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Affiliation(s)
- Noemi Cerovska
- Institute of Experimental Botany, v. v. i., Academy of Sciences of Czech Republic, Na Karlovce 1a, 16000 Prague 6, Czech Republic
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27
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Mathioudakis MM, Veiga R, Ghita M, Tsikou D, Medina V, Canto T, Makris AM, Livieratos IC. Pepino mosaic virus capsid protein interacts with a tomato heat shock protein cognate 70. Virus Res 2012; 163:28-39. [PMID: 21884738 DOI: 10.1016/j.virusres.2011.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 11/29/2022]
Abstract
Plant viral capsid proteins (CP) can be involved in virus movement, replication and symptom development as a result of their interaction with host factors. The identification of such interactions may thus provide information about viral pathogenesis. In this study, Pepino mosaic virus (PepMV) CP was used as bait to screen a tomato (Solanum lycopersicum) cDNA library for potential interactors in yeast. Of seven independent interacting clones, six were predicted to encode the C-termini of the heat shock cognate 70 (Hsc70) proteins. Three full length tomato Hsc70s (named Hsc70.1, .2, .3) were used to confirm the interaction in the yeast two hybrid assay and bimolecular fluorescent complementation (BiFC) in planta. The PepMV CP-Hsc70 interaction was confirmed only in the case of Hsc70.3 for both assays. In BiFC, the interaction was visualized in the cytoplasm and nucleus of agroinfiltrated Nicotiana benthamiana epidermal cells. During PepMV infection, Hsc70.3 mRNA levels were induced and protein accumulation increased at 48 and 72 h post inoculation. In transmission electron microscopy using immunogold labelling techniques, Hsc70 was detected to co-localize with virions in the phloem of PepMV-infected tomato leaves. These observations, together with the co-purification of Hsc70 with PepMV virions further support the notion of a PepMV CP/Hsc70 interaction during virus infection.
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Affiliation(s)
- Matthaios M Mathioudakis
- Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, Alsylio Agrokepion, GR-73100 Chania, Crete, Greece.
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28
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The interaction between bamboo mosaic virus replication protein and coat protein is critical for virus movement in plant hosts. J Virol 2011; 85:12022-31. [PMID: 21917973 DOI: 10.1128/jvi.05595-11] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bamboo mosaic virus (BaMV) is a positive-sense RNA virus belonging to the genus Potexvirus. Open reading frame 1 (ORF1) encodes the viral replication protein that consists of a capping enzyme domain, a helicase-like domain (HLD), and an RNA-dependent RNA polymerase domain from the N to C terminus. ORF5 encodes the viral coat protein (CP) required for genome encapsidation and the virus movement in plants. In this study, application of a yeast-two hybrid assay detected an interaction between the viral HLD and CP. However, the interaction did not affect the NTPase activity of the HLD. To identify the critical amino acids of CP interacting with the HLD, a random mutational library of CP was created using error-prone PCR, and the mutations adversely affecting the interaction were screened by a bacterial two-hybrid system. As a result, the mutations A209G and N210S in CP were found to weaken the interaction. To determine the significance of the interaction, the mutations were introduced into a BaMV infectious clone, and the mutational effects on viral replication, movement, and genome encapsidation were investigated. There was no effect on accumulations of BaMV CP and genomic RNAs within protoplasts; however, the virus cell-to-cell movement in plants was restricted. Sequence alignment revealed that A209 of BaMV CP is conserved in many potexviruses. Mutation of the corresponding residue in Foxtail mosaic virus CP also reduced the viral HLD-CP interaction and restricted the virus movement, suggesting that interaction between CP and a widely conserved HLD in the potexviral replication protein is crucial for viral trafficking through plasmodesmata.
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29
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Hyun TK, Uddin MN, Rim Y, Kim JY. Cell-to-cell trafficking of RNA and RNA silencing through plasmodesmata. PROTOPLASMA 2011; 248:101-16. [PMID: 21042816 DOI: 10.1007/s00709-010-0225-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 10/14/2010] [Indexed: 05/05/2023]
Abstract
Plasmodesmata (PD) are plasma membrane-lined cytoplasmic channels that cross the cell wall and establish symplasmic continuity between neighboring cells in plants. Recently, a wide range of cellular RNAs (including mRNAs and small RNAs (sRNAs)) have been reported to move from cell to cell through PD trafficking pathways. sRNAs are key molecules that function in transcriptional and post-transcriptional RNA silencing, which is a gene expression regulatory mechanism that is conserved among eukaryotes and is important for protection against invading nucleic acids (such as viruses and transposons) and for developmental and physiological regulation. One of the most intriguing aspects of RNA silencing is that it can function either cell autonomously or non-cell autonomously in post-transcriptional RNA silencing pathways. Although the mechanisms underlying cell-to-cell trafficking of RNA and RNA silencing signals are not fully understood, the movement of specific RNAs seems to play a critical role in cell-to-cell and long-distance regulation of gene expression, thereby coordinating growth and developmental processes, gene silencing, and stress responses. In this review, we summarize the current knowledge regarding cell-to-cell trafficking of RNA molecules (including small RNAs), and we discuss potential molecular mechanisms of cell-to-cell trafficking that are mediated by complex networks.
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Affiliation(s)
- Tae Kyung Hyun
- Department of Biochemistry, Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, South Korea
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30
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Slootweg E, Roosien J, Spiridon LN, Petrescu AJ, Tameling W, Joosten M, Pomp R, van Schaik C, Dees R, Borst JW, Smant G, Schots A, Bakker J, Goverse A. Nucleocytoplasmic distribution is required for activation of resistance by the potato NB-LRR receptor Rx1 and is balanced by its functional domains. THE PLANT CELL 2010; 22:4195-215. [PMID: 21177483 PMCID: PMC3027179 DOI: 10.1105/tpc.110.077537] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 10/18/2010] [Accepted: 11/19/2010] [Indexed: 05/18/2023]
Abstract
The Rx1 protein, as many resistance proteins of the nucleotide binding-leucine-rich repeat (NB-LRR) class, is predicted to be cytoplasmic because it lacks discernable nuclear targeting signals. Here, we demonstrate that Rx1, which confers extreme resistance to Potato virus X, is located both in the nucleus and cytoplasm. Manipulating the nucleocytoplasmic distribution of Rx1 or its elicitor revealed that Rx1 is activated in the cytoplasm and cannot be activated in the nucleus. The coiled coil (CC) domain was found to be required for accumulation of Rx1 in the nucleus, whereas the LRR domain promoted the localization in the cytoplasm. Analyses of structural subdomains of the CC domain revealed no autonomous signals responsible for active nuclear import. Fluorescence recovery after photobleaching and nuclear fractionation indicated that the CC domain binds transiently to large complexes in the nucleus. Disruption of the Rx1 resistance function and protein conformation by mutating the ATP binding phosphate binding loop in the NB domain, or by silencing the cochaperone SGT1, impaired the accumulation of Rx1 protein in the nucleus, while Rx1 versions lacking the LRR domain were not affected in this respect. Our results support a model in which interdomain interactions and folding states determine the nucleocytoplasmic distribution of Rx1.
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Affiliation(s)
- Erik Slootweg
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands.
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31
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Verchot-Lubicz J, Torrance L, Solovyev AG, Morozov SY, Jackson AO, Gilmer D. Varied movement strategies employed by triple gene block-encoding viruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1231-47. [PMID: 20831404 DOI: 10.1094/mpmi-04-10-0086] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Several RNA virus genera belonging to the Virgaviridae and Flexiviridae families encode proteins organized in a triple gene block (TGB) that facilitate cell-to-cell and long-distance movement. The TGB proteins have been traditionally classified as hordei-like or potex-like based on phylogenetic comparisons and differences in movement mechanisms of the Hordeivirus and Potexvirus spp. However, accumulating data from other model viruses suggests that a revised framework is needed to accommodate the profound differences in protein interactions occurring during infection and ancillary capsid protein requirements for movement. The goal of this article is to highlight common features of the TGB proteins and salient differences in movement properties exhibited by individual viruses encoding these proteins. We discuss common and divergent aspects of the TGB transport machinery, describe putative nucleoprotein movement complexes, highlight recent data on TGB protein interactions and topological properties, and review membrane associations occurring during subcellular targeting and cell-to-cell movement. We conclude that the existing models cannot be used to explain all TGB viruses, and we propose provisional Potexvirus, Hordeivirus, and Pomovirus models. We also suggest areas that might profit from future research on viruses harboring this intriguing arrangement of movement proteins.
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Affiliation(s)
- Jeanmarie Verchot-Lubicz
- Oklahoma State University, Department of Entomology and Plant Pathology, Stillwater, OK 74078, USA.
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32
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Fajolu OL, Wen RH, Windham AS, Windham MT, Moulton JK, Hajimorad MR. Genetic variability and phylogenetic analysis of hosta virus X. Arch Virol 2009; 154:1909-16. [DOI: 10.1007/s00705-009-0522-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 09/17/2009] [Indexed: 10/20/2022]
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Ozeki J, Hashimoto M, Komatsu K, Maejima K, Himeno M, Senshu H, Kawanishi T, Kagiwada S, Yamaji Y, Namba S. The N-terminal region of the Plantago asiatica mosaic virus coat protein is required for cell-to-cell movement but is dispensable for virion assembly. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:677-85. [PMID: 19445592 DOI: 10.1094/mpmi-22-6-0677] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Potexvirus cell-to-cell movement requires coat protein (CP) and movement proteins. In this study, mutations in two conserved in-frame AUG codons in the 5' region of the CP open reading frame of Plantago asiatica mosaic virus (PlAMV) were introduced, and virus accumulation of these mutants was analyzed in inoculated and upper noninoculated leaves. When CP was translated only from the second AUG codon, virus accumulation in inoculated leaves was lower than that of wild-type PlAMV, and the viral spread was impaired. Trans-complementation analysis showed that the leucine residue at the third position (Leu-3) of CP is important for cell-to-cell movement of PlAMV. The 14-amino-acid N-terminal region of CP was dispensable for virion formation. Immunoprecipitation assays conducted with an anti-TGBp1 antibody indicated that PlAMV CP interacts with TGBp1 in vivo and that this interaction is not affected by alanine substitution at Leu-3. These results support the concept that the N-terminal region of potexvirus CP can be separated into two distinct functional domains.
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Affiliation(s)
- Johji Ozeki
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
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34
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Lu HC, Chen CE, Tsai MH, Wang HI, Su HJ, Yeh HH. Cymbidium mosaic potexvirus isolate-dependent host movement systems reveal two movement control determinants and the coat protein is the dominant. Virology 2009; 388:147-59. [PMID: 19345971 PMCID: PMC7103407 DOI: 10.1016/j.virol.2009.02.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 01/28/2009] [Accepted: 02/28/2009] [Indexed: 11/30/2022]
Abstract
Little is known about how plant viruses of a single species exhibit different movement behavior in different host species. Two Cymbidium mosaic potexvirus (CymMV) isolates, M1 and M2, were studied. Both can infect Phalaenopsis orchids, but only M1 can systemically infect Nicotiana benthamiana plants. Protoplast inoculation and whole-mount in situ hybridization revealed that both isolates can replicate in N. benthamiana; however, M2 was restricted to the initially infected cells. Genome shuffling between M1 and M2 revealed that two control modes are involved in CymMV host dependent movement. The M1 coat protein (CP) plays a dominant role in controlling CymMV movement between cells, because all chimeric CymMV viruses containing the M1 CP systemically infected N. benthamiana plants. Without the M1 CP, one chimeric virus containing the combination of the M1 triple gene block proteins (TGBps), the M2 5' RNA (1-4333), and the M2 CP effectively moved in N. benthamiana plants. Further complementation analysis revealed that M1 TGBp1 and TGBp3 are co-required to complement the movement of the chimeric viruses in N. benthamiana. The amino acids within the CP, TGBp1 and TGBp3 which are required or important for CymMV M2 movement in N. benthamiana plants were mapped. The required amino acids within the CP map to the predicted RNA binding domain. RNA-protein binding assays revealed that M1 CP has higher RNA binding affinity than does M2 CP. Yeast two-hybrid assays to detect all possible interactions of M1 TGBps and CP, and only TGBp1 and CP self-interactions were observed.
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Affiliation(s)
- Hsiang-Chia Lu
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Cheng-En Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Meng-Hsiun Tsai
- Department of Management Information Systems, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Hsiang-iu Wang
- Department of Computer Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Hong-Ji Su
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Hsin-Hung Yeh
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
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35
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Park MR, Park SH, Cho SY, Kim KH. Nicotiana benthamiana protein, NbPCIP1, interacting with Potato virus X coat protein plays a role as susceptible factor for viral infection. Virology 2009; 386:257-69. [PMID: 19215953 DOI: 10.1016/j.virol.2008.12.044] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 11/01/2008] [Accepted: 12/31/2008] [Indexed: 11/24/2022]
Abstract
The interactions of viral coat protein (CP) and host factors play an important role in viral replication and/or host defense mechanism. In this study, we constructed Nicotiana benthamiana cDNA library to find host factors interacting with Potato virus X (PVX) CP. Using yeast two-hybrid assay, we screened 3.3 x 10(6) independent yeast transformants from N. benthamiana cDNA library and identified six positive clones. One positive clone, named PVX CP-interacting protein 1 (NbPCIP1), is a plant-specific protein with homologue in N. tabacum (GenBank accession no. AB04049). We confirmed the PVX CP-NbPCIP1 interaction using yeast-two hybrid assay in yeast, protein-protein binding assay in vitro, and bimolecular fluorescent complementation assay in planta. Quantitative real-time RT-PCR analysis showed that the mRNA level of NbPCIP1 increased in PVX-infected N. benthamiana plants as compared to that of healthy plants. The green fluorescent protein (sGFP)-fused NbPCIP1 (NbPCIP1-sGFP) was localized in ER or ER-associated granular-like structure of cells. When we co-express NbPCIP1-sGFP and red fluorescent protein (RFP)-fused PVX CP (PVX CP-RFP), which were introduced by transiently expressing these proteins in N. benthamiana protoplasts and epidermal cells, however, we observed the co-localization of these proteins in the inclusion body-like complex in areas surrounding nucleus. Transient over-expression and transgene silencing of NbPCIP1 assay analysis indicated that NbPCIP1 plays a critical role in viral replication during PVX infection in host plant.
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Affiliation(s)
- Mi-Ri Park
- Department of Agricultural Biotechnology and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Republic of Korea
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36
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Li C, Zhang K, Zeng X, Jackson S, Zhou Y, Hong Y. A cis element within flowering locus T mRNA determines its mobility and facilitates trafficking of heterologous viral RNA. J Virol 2009; 83:3540-8. [PMID: 19193810 PMCID: PMC2663265 DOI: 10.1128/jvi.02346-08] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 01/22/2009] [Indexed: 01/18/2023] Open
Abstract
The Arabidopsis flowering locus T (FT) gene encodes the mobile florigen essential for floral induction. While movement of the FT protein has been shown to occur within plants, systemic spread of FT mRNA remains to be unequivocally demonstrated. Utilizing novel RNA mobility assay vectors based on two distinct movement-defective viruses, Potato virus X and Turnip crinkle virus, and an agroinfiltration assay, we demonstrate that nontranslatable FT mRNA, independent of the FT protein, moves throughout Nicotiana benthamiana and mutant Arabidopsis plants and promotes systemic trafficking of viral and green fluorescence protein RNAs. Viral ectopic expression of FT induced flowering in the short-day N. tabacum Maryland Mammoth tobacco under long-day conditions. Recombinant Potato virus X bearing FT RNA spread and established systemic infection more quickly than the parental virus. The cis-acting element essential for RNA movement was mapped to the nucleotides 1 to 102 of the FT mRNA coding sequence. These data demonstrate that a plant self-mobile RNA molecule can mediate long-distance trafficking of heterologous RNAs and raise the possibility that FT RNA, along with the FT protein, may be involved in the spread of the floral stimulus throughout the plant.
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Affiliation(s)
- Chunyang Li
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, United Kingdom.
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37
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Zayakina O, Arkhipenko M, Kozlovsky S, Nikitin N, Smirnov A, Susi P, Rodionova N, Karpova O, Atabekov J. Mutagenic analysis of potato virus X movement protein (TGBp1) and the coat protein (CP): in vitro TGBp1-CP binding and viral RNA translation activation. MOLECULAR PLANT PATHOLOGY 2008; 9:37-44. [PMID: 18705882 PMCID: PMC6640483 DOI: 10.1111/j.1364-3703.2007.00445.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Previously, we have shown that encapsidated Potato virus X (PVX) RNA was non-translatable in vitro, but could be converted into a translatable form by binding of the PVX movement protein TGBp1 to one end of the virion or by coat protein (CP) phosphorylation. Here, a mutagenic analysis of PVX CP and TGBp1 was used to identify the regions involved in TGBp1-CP binding and translational activation of PVX RNA by TGBp1. It was found that the C-terminal (C-ter) 10/18 amino acids region was not essential for virus-like particle (VP) assembly from CP and RNA. However, the VPs assembled from the CP lacking C-ter 10/18 amino acids were incapable of TGBp1 binding and being translationally activated. It was suggested that the 10-amino-acid C-ter regions of protein subunits located at one end of a polar helical PVX particle contain a domain accessible to TGBp1 binding and PVX remodelling. The non-translatable particles assembled from the C-ter mutant CP could be converted into a translatable form by CP phosphorylation. The TGBp1-CP binding activity was preserved unless a conservative motif IV was removed from TGBp1. By contrast, TGBp1-dependent activation of PVX RNA translation was abolished by deletions of various NTPase/helicase conservative motifs and their combinations. The motif IV might be essential for TGBp1-CP binding, but insufficient for PVX RNA translation activation. The evidence to discriminate between these two events, i.e. TGBp1 binding to the CP-helix and TGBp1-dependent RNA translation activation, is discussed.
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Affiliation(s)
- Olga Zayakina
- Department of Virology, Moscow State University, Moscow 119991, Russia
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38
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Latham JR, Wilson AK. Transcomplementation and synergism in plants: implications for viral transgenes? MOLECULAR PLANT PATHOLOGY 2008; 9:85-103. [PMID: 18705887 PMCID: PMC6640258 DOI: 10.1111/j.1364-3703.2007.00441.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In plants, viral synergisms occur when one virus enhances infection by a distinct or unrelated virus. Such synergisms may be unidirectional or mutualistic but, in either case, synergism implies that protein(s) from one virus can enhance infection by another. A mechanistically related phenomenon is transcomplementation, in which a viral protein, usually expressed from a transgene, enhances or supports the infection of a virus from a distinct species. To gain an insight into the characteristics and limitations of these helper functions of individual viral genes, and to assess their effects on the plant-pathogen relationship, reports of successful synergism and transcomplementation were compiled from the peer-reviewed literature and combined with data from successful viral gene exchange experiments. Results from these experiments were tabulated to highlight the phylogenetic relationship between the helper and dependent viruses and, where possible, to identify the protein responsible for the altered infection process. The analysis of more than 150 publications, each containing one or more reports of successful exchanges, transcomplementation or synergism, revealed the following: (i) diverse viral traits can be enhanced by synergism and transcomplementation; these include the expansion of host range, acquisition of mechanical transmission, enhanced specific infectivity, enhanced cell-to-cell and long-distance movement, elevated or novel vector transmission, elevated viral titre and enhanced seed transmission; (ii) transcomplementation and synergism are mediated by many viral proteins, including inhibitors of gene silencing, replicases, coat proteins and movement proteins; (iii) although more frequent between closely related viruses, transcomplementation and synergism can occur between viruses that are phylogenetically highly divergent. As indicators of the interoperability of viral genes, these results are of general interest, but they can also be applied to the risk assessment of transgenic crops expressing viral proteins. In particular, they can contribute to the identification of potential hazards, and can be used to identify data gaps and limitations in predicting the likelihood of transgene-mediated transcomplementation.
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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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40
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Giritch A, Marillonnet S, Engler C, van Eldik G, Botterman J, Klimyuk V, Gleba Y. Rapid high-yield expression of full-size IgG antibodies in plants coinfected with noncompeting viral vectors. Proc Natl Acad Sci U S A 2006; 103:14701-6. [PMID: 16973752 PMCID: PMC1566189 DOI: 10.1073/pnas.0606631103] [Citation(s) in RCA: 288] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Indexed: 01/15/2023] Open
Abstract
Plant viral vectors allow expression of heterologous proteins at high yields, but so far, they have been unable to express heterooligomeric proteins efficiently. We describe here a rapid and indefinitely scalable process for high-level expression of functional full-size mAbs of the IgG class in plants. The process relies on synchronous coinfection and coreplication of two viral vectors, each expressing a separate antibody chain. The two vectors are derived from two different plant viruses that were found to be noncompeting. Unlike vectors derived from the same virus, noncompeting vectors effectively coexpress the heavy and light chains in the same cell throughout the plant body, resulting in yields of up to 0.5 g of assembled mAbs per kg of fresh-leaf biomass. This technology allows production of gram quantities of mAbs for research purposes in just several days, and the same protocol can be used on an industrial scale in situations requiring rapid response, such as pandemic or terrorism events.
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Affiliation(s)
- Anatoli Giritch
- *Icon Genetics GmbH, Weinbergweg 22, 06120 Halle, Germany; and
| | | | - Carola Engler
- *Icon Genetics GmbH, Weinbergweg 22, 06120 Halle, Germany; and
| | | | - Johan Botterman
- Bayer BioScience N.V., Technologiepark 38, B-9052 Gent, Belgium
| | - Victor Klimyuk
- *Icon Genetics GmbH, Weinbergweg 22, 06120 Halle, Germany; and
| | - Yuri Gleba
- *Icon Genetics GmbH, Weinbergweg 22, 06120 Halle, Germany; and
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41
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Lico C, Capuano F, Renzone G, Donini M, Marusic C, Scaloni A, Benvenuto E, Baschieri S. Peptide display on Potato virus X: molecular features of the coat protein-fused peptide affecting cell-to-cell and phloem movement of chimeric virus particles. J Gen Virol 2006; 87:3103-3112. [PMID: 16963770 DOI: 10.1099/vir.0.82097-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The potexvirus Potato virus X (PVX) can be modified genetically to generate chimeric virus particles (CVPs) carrying heterologous peptides fused to coat protein (CP) subunits. A spontaneous PVX mutant expressing a truncated, but functional, form of the CP has been isolated. With the aim of exploiting this virus to display peptides useful for vaccine formulations, two novel viral expression vectors based on pPVX201 (bearing the wild-type PVX genome) were constructed encoding the truncated CP. Both vectors were able to produce infectious virus particles in planta and were used to insert a panel of sequences encoding peptides of biopharmaceutical interest as N-terminal fusions to the truncated cp gene. The analysis of infection progression induced by the different constructs enabled identification of two important structural features of the fused peptide, namely tryptophan content and isoelectric point, critically affecting the formation of PVX CVPs and virus movement through the plant. These results are discussed in view of the rising interest in engineered plant viruses for development of peptide-based epitope vaccines.
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Affiliation(s)
- Chiara Lico
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
| | - Floriana Capuano
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
| | - Giovanni Renzone
- Proteomics and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy
| | - Marcello Donini
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
| | - Carla Marusic
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
| | - Andrea Scaloni
- Proteomics and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy
| | - Eugenio Benvenuto
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
| | - Selene Baschieri
- Sezione di Genetica e Genomica Vegetale, ENEA CR Casaccia, Via Anguillarese 301, 00060 Rome, Italy
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42
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Rakitina DV, Kantidze OL, Leshchiner AD, Solovyev AG, Novikov VK, Morozov SY, Kalinina NO. Coat proteins of two filamentous plant viruses display NTPase activity in vitro. FEBS Lett 2005; 579:4955-60. [PMID: 16115626 DOI: 10.1016/j.febslet.2005.07.083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Revised: 06/22/2005] [Accepted: 07/19/2005] [Indexed: 10/25/2022]
Abstract
Coat proteins (CPs) of plant viruses are involved in different stages of the viral life cycle such as virion assembly, replication, movement, vector transmission, and regulation of host defense responses. Here, we report that the CPs of two filamentous RNA viruses, potato virus X (PVX, Potexvirus) and potato virus A (PVA, Potyvirus) exhibit an enzyme activity. The CP isolated from PVX virions possesses ATP-binding and ATPase activities. Recombinant PVX and PVA CPs produced in Escherichia coli show Mg2+-dependent ATPase and UTPase activities inhibited by antibodies against virus particles. Deletion of the C-terminal regions of these proteins diminishes their ATPase activity.
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Affiliation(s)
- Daria V Rakitina
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119992, Russia.
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43
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Schepetilnikov MV, Manske U, Solovyev AG, Zamyatnin AA, Schiemann J, Morozov SY. The hydrophobic segment of Potato virus X TGBp3 is a major determinant of the protein intracellular trafficking. J Gen Virol 2005; 86:2379-2391. [PMID: 16033986 DOI: 10.1099/vir.0.80865-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Potato virus X (PVX) encodes three movement proteins, TGBp1, TGBp2 and TGBp3. The 8 kDa TGBp3 is a membrane-embedded protein that has an N-terminal hydrophobic sequence segment and a hydrophilic C terminus. TGBp3 mutants with deletions in the C-terminal hydrophilic region retain the ability to be targeted to cell peripheral structures and to support limited PVX cell-to-cell movement, suggesting that the basic TGBp3 functions are associated with its N-terminal transmembrane region. Fusion of green fluorescent protein to the TGBp3 N terminus abrogates protein activities in intracellular trafficking and virus movement. The intracellular transport of TGBp3 from sites of its synthesis in the rough endoplasmic reticulum (ER) to ER-derived peripheral bodies involves a non-conventional COPII-independent pathway. However, integrity of the C-terminal hydrophilic sequence is required for entrance to this non-canonical route.
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Affiliation(s)
- M V Schepetilnikov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia
| | - U Manske
- Institute of Plant Virology, Microbiology and Biosafety, Federal Biological Research Centre for Agriculture and Forestry, Messeweg 11/12, D-38104 Braunschweig, Germany
| | - A G Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia
| | - A A Zamyatnin
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), PO Box 7080, S-750 07 Uppsala, Sweden
- Natural Sciences Center of A. M. Prokhorov, General Physics Institute, Russian Academy of Sciences, Bld L-2, 38 Vavilov Str., Moscow 119991, Russia
| | - J Schiemann
- Institute of Plant Virology, Microbiology and Biosafety, Federal Biological Research Centre for Agriculture and Forestry, Messeweg 11/12, D-38104 Braunschweig, Germany
| | - S Yu Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia
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44
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Tzanetakis IE, Postman JD, Martin RR. Mint virus X: a novel potexvirus associated with symptoms in ‘Variegata’ mint. Arch Virol 2005; 151:143-53. [PMID: 16096710 DOI: 10.1007/s00705-005-0586-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 05/13/2005] [Indexed: 10/25/2022]
Abstract
Mentha x gracilis 'Variegata', an ornamental mint clone first described about 200 years ago, exhibits virus-like vein banding symptoms. Double-stranded RNA and virion isolations revealed the presence of three viruses in a 'Variegata' plant. Cloning and sequencing disclosed that one of the viruses was a previously unidentified species with similarities to members of the Flexiviridae family, designated as Mint virus X (MVX). The complete nucleotide sequence of the virus was determined. Phylogenetic analysis divulged the close relationship of the virus with lily virus X and strawberry mild yellow edge virus, members of the Potexvirus genus. A reverse transcription-polymerase chain reaction protocol was developed and used for detection of MVX in other 'Variegata' plants. All clones tested, obtained from nurseries around the United States were infected with MVX, making the virus a possible causal agent of the variegated symptoms.
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Affiliation(s)
- I E Tzanetakis
- Department of Botany and Plant Pathology and Center for Gene Research and Biotechnology, Oregon State University, Corvallis, OR 97330, USA.
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45
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Ajjikuttira P, Loh CS, Wong SM. Reciprocal function of movement proteins and complementation of long-distance movement of Cymbidium mosaic virus RNA by Odontoglossum ringspot virus coat protein. J Gen Virol 2005; 86:1543-1553. [PMID: 15831968 DOI: 10.1099/vir.0.80772-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Complementation of movement and coat proteins of the orchid-infecting potexvirus Cymbidium mosaic virus (CymMV) and tobamovirus Odontoglossum ringspot virus (ORSV) was investigated. Nicotiana benthamiana, which is susceptible to both CymMV and ORSV, was used as a model system. Four transgenic lines, each harbouring one of the movement protein (MP) or coat protein (CP) genes of CymMV or ORSV, were constructed. The MP of CymMV consists of three overlapping open reading frames, together called the triple-gene block (TGB). CymMV and ORSV mutants, each carrying an inactivated MP or CP, were generated from the respective biologically active full-length cDNA clones. Complementation was studied by infecting transgenic plants with in vitro transcripts generated from these mutants. The cell-to-cell movement of a movement-deficient CymMV was restored in transgenic plants carrying the ORSV MP transgene. Similarly, CymMV TGB1 transgenic plants were able to rescue the cell-to-cell movement of a movement-deficient ORSV mutant. ORSV CP transgenic plants supported systemic movement of a CymMV CP-deficient mutant. However, in these plants, neither encapsidation of CymMV RNA with ORSV CP nor CymMV CP expression was detected. Long-distance movement of an ORSV CP-deficient mutant was not supported by CymMV CP. The complementation of MPs and CPs of CymMV and ORSV facilitates movement of these viruses in plants, except for long-distance movement of ORSV RNA by CymMV CP.
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Affiliation(s)
- Prabha Ajjikuttira
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Chiang-Shiong Loh
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Sek-Man Wong
- Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604, Singapore
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
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46
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Verchot-Lubicz J. A new cell-to-cell transport model for Potexviruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:283-90. [PMID: 15828680 DOI: 10.1094/mpmi-18-0283] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In the last five years, we have gained significant insight into the role of the Potexvirus proteins in virus movement and RNA silencing. Potexviruses require three movement proteins, named triple gene block (TGB)p1, TGBp2, and TGBp3, and the viral coat protein (CP) to facilitate viral cell-to-cell and vascular transport. TGBp1 is a multifunctional protein that has RNA helicase activity, promotes translation of viral RNAs, increases plasmodesmal size exclusion limits, and suppresses RNA silencing. TGBp2 and TGBp3 are membrane-binding proteins. CP is required for genome encapsidation and forms ribonucleoprotein complexes along with TGBp1 and viral RNA. This review considers the functions of the TGB proteins, how they interact with each other and CP, and how silencing suppression might be linked to viral transport. A new model of the mechanism for Potexvirus transport is proposed.
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Affiliation(s)
- Jeanmarie Verchot-Lubicz
- Oklahoma State University, Department of Entomology and Plant Pathology, Stillwater, OK 74078, USA.
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47
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Ryang BS, Kobori T, Matsumoto T, Kosaka Y, Ohki ST. Cucumber mosaic virus 2b protein compensates for restricted systemic spread of Potato virus Y in doubly infected tobacco. J Gen Virol 2004; 85:3405-3414. [PMID: 15483258 DOI: 10.1099/vir.0.80176-0] [Citation(s) in RCA: 26] [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
Tobacco plants (Nicotiana tabacum cv. Xanthi-nc) inoculated with a necrotic strain of Potato virus Y (PVY, T01 isolate) developed necrotic symptoms in some systemically infected leaves, but not in younger leaves. However, PVY expressed distinct symptoms not only in the older leaves, but also in the younger leaves, of plants that had been doubly inoculated with PVY and with Cucumber mosaic virus (CMV, strain Pepo). A tissue blot immunoassay of tissues from various positions of the stem detected PVY weakly in each stem, but not in the shoot apex, of singly infected plants, whereas PVY was detected at high levels in almost all sections of doubly infected plants. CMV was also detected at high levels in sections of singly and doubly infected plants. Immunohistochemistry of stem tissues showed that in singly infected plants, PVY was confined to external phloem cells and was not detected in internal phloem cells. However, in doubly infected plants, PVY was distributed uniformly throughout whole tissues, including the external phloem, xylem parenchyma and internal phloem cells. In plants that were doubly infected with PVY and Pepo Delta 2b, a modified CMV that cannot translate the 2b protein, the spread of PVY was restricted as in singly infected plants. These results suggested that the plant host has a counterdefence mechanism that restricts systemic spread of PVY T01, and that the 2b protein of CMV strain Pepo negates this restriction.
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Affiliation(s)
- Bo-Song Ryang
- Kyoto Prefectural Institute of Agricultural Biotechnology, Seika-cho, Soraku-gun, Kyoto 619-0244, Japan
- Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8531, Japan
| | - Takashi Kobori
- Kyoto Prefectural Institute of Agricultural Biotechnology, Seika-cho, Soraku-gun, Kyoto 619-0244, Japan
| | - Tadashi Matsumoto
- Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8531, Japan
| | - Yoshitaka Kosaka
- Kyoto Prefectural Institute of Agricultural Biotechnology, Seika-cho, Soraku-gun, Kyoto 619-0244, Japan
| | - Satoshi T Ohki
- Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8531, Japan
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48
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Zamyatnin AA, Solovyev AG, Savenkov EI, Germundsson A, Sandgren M, Valkonen JPT, Morozov SY. Transient coexpression of individual genes encoded by the triple gene block of potato mop-top virus reveals requirements for TGBp1 trafficking. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2004; 17:921-30. [PMID: 15305613 DOI: 10.1094/mpmi.2004.17.8.921] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
TGBp1, TGBp2, and TGBp3, three plant virus movement proteins encoded by the "triple gene block" (TGB), may act in concert to facilitate cell-to-cell transport of viral RNA genomes. Transient expression of Potato mop-top virus (genus Pomovirus) movement proteins was used as a model to reconstruct interactions between TGB proteins. In bombarded epidermal cells of Nicotiana benthamiana, green fluorescent protein (GFP)-TGBp1 was distributed uniformly. However, in the presence of TGBp2 and TGBp3, GFP-TGBp1 was directed to intermediate bodies at the cell periphery, and to cell wall-embedded punctate bodies. Moreover, GFP-TGBp1 migrated into cells immediately adjacent to the bombarded cell. These data suggest that TGBp2 and TGBp3 mediate transport of GFP-TGBp1 to and through plasmodesmata. Mutagenesis of TGBp1 suggested that the NTPase and helicase activities of TGBp1 were not required for its transport to intermediate bodies directed by TGBp2 and TGBp3, but these activities were essential for the protein association with cell wall-embedded punctate bodies and translocation of TGBpl to neighboring cells. The C-terminal region of TGBp1 was critical for trafficking mediated by TGBp2 and TGBp3. Mutation analysis also suggested an involvement of the TGBp2 C-terminal region in interactions with TGBp1.
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Affiliation(s)
- Andrey A Zamyatnin
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), SE-750 07 Uppsala, Sweden.
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49
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Baratova LA, Fedorova NV, Dobrov EN, Lukashina EV, Kharlanov AN, Nasonov VV, Serebryakova MV, Kozlovsky SV, Zayakina OV, Rodionova NP. N-Terminal segment of potato virus X coat protein subunits is glycosylated and mediates formation of a bound water shell on the virion surface. ACTA ACUST UNITED AC 2004; 271:3136-45. [PMID: 15265033 DOI: 10.1111/j.1432-1033.2004.04243.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The primary structures of N-terminal 19-mer peptides, released by limited trypsin treatment of coat protein (CP) subunits in intact virions of three potato virus X (PVX) isolates, were analyzed. Two wild-type PVX strains, Russian (Ru) and British (UK3), were used and also the ST mutant of UK3 in which all 12 serine and threonine residues in the CP N-terminal segment were replaced by glycine or alanine. With the help of direct carbohydrate analysis and MS, it was found that the acetylated N-terminal peptides of both wild-type strains are glycosylated by a single monosaccharide residue (galactose or fucose) at NAcSer in the first position of the CP sequence, whereas the acetylated N-terminal segment of the ST mutant CP is unglycosylated. Fourier transform infrared spectra in the 1000-4000 cm(-1) region were measured for films of the intact and in situ trypsin-degraded PVX preparations at low and high humidity. These spectra revealed the presence of a broad-band in the region of valent vibrations of OH bonds (3100-3700 cm(-1)), which can be represented by superposition of three bands corresponding to tightly bound, weakly bound, and free OH groups. On calculating difference ('wet' minus 'dry') spectra, it was found that the intact wild-type PVX virions are characterized by high water-absorbing capacity and the ability to order a large number of water molecules on the virus particle. This effect was much weaker for the ST mutant and completely absent in the trypsin-treated PVX. It is proposed that the surface-located and glycosylated N-terminal CP segments of intact PVX virions induce the formation of a columnar-type shell from bound water molecules around the virions, which probably play a major role in maintaining the virion surface structure.
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Affiliation(s)
- Lyudmila A Baratova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
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50
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Wagner B, Fuchs H, Adhami F, Ma Y, Scheiner O, Breiteneder H. Plant virus expression systems for transient production of recombinant allergens in Nicotiana benthamiana. Methods 2004; 32:227-34. [PMID: 14962756 DOI: 10.1016/j.ymeth.2003.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2003] [Indexed: 11/15/2022] Open
Abstract
In recent years, several studies have demonstrated the use of autonomously replicating plant viruses as vehicles to express a variety of therapeutic molecules of pharmaceutical interest. Plant virus vectors for expression of heterologous proteins in plants represent an attractive biotechnological tool to complement the conventional production of recombinant proteins in bacterial, fungal, or mammalian cells. Virus vectors are advantageous when high levels of gene expression are desired within a short time, although the instability of the foreign genes in the viral genome may present problems. Similar levels of foreign protein production in transgenic plants often are unattainable, in some cases because of the toxicity of the foreign protein. Now virus-based vectors are for the first time investigated as a means of producing recombinant allergens in plants. Several plant virus vectors have been developed for the expression of foreign proteins. Here, we describe the utilization of tobacco mosaic virus- and potato virus X-based vectors for the transient expression of plant allergens in Nicotiana benthamiana plants. One approach involves the inoculation of tobacco plants with infectious RNA transcribed in vitro from a cDNA copy of the recombinant viral genome. Another approach utilizes the transfection of whole plants from wounds inoculated with Agrobacterium tumefaciens containing cDNA copies of recombinant plus-sense RNA viruses.
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Affiliation(s)
- Birgit Wagner
- Department of Pathophysiology, University of Vienna, General Hospital Vienna, EBO-3Q, Waehringer Guertel 18-20, 1090 Vienna, Austria.
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