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Zhao S, Gong P, Liu J, Liu H, Lozano-Durán R, Zhou X, Li F. Geminivirus C5 proteins mediate formation of virus complexes at plasmodesmata for viral intercellular movement. PLANT PHYSIOLOGY 2023; 193:322-338. [PMID: 37306279 DOI: 10.1093/plphys/kiad338] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 04/21/2023] [Accepted: 05/16/2023] [Indexed: 06/13/2023]
Abstract
Movement proteins (MPs) encoded by plant viruses deliver viral genomes to plasmodesmata (PD) to ensure intracellular and intercellular transport. However, how the MPs encoded by monopartite geminiviruses are targeted to PD is obscure. Here, we demonstrate that the C5 protein of tomato yellow leaf curl virus (TYLCV) anchors to PD during the viral infection following trafficking from the nucleus along microfilaments in Nicotiana benthamiana. C5 could move between cells and partially complement the traffic of a movement-deficient turnip mosaic virus (TuMV) mutant (TuMV-GFP-P3N-PIPO-m1) into adjacent cells. The TYLCV-C5 null mutant (TYLCV-mC5) attenuates viral pathogenicity and decreases viral DNA and protein accumulation, and ectopic overexpression of C5 enhances viral DNA accumulation. Interaction assays between TYLCV-C5 and the other eight viral proteins described in TYLCV reveal that C5 associates with C2 in the nucleus and with V2 in the cytoplasm and at PD. The V2 protein is mainly localized in the nucleus and cytoplasmic granules when expressed alone; in contrast, V2 forms small punctate granules at PD when co-expressed with C5 or in TYLCV-infected cells. The interaction of V2 and C5 also facilitates their nuclear export. Furthermore, C5-mediated PD localization of V2 is conserved in two other geminiviruses. Therefore, this study solves a long-sought-after functional connection between PD and the geminivirus movement and improves our understanding of geminivirus-encoded MPs and their potential cellular and molecular mechanisms.
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Affiliation(s)
- Siwen Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Pan Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Hui Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Rosa Lozano-Durán
- Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, Tübingen D-72076, Germany
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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2
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Breves SS, Silva FA, Euclydes NC, Saia TFF, Jean-Baptiste J, Andrade Neto ER, Fontes EPB. Begomovirus-Host Interactions: Viral Proteins Orchestrating Intra and Intercellular Transport of Viral DNA While Suppressing Host Defense Mechanisms. Viruses 2023; 15:1593. [PMID: 37515277 PMCID: PMC10384534 DOI: 10.3390/v15071593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Begomoviruses, which belong to the Geminiviridae family, are intracellular parasites transmitted by whiteflies to dicotyledonous plants thatsignificantly damage agronomically relevant crops. These nucleus-replicating DNA viruses move intracellularly from the nucleus to the cytoplasm and then, like other plant viruses, cause disease by spreading systemically throughout the plant. The transport proteins of begomoviruses play a crucial role in recruiting host components for the movement of viral DNA within and between cells, while exhibiting functions that suppress the host's immune defense. Pioneering studies on species of the Begomovirus genus have identified specific viral transport proteins involved in intracellular transport, cell-to-cell movement, and systemic spread. Recent research has primarily focused on viral movement proteins and their interactions with the cellular host transport machinery, which has significantly expanded understanding on viral infection pathways. This review focuses on three components within this context: (i) the role of viral transport proteins, specifically movement proteins (MPs) and nuclear shuttle proteins (NSPs), (ii) their ability to recruit host factors for intra- and intercellular viral movement, and (iii) the suppression of antiviral immunity, with a particular emphasis on bipartite begomoviral movement proteins.
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Affiliation(s)
- Sâmera S Breves
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - Fredy A Silva
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - Nívea C Euclydes
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - Thainá F F Saia
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - James Jean-Baptiste
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - Eugenio R Andrade Neto
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
| | - Elizabeth P B Fontes
- Department of Biochemistry and Molecular Biology/Bioagro, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa 36570.000, MG, Brazil
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3
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Chang H, Lee C, Chang C, Jan F. FKBP-type peptidyl-prolyl cis-trans isomerase interacts with the movement protein of tomato leaf curl New Delhi virus and impacts viral replication in Nicotiana benthamiana. MOLECULAR PLANT PATHOLOGY 2022; 23:561-575. [PMID: 34984809 PMCID: PMC8916215 DOI: 10.1111/mpp.13181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/29/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Begomoviruses belonging to the family Geminiviridae are plant-infecting DNA viruses. Begomoviral movement protein (MP) has been reported to be required for virus movement, host range determination, and symptom development. In the present study, the FK506-binding protein (FKBP)-type peptidyl-prolyl cis-trans isomerase (NbFKPPIase) of Nicotiana benthamiana was identified by a yeast two-hybrid screening system using the MP of tomato leaf curl New Delhi virus (ToLCNDV) oriental melon (OM) isolate (MPOM ) as bait. Transient silencing of the gene encoding NbFKPPIase increased replication of three test begomoviruses, and transient overexpression decreased viral replication, indicating that NbFKPPIase plays a role in defence against begomoviruses. However, infection of N. benthamiana by ToLCNDV-OM or overexpression of the gene encoding MPOM drastically reduced the expression of the gene encoding NbFKPPIase. Fluorescence resonance energy transfer analysis revealed that MPOM interacted with NbFKPPIase in the periphery of cells. Expression of the gene encoding NbFKPPIase was induced by salicylic acid but not by methyl jasmonate or ethylene. Moreover, the expression of the gene encoding NbFKPPIase was down-regulated in response to 6-benzylaminopurine and up-regulated in response to gibberellin or indole-3-acetic acid, suggesting a role of NbFKPPIase in plant development. Transcriptome analysis and comparison of N. benthamiana transient silencing and overexpression of the gene encoding MPOM led to the identification of several differentially expressed genes whose functions are probably associated with cell cycle regulation. Our results indicate that begomoviruses could suppress NbFKPPIase-mediated defence and biological functions by transcriptional inhibition and physical interaction between MP and NbFKPPIase to facilitate infection.
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Affiliation(s)
- Ho‐Hsiung Chang
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
| | - Chia‐Hwa Lee
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Ph.D. Program in Microbial GenomicsNational Chung Hsing University and Academia SinicaTaichung and TaipeiTaiwan
| | - Chung‐Jan Chang
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Department of Plant PathologyUniversity of GeorgiaGriffinGeorgiaUSA
| | - Fuh‐Jyh Jan
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Ph.D. Program in Microbial GenomicsNational Chung Hsing University and Academia SinicaTaichung and TaipeiTaiwan
- Advanced Plant Biotechnology CenterNational Chung Hsing UniversityTaichungTaiwan
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4
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Devendran R, Namgial T, Reddy KK, Kumar M, Zarreen F, Chakraborty S. Insights into the multifunctional roles of geminivirus-encoded proteins in pathogenesis. Arch Virol 2022; 167:307-326. [PMID: 35079902 DOI: 10.1007/s00705-021-05338-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 10/23/2021] [Indexed: 12/18/2022]
Abstract
Geminiviruses are a major threat to agriculture in tropical and subtropical regions of the world. Geminiviruses have small genome with limited coding capacity. Despite this limitation, these viruses have mastered hijacking the host cellular metabolism for their survival. To compensate for the small size of their genome, geminiviruses encode multifunctional proteins. In addition, geminiviruses associate themselves with satellite DNA molecules which also encode proteins that support the virus in establishing successful infection. Geminiviral proteins recruit multiple host factors, suppress the host defense, and manipulate host metabolism to establish infection. We have updated the knowledge accumulated about the proteins of geminiviruses and their satellites in the context of pathogenesis in a single review. We also discuss their interactions with host factors to provide a mechanistic understanding of the infection process.
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Affiliation(s)
- Ragunathan Devendran
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Tsewang Namgial
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Kishore Kumar Reddy
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Manish Kumar
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Fauzia Zarreen
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
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5
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Gouveia-Mageste BC, Martins LGC, Dal-Bianco M, Machado JPB, da Silva JCF, Kim AY, Yazaki J, dos Santos AA, Ecker JR, Fontes EPB. A plant-specific syntaxin-6 protein contributes to the intracytoplasmic route for the begomovirus CabLCV. PLANT PHYSIOLOGY 2021; 187:158-173. [PMID: 34618135 PMCID: PMC8418432 DOI: 10.1093/plphys/kiab252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/09/2021] [Indexed: 06/13/2023]
Abstract
Because of limited free diffusion in the cytoplasm, viruses must use active transport mechanisms to move intracellularly. Nevertheless, how the plant single-stranded DNA begomoviruses hijack the host intracytoplasmic transport machinery to move from the nucleus to the plasmodesmata remains enigmatic. Here, we identified nuclear shuttle protein (NSP)-interacting proteins from Arabidopsis (Arabidopsis thaliana) by probing a protein microarray and demonstrated that the cabbage leaf curl virus NSP, a facilitator of the nucleocytoplasmic trafficking of viral (v)DNA, interacts in planta with an endosomal vesicle-localized, plant-specific syntaxin-6 protein, designated NSP-interacting syntaxin domain-containing protein (NISP). NISP displays a proviral function, unlike the syntaxin-6 paralog AT2G18860 that failed to interact with NSP. Consistent with these findings, nisp-1 mutant plants were less susceptible to begomovirus infection, a phenotype reversed by NISP complementation. NISP-overexpressing lines accumulated higher levels of vDNA than wild-type. Furthermore, NISP interacted with an NSP-interacting GTPase (NIG) involved in NSP-vDNA nucleocytoplasmic translocation. The NISP-NIG interaction was enhanced by NSP. We also showed that endosomal NISP associates with vDNA. NISP may function as a docking site for recruiting NIG and NSP into endosomes, providing a mechanism for the intracytoplasmic translocation of the NSP-vDNA complex toward and from the cell periphery.
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Affiliation(s)
- Bianca Castro Gouveia-Mageste
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Laura Gonçalves Costa Martins
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Maximiller Dal-Bianco
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - João Paulo Batista Machado
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
- Agronomy Institute, Universidade Federal de Viçosa, Campus Florestal, Florestal, Minas Gerais 35690-000, Brazil
| | - José Cleydson Ferreira da Silva
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Alice Y. Kim
- Genomic Analysis Laboratory, Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Junshi Yazaki
- Genomic Analysis Laboratory, Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
- RIKEN Center for Integrative Medical Sciences, Yokohama City, Kanagawa 230-0045, Japan
| | - Anésia Aparecida dos Santos
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
- Departament of General Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Joseph R. Ecker
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute of Biological Studies, La Jolla, California 92037, USA
| | - Elizabeth Pacheco Batista Fontes
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
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6
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Loriato VAP, Martins LGC, Euclydes NC, Reis PAB, Duarte CEM, Fontes EPB. Engineering resistance against geminiviruses: A review of suppressed natural defenses and the use of RNAi and the CRISPR/Cas system. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 292:110410. [PMID: 32005374 DOI: 10.1016/j.plantsci.2020.110410] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/22/2019] [Accepted: 01/07/2020] [Indexed: 05/21/2023]
Abstract
The Geminiviridae family is one of the most successful and largest families of plant viruses that infect a large variety of important dicotyledonous and monocotyledonous crops and cause significant yield losses worldwide. This broad spectrum of host range is only possible because geminiviruses have evolved sophisticated strategies to overcome the arsenal of antiviral defenses in such diverse plant species. In addition, geminiviruses evolve rapidly through recombination and pseudo-recombination to naturally create a great diversity of virus species with divergent genome sequences giving the virus an advantage over the host recognition system. Therefore, it is not surprising that efficient molecular strategies to combat geminivirus infection under open field conditions have not been fully addressed. In this review, we present the anti-geminiviral arsenal of plant defenses, the evolved virulence strategies of geminiviruses to overcome these plant defenses and the most recent strategies that have been engineered for transgenic resistance. Although, the in vitro reactivation of suppressed natural defenses as well as the use of RNAi and CRISPR/Cas systems hold the potential for achieving broad-range resistance and/or immunity, potential drawbacks have been associated with each case.
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Affiliation(s)
- Virgílio A P Loriato
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil; Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil
| | - Laura G C Martins
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil
| | - Nívea C Euclydes
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil
| | - Pedro A B Reis
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil; Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil
| | - Christiane E M Duarte
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil; Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil
| | - Elizabeth P B Fontes
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil; Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-000, Brazil.
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7
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Martins LGC, Raimundo GAS, Ribeiro NGA, Silva JCF, Euclydes NC, Loriato VAP, Duarte CEM, Fontes EPB. A Begomovirus Nuclear Shuttle Protein-Interacting Immune Hub: Hijacking Host Transport Activities and Suppressing Incompatible Functions. FRONTIERS IN PLANT SCIENCE 2020; 11:398. [PMID: 32322262 PMCID: PMC7156597 DOI: 10.3389/fpls.2020.00398] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/19/2020] [Indexed: 05/21/2023]
Abstract
Begomoviruses (Geminiviridae family) represent a severe constraint to agriculture worldwide. As ssDNA viruses that replicate in the nuclei of infected cells, the nascent viral DNA has to move to the cytoplasm and then to the adjacent cell to cause disease. The begomovirus nuclear shuttle protein (NSP) assists the intracellular transport of viral DNA from the nucleus to the cytoplasm and cooperates with the movement protein (MP) for the cell-to-cell translocation of viral DNA to uninfected cells. As a facilitator of intra- and intercellular transport of viral DNA, NSP is predicted to associate with host proteins from the nuclear export machinery, the intracytoplasmic active transport system, and the cell-to-cell transport complex. Furthermore, NSP functions as a virulence factor that suppresses antiviral immunity against begomoviruses. In this review, we focus on the protein-protein network that converges on NSP with a high degree of centrality and forms an immune hub against begomoviruses. We also describe the compatible host functions hijacked by NSP to promote the nucleocytoplasmic and intracytoplasmic movement of viral DNA. Finally, we discuss the NSP virulence function as a suppressor of the recently described NSP-interacting kinase 1 (NIK1)-mediated antiviral immunity. Understanding the NSP-host protein-protein interaction (PPI) network will probably pave the way for strategies to generate more durable resistance against begomoviruses.
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8
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Teixeira RM, Ferreira MA, Raimundo GAS, Loriato VAP, Reis PAB, Fontes EPB. Virus perception at the cell surface: revisiting the roles of receptor-like kinases as viral pattern recognition receptors. MOLECULAR PLANT PATHOLOGY 2019; 20:1196-1202. [PMID: 31094066 PMCID: PMC6715618 DOI: 10.1111/mpp.12816] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Activation of antiviral innate immune responses depends on the recognition of viral components or viral effectors by host receptors. This virus recognition system can activate two layers of host defence, pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI). While ETI has long been recognized as an efficient plant defence against viruses, the concept of antiviral PTI has only recently been integrated into virus-host interaction models, such as the RNA silencing-based defences that are triggered by viral dsRNA PAMPs produced during infection. Emerging evidence in the literature has included the classical PTI in the antiviral innate immune arsenal of plant cells. Therefore, our understanding of PAMPs has expanded to include not only classical PAMPS, such as bacterial flagellin or fungal chitin, but also virus-derived nucleic acids that may also activate PAMP recognition receptors like the well-documented phenomenon observed for mammalian viruses. In this review, we discuss the notion that plant viruses can activate classical PTI, leading to both unique antiviral responses and conserved antipathogen responses. We also present evidence that virus-derived nucleic acid PAMPs may elicit the NUCLEAR SHUTTLE PROTEIN-INTERACTING KINASE 1 (NIK1)-mediated antiviral signalling pathway that transduces an antiviral signal to suppress global host translation.
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Affiliation(s)
- Ruan M. Teixeira
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Departament of Biochemistry and Molecular BiologyUniversidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
| | - Marco Aurélio Ferreira
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Departament of Biochemistry and Molecular BiologyUniversidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
| | - Gabriel A. S. Raimundo
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Agronomy Institute, Universidade Federal de ViçosaCampus FlorestalFlorestalMinas Gerais35690‐000Brazil
| | - Virgílio A. P. Loriato
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Departament of Biochemistry and Molecular BiologyUniversidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
| | - Pedro A. B. Reis
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Departament of Biochemistry and Molecular BiologyUniversidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
| | - Elizabeth P. B. Fontes
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Universidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
- Departament of Biochemistry and Molecular BiologyUniversidade Federal de ViçosaViçosaMinas Gerais36570‐000Brazil
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9
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Calil IP, Quadros IPS, Araújo TC, Duarte CEM, Gouveia-Mageste BC, Silva JCF, Brustolini OJB, Teixeira RM, Oliveira CN, Milagres RWMM, Martins GS, Chory J, Reis PAB, Machado JPB, Fontes EPB. A WW Domain-Containing Protein Forms Immune Nuclear Bodies against Begomoviruses. MOLECULAR PLANT 2018; 11:1449-1465. [PMID: 30296599 DOI: 10.1016/j.molp.2018.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/27/2018] [Accepted: 09/28/2018] [Indexed: 05/23/2023]
Abstract
The bipartite begomoviruses (Geminiviridae family), which are DNA viruses that replicate in the nucleus of infected cells, encode the nuclear shuttle protein (NSP) to facilitate the translocation of viral DNA from the nucleus to the cytoplasm via nuclear pores. This intracellular trafficking of NSP-DNA complexes is accessorized by the NSP-interacting guanosine triphosphatase (NIG) at the cytosolic side. Here, we report the nuclear redistribution of NIG by AtWWP1, a WW domain-containing protein that forms immune nuclear bodies (NBs) against begomoviruses. We demonstrated that AtWWP1 relocates NIG from the cytoplasm to the nucleus where it is confined to AtWWP1-NBs, suggesting that the NIG-AtWWP1 interaction may interfere with the NIG pro-viral function associated with its cytosolic localization. Consistent with this assumption, loss of AtWWP1 function cuased plants more susceptible to begomovirus infection, whereas overexpression of AtWWP1 enhanced plant resistance to begomovirus. Furthermore, we found that a mutant version of AtWWP1 defective for NB formation was no longer capable of interacting with and relocating NIG to the nucleus and lost its immune function against begomovirus. The antiviral function of AtWWP1-NBs, however, could be antagonized by viral infection that induced either the disruption or a decrease in the number of AtWWP1-NBs. Collectively, these results led us to propose that AtWWP1 organizes nuclear structures into nuclear foci, which provide intrinsic immunity against begomovirus infection.
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Affiliation(s)
- Iara P Calil
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Iana P S Quadros
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Thais C Araújo
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Christiane E M Duarte
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Bianca C Gouveia-Mageste
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - José Cleydson F Silva
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Otávio J B Brustolini
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Ruan M Teixeira
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Cauê N Oliveira
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Rafael W M M Milagres
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Gilberto S Martins
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; Departament of Genetics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Joanne Chory
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute of Biological Studies, La Jolla, CA 92037, USA
| | - Pedro A B Reis
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Joao Paulo B Machado
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; Agronomy Institute, Universidade Federal de Viçosa, Campus Florestal, Florestal, Minas Gerais 35690-000, Brazil.
| | - Elizabeth P B Fontes
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil.
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Kushawaha AK, Dasgupta I. Infectivity of cloned begomoviral DNAs: an appraisal. Virusdisease 2018; 30:13-21. [PMID: 31143828 DOI: 10.1007/s13337-018-0453-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 04/18/2018] [Indexed: 11/28/2022] Open
Abstract
Infectivity of cloned begomoviral DNAs is an important criterion to establish the etiology of the disease it causes, to study viral gene functions and host-virus interactions. Three main methods have been employed to study infectivity; mechanical inoculation with cloned viral DNA using abrasives, Agrobacterium-mediated inoculation (agroinoculation) of cloned viral DNA and bombardment using microprojectiles coated with cloned viral DNA (biolistics). Each method has its own advantages and disadvantages and the adoption of one over the other for demonstrating infectivity depends on various factors. This review compares the various features associated with the above three methods.
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Affiliation(s)
- Akhilesh Kumar Kushawaha
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Indranil Dasgupta
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
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11
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Shen Q, Hu T, Bao M, Cao L, Zhang H, Song F, Xie Q, Zhou X. Tobacco RING E3 Ligase NtRFP1 Mediates Ubiquitination and Proteasomal Degradation of a Geminivirus-Encoded βC1. MOLECULAR PLANT 2016; 9:911-25. [PMID: 27018391 DOI: 10.1016/j.molp.2016.03.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 02/17/2016] [Accepted: 03/03/2016] [Indexed: 05/19/2023]
Abstract
The βC1 protein encoded by the Tomato yellow leaf curl China virus-associated betasatellite functions as a pathogenicity determinant. To better understand the molecular basis whereby βC1 functions in pathogenicity, a yeast two-hybrid screen of a tobacco cDNA library was carried out using βC1 as the bait. The screen revealed that βC1 interacts with a tobacco RING-finger protein designated NtRFP1, which was further confirmed by the bimolecular fluorescence complementation and co-immunoprecipitation assays in Nicotiana benthamiana cells. Expression of NtRFP1 was induced by βC1, and in vitro ubiquitination assays showed that NtRFP1 is a functional E3 ubiquitin ligase that mediates βC1 ubiquitination. In addition, βC1 was shown to be ubiquitinated in vivo and degraded by the plant 26S proteasome. After viral infection, plants overexpressing NtRFP1 developed attenuated symptoms, whereas plants with silenced expression of NtRFP1 showed severe symptoms. Other lines of evidence showed that NtRFP1 attenuates βC1-induced symptoms through promoting its degradation by the 26S proteasome. Taken together, our results suggest that tobacco RING E3 ligase NtRFP1 attenuates disease symptoms by interacting with βC1 to mediate its ubiquitination and degradation via the ubiquitin/26S proteasome system.
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Affiliation(s)
- Qingtang Shen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Tao Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Min Bao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Linge Cao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Huawei Zhang
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Fengmin Song
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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12
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Brustolini OJ, Machado JPB, Condori-Apfata JA, Coco D, Deguchi M, Loriato VA, Pereira WA, Alfenas-Zerbini P, Zerbini FM, Inoue-Nagata AK, Santos AA, Chory J, Silva FF, Fontes EP. Sustained NIK-mediated antiviral signalling confers broad-spectrum tolerance to begomoviruses in cultivated plants. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:1300-1311. [PMID: 25688422 PMCID: PMC4857726 DOI: 10.1111/pbi.12349] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 12/30/2014] [Accepted: 01/06/2015] [Indexed: 05/20/2023]
Abstract
Begomovirus-associated epidemics currently threaten tomato production worldwide due to the emergence of highly pathogenic virus species and the proliferation of a whitefly B biotype vector that is adapted to tomato. To generate an efficient defence against begomovirus, we modulated the activity of the immune defence receptor nuclear shuttle protein (NSP)-interacting kinase (NIK) in tomato plants; NIK is a virulence target of the begomovirus NSP during infection. Mutation of T474 within the kinase activation loop promoted the constitutive activation of NIK-mediated defences, resulting in the down-regulation of translation-related genes and the suppression of global translation. Consistent with these findings, transgenic lines harbouring an activating mutation (T474D) were tolerant to the tomato-infecting begomoviruses ToYSV and ToSRV. This phenotype was associated with reduced loading of coat protein viral mRNA in actively translating polysomes, lower infection efficiency and reduced accumulation of viral DNA in systemic leaves. Our results also add some relevant insights into the mechanism underlying the NIK-mediated defence. We observed that the mock-inoculated T474D-overexpressing lines showed a constitutively infected wild-type transcriptome, indicating that the activation of the NIK-mediated signalling pathway triggers a typical response to begomovirus infection. In addition, the gain-of-function mutant T474D could sustain an activated NIK-mediated antiviral response in the absence of the virus, further confirming that phosphorylation of Thr-474 is the crucial event that leads to the activation of the kinase.
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Affiliation(s)
- Otávio J.B. Brustolini
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Joao Paulo B. Machado
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Jorge A. Condori-Apfata
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Daniela Coco
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Michihito Deguchi
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Virgílio A.P. Loriato
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Welison A. Pereira
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Poliane Alfenas-Zerbini
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Francisco M. Zerbini
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Alice K. Inoue-Nagata
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
- Embrapa Vegetables, Brasília, DF, Brazil
| | - Anesia A. Santos
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
| | - Joanne Chory
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Fabyano F. Silva
- Departamento de Zootecnia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Elizabeth P.B. Fontes
- Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil
- National Institute of Science and Technology in Plant–Pest Interactions, Bioagro, Viçosa, MG, Brazil
- Correspondence (Tel +55 31 3899 2948; fax +55-31-38992864; )
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13
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Hanley-Bowdoin L, Bejarano ER, Robertson D, Mansoor S. Geminiviruses: masters at redirecting and reprogramming plant processes. Nat Rev Microbiol 2013; 11:777-88. [DOI: 10.1038/nrmicro3117] [Citation(s) in RCA: 484] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
Geminiviruses are a family of plant viruses that cause economically important plant diseases worldwide. These viruses have circular single-stranded DNA genomes and four to eight genes that are expressed from both strands of the double-stranded DNA replicative intermediate. The transcription of these genes occurs under the control of two bidirectional promoters and one monodirectional promoter. The viral proteins function to facilitate virus replication, virus movement, the assembly of virus-specific nucleoprotein particles, vector transmission and to counteract plant host defence responses. Recent research findings have provided new insights into the structure and function of these proteins and have identified numerous host interacting partners. Most of the viral proteins have been shown to be multifunctional, participating in multiple events during the infection cycle and have, indeed, evolved coordinated interactions with host proteins to ensure a successful infection. Here, an up-to-date review of viral protein structure and function is presented, and some areas requiring further research are identified.
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Affiliation(s)
- Vincent N Fondong
- Department of Biological Sciences, Delaware State University, 1200 North DuPont Highway, Dover, DE 19901, USA.
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15
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Krenz B, Jeske H, Kleinow T. The induction of stromule formation by a plant DNA-virus in epidermal leaf tissues suggests a novel intra- and intercellular macromolecular trafficking route. FRONTIERS IN PLANT SCIENCE 2012; 3:291. [PMID: 23293643 PMCID: PMC3530832 DOI: 10.3389/fpls.2012.00291] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 12/06/2012] [Indexed: 05/20/2023]
Abstract
Stromules are dynamic thin protrusions of membrane envelope from plant cell plastids. Despite considerable progress in understanding the importance of certain cytoskeleton elements and motor proteins for stromule maintenance, their function within the cell has yet to be unraveled. Several viruses cause a remodulation of plastid structures and stromule biogenesis within their host plants. For RNA-viruses these interactions were demonstrated to be relevant to the infection process. An involvement of plastids and stromules is assumed in the DNA-virus life cycle as well, but their functional role needs to be determined. Recent findings support a participation of heat shock cognate 70 kDa protein (cpHSC70-1)-containing stromules induced by a DNA-virus infection (Abutilon mosaic virus, AbMV, Geminiviridae) in intra- and intercellular molecule exchange. The chaperone cpHSC70-1 was shown to interact with the AbMV movement protein (MP). Bimolecular fluorescence complementation confirmed the interaction of cpHSC70-1 and MP, and showed a homo-oligomerization of either protein in planta. The complexes were detected at the cellular margin and co-localized with plastids. In healthy plant tissues cpHSC70-1-oligomers occurred in distinct spots at chloroplasts and in small filaments extending from plastids to the cell periphery. AbMV-infection induced a cpHSC70-1-containing stromule network that exhibits elliptical dilations and transverses whole cells. Silencing of the cpHSC70 gene revealed an impact of cpHSC70 on chloroplast stability and restricted AbMV movement, but not viral DNA accumulation. Based on these data, a model is suggested in which these stromules function in molecule exchange between plastids and other organelles and perhaps other cells. AbMV may utilize cpHSC70-1 for trafficking along plastids and stromules into a neighboring cell or from plastids into the nucleus. Experimental approaches to investigate this hypothesis are discussed.
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Affiliation(s)
- Björn Krenz
- Plant Pathology and Plant-Microbe Biology, Cornell UniversityIthaca, NY, USA
| | - Holger Jeske
- Molecular Biology and Plant Virology, Institute of Biology, Universität StuttgartStuttgart, Germany
| | - Tatjana Kleinow
- Molecular Biology and Plant Virology, Institute of Biology, Universität StuttgartStuttgart, Germany
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16
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Shen Q, Liu Z, Song F, Xie Q, Hanley-Bowdoin L, Zhou X. Tomato SlSnRK1 protein interacts with and phosphorylates βC1, a pathogenesis protein encoded by a geminivirus β-satellite. PLANT PHYSIOLOGY 2011; 157:1394-406. [PMID: 21885668 PMCID: PMC3252149 DOI: 10.1104/pp.111.184648] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 08/29/2011] [Indexed: 05/19/2023]
Abstract
The βC1 protein of tomato yellow leaf curl China β-satellite functions as a pathogenicity determinant. To better understand the molecular basis of βC1 in pathogenicity, a yeast two-hybrid screen of a tomato (Solanum lycopersicum) cDNA library was carried out using βC1 as bait. βC1 interacted with a tomato SUCROSE-NONFERMENTING1-related kinase designated as SlSnRK1. Their interaction was confirmed using a bimolecular fluorescence complementation assay in Nicotiana benthamiana cells. Plants overexpressing SnRK1 were delayed for symptom appearance and contained lower levels of viral and satellite DNA, while plants silenced for SnRK1 expression developed symptoms earlier and accumulated higher levels of viral DNA. In vitro kinase assays showed that βC1 is phosphorylated by SlSnRK1 mainly on serine at position 33 and threonine at position 78. Plants infected with βC1 mutants containing phosphorylation-mimic aspartate residues in place of serine-33 and/or threonine-78 displayed delayed and attenuated symptoms and accumulated lower levels of viral DNA, while plants infected with phosphorylation-negative alanine mutants contained higher levels of viral DNA. These results suggested that the SlSnRK1 protein attenuates geminivirus infection by interacting with and phosphorylating the βC1 protein.
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17
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Santos AA, Carvalho CM, Florentino LH, Ramos HJO, Fontes EPB. Conserved threonine residues within the A-loop of the receptor NIK differentially regulate the kinase function required for antiviral signaling. PLoS One 2009; 4:e5781. [PMID: 19492062 PMCID: PMC2686266 DOI: 10.1371/journal.pone.0005781] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 05/12/2009] [Indexed: 11/18/2022] Open
Abstract
NSP-interacting kinase (NIK1) is a receptor-like kinase identified as a virulence target of the begomovirus nuclear shuttle protein (NSP). We found that NIK1 undergoes a stepwise pattern of phosphorylation within its activation-loop domain (A-loop) with distinct roles for different threonine residues. Mutations at Thr-474 or Thr-468 impaired autophosphorylation and were defective for kinase activation. In contrast, a mutation at Thr-469 did not impact autophosphorylation and increased substrate phosphorylation, suggesting an inhibitory role for Thr-469 in kinase function. To dissect the functional significance of these results, we used NSP-expressing virus infection as a mechanism to interfere with wild type and mutant NIK1 action in plants. The NIK1 knockout mutant shows enhanced susceptibility to virus infections, a phenotype that could be complemented with ectopic expression of a 35S-NIK1 or 35S-T469A NIK1 transgenes. However, ectopic expression of an inactive kinase or the 35S-T474A NIK1 mutant did not reverse the enhanced susceptibility phenotype of knockout lines, demonstrating that Thr-474 autophosphorylation was needed to transduce a defense response to geminiviruses. Furthermore, mutations at Thr-474 and Thr-469 residues antagonistically affected NIK-mediated nuclear relocation of the downstream effector rpL10. These results establish that NIK1 functions as an authentic defense receptor as it requires activation to elicit a defense response. Our data also suggest a model whereby phosphorylation-dependent activation of a plant receptor-like kinase enables the A-loop to control differentially auto- and substrate phosphorylation.
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Affiliation(s)
- Anésia A. Santos
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Claudine M. Carvalho
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Lilian H. Florentino
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Humberto J. O. Ramos
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Elizabeth P. B. Fontes
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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