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Chakraborty J, Sobol G, Xia F, Zhang N, Martin GB, Sessa G. PP2C phosphatase Pic14 negatively regulates tomato Pto/Prf-triggered immunity by inhibiting MAPK activation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 39032095 DOI: 10.1111/tpj.16937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/28/2024] [Accepted: 07/09/2024] [Indexed: 07/22/2024]
Abstract
Type 2C protein phosphatases (PP2Cs) are emerging as important regulators of plant immune responses, although little is known about how they might impact nucleotide-binding, leucine-rich repeat (NLR)-triggered immunity (NTI). We discovered that expression of the PP2C immunity-associated candidate 14 gene (Pic14) is induced upon activation of the Pto/Prf-mediated NTI response in tomato. Pto/Prf recognizes the effector AvrPto translocated into plant cells by the pathogen Pseudomonas syringae pv. tomato (Pst) and activate a MAPK cascade and other responses which together confer resistance to bacterial speck disease. Pic14 encodes a PP2C with an N-terminal kinase-interacting motif (KIM) and a C-terminal phosphatase domain. Upon inoculation with Pst-AvrPto, Pto/Prf-expressing tomato plants with loss-of-function mutations in Pic14 developed less speck disease, specifically in older leaves, compared to wild-type plants. Transient expression of Pic14 in leaves of Nicotiana benthamiana and tomato inhibited cell death typically induced by Pto/Prf and the MAPK cascade members M3Kα and Mkk2. The cell death-suppressing activity of Pic14 was dependent on the KIM and the catalytic phosphatase domain. Pic14 inhibited M3Kα- and Mkk2-mediated activation of immunity-associated MAPKs and Pic14 was shown to be an active phosphatase that physically interacts with and dephosphorylates Mkk2 in a KIM-dependent manner. Together, our results reveal Pic14 as an important negative regulator of Pto/Prf-triggered immunity by interacting with and dephosphorylating Mkk2.
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Affiliation(s)
- Joydeep Chakraborty
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Guy Sobol
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Fan Xia
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
| | - Ning Zhang
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, 14853, USA
| | - Guido Sessa
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
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Qi N, Yan J, Lei P, Kang W, Liu X, Xuan Y, Fan H, Wang Y, Yang N, Chen L, Duan Y, Zhu X. Transcriptome Analysis of GmPUB20A Overexpressing and RNA-Interferencing Transgenic Hairy Roots Reveals Underlying Negative Role in Soybean Resistance to Cyst Nematode. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:18059-18073. [PMID: 37948664 DOI: 10.1021/acs.jafc.3c05617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Ubiquitination genes are key components of plant responses to biotic stress. GmPUB20A, a ubiquitination gene, plays a negative role in soybean resistance to soybean cyst nematode (SCN). In this study, we employed high-throughput sequencing to investigate transcriptional changes in GmPUB20A overexpressing and RNA-interfering transgenic hairy roots. Totally, 7661 differentially expressed genes (DEGs) were identified. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that DEGs were significantly enriched in disease resistance and signal transduction pathways. In addition, silencing Glyma.15G021600 and Glyma.09G284700 by siRNA, the total number of nematodes was decreased by 33.48% and 27.47% than control plants, respectively. Further, GUS activity and reactive oxygen species (ROS) assays revealed that GmPUB20A, Glyma.15G021600, and Glyma.09G284700 respond to SCN parasitism and interfere with the accumulation of ROS in plant roots, respectively. Collectively, our study provides insights into the molecular mechanism of GmPUB20A in soybean resistance to SCN.
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Affiliation(s)
- Nawei Qi
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
- College of Life Science, Shenyang Normal University, Shenyang 110034, China
| | - Jichen Yan
- Institute of Plant Protection, Liaoning Academy of Agriculture Sciences, Shenyang 100161, China
| | - Piao Lei
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wenshu Kang
- College of Environment, Shenyang University, Shenyang 110044, China
| | - Xiaoyu Liu
- College of Sciences, Shenyang Agricultural University, Shenyang 110866, China
| | - Yuanhu Xuan
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Haiyan Fan
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Yuanyuan Wang
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Biological Science and Technology, Shenyang Agricultural University, Shenyang 110866, China
| | - Ning Yang
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Lijie Chen
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Yuxi Duan
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiaofeng Zhu
- Nematology Institute of Northern China, Shenyang Agricultural University, Shenyang 110866, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
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3
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Kong Y, Chen J, Jiang L, Chen H, Shen Y, Wang L, Yan Y, Zhou H, Zheng H, Yu F, Ming Z. Structural and biochemical basis of Arabidopsis FERONIA receptor kinase-mediated early signaling initiation. PLANT COMMUNICATIONS 2023:100559. [PMID: 36774537 PMCID: PMC10363478 DOI: 10.1016/j.xplc.2023.100559] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/11/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Accumulating evidence indicates that early and essential events for receptor-like kinase (RLK) function involve both autophosphorylation and substrate phosphorylation. However, the structural and biochemical basis for these events is largely unclear. Here, we used RLK FERONIA (FER) as a model and crystallized its core kinase domain (FER-KD) and two FER-KD mutants (K565R, S525A) in complexes with ATP/ADP and Mg2+ in the unphosphorylated state. Unphosphorylated FER-KD was found to adopt an unexpected active conformation in its crystal structure. Moreover, unphosphorylated FER-KD mutants with reduced (S525A) or no catalytic activity (K565R) also adopt similar active conformations. Biochemical studies revealed that FER-KD is a dual-specificity kinase, and its autophosphorylation is accomplished via an intermolecular mechanism. Further investigations confirmed that initiating substrate phosphorylation requires autophosphorylation of the activation segment on T696, S701, and Y704. This study reveals the structural and biochemical basis for the activation and regulatory mechanism of FER, providing a paradigm for the early steps in RLK signaling initiation.
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Affiliation(s)
- Yanqiong Kong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi Key Laboratory for Sugarcane Biology, Guangxi University, Nanning 530004, P.R. China
| | - Jia Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Lingli Jiang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Hong Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Yanan Shen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Lifeng Wang
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, P.R. China
| | - Yujie Yan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Huan Zhou
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, P.R. China
| | - Heping Zheng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China
| | - Feng Yu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha 410082, P.R. China; State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, P.R. China.
| | - Zhenhua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi Key Laboratory for Sugarcane Biology, Guangxi University, Nanning 530004, P.R. China.
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Kotsaridis K, Tsakiri D, Sarris PF. Understanding enemy's weapons to an effective prevention: common virulence effects across microbial phytopathogens kingdoms. Crit Rev Microbiol 2022:1-15. [PMID: 35709325 DOI: 10.1080/1040841x.2022.2083939] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Plant-pathogens interaction is an ongoing confrontation leading to the emergence of new diseases. The majority of the invading microorganisms inject effector proteins into the host cell, to bypass the sophisticated defense system of the host. However, the effectors could also have other specialized functions, which can disrupt various biological pathways of the host cell. Pathogens can enrich their effectors arsenal to increase infection success or expand their host range. This usually is accomplished by the horizontal gene transfer. Nowadays, the development of specialized software that can predict proteins structure, has changed the experimental designing in effectors' function research. Different effectors of distinct plant pathogens tend to fold alike and have the same function and focussed structural studies on microbial effectors can help to uncover their catalytic/functional activities, while the structural similarity can enable cataloguing the great number of pathogens' effectors. In this review, we collectively present phytopathogens' effectors with known enzymatic functions and proteins structure, originated from all the kingdoms of microbial plant pathogens. Presentation of their common domains and motifs is also included. We believe that the in-depth understanding of the enemy's weapons will help the development of new strategies to prevent newly emerging or re-emerging plant pathogens.
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Affiliation(s)
| | | | - Panagiotis F Sarris
- Department of Biology, University of Crete, Crete, Greece.,Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Crete, Greece.,Biosciences, University of Exeter, Exeter, UK
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5
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Sun M, Qiu L, Liu Y, Zhang H, Zhang Y, Qin Y, Mao Y, Zhou M, Du X, Qin Z, Dai S. Pto Interaction Proteins: Critical Regulators in Plant Development and Stress Response. FRONTIERS IN PLANT SCIENCE 2022; 13:774229. [PMID: 35360329 PMCID: PMC8960991 DOI: 10.3389/fpls.2022.774229] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Pto interaction (Pti) proteins are a group of proteins that can be phosphorylated by serine/threonine protein kinase Pto, which have diverse functions in plant development and stress response. In this study, we analyzed the phylogenetic relationship, gene structure, and conserved motifs of Pti1s and predicted the potential cis-elements in the promoters of Pti1 genes using bioinformatics methods. Importantly, we systematically summarized the diverse functions of Pti1s in tomato, rice, Arabidopsis, potato, apple, and cucumber. The potential cis-elements in promoters of Pti1s decide their functional diversity in response to various biotic and abiotic stresses. The protein kinase Pti1 was phosphorylated by Pto and then modulated the downstream signaling pathways for PTI and ETI in the disease insistence process. In addition, some transcription factors have been defined as Ptis (e.g., Pti4, Pti5, and Pti6) originally, which actually were ethylene-response factors (ERFs). Pti4, Pti5, and Pti6 were modulated by salicylic acid (SA), jasmonate (JA), and ethylene signaling pathways and regulated diverse defense-related gene expression to cope with Pst infection and insect wounding.
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6
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Binder design for targeting SARS-CoV-2 spike protein: An in silico perspective. GENE REPORTS 2021; 26:101452. [PMID: 34849425 PMCID: PMC8616691 DOI: 10.1016/j.genrep.2021.101452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/22/2022]
Abstract
Introduction The COVID-19 pandemic is now affecting all people around the world and getting worse. New antiviral medications are desperately needed other than the few approved medications that have shown no promising efficacy so far. Methods Here we report three blocking binders for targeting SARS-CoV-2 spike protein to block the interaction between the spike protein on the SARS-CoV-2 and the angiotensin-converting enzyme 2 (ACE2) receptors, responsible for viral homing into the alveolar epithelium type II cells (AECII). Results The design process is based on the collected natural scaffolds and using Rosetta interface for designing the binders. Conclusion Based on the structural analysis, three binders were selected, and the results showed that they might be promising as new therapeutic targets for blocking COVID-19.
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7
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Gazi AD, Kokkinidis M, Fadouloglou VE. α-Helices in the Type III Secretion Effectors: A Prevalent Feature with Versatile Roles. Int J Mol Sci 2021; 22:ijms22115412. [PMID: 34063760 PMCID: PMC8196651 DOI: 10.3390/ijms22115412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 12/16/2022] Open
Abstract
Type III Secretion Systems (T3SSs) are multicomponent nanomachines located at the cell envelope of Gram-negative bacteria. Their main function is to transport bacterial proteins either extracellularly or directly into the eukaryotic host cell cytoplasm. Type III Secretion effectors (T3SEs), latest to be secreted T3S substrates, are destined to act at the eukaryotic host cell cytoplasm and occasionally at the nucleus, hijacking cellular processes through mimicking eukaryotic proteins. A broad range of functions is attributed to T3SEs, ranging from the manipulation of the host cell's metabolism for the benefit of the bacterium to bypassing the host's defense mechanisms. To perform this broad range of manipulations, T3SEs have evolved numerous novel folds that are compatible with some basic requirements: they should be able to easily unfold, pass through the narrow T3SS channel, and refold to an active form when on the other side. In this review, the various folds of T3SEs are presented with the emphasis placed on the functional and structural importance of α-helices and helical domains.
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Affiliation(s)
- Anastasia D. Gazi
- Unit of Technology & Service Ultrastructural Bio-Imaging (UTechS UBI), Institut Pasteur, 75015 Paris, France
- Correspondence: (A.D.G.); (V.E.F.)
| | - Michael Kokkinidis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, Heraklion, 70013 Crete, Greece;
- Department of Biology, Voutes University Campus, University of Crete, Heraklion, 70013 Crete, Greece
| | - Vasiliki E. Fadouloglou
- Department of Molecular Biology & Genetics, Democritus University of Thrace, 68100 Alexandroupolis, Greece
- Correspondence: (A.D.G.); (V.E.F.)
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8
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Lin Y, Hu Q, Zhou J, Yin W, Yao D, Shao Y, Zhao Y, Guo B, Xia Y, Chen Q, Wang Y, Ye W, Xie Q, Tyler BM, Xing W, Wang Y. Phytophthora sojae effector Avr1d functions as an E2 competitor and inhibits ubiquitination activity of GmPUB13 to facilitate infection. Proc Natl Acad Sci U S A 2021; 118:e2018312118. [PMID: 33658365 PMCID: PMC7958378 DOI: 10.1073/pnas.2018312118] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Oomycete pathogens such as Phytophthora secrete a repertoire of effectors into host cells to manipulate host immunity and benefit infection. In this study, we found that an RxLR effector, Avr1d, promoted Phytophthora sojae infection in soybean hairy roots. Using a yeast two-hybrid screen, we identified the soybean E3 ubiquitin ligase GmPUB13 as a host target for Avr1d. By coimmunoprecipitation (Co-IP), gel infiltration, and isothermal titration calorimetry (ITC) assays, we confirmed that Avr1d interacts with GmPUB13 both in vivo and in vitro. Furthermore, we found that Avr1d inhibits the E3 ligase activity of GmPUB13. The crystal structure Avr1d in complex with GmPUB13 was solved and revealed that Avr1d occupies the binding site for E2 ubiquitin conjugating enzyme on GmPUB13. In line with this, Avr1d competed with E2 ubiquitin conjugating enzymes for GmPUB13 binding in vitro, thereby decreasing the E3 ligase activity of GmPUB13. Meanwhile, we found that inactivation of the ubiquitin ligase activity of GmPUB13 stabilized GmPUB13 by blocking GmPUB13 degradation. Silencing of GmPUB13 in soybean hairy roots decreased P. sojae infection, suggesting that GmPUB13 acts as a susceptibility factor. Altogether, this study highlights a virulence mechanism of Phytophthora effectors, by which Avr1d competes with E2 for GmPUB13 binding to repress the GmPUB13 E3 ligase activity and thereby stabilizing the susceptibility factor GmPUB13 to facilitate Phytophthora infection. This study unravels the structural basis for modulation of host targets by Phytophthora effectors and will be instrumental for boosting plant resistance breeding.
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Affiliation(s)
- Yachun Lin
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Qinli Hu
- Shanghai Center for Plant Stress Biology and Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia Zhou
- Shanghai Center for Plant Stress Biology and Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weixiao Yin
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, 430070 Wuhan, China
| | - Deqiang Yao
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Yuanyuan Shao
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
| | - Yao Zhao
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Baodian Guo
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Yeqiang Xia
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Qian Chen
- Ministry of Agriculture Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, 100193 Beijing, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Brett M Tyler
- Center for Genome Research and Biocomputing, Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Weiman Xing
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China;
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing Agricultural University, 210095 Nanjing, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, 210095 Nanjing, China
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Wang Y, Feng G, Zhang Z, Liu Y, Ma Y, Wang Y, Ma F, Zhou Y, Gross R, Xu H, Wang R, Xiao F, Liu Y, Niu X. Overexpression of Pti4, Pti5, and Pti6 in tomato promote plant defense and fruit ripening. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 302:110702. [PMID: 33288015 DOI: 10.1016/j.plantsci.2020.110702] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/19/2020] [Accepted: 09/29/2020] [Indexed: 06/12/2023]
Abstract
Pseudomonas syringae pv. tomato (Pst) is a pathogenic microorganism that causes bacterial speck disease and affects tomato yield and quality. Pto is a disease resistant gene for plant to recognize and defense against Pst. Pto interacts with Pti (Pto interacting) proteins, which include three transcription factors, Pti4, Pti5, Pti6, and they were thought to be downstream of Pto-mediated pathway to promote the expression of disease-related genes. In the present work, the overexpression plants of Pti4, Pti5 or Pti6 were obtained by Agrobacterium-mediated transformation in tomato. The Pti4/5/6-overexpressed lines indicated enhanced expression of pathogenesis-related genes and resistance to pathogenic bacteria Pst DC3000. Meanwhile, the transgenic plants showed that Pti4/5/6 function in ripening but performed no obvious adverse influence on flowering time, seed-setting rate, weight and soluble solids content of fruits. Furthermore, Pti-overexpressed fruits exhibited increased enzymatic activities of phenylalnine ammonialyase, catalase, peroxidase and decreased content of malondialdehyde. Additionally, cell-free and in vivo ubiquitination assay indicated that Pti4, Pti5 and Pti6 degraded by 26S proteasome which suggested that these Pti transcription regulators' functions could be regulated by ubiquitin-mediated post translational regulation in tomato.
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Affiliation(s)
- Yang Wang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Guodong Feng
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Zheng Zhang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Ying Liu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yilong Ma
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yingying Wang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Fei Ma
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yu Zhou
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Rachel Gross
- Department of Plant Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Huanhuan Xu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Ruipeng Wang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Fangming Xiao
- Department of Plant Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Yongsheng Liu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China; School of Horticulture, Anhui Agricultural University, Hefei, Anhui, 230036, China
| | - Xiangli Niu
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.
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10
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Song W, Forderer A, Yu D, Chai J. Structural biology of plant defence. THE NEW PHYTOLOGIST 2021; 229:692-711. [PMID: 32880948 DOI: 10.1111/nph.16906] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Plants employ the innate immune system to discriminate between self and invaders through two types of immune receptors, one on the plasma membrane and the other in the intracellular space. The immune receptors on the plasma membrane are pattern recognition receptors (PRRs) that can perceive pathogen-associated molecular patterns (PAMPs) or host-derived damage-associated molecular patterns (DAMPs) leading to pattern-triggered immunity (PTI). Particular pathogens are capable of overcoming PTI by secreting specific effectors into plant cells to perturb different components of PTI signalling through various mechanisms. Most of the immune receptors from the intracellular space are the nucleotide-binding leucine-rich repeat receptors (NLRs), which specifically recognize pathogen-secreted effectors to mediate effector-triggered immunity (ETI). In this review, we will summarize recent progress in structural studies of PRRs, NLRs, and effectors, and discuss how these studies shed light on ligand recognition and activation mechanisms of the two types of immune receptors and the diversified mechanisms used by effectors to manipulate plant immune signalling.
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Affiliation(s)
- Wen Song
- Max-Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Institute of Biochemistry, University of Cologne, Cologne, 50923, Germany
| | - Alexander Forderer
- Max-Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Institute of Biochemistry, University of Cologne, Cologne, 50923, Germany
| | - Dongli Yu
- Max-Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Institute of Biochemistry, University of Cologne, Cologne, 50923, Germany
| | - Jijie Chai
- Max-Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Institute of Biochemistry, University of Cologne, Cologne, 50923, Germany
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11
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NOD-like receptor-mediated plant immunity: from structure to cell death. Nat Rev Immunol 2020; 21:305-318. [PMID: 33293618 DOI: 10.1038/s41577-020-00473-z] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2020] [Indexed: 12/25/2022]
Abstract
Animal and plant immune systems use intracellular nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) to detect pathogens, resulting in the activation of immune responses that are often associated with localized host cell death. Whereas vertebrate NLRs detect evolutionarily conserved molecular patterns and have undergone comparatively little copy number expansion, plant NLRs detect virulence factors that have often diversified in plant pathogen populations, and thus plant NLRs have been subject to parallel diversification. Plant NLRs sense the presence of virulence factors with enzymatic virulence activity often indirectly through their modification of host target proteins. By contrast, phytopathogenic virulence factors without enzymatic activity are usually recognized by NLRs directly by their structure. Structural and biochemical analyses have shown that both indirect and direct recognition of plant pathogens trigger the oligomerization of plant NLRs into active complexes. Assembly into three-layered ring-like structures has emerged as a common principle of NLR activation in plants and animals, but with distinct amino-terminal domains initiating different signalling pathways. Collectively, these analyses point to host cell membranes as a convergence point for activated plant NLRs and the disruption of cellular ion homeostasis as a possible major factor in NLR-triggered cell death signalling.
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12
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Bentham AR, De la Concepcion JC, Mukhi N, Zdrzałek R, Draeger M, Gorenkin D, Hughes RK, Banfield MJ. A molecular roadmap to the plant immune system. J Biol Chem 2020; 295:14916-14935. [PMID: 32816993 PMCID: PMC7606695 DOI: 10.1074/jbc.rev120.010852] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 08/17/2020] [Indexed: 12/15/2022] Open
Abstract
Plant diseases caused by pathogens and pests are a constant threat to global food security. Direct crop losses and the measures used to control disease (e.g. application of pesticides) have significant agricultural, economic, and societal impacts. Therefore, it is essential that we understand the molecular mechanisms of the plant immune system, a system that allows plants to resist attack from a wide variety of organisms ranging from viruses to insects. Here, we provide a roadmap to plant immunity, with a focus on cell-surface and intracellular immune receptors. We describe how these receptors perceive signatures of pathogens and pests and initiate immune pathways. We merge existing concepts with new insights gained from recent breakthroughs on the structure and function of plant immune receptors, which have generated a shift in our understanding of cell-surface and intracellular immunity and the interplay between the two. Finally, we use our current understanding of plant immunity as context to discuss the potential of engineering the plant immune system with the aim of bolstering plant defenses against disease.
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Affiliation(s)
- Adam R Bentham
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | | | - Nitika Mukhi
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Rafał Zdrzałek
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Markus Draeger
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Danylo Gorenkin
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Richard K Hughes
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Mark J Banfield
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom.
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13
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Roberts R, Liu AE, Wan L, Geiger AM, Hind SR, Rosli HG, Martin GB. Molecular Characterization of Differences between the Tomato Immune Receptors Flagellin Sensing 3 and Flagellin Sensing 2. PLANT PHYSIOLOGY 2020; 183:1825-1837. [PMID: 32503903 PMCID: PMC7401135 DOI: 10.1104/pp.20.00184] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/01/2020] [Indexed: 05/05/2023]
Abstract
Plants mount defense responses by recognizing indicators of pathogen invasion, including microbe-associated molecular patterns (MAMPs). Flagellin, from the bacterial pathogen Pseudomonas syringae pv. tomato (Pst), contains two MAMPs, flg22 and flgII-28, that are recognized by tomato (Solanum lycopersicum) receptors Flagellin sensing2 (Fls2) and Fls3, respectively, but to what degree each receptor contributes to immunity and whether they promote immune responses using the same molecular mechanisms are unknown. Here, we characterized CRISPR/Cas9-generated Fls2 and Fls3 tomato mutants and found that the two receptors contribute equally to disease resistance both on the leaf surface and in the apoplast. However, we observed striking differences in certain host responses mediated by the two receptors. Compared to Fls2, Fls3 mediated a more sustained production of reactive oxygen species and an increase in transcript abundance of 44 tomato genes, with two genes serving as specific reporters for the Fls3 pathway. Fls3 had greater in vitro kinase activity than Fls2 and could transphosphorylate a substrate. Using chimeric Fls2/Fls3 proteins, we found no evidence that a single receptor domain is responsible for the Fls3-sustained reactive oxygen species, suggesting involvement of multiple structural features or a nullified function of the chimeric construct. This work reveals differences in certain immunity outputs between Fls2 and Fls3, suggesting that they might use distinct molecular mechanisms to activate pattern-triggered immunity in response to flagellin-derived MAMPs.
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Affiliation(s)
- Robyn Roberts
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Alexander E Liu
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Lingwei Wan
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Annie M Geiger
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Sarah R Hind
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Hernan G Rosli
- Instituto de Fisiología Vegetal, Universidad Nacional de La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Buenos Aires, Argentina
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853
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14
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Bastedo DP, Khan M, Martel A, Seto D, Kireeva I, Zhang J, Masud W, Millar D, Lee JY, Lee AHY, Gong Y, Santos-Severino A, Guttman DS, Desveaux D. Perturbations of the ZED1 pseudokinase activate plant immunity. PLoS Pathog 2019; 15:e1007900. [PMID: 31269090 PMCID: PMC6634424 DOI: 10.1371/journal.ppat.1007900] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/16/2019] [Accepted: 06/08/2019] [Indexed: 11/19/2022] Open
Abstract
The Pseudomonas syringae acetyltransferase HopZ1a is delivered into host cells by the type III secretion system to promote bacterial growth. However, in the model plant host Arabidopsis thaliana, HopZ1a activity results in an effector-triggered immune response (ETI) that limits bacterial proliferation. HopZ1a-triggered immunity requires the nucleotide-binding, leucine-rich repeat domain (NLR) protein, ZAR1, and the pseudokinase, ZED1. Here we demonstrate that HopZ1a can acetylate members of a family of ‘receptor-like cytoplasmic kinases’ (RLCK family VII; also known as PBS1-like kinases, or PBLs) and promote their interaction with ZED1 and ZAR1 to form a ZAR1-ZED1-PBL ternary complex. Interactions between ZED1 and PBL kinases are determined by the pseudokinase features of ZED1, and mutants designed to restore ZED1 kinase motifs can (1) bind to PBLs, (2) recruit ZAR1, and (3) trigger ZAR1-dependent immunity in planta, all independently of HopZ1a. A ZED1 mutant that mimics acetylation by HopZ1a also triggers immunity in planta, providing evidence that effector-induced perturbations of ZED1 also activate ZAR1. Overall, our results suggest that interactions between these two RLCK families are promoted by perturbations of structural features that distinguish active from inactive kinase domain conformations. We propose that effector-induced interactions between ZED1/ZRK pseudokinases (RLCK family XII) and PBL kinases (RLCK family VII) provide a sensitive mechanism for detecting perturbations of either kinase family to activate ZAR1-mediated ETI. All plants must ward off potentially infectious microbes, and those grown in large-scale crop operations are especially vulnerable to the rapid spread of disease by successful pathogens. Although many bacteria and fungi can supress plant immune responses by producing specialized virulence proteins called ‘effectors’, these effectors can also trigger immune responses that render plants resistant to infection. We studied the molecular mechanisms underlying one such effector-triggered immune response elicited by the bacterial effector HopZ1a in the model plant host Arabidopsis thaliana. We have shown that HopZ1a promotes binding between a ZED1, a ‘pseudokinase’ required for HopZ1a-triggered immunity, and several ‘true kinases’ (known as PBLs) that are likely targets of HopZ1a activity in planta. HopZ1a-induced ZED1-PBL interactions also recruit ZAR1, an Arabidopsis ‘resistance protein’ previously implicated in HopZ1a-triggered immunity. Importantly, ZED1 mutants that restore degenerate kinase motifs can bridge interactions between PBLs and ZAR1 (independently of HopZ1a) and trigger immunity in planta. Our results suggest that equilibria between active and inactive kinase domain conformations regulate ZED1-PBL interactions and formation of ternary complexes with ZAR1. Improved models describing molecular interactions between immunity determinants, effectors and effector targets will inform efforts to exploit natural diversity for development of crops with enhanced disease resistance.
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Affiliation(s)
- D. Patrick Bastedo
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Madiha Khan
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Alexandre Martel
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Derek Seto
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Inga Kireeva
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - Jianfeng Zhang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Wardah Masud
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - David Millar
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jee Yeon Lee
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - Amy Huei-Yi Lee
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yunchen Gong
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - André Santos-Severino
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (DSG); (DD)
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (DSG); (DD)
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15
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Borah SM, Jha AN. Identification and analysis of structurally critical fragments in HopS2. BMC Bioinformatics 2019; 19:552. [PMID: 30717655 PMCID: PMC7394326 DOI: 10.1186/s12859-018-2551-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 11/30/2018] [Indexed: 12/02/2022] Open
Abstract
Background Among the diverse roles of the Type III secretion-system (T3SS), one of the notable functions is that it serves as unique nano machineries in gram-negative bacteria that facilitate the translocation of effector proteins from bacteria into their host. These effector proteins serve as potential targets to control the pathogenicity conferred to the bacteria. Despite being ideal choices to disrupt bacterial systems, it has been quite an ordeal in the recent times to experimentally reveal and establish a concrete sequence-structure-function relationship for these effector proteins. This work focuses on the disease-causing spectrum of an effector protein, HopS2 secreted by the phytopathogen Pseudomonas syringae pv. tomato DC3000. Results The study addresses the structural attributes of HopS2 via a bioinformatics approach to by-pass some of the experimental shortcomings resulting in mining some critical regions in the effector protein. We have elucidated the functionally important regions of HopS2 with the assistance of sequence and structural analyses. The sequence based data supports the presence of important regions in HopS2 that are present in the other functional parts of Hop family proteins. Furthermore, these regions have been validated by an ab-initio structure prediction of the protein followed by 100 ns long molecular dynamics (MD) simulation. The assessment of these secondary structural regions has revealed the stability and importance of these regions in the protein structure. Conclusions The analysis has provided insights on important functional regions that may be vital to the effector functioning. In dearth of ample experimental evidence, such a bioinformatics approach has helped in the revelation of a few structural regions which will aid in future experiments to attain and evaluate the structural and functional aspects of this protein family. Electronic supplementary material The online version of this article (10.1186/s12859-018-2551-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sapna M Borah
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India
| | - Anupam Nath Jha
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India.
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16
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Bastedo DP, Lo T, Laflamme B, Desveaux D, Guttman DS. Diversity and Evolution of Type III Secreted Effectors: A Case Study of Three Families. Curr Top Microbiol Immunol 2019; 427:201-230. [DOI: 10.1007/82_2019_165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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17
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Qin J, Zhou X, Sun L, Wang K, Yang F, Liao H, Rong W, Yin J, Chen H, Chen X, Zhang J. The Xanthomonas effector XopK harbours E3 ubiquitin-ligase activity that is required for virulence. THE NEW PHYTOLOGIST 2018; 220:219-231. [PMID: 29949665 DOI: 10.1111/nph.15287] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/22/2018] [Indexed: 05/26/2023]
Abstract
Xanthomonas oryzae pv. oryzae is the causative agent of rice bacterial leaf blight. While the type III secretion system of X. oryzae pv. oryzae is essential for virulence, the biochemical activities and virulence mechanisms of non-transcription activator-like (non-TAL) effectors delivered by this system are largely unknown. Here, by screening for non-TAL effectors that contribute to X. oryzae pv. oryzae virulence, we revealed that Xanthomonas outer protein K (XopK) inhibits pathogen-associated molecular pattern-triggered immunity upstream of mitogen-activated protein kinase cascades. Specifically, XopK interacted with and directly ubiquitinated rice somatic embryogenic receptor kinase 2 (OsSERK2), resulting in its degradation. Accordingly, mutation of a putative ubiquitin-conjugation enzyme (E2) binding site abolished XopK-induced degradation of OsSERK2 and compromised XopK-dependent virulence. As crucial immune regulators associated with a multitude of immune receptors, SERKs have been shown to be perturbed by Pseudomonas effectors via different mechanisms. Our study revealed a distinct perturbation mechanism of SERK activity via ubiquitination achieved by Xanthomonas non-TAL effector.
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Affiliation(s)
- Jun Qin
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaogang Zhou
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Kailun Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fan Yang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haicheng Liao
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Wei Rong
- College of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Junjie Yin
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xuewei Chen
- State Key Laboratory of Hybrid Rice, Key Laboratory of Major Crop Diseases and Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan, 611130, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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18
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Liang X, Zhou JM. Receptor-Like Cytoplasmic Kinases: Central Players in Plant Receptor Kinase-Mediated Signaling. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:267-299. [PMID: 29719165 DOI: 10.1146/annurev-arplant-042817-040540] [Citation(s) in RCA: 239] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Receptor kinases (RKs) are of paramount importance in transmembrane signaling that governs plant reproduction, growth, development, and adaptation to diverse environmental conditions. Receptor-like cytoplasmic kinases (RLCKs), which lack extracellular ligand-binding domains, have emerged as a major class of signaling proteins that regulate plant cellular activities in response to biotic/abiotic stresses and endogenous extracellular signaling molecules. By associating with immune RKs, RLCKs regulate multiple downstream signaling nodes to orchestrate a complex array of defense responses against microbial pathogens. RLCKs also associate with RKs that perceive brassinosteroids and signaling peptides to coordinate growth, pollen tube guidance, embryonic and stomatal patterning, floral organ abscission, and abiotic stress responses. The activity and stability of RLCKs are dynamically regulated not only by RKs but also by other RLCK-associated proteins. Analyses of RLCK-associated components and substrates have suggested phosphorylation relays as a major mechanism underlying RK-mediated signaling.
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Affiliation(s)
- Xiangxiu Liang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, 100101 Beijing, China;
| | - Jian-Min Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, 100101 Beijing, China;
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19
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Büttner D. Behind the lines-actions of bacterial type III effector proteins in plant cells. FEMS Microbiol Rev 2018; 40:894-937. [PMID: 28201715 PMCID: PMC5091034 DOI: 10.1093/femsre/fuw026] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/31/2016] [Accepted: 07/03/2016] [Indexed: 01/30/2023] Open
Abstract
Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed.
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Affiliation(s)
- Daniela Büttner
- Genetics Department, Institute of Biology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
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20
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Wu J, van der Burgh AM, Bi G, Zhang L, Alfano JR, Martin GB, Joosten MHAJ. The Bacterial Effector AvrPto Targets the Regulatory Coreceptor SOBIR1 and Suppresses Defense Signaling Mediated by the Receptor-Like Protein Cf-4. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:75-85. [PMID: 28876174 DOI: 10.1094/mpmi-08-17-0203-fi] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Receptor-like proteins (RLPs) and receptor-like kinases (RLKs) are cell-surface receptors that are essential for detecting invading pathogens and subsequent activation of plant defense responses. RLPs lack a cytoplasmic kinase domain to trigger downstream signaling leading to host resistance. The RLK SOBIR1 constitutively interacts with the tomato RLP Cf-4, thereby providing Cf-4 with a kinase domain. SOBIR1 is required for Cf-4-mediated resistance to strains of the fungal tomato pathogen Cladosporium fulvum that secrete the effector Avr4. Upon perception of this effector by the Cf-4/SOBIR1 complex, the central regulatory RLK SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3a (SERK3a) is recruited to the complex and defense signaling is triggered. SOBIR1 is also required for RLP-mediated resistance to bacterial, fungal ,and oomycete pathogens, and we hypothesized that SOBIR1 is targeted by effectors of such pathogens to suppress host defense responses. In this study, we show that Pseudomonas syringae pv. tomato DC3000 effector AvrPto interacts with Arabidopsis SOBIR1 and its orthologs of tomato and Nicotiana benthamiana, independent of SOBIR1 kinase activity. Interestingly, AvrPto suppresses Arabidopsis SOBIR1-induced cell death in N. benthamiana. Furthermore, AvrPto compromises Avr4-triggered cell death in Cf-4-transgenic N. benthamiana, without affecting Cf-4/SOBIR1/SERK3a complex formation. Our study shows that the RLP coreceptor SOBIR1 is targeted by a bacterial effector, which results in compromised defense responses.
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Affiliation(s)
- Jinbin Wu
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Aranka M van der Burgh
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Guozhi Bi
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Lisha Zhang
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - James R Alfano
- 2 Center for Plant Science Innovation and
- 3 Department of Plant Pathology, University of Nebraska, Lincoln, NE 68588, U.S.A
| | - Gregory B Martin
- 4 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
- 5 Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Matthieu H A J Joosten
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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21
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Schwizer S, Kraus CM, Dunham DM, Zheng Y, Fernandez-Pozo N, Pombo MA, Fei Z, Chakravarthy S, Martin GB. The Tomato Kinase Pti1 Contributes to Production of Reactive Oxygen Species in Response to Two Flagellin-Derived Peptides and Promotes Resistance to Pseudomonas syringae Infection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:725-738. [PMID: 28535079 DOI: 10.1094/mpmi-03-17-0056-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The Pti1 kinase was identified from a reverse genetic screen as contributing to pattern-triggered immunity (PTI) against Pseudomonas syringae pv. tomato (Pst). The tomato genome has two Pti1 genes, referred to as Pti1a and Pti1b. A hairpin-Pti1 (hpPti1) construct was developed and was used to generate two independent stable transgenic tomato lines that had reduced transcript abundance of both genes. In response to P. syringae pv. tomato inoculation, these hpPti1 plants developed more severe disease symptoms, supported higher bacterial populations, and had reduced transcript accumulation of PTI-associated genes, as compared with wild-type plants. In response to two flagellin-derived peptides, the hpPti1 plants produced lesser amounts of reactive oxygen species (ROS) but showed no difference in mitogen-activated protein kinase (MAPK). Synthetic Pti1a and Pti1b genes designed to avoid silencing were transiently expressed in the hpPti1 plants and restored the ability of the plants to produce wild-type levels of ROS. Our results identify a new component of PTI in tomato that, because it affects ROS production but not MAPK signaling, appears to act early in the immune response.
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Affiliation(s)
- Simon Schwizer
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
- 2 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Christine M Kraus
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
- 2 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Diane M Dunham
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
| | - Yi Zheng
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
| | - Noé Fernandez-Pozo
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
| | - Marina A Pombo
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
| | - Zhangjun Fei
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
- 2 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Suma Chakravarthy
- 2 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Gregory B Martin
- 1 Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; and
- 2 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
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Velásquez AC, Oney M, Huot B, Xu S, He SY. Diverse mechanisms of resistance to Pseudomonas syringae in a thousand natural accessions of Arabidopsis thaliana. THE NEW PHYTOLOGIST 2017; 214:1673-1687. [PMID: 28295393 PMCID: PMC5423860 DOI: 10.1111/nph.14517] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/07/2017] [Indexed: 05/03/2023]
Abstract
Plants are continuously threatened by pathogen attack and, as such, they have evolved mechanisms to evade, escape and defend themselves against pathogens. However, it is not known what types of defense mechanisms a plant would already possess to defend against a potential pathogen that has not co-evolved with the plant. We addressed this important question in a comprehensive manner by studying the responses of 1041 accessions of Arabidopsis thaliana to the foliar pathogen Pseudomonas syringae pv. tomato (Pst) DC3000. We characterized the interaction using a variety of established methods, including different inoculation techniques, bacterial mutant strains, and assays for the hypersensitive response, salicylic acid (SA) accumulation and reactive oxygen species production . Fourteen accessions showed resistance to infection by Pst DC3000. Of these, two accessions had a surface-based mechanism of resistance, six showed a hypersensitive-like response while three had elevated SA levels. Interestingly, A. thaliana was discovered to have a recognition system for the effector AvrPto, and HopAM1 was found to modulate Pst DC3000 resistance in two accessions. Our comprehensive study has significant implications for the understanding of natural disease resistance mechanisms at the species level and for the ecology and evolution of plant-pathogen interactions.
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Affiliation(s)
| | - Matthew Oney
- MSU-DOE Plant Research Laboratory, East Lansing, MI 48824, USA
| | - Bethany Huot
- MSU-DOE Plant Research Laboratory, East Lansing, MI 48824, USA
- Cell and Molecular Biology Program, Michigan State University, East Lansing, MI 48824, USA
| | - Shu Xu
- MSU-DOE Plant Research Laboratory, East Lansing, MI 48824, USA
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, P. R. China
| | - Sheng Yang He
- MSU-DOE Plant Research Laboratory, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
- Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA
- Howard Hughes Medical Institute, Gordon and Betty Moore Foundation, Michigan State University, East Lansing, MI 48824, USA
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23
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Phosphorylation of the dimeric cytoplasmic domain of the phytosulfokine receptor, PSKR1. Biochem J 2016; 473:3081-98. [PMID: 27487840 DOI: 10.1042/bcj20160593] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/03/2016] [Indexed: 11/17/2022]
Abstract
Phytosulfokines (PSKs) are plant peptide hormones that co-regulate plant growth, differentiation and defense responses. PSKs signal through a plasma membrane localized leucine-rich repeat receptor-like kinase (phytosulfokine receptor 1, PSKR1) that also contains a functional cytosolic guanylate cyclase with its cyclase catalytic center embedded within the kinase domain. To functionally characterize this novel type of overlapping dual catalytic function, we investigated the phosphorylation of PSKR1 in vitro Tandem mass spectrometry of the cytoplasmic domain of PSKR1 (PSKR1cd) revealed at least 11 phosphorylation sites (8 serines, 2 threonines and 1 tyrosine) within the PSKR1cd. Phosphomimetic mutations of three serine residues (Ser686, Ser696 and Ser698) in tandem at the juxta-membrane position resulted in enhanced kinase activity in the on-mutant that was suppressed in the off-mutant, but both mutations reduced guanylate cyclase activity. Both the on and off phosphomimetic mutations of the phosphotyrosine (Tyr888) residue in the activation loop suppressed kinase activity, while neither mutation affected guanylate cyclase activity. Size exclusion and analytical ultracentrifugation analysis of the PSKR1cd suggest that it is reversibly dimeric in solution, which was further confirmed by biflourescence complementation. Taken together, these data suggest that in this novel type of receptor domain architecture, specific phosphorylation and dimerization are possibly essential mechanisms for ligand-mediated catalysis and signaling.
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Maqbool A, Hughes RK, Dagdas YF, Tregidgo N, Zess E, Belhaj K, Round A, Bozkurt TO, Kamoun S, Banfield MJ. Structural Basis of Host Autophagy-related Protein 8 (ATG8) Binding by the Irish Potato Famine Pathogen Effector Protein PexRD54. J Biol Chem 2016; 291:20270-20282. [PMID: 27458016 PMCID: PMC5025708 DOI: 10.1074/jbc.m116.744995] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Indexed: 11/06/2022] Open
Abstract
Filamentous plant pathogens deliver effector proteins to host cells to promote infection. The Phytophthora infestans RXLR-type effector PexRD54 binds potato ATG8 via its ATG8 family-interacting motif (AIM) and perturbs host-selective autophagy. However, the structural basis of this interaction remains unknown. Here, we define the crystal structure of PexRD54, which includes a modular architecture, including five tandem repeat domains, with the AIM sequence presented at the disordered C terminus. To determine the interface between PexRD54 and ATG8, we solved the crystal structure of potato ATG8CL in complex with a peptide comprising the effector's AIM sequence, and we established a model of the full-length PexRD54-ATG8CL complex using small angle x-ray scattering. Structure-informed deletion of the PexRD54 tandem domains reveals retention of ATG8CL binding in vitro and in planta This study offers new insights into structure/function relationships of oomycete RXLR effectors and how these proteins engage with host cell targets to promote disease.
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Affiliation(s)
- Abbas Maqbool
- From the Department of Biological Chemistry, John Innes Centre, and
| | - Richard K Hughes
- From the Department of Biological Chemistry, John Innes Centre, and
| | - Yasin F Dagdas
- the Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | | | - Erin Zess
- the Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Khaoula Belhaj
- the Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Adam Round
- EMBL Grenoble, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France, and.,EPSAM, Keele University, Keele ST5 5GB, United Kingdom
| | - Tolga O Bozkurt
- the Department of Life Sciences, Imperial College, London SW7 2AZ, United Kingdom
| | - Sophien Kamoun
- the Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Mark J Banfield
- From the Department of Biological Chemistry, John Innes Centre, and
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25
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Sukarta OCA, Slootweg EJ, Goverse A. Structure-informed insights for NLR functioning in plant immunity. Semin Cell Dev Biol 2016; 56:134-149. [PMID: 27208725 DOI: 10.1016/j.semcdb.2016.05.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 01/07/2023]
Abstract
To respond to foreign invaders, plants have evolved a cell autonomous multilayered immune system consisting of extra- and intracellular immune receptors. Nucleotide binding and oligomerization domain (NOD)-like receptors (NLRs) mediate recognition of pathogen effectors inside the cell and trigger a host specific defense response, often involving controlled cell death. NLRs consist of a central nucleotide-binding domain, which is flanked by an N-terminal CC or TIR domain and a C-terminal leucine-rich repeat domain (LRR). These multidomain proteins function as a molecular switch and their activity is tightly controlled by intra and inter-molecular interactions. In contrast to metazoan NLRs, the structural basis underlying NLR functioning as a pathogen sensor and activator of immune responses in plants is largely unknown. However, the first crystal structures of a number of plant NLR domains were recently obtained. In addition, biochemical and structure-informed analyses revealed novel insights in the cooperation between NLR domains and the formation of pre- and post activation complexes, including the coordinated activity of NLR pairs as pathogen sensor and executor of immune responses. Moreover, the discovery of novel integrated domains underscores the structural diversity of NLRs and provides alternative models for how these immune receptors function in plants. In this review, we will highlight these recent advances to provide novel insights in the structural, biochemical and molecular aspects involved in plant NLR functioning.
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Affiliation(s)
- Octavina C A Sukarta
- Dept. of Plant Sciences, Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Erik J Slootweg
- Dept. of Plant Sciences, Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Aska Goverse
- Dept. of Plant Sciences, Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
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26
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Kraus CM, Munkvold KR, Martin GB. Natural Variation in Tomato Reveals Differences in the Recognition of AvrPto and AvrPtoB Effectors from Pseudomonas syringae. MOLECULAR PLANT 2016; 9:639-649. [PMID: 26993968 DOI: 10.1016/j.molp.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 05/13/2023]
Abstract
The Pto protein kinase from Solanum pimpinellifolium interacts with Pseudomonas syringae effectors AvrPto or AvrPtoB to activate effector-triggered immunity. The previously solved crystal structures of the AvrPto-Pto and AvrPtoB-Pto complexes revealed that Pto binds each effector through both a shared and a unique interface. Here we use natural variation in wild species of tomato to further investigate Pto recognition of these two effectors. One species, Solanum chmielewskii, was found to have many accessions that recognize only AvrPtoB. The Pto ortholog from one of these accessions was responsible for recognition of AvrPtoB and it differed from Solanum pimpinellifolium Pto by only 14 amino acids, including two in the AvrPto-specific interface, glutamate-49/glycine-51. Converting these two residues to those in Pto (histidine-49/valine-51) did not restore recognition of AvrPto. Subsequent experiments revealed that a single substitution of a histidine-to-aspartate at position 193 in Pto, which is not near the AvrPto-specific interface, was sufficient for conferring recognition of AvrPto in plant cells. The reciprocal substitution of aspartate-to-histidine-193 in Pto abolished AvrPto recognition, confirming the importance of this residue. Our results reveal new aspects about effector recognition by Pto and demonstrate the value of using natural variation to understand the interaction between resistance proteins and pathogen effectors.
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Affiliation(s)
- Christine M Kraus
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA; Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Kathy R Munkvold
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA; Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
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27
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Of guards, decoys, baits and traps: pathogen perception in plants by type III effector sensors. Curr Opin Microbiol 2015; 29:49-55. [PMID: 26599514 DOI: 10.1016/j.mib.2015.10.006] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 12/17/2022]
Abstract
Effector-triggered immunity (ETI) is conferred by dominant plant resistance (R) genes, which encode predominantly nucleotide-binding and leucine-rich repeat domain proteins (NLRs), against cognate microbial avirulence (Avr) genes, which include bacterial type III secreted effectors (T3Es). The 'guard model' describes the mechanism of T3E perception by plants, whereby NLRs monitor host proteins ('sensors') for T3E-induced perturbations. This model has provided a molecular framework to understand T3E perception and has rationalized how plants can use a limited number of NLRs (∼160 in Arabidopsis) to contend with a potentially limitless number of evolving effectors. In this review we provide a characteristic overview of plant T3E sensors and discuss how these sensors convey the presence of T3Es to NLR proteins to activate ETI.
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28
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Abstract
Over 30 receptor-like kinases contain a guanylate cyclase (GC) catalytic centre embedded within the C-terminal region of their kinase domain in the model plant Arabidopsis. A number of the kinase GCs contain both functional kinase and GC activity in vitro and the natural ligands of these receptors stimulate increases in cGMP within isolated protoplasts. The GC activity could be described as a minor or moonlighting activity. We have also identified mammalian proteins that contain the novel GC centre embedded within kinase domains. One example is the interleukin 1 receptor-associated kinase 3 (IRAK3). We compare the GC functionality of the mammalian protein IRAK3 with the cytoplasmic domain of the plant prototype molecule, the phytosulfokine receptor 1 (PSKR1). We have developed homology models of these molecules and have undertaken in vitro experiments to compare their functionality and structural features. Recombinant IRAK3 produces cGMP at levels comparable to those produced by PSKR1, suggesting that IRAK3 contains GC activity. Our findings raise the possibility that kinase-GCs may switch between downstream kinase-mediated or cGMP-mediated signalling cascades to elicit desired outputs to particular stimuli. The challenge now lies in understanding the interaction between the GC and kinase domains and how these molecules utilize their dual functionality within cells.
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29
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Keller B, Manzanares C, Jara C, Lobaton JD, Studer B, Raatz B. Fine-mapping of a major QTL controlling angular leaf spot resistance in common bean (Phaseolus vulgaris L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015; 128:813-26. [PMID: 25740562 PMCID: PMC4544502 DOI: 10.1007/s00122-015-2472-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/31/2015] [Indexed: 05/07/2023]
Abstract
KEY MESSAGE A major QTL for angular leaf spot resistance in the common bean accession G5686 was fine-mapped to a region containing 36 candidate genes. Markers have been developed for marker-assisted selection. Common bean (Phaseolus vulgaris L.) is an important grain legume and an essential protein source for human nutrition in developing countries. Angular leaf spot (ALS) caused by the pathogen Pseudocercospora griseola (Sacc.) Crous and U. Braun is responsible for severe yield losses of up to 80%. Breeding for resistant cultivars is the most ecological and economical means to control ALS and is particularly important for yield stability in low-input agriculture. Here, we report on a fine-mapping approach of a major quantitative trait locus (QTL) ALS4.1(GS, UC) for ALS resistance in a mapping population derived from the resistant genotype G5686 and the susceptible cultivar Sprite. 180 F3 individuals of the mapping population were evaluated for ALS resistance and genotyped with 22 markers distributed over 11 genome regions colocating with previously reported QTL for ALS resistance. Multiple QTL analysis identified three QTL regions, including one major QTL on chromosome Pv04 at 43.7 Mbp explaining over 75% of the observed variation for ALS resistance. Additional evaluation of 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants with markers in the region of the major QTL delimited the region to 418 kbp harboring 36 candidate genes. Among these, 11 serine/threonine protein kinases arranged in a repetitive array constitute promising candidate genes for controlling ALS resistance. Single nucleotide polymorphism markers cosegregating with the major QTL for ALS resistance have been developed and constitute the basis for marker-assisted introgression of ALS resistance into advanced breeding germplasm of common bean.
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Affiliation(s)
- Beat Keller
- Forage Crop Genetics, Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse 2, 8092 Zurich, Switzerland
| | - Chloe Manzanares
- Forage Crop Genetics, Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse 2, 8092 Zurich, Switzerland
| | - Carlos Jara
- Agrobiodiversity Research Area, Bean Program, CIAT Cali-Palmira, A. A. 6713, Cali, Colombia
| | - Juan David Lobaton
- Agrobiodiversity Research Area, Bean Program, CIAT Cali-Palmira, A. A. 6713, Cali, Colombia
| | - Bruno Studer
- Forage Crop Genetics, Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse 2, 8092 Zurich, Switzerland
| | - Bodo Raatz
- Agrobiodiversity Research Area, Bean Program, CIAT Cali-Palmira, A. A. 6713, Cali, Colombia
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30
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Saur IML, Conlan BF, Rathjen JP. The N-terminal domain of the tomato immune protein Prf contains multiple homotypic and Pto kinase interaction sites. J Biol Chem 2015; 290:11258-67. [PMID: 25792750 DOI: 10.1074/jbc.m114.616532] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Indexed: 01/12/2023] Open
Abstract
Resistance to Pseudomonas syringae bacteria in tomato (Solanum lycopersicum) is conferred by the Prf recognition complex, composed of the nucleotide-binding leucine-rich repeats protein Prf and the protein kinase Pto. The complex is activated by recognition of the P. syringae effectors AvrPto and AvrPtoB. The N-terminal domain is responsible for Prf homodimerization, which brings two Pto kinases into close proximity and holds them in inactive conformation in the absence of either effector. Negative regulation is lost by effector binding to the catalytic cleft of Pto, leading to disruption of its P+1 loop within the activation segment. This change is translated through Prf to a second Pto molecule in the complex. Here we describe a schematic model of the unique Prf N-terminal domain dimer and its interaction with the effector binding determinant Pto. Using heterologous expression in Nicotiana benthamiana, we define multiple sites of N domain homotypic interaction and infer that it forms a parallel dimer folded centrally to enable contact between the N and C termini. Furthermore, we found independent binding sites for Pto at either end of the N-terminal domain. Using the constitutively active mutant ptoL205D, we identify a potential repression site for Pto in the first ∼100 amino acids of Prf. Finally, we find that the Prf leucine-rich repeats domain also binds the N-terminal region, highlighting a possible mechanism for transfer of the effector binding signal to the NB-LRR regulatory unit (consisting of a central nucleotide binding and C-terminal leucine-rich repeats).
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Affiliation(s)
- Isabel Marie-Luise Saur
- From the Research School of Biology, The Australian National University, Acton ACT 2601, Australia
| | - Brendon Francis Conlan
- From the Research School of Biology, The Australian National University, Acton ACT 2601, Australia
| | - John Paul Rathjen
- From the Research School of Biology, The Australian National University, Acton ACT 2601, Australia
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Mesarich CH, Bowen JK, Hamiaux C, Templeton MD. Repeat-containing protein effectors of plant-associated organisms. FRONTIERS IN PLANT SCIENCE 2015; 6:872. [PMID: 26557126 PMCID: PMC4617103 DOI: 10.3389/fpls.2015.00872] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/01/2015] [Indexed: 05/10/2023]
Abstract
Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms.
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Affiliation(s)
- Carl H. Mesarich
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
- *Correspondence: Carl H. Mesarich
| | - Joanna K. Bowen
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
| | - Cyril Hamiaux
- Human Responses, The New Zealand Institute for Plant & Food Research LimitedAuckland, New Zealand
| | - Matthew D. Templeton
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
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Pilotti M, Brunetti A, Uva P, Lumia V, Tizzani L, Gervasi F, Iacono M, Pindo M. Kinase domain-targeted isolation of defense-related receptor-like kinases (RLK/Pelle) in Platanus×acerifolia: phylogenetic and structural analysis. BMC Res Notes 2014; 7:884. [PMID: 25486898 PMCID: PMC4295470 DOI: 10.1186/1756-0500-7-884] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 11/18/2014] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Plant receptor-like kinase (RLK/Pelle) family regulates growth and developmental processes and interaction with pathogens and symbionts.Platanaceae is one of the earliest branches of Eudicots temporally located before the split which gave rise to Rosids and Asterids. Thus investigations into the RLK family in Platanus can provide information on the evolution of this gene family in the land plants.Moreover RLKs are good candidates for finding genes that are able to confer resistance to Platanus pathogens. RESULTS Degenerate oligonucleotide primers targeting the kinase domain of stress-related RLKs were used to isolate for the first time 111 RLK gene fragments in Platanus×acerifolia. Sequences were classified as candidates of the following subfamilies: CrRLK1L, LRR XII, WAK-like, and LRR X-BRI1 group. All the structural features typical of the RLK kinase domain were identified, including the non-RD motif which marks potential pathogen recognition receptors (PRRs). The LRR XII candidates, whose counterpart in Arabidopsis and rice comprises non-RD PRRs, were mostly non-RD kinases, suggesting a group of PRRs. Region-specific signatures of a relaxed purifying selection in the LRR XII candidates were also found, which is novel for plant RLK kinase domain and further supports the role of LRR XII candidates as PRRs. As we obtained CrRLK1L candidates using primers designed on Pto of tomato, we analysed the phylogenetic relationship between CrRLK1L and Pto-like of plant species. We thus classified all non-solanaceous Pto-like genes as CrRLK1L and highlighted for the first time the close phylogenetic vicinity between CrRLK1L and Pto group. The origins of Pto from CrRLK1L is proposed as an evolutionary mechanism. CONCLUSIONS The signatures of relaxed purifying selection highlight that a group of RLKs might have been involved in the expression of phenotypic plasticity and is thus a good candidate for investigations into pathogen resistance.Search of Pto-like genes in Platanus highlighted the close relationship between CrRLK1L and Pto group. It will be exciting to verify if sensu strictu Pto are present in taxonomic groups other than Solanaceae, in order to further clarify the evolutionary link with CrRLK1L.We obtained a first valuable resource useful for an in-depth study on stress perception systems.
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Affiliation(s)
- Massimo Pilotti
- />Plant Pathology Research Center, CRA-PAV Agricultural Research Council, V. C.G. Bertero 22, 00156 Rome, Italy
| | - Angela Brunetti
- />Plant Pathology Research Center, CRA-PAV Agricultural Research Council, V. C.G. Bertero 22, 00156 Rome, Italy
| | - Paolo Uva
- />CRS4 Bioinformatics Laboratory POLARIS Science and Technology Park, 09010 Pula, Cagliari, Italy
| | - Valentina Lumia
- />Plant Pathology Research Center, CRA-PAV Agricultural Research Council, V. C.G. Bertero 22, 00156 Rome, Italy
| | - Lorenza Tizzani
- />Plant Pathology Research Center, CRA-PAV Agricultural Research Council, V. C.G. Bertero 22, 00156 Rome, Italy
| | - Fabio Gervasi
- />Fruit Tree Research Center, CRA-FRU Agricultural Research Council, V. Fioranello, 52, 00134 Rome, Italy
| | - Michele Iacono
- />Roche Diagnostics SpA, V. G.B. Stucchi 110, 20052 Monza Milano, Italy
| | - Massimo Pindo
- />Research and Innovation Centre, Edmund Mach Foundation, V. E. Mach 1, 38010 San Michele a/A, Trento, Italy
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33
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Banfield MJ. Perturbation of host ubiquitin systems by plant pathogen/pest effector proteins. Cell Microbiol 2014; 17:18-25. [PMID: 25339602 PMCID: PMC4312480 DOI: 10.1111/cmi.12385] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 09/26/2014] [Accepted: 10/09/2014] [Indexed: 12/26/2022]
Abstract
Microbial pathogens and pests of animals and plants secrete effector proteins into host cells, altering cellular physiology to the benefit of the invading parasite. Research in the past decade has delivered significant new insights into the molecular mechanisms of how these effector proteins function, with a particular focus on modulation of host immunity-related pathways. One host system that has emerged as a common target of effectors is the ubiquitination system in which substrate proteins are post-translationally modified by covalent conjugation with the small protein ubiquitin. This modification, typically via isopeptide bond formation through a lysine side chain of ubiquitin, can result in target degradation, relocalization, altered activity or affect protein–protein interactions. In this review, I focus primarily on how effector proteins from bacterial and filamentous pathogens of plants and pests perturb host ubiquitination pathways that ultimately include the 26S proteasome. The activities of these effectors, in how they affect ubiquitin pathways in plants, reveal how pathogens have evolved to identify and exploit weaknesses in this system that deliver increased pathogen fitness.
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Affiliation(s)
- Mark J Banfield
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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34
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Muleya V, Wheeler JI, Ruzvidzo O, Freihat L, Manallack DT, Gehring C, Irving HR. Calcium is the switch in the moonlighting dual function of the ligand-activated receptor kinase phytosulfokine receptor 1. Cell Commun Signal 2014. [PMID: 25245092 DOI: 10.1186/preaccept-3431251013169955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023] Open
Abstract
BACKGROUND A number of receptor kinases contain guanylate cyclase (GC) catalytic centres encapsulated in the cytosolic kinase domain. A prototypical example is the phytosulfokine receptor 1 (PSKR1) that is involved in regulating growth responses in plants. PSKR1 contains both kinase and GC activities however the underlying mechanisms regulating the dual functions have remained elusive. FINDINGS Here, we confirm the dual activity of the cytoplasmic domain of the PSKR1 receptor. We show that mutations within the guanylate cyclase centre modulate the GC activity while not affecting the kinase catalytic activity. Using physiologically relevant Ca2+ levels, we demonstrate that its GC activity is enhanced over two-fold by Ca2+ in a concentration-dependent manner. Conversely, increasing Ca2+ levels inhibits kinase activity up to 500-fold at 100 nM Ca2+. CONCLUSIONS Changes in calcium at physiological levels can regulate the kinase and GC activities of PSKR1. We therefore propose a functional model of how calcium acts as a bimodal switch between kinase and GC activity in PSKR1 that could be relevant to other members of this novel class of ligand-activated receptor kinases.
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35
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Muleya V, Wheeler JI, Ruzvidzo O, Freihat L, Manallack DT, Gehring C, Irving HR. Calcium is the switch in the moonlighting dual function of the ligand-activated receptor kinase phytosulfokine receptor 1. Cell Commun Signal 2014; 12:60. [PMID: 25245092 PMCID: PMC4180545 DOI: 10.1186/s12964-014-0060-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/11/2014] [Indexed: 11/11/2022] Open
Abstract
Background A number of receptor kinases contain guanylate cyclase (GC) catalytic centres encapsulated in the cytosolic kinase domain. A prototypical example is the phytosulfokine receptor 1 (PSKR1) that is involved in regulating growth responses in plants. PSKR1 contains both kinase and GC activities however the underlying mechanisms regulating the dual functions have remained elusive. Findings Here, we confirm the dual activity of the cytoplasmic domain of the PSKR1 receptor. We show that mutations within the guanylate cyclase centre modulate the GC activity while not affecting the kinase catalytic activity. Using physiologically relevant Ca2+ levels, we demonstrate that its GC activity is enhanced over two-fold by Ca2+ in a concentration-dependent manner. Conversely, increasing Ca2+ levels inhibits kinase activity up to 500-fold at 100 nM Ca2+. Conclusions Changes in calcium at physiological levels can regulate the kinase and GC activities of PSKR1. We therefore propose a functional model of how calcium acts as a bimodal switch between kinase and GC activity in PSKR1 that could be relevant to other members of this novel class of ligand-activated receptor kinases. Electronic supplementary material The online version of this article (doi:10.1186/s12964-014-0060-z) contains supplementary material, which is available to authorized users.
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Ntoukakis V, Saur IML, Conlan B, Rathjen JP. The changing of the guard: the Pto/Prf receptor complex of tomato and pathogen recognition. CURRENT OPINION IN PLANT BIOLOGY 2014; 20:69-74. [PMID: 24845576 DOI: 10.1016/j.pbi.2014.04.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 04/07/2014] [Accepted: 04/17/2014] [Indexed: 05/05/2023]
Abstract
One important model for disease resistance is the Prf recognition complex of tomato, which responds to different bacterial effectors. Prf incorporates a protein kinase called Pto as its recognition domain that mimics effector virulence targets, and activates resistance after interaction with specific effectors. Recent findings show that this complex is oligomeric, and reveal how this impacts mechanism. Oligomerisation brings two or more kinases into proximity, where they can phosphorylate each other after effector perception. Effector attack on one kinase activates another in trans, constituting a molecular trap for the effector. Oligomerisation of plant resistance proteins may be a general concept that broadens pathogen recognition and restricts the ability of pathogens to evolve virulence.
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Affiliation(s)
- Vardis Ntoukakis
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Isabel M L Saur
- Research School of Biology, The Australian National University, Acton 0200, Australian Capital Territory, Australia
| | - Brendon Conlan
- Research School of Biology, The Australian National University, Acton 0200, Australian Capital Territory, Australia
| | - John P Rathjen
- Research School of Biology, The Australian National University, Acton 0200, Australian Capital Territory, Australia.
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37
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Pto kinase binds two domains of AvrPtoB and its proximity to the effector E3 ligase determines if it evades degradation and activates plant immunity. PLoS Pathog 2014; 10:e1004227. [PMID: 25058029 PMCID: PMC4110037 DOI: 10.1371/journal.ppat.1004227] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/16/2014] [Indexed: 11/19/2022] Open
Abstract
The tomato--Pseudomonas syringae pv. tomato (Pst)--pathosystem is one of the best understood models for plant-pathogen interactions. Certain wild relatives of tomato express two closely related members of the same kinase family, Pto and Fen, which recognize the Pst virulence protein AvrPtoB and activate effector-triggered immunity (ETI). AvrPtoB, however, contains an E3 ubiquitin ligase domain in its carboxyl terminus which causes degradation of Fen and undermines its ability to activate ETI. In contrast, Pto evades AvrPtoB-mediated degradation and triggers ETI in response to the effector. It has been reported recently that Pto has higher kinase activity than Fen and that this difference allows Pto to inactivate the E3 ligase through phosphorylation of threonine-450 (T450) in AvrPtoB. Here we show that, in contrast to Fen which can only interact with a single domain proximal to the E3 ligase of AvrPtoB, Pto binds two distinct domains of the effector, the same site as Fen and another N-terminal domain. In the absence of E3 ligase activity Pto binds to either domain of AvrPtoB to activate ETI. However, the presence of an active E3 ligase domain causes ubiquitination of Pto that interacts with the domain proximal to the E3 ligase, identical to ubiquitination of Fen. Only when Pto binds its unique distal domain can it resist AvrPtoB-mediated degradation and activate ETI. We show that phosphorylation of T450 is not required for Pto-mediated resistance in vivo and that a kinase-inactive version of Pto is still capable of activating ETI in response to AvrPtoB. Our results demonstrate that the ability of Pto to interact with a second site distal to the E3 ligase domain in AvrPtoB, and not a higher kinase activity or T450 phosphorylation, allows Pto to evade ubiquitination and to confer immunity to Pst.
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38
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Grzeskowiak L, Stephan W, Rose LE. Epistatic selection and coadaptation in the Prf resistance complex of wild tomato. INFECTION GENETICS AND EVOLUTION 2014; 27:456-71. [PMID: 24997333 DOI: 10.1016/j.meegid.2014.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 06/24/2014] [Accepted: 06/25/2014] [Indexed: 11/26/2022]
Abstract
Natural selection imposed by pathogens is a strong and pervasive evolutionary force structuring genetic diversity within their hosts' genomes and populations. As a model system for understanding the genomic impact of host-parasite coevolution, we have been studying the evolutionary dynamics of disease resistance genes in wild relatives of the cultivated tomato species. In this study, we investigated the sequence variation and evolutionary history of three linked genes involved in pathogen resistance in populations of Solanum peruvianum (Pto, Fen, and Prf). These genes encode proteins, which form a multimeric complex and together activate defense responses. We used standard linkage disequilibrium, as well as partitioning of linkage disequilibrium components across populations and correlated substitution analysis to identify amino acid positions that are candidates for coevolving sites between Pto/Fen and Prf. These candidates were mapped onto known and predicted structures of Pto, Fen and Prf to visualize putative coevolving regions between proteins. We discuss the functional significance of these coevolving pairs in the context of what is known from previous structure-function studies of Pto, Fen and Prf.
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Affiliation(s)
- Lukasz Grzeskowiak
- Section of Evolutionary Biology, Ludwig Maximilian University Munich, Grosshadernerstr. 2, 82152 Planegg, Germany; Center for Research and Innovation, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all'Adige, Italy
| | - Wolfgang Stephan
- Section of Evolutionary Biology, Ludwig Maximilian University Munich, Grosshadernerstr. 2, 82152 Planegg, Germany
| | - Laura E Rose
- Section of Evolutionary Biology, Ludwig Maximilian University Munich, Grosshadernerstr. 2, 82152 Planegg, Germany; Institute of Population Genetics, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
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39
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Marín M, Ott T. Intrinsic disorder in plant proteins and phytopathogenic bacterial effectors. Chem Rev 2014; 114:6912-32. [PMID: 24697726 DOI: 10.1021/cr400488d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Macarena Marín
- Genetics Institute, Faculty of Biology, Ludwig-Maximilians-University of Munich , Grosshaderner Strasse 2-4, 82152 Martinsried, Germany
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40
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Lin W, Ma X, Shan L, He P. Big roles of small kinases: the complex functions of receptor-like cytoplasmic kinases in plant immunity and development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:1188-97. [PMID: 23710768 PMCID: PMC4391744 DOI: 10.1111/jipb.12071] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 05/21/2013] [Indexed: 05/19/2023]
Abstract
Plants have evolved a large number of receptor-like cytoplasmic kinases (RLCKs) that often functionally and physically associate with receptor-like kinases (RLKs) to modulate plant growth, development and immune responses. Without any apparent extracellular domain, RLCKs relay intracellular signaling often via RLK complex-mediated transphosphorylation events. Recent advances have suggested essential roles of diverse RLCKs in concert with RLKs in regulating various cellular and physiological responses. We summarize here the complex roles of RLCKs in mediating plant immune responses and growth regulation, and discuss specific and overlapping functions of RLCKs in transducing diverse signaling pathways. [Figure: see text] Ping He (Corresponding author).
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Affiliation(s)
- Wenwei Lin
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843, USA
| | - Xiyu Ma
- Department of Biochemistry and Biophysics, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843, USA
| | - Libo Shan
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843, USA
| | - Ping He
- Department of Biochemistry and Biophysics, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas 77843, USA
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41
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Hao W, Collier SM, Moffett P, Chai J. Structural basis for the interaction between the potato virus X resistance protein (Rx) and its cofactor Ran GTPase-activating protein 2 (RanGAP2). J Biol Chem 2013; 288:35868-76. [PMID: 24194517 DOI: 10.1074/jbc.m113.517417] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The potato (Solanum tuberosum) disease resistance protein Rx has a modular arrangement that contains coiled-coil (CC), nucleotide-binding (NB), and leucine-rich repeat (LRR) domains and mediates resistance to potato virus X. The Rx N-terminal CC domain undergoes an intramolecular interaction with the Rx NB-LRR region and an intermolecular interaction with the Rx cofactor RanGAP2 (Ran GTPase-activating protein 2). Here, we report the crystal structure of the Rx CC domain in complex with the Trp-Pro-Pro (WPP) domain of RanGAP2. The structure reveals that the Rx CC domain forms a heterodimer with RanGAP2, in striking contrast to the homodimeric structure of the CC domain of the barley disease resistance protein MLA10. Structure-based mutagenesis identified residues from both the Rx CC domain and the RanGAP2 WPP domain that are crucial for their interaction and function in vitro and in vivo. Our results reveal the molecular mechanism underlying the interaction of Rx with RanGAP2 and identify the distinct surfaces of the Rx CC domain that are involved in intramolecular and intermolecular interactions.
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Affiliation(s)
- Wei Hao
- From the College of Biological Sciences, China Agricultural University, Beijing 100193, China
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42
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Abstract
Over the past decade, considerable advances have been made in understanding the molecular mechanisms that underpin the arms race between plant pathogens and their hosts. Alongside genomic, bioinformatic, proteomic, biochemical and cell biological analyses of plant-pathogen interactions, three-dimensional structural studies of virulence proteins deployed by pathogens to promote infection, in some cases complexed with their plant cell targets, have uncovered key insights into the functions of these molecules. Structural information on plant immune receptors, which regulate the response to pathogen attack, is also starting to emerge. Structural studies of bacterial plant pathogen-host systems have been leading the way, but studies of filamentous plant pathogens are gathering pace. In this Review, we summarize the key developments in the structural biology of plant pathogen-host interactions.
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43
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A novel predicted calcium-regulated kinase family implicated in neurological disorders. PLoS One 2013; 8:e66427. [PMID: 23840464 PMCID: PMC3696010 DOI: 10.1371/journal.pone.0066427] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 05/08/2013] [Indexed: 12/03/2022] Open
Abstract
The catalogues of protein kinases, the essential effectors of cellular signaling, have been charted in Metazoan genomes for a decade now. Yet, surprisingly, using bioinformatics tools, we predicted protein kinase structure for proteins coded by five related human genes and their Metazoan homologues, the FAM69 family. Analysis of three-dimensional structure models and conservation of the classic catalytic motifs of protein kinases present in four out of five human FAM69 proteins suggests they might have retained catalytic phosphotransferase activity. An EF-hand Ca2+-binding domain in FAM69A and FAM69B proteins, inserted within the structure of the kinase domain, suggests they may function as Ca2+-dependent kinases. The FAM69 genes, FAM69A, FAM69B, FAM69C, C3ORF58 (DIA1) and CXORF36 (DIA1R), are by large uncharacterised molecularly, yet linked to several neurological disorders in genetics studies. The C3ORF58 gene is found deleted in autism, and resides in the Golgi. Unusually high cysteine content and presence of signal peptides in some of the family members suggest that FAM69 proteins may be involved in phosphorylation of proteins in the secretory pathway and/or of extracellular proteins.
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44
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Robatzek S, Wirthmueller L. Mapping FLS2 function to structure: LRRs, kinase and its working bits. PROTOPLASMA 2013; 250:671-81. [PMID: 23053766 DOI: 10.1007/s00709-012-0459-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 09/21/2012] [Indexed: 05/26/2023]
Abstract
The plasma membrane-localised FLAGELLIN SENSING 2 (FLS2) receptor is an important component of plant immunity against potentially pathogenic bacteria, acting to recognise the conserved flg22 peptide of flagellin. FLS2 shares the common structure of transmembrane receptor kinases with a receptor-like ectodomain composed of leucine-rich repeats (LRR) and an active intracellular kinase domain. Upon ligand binding, FLS2 dimerises with the regulatory LRR-receptor kinase BRI1-associated kinase 1, which in turn triggers downstream signalling cascades. Although lacking crystal structure data, recent advances have been made in our understanding of flg22 recognition based on structural and functional analyses of FLS2. These studies have revealed critical regions/residues of FLS2 and post-translational modifications that regulate the abundance and activity of this receptor. In this review, we present the current knowledge on the structural mechanism of the FLS2-flg22 interaction and subsequent receptor-mediated signalling.
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Affiliation(s)
- Silke Robatzek
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
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45
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Structural basis of eukaryotic cell targeting by type III secretion system (T3SS) effectors. Res Microbiol 2013; 164:605-19. [PMID: 23541478 DOI: 10.1016/j.resmic.2013.03.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/27/2013] [Indexed: 02/06/2023]
Abstract
Type III secretion systems (T3SS) are macromolecular complexes that translocate a wide number of effector proteins into eukaryotic host cells. Once within the cytoplasm, many T3SS effectors mimic the structure and/or function of eukaryotic proteins in order to manipulate signaling cascades, and thus play pivotal roles in colonization, invasion, survival and virulence. Structural biology techniques have played key roles in the unraveling of bacterial strategies employed for mimicry and targeting. This review provides an overall view of our current understanding of structure and function of T3SS effectors, as well as of the different classes of eukaryotic proteins that are targeted and the consequences for the infected cell.
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Huang W, Miao M, Kud J, Niu X, Ouyang B, Zhang J, Ye Z, Kuhl JC, Liu Y, Xiao F. SlNAC1, a stress-related transcription factor, is fine-tuned on both the transcriptional and the post-translational level. THE NEW PHYTOLOGIST 2013; 197:1214-1224. [PMID: 23278405 DOI: 10.1111/nph.12096] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 11/11/2012] [Indexed: 05/02/2023]
Abstract
The plant-specific NAC (NAM, ATAF1,2, CUC2) transcription factors play significant roles in diverse physiological processes. In this study, we determined the regulation of a stress-related tomato (Solanum lycopersicum) NAC1 (SlNAC1) transcription factor at both the transcriptional and the post-translational level. The SlNAC1 protein was found to be stable in the presence of proteasome-specific inhibitor MG132 or MG115 and ubiquitinated in plant cells, suggesting that the SlNAC1 is subject to the ubiquitin-proteasome system-mediated degradation. Deletion analysis identified a short segment of 10 amino acids (aa261-270) that was required for ubiquitin-proteasome system-mediated degradation, among which two leucine residues (L268 and L269) were critical for the protein instability of SlNAC1. Fusion of the degron (SlNAC1(191-270) ) containing these 10 amino acids to green fluorescent protein was found to be sufficient to trigger the degradation of the fusion protein. In addition, the SlNAC1 gene is strongly upregulated during Pseudomonas infection, while repression of the NAC1 ortholog in Nicotiana benthamiana resulted in enhanced susceptibility to Pseudomonas bacteria. These results suggest that rapid upregulation of the NAC1 gene resulting in more protein production is likely one of the strategies plants use to defend themselves against pathogen infection.
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Affiliation(s)
- Weizao Huang
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, 83844-2339, USA
- Sichuan Academy of Agricultural Sciences, Chengdu, Sichuan, 610066, China
| | - Min Miao
- Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Joanna Kud
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, 83844-2339, USA
| | - Xiangli Niu
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, 83844-2339, USA
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Bo Ouyang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Junhong Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Zhibiao Ye
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Joseph C Kuhl
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, 83844-2339, USA
| | - Yongsheng Liu
- Sichuan Academy of Agricultural Sciences, Chengdu, Sichuan, 610066, China
- School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Fangming Xiao
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID, 83844-2339, USA
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47
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Kud J, Zhao Z, Du X, Liu Y, Zhao Y, Xiao F. SGT1 interacts with the Prf resistance protein and is required for Prf accumulation and Prf-mediated defense signaling. Biochem Biophys Res Commun 2013; 431:501-5. [PMID: 23333384 DOI: 10.1016/j.bbrc.2013.01.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/08/2013] [Indexed: 01/04/2023]
Abstract
The highly conserved eukaryotic co-chaperone SGT1 (suppressor of the G2 allele of skp1) is an important signaling component of plant defense responses and positively regulates disease resistance conferred by many resistance (R) proteins. In this study, we investigated the contribution of SGT1 in the Prf-mediated defense responses in both Nicotiana benthamiana and tomato (Solanum lycopersicum). SGT1 was demonstrated to interact with Prf in plant cells by co-immunoprecipitation. The requirement of SGT1 in the accumulation of Prf or autoactive Prf(D1416V) was determined by the degradation of these proteins in N. benthamiana, in which SGT1 was repressed by virus-induced gene silencing (VIGS). Pseudomonas pathogen assay on the SGT1-silenced tomato plants implicates SGT1 is required for the Prf-mediated full resistance to Pseudomonas syringae pv. tomato (Pst). These results suggest that, in both N. benthamiana and tomato, SGT1 contributes to the Prf-mediated defense responses by stabilizing Prf protein via its co-chaperone activity.
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Affiliation(s)
- Joanna Kud
- Department of Plant, Soil & Entomological Science, University of Idaho, Moscow, ID 83844, USA
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48
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Ntoukakis V, Balmuth AL, Mucyn TS, Gutierrez JR, Jones AME, Rathjen JP. The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation. PLoS Pathog 2013; 9:e1003123. [PMID: 23382672 PMCID: PMC3561153 DOI: 10.1371/journal.ppat.1003123] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 11/27/2012] [Indexed: 02/02/2023] Open
Abstract
The major virulence strategy of phytopathogenic bacteria is to secrete effector proteins into the host cell to target the immune machinery. AvrPto and AvrPtoB are two such effectors from Pseudomonas syringae, which disable an overlapping range of kinases in Arabidopsis and Tomato. Both effectors target surface-localized receptor-kinases to avoid bacterial recognition. In turn, tomato has evolved an intracellular effector-recognition complex composed of the NB-LRR protein Prf and the Pto kinase. Structural analyses have shown that the most important interaction surface for AvrPto and AvrPtoB is the Pto P+1 loop. AvrPto is an inhibitor of Pto kinase activity, but paradoxically, this kinase activity is a prerequisite for defense activation by AvrPto. Here using biochemical approaches we show that disruption of Pto P+1 loop stimulates phosphorylation in trans, which is possible because the Pto/Prf complex is oligomeric. Both P+1 loop disruption and transphosphorylation are necessary for signalling. Thus, effector perturbation of one kinase molecule in the complex activates another. Hence, the Pto/Prf complex is a sophisticated molecular trap for effectors that target protein kinases, an essential aspect of the pathogen's virulence strategy. The data presented here give a clear view of why bacterial virulence and host recognition mechanisms are so often related and how the slowly evolving host is able to keep pace with the faster-evolving pathogen.
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Affiliation(s)
- Vardis Ntoukakis
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
- * E-mail: (VN); (JPN)
| | - Alexi L. Balmuth
- The Sainsbury Laboratory, Norwich Research Park, Colney, United Kingdom
| | - Tatiana S. Mucyn
- The Sainsbury Laboratory, Norwich Research Park, Colney, United Kingdom
| | - Jose R. Gutierrez
- The Sainsbury Laboratory, Norwich Research Park, Colney, United Kingdom
| | | | - John P. Rathjen
- The Sainsbury Laboratory, Norwich Research Park, Colney, United Kingdom
- * E-mail: (VN); (JPN)
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49
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Sohn KH, Hughes RK, Piquerez SJ, Jones JDG, Banfield MJ. Distinct regions of the Pseudomonas syringae coiled-coil effector AvrRps4 are required for activation of immunity. Proc Natl Acad Sci U S A 2012; 109:16371-6. [PMID: 22988101 PMCID: PMC3479578 DOI: 10.1073/pnas.1212332109] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gram-negative phytopathogenic bacteria translocate effector proteins into plant cells to subvert host defenses. These effectors can be recognized by plant nucleotide-binding-leucine-rich repeat immune receptors, triggering defense responses that restrict pathogen growth. AvrRps4, an effector protein from Pseudomonas syringae pv. pisi, triggers RPS4-dependent immunity in resistant accessions of Arabidopsis. To better understand the molecular basis of AvrRps4-triggered immunity, we determined the crystal structure of processed AvrRps4 (AvrRps4(C), residues 134-221), revealing that it forms an antiparallel α-helical coiled coil. Structure-informed mutagenesis reveals an electronegative surface patch in AvrRps4(C) required for recognition by RPS4; mutations in this region can also uncouple triggering of the hypersensitive response from disease resistance. This uncoupling may result from a lower level of defense activation, sufficient for avirulence but not for triggering a hypersensitive response. Natural variation in AvrRps4 reveals distinct recognition specificities that involve a surface-exposed residue. Recently, a direct interaction between AvrRps4 and Enhanced Disease Susceptibility 1 has been implicated in activation of immunity. However, we were unable to detect direct interaction between AvrRps4 and Enhanced Disease Susceptibility 1 after coexpression in Nicotiana benthamiana or in yeast cells. How intracellular plant immune receptors activate defense upon effector perception remains an unsolved problem. The structure of AvrRps4(C), and identification of functionally important residues for its activation of plant immunity, advances our understanding of these processes in a well-defined model pathosystem.
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Affiliation(s)
- Kee Hoon Sohn
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom; and
| | - Richard K. Hughes
- Department of Biological Chemistry, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Sophie J. Piquerez
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom; and
| | - Jonathan D. G. Jones
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom; and
| | - Mark J. Banfield
- Department of Biological Chemistry, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
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50
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Du X, Miao M, Ma X, Liu Y, Kuhl JC, Martin GB, Xiao F. Plant programmed cell death caused by an autoactive form of Prf is suppressed by co-expression of the Prf LRR domain. MOLECULAR PLANT 2012; 5:1058-67. [PMID: 22451646 DOI: 10.1093/mp/sss014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In tomato, the NBARC-LRR resistance (R) protein Prf acts in concert with the Pto or Fen kinase to determine immunity against Pseudomonas syringae pv. tomato (Pst). Prf-mediated defense signaling is initiated by the recognition of two sequence-unrelated Pst-secreted effector proteins, AvrPto and AvrPtoB, by tomato Pto or Fen. Prf detects these interactions and activates signaling leading to host defense responses including localized programmed cell death (PCD) that is associated with the arrest of Pst growth. We found that Prf variants with single amino acid substitutions at D1416 in the IHD motif (isoleucine-histidine-aspartic acid) in the NBARC domain cause effector-independent PCD when transiently expressed in leaves of Nicotiana benthamiana, suggesting D1416 plays an important role in activation of Prf. The N-terminal region of Prf (NPrf) and the LRR domain are required for this autoactive Prf cell death signaling but dispensable for accumulation of the Prf(D1416V) protein. Significantly, co-expression of the Prf LRR but not NPrf, with Prf(D1416V), AvrPto/Pto, AvrPtoB/Pto, an autoactive form of Pto (Pto(Y207D)), or Fen completely suppresses PCD. However, the Prf LRR does not interfere with PCD caused by Rpi-blb1(D475V), a distinct R protein-mediated PCD signaling event, or that caused by overexpression of MAPKKKα, a protein acting downstream of Prf. Furthermore, we found the Prf(D1416V) protein is unable to accumulate in plant cells when co-expressed with the Prf LRR domain, likely explaining the cell death suppression. The mechanism for the LRR-induced degradation of Prf(D1416V) is unknown but may involve interference in the intramolecular interactions of Prf or to binding of the unattached LRR to other host proteins that are needed for Prf stability.
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Affiliation(s)
- Xinran Du
- Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844, USA
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