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Zdrzałek R, Xi Y, Langner T, Bentham AR, Petit-Houdenot Y, De la Concepcion JC, Harant A, Shimizu M, Were V, Talbot NJ, Terauchi R, Kamoun S, Banfield MJ. Bioengineering a plant NLR immune receptor with a robust binding interface toward a conserved fungal pathogen effector. Proc Natl Acad Sci U S A 2024; 121:e2402872121. [PMID: 38968126 PMCID: PMC11252911 DOI: 10.1073/pnas.2402872121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 05/21/2024] [Indexed: 07/07/2024] Open
Abstract
Bioengineering of plant immune receptors has emerged as a key strategy for generating novel disease resistance traits to counteract the expanding threat of plant pathogens to global food security. However, current approaches are limited by rapid evolution of plant pathogens in the field and may lack durability when deployed. Here, we show that the rice nucleotide-binding, leucine-rich repeat (NLR) immune receptor Pik-1 can be engineered to respond to a conserved family of effectors from the multihost blast fungus pathogen Magnaporthe oryzae. We switched the effector binding and response profile of the Pik NLR from its cognate rice blast effector AVR-Pik to the host-determining factor pathogenicity toward weeping lovegrass 2 (Pwl2) by installing a putative host target, OsHIPP43, in place of the native integrated heavy metal-associated domain (generating Pikm-1OsHIPP43). This chimeric receptor also responded to other PWL alleles from diverse blast isolates. The crystal structure of the Pwl2/OsHIPP43 complex revealed a multifaceted, robust interface that cannot be easily disrupted by mutagenesis, and may therefore provide durable, broad resistance to blast isolates carrying PWL effectors in the field. Our findings highlight how the host targets of pathogen effectors can be used to bioengineer recognition specificities that have more robust properties compared to naturally evolved disease resistance genes.
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Affiliation(s)
- Rafał Zdrzałek
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Yuxuan Xi
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Thorsten Langner
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Adam R. Bentham
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | | | - Juan Carlos De la Concepcion
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Adeline Harant
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Motoki Shimizu
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate024-0003, Japan
| | - Vincent Were
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Nicholas J. Talbot
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Ryohei Terauchi
- Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate024-0003, Japan
- Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kyoto606-8501, Japan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, NorwichNR4 7UH, United Kingdom
| | - Mark J. Banfield
- Department of Biochemistry and Metabolism, John Innes Centre, NorwichNR4 7UH, United Kingdom
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Brabham HJ, Gómez De La Cruz D, Were V, Shimizu M, Saitoh H, Hernández-Pinzón I, Green P, Lorang J, Fujisaki K, Sato K, Molnár I, Šimková H, Doležel J, Russell J, Taylor J, Smoker M, Gupta YK, Wolpert T, Talbot NJ, Terauchi R, Moscou MJ. Barley MLA3 recognizes the host-specificity effector Pwl2 from Magnaporthe oryzae. THE PLANT CELL 2024; 36:447-470. [PMID: 37820736 PMCID: PMC10827324 DOI: 10.1093/plcell/koad266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/20/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Plant nucleotide-binding leucine-rich repeat (NLRs) immune receptors directly or indirectly recognize pathogen-secreted effector molecules to initiate plant defense. Recognition of multiple pathogens by a single NLR is rare and usually occurs via monitoring for changes to host proteins; few characterized NLRs have been shown to recognize multiple effectors. The barley (Hordeum vulgare) NLR gene Mildew locus a (Mla) has undergone functional diversification, and the proteins encoded by different Mla alleles recognize host-adapted isolates of barley powdery mildew (Blumeria graminis f. sp. hordei [Bgh]). Here, we show that Mla3 also confers resistance to the rice blast fungus Magnaporthe oryzae in a dosage-dependent manner. Using a forward genetic screen, we discovered that the recognized effector from M. oryzae is Pathogenicity toward Weeping Lovegrass 2 (Pwl2), a host range determinant factor that prevents M. oryzae from infecting weeping lovegrass (Eragrostis curvula). Mla3 has therefore convergently evolved the capacity to recognize effectors from diverse pathogens.
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Affiliation(s)
- Helen J Brabham
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- 2Blades, Evanston, IL 60201, USA
| | - Diana Gómez De La Cruz
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Vincent Were
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Motoki Shimizu
- Iwate Biotechnology Research Centre, Kitakami 024-0003, Japan
| | - Hiromasa Saitoh
- Department of Molecular Microbiology, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | | | - Phon Green
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jennifer Lorang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Koki Fujisaki
- Iwate Biotechnology Research Centre, Kitakami 024-0003, Japan
| | - Kazuhiro Sato
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - István Molnár
- Institute of Experimental Botany of the Czech Academy of Sciences, 779 00 Olomouc, Czech Republic
| | - Hana Šimková
- Institute of Experimental Botany of the Czech Academy of Sciences, 779 00 Olomouc, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany of the Czech Academy of Sciences, 779 00 Olomouc, Czech Republic
| | - James Russell
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jodie Taylor
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Matthew Smoker
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Yogesh Kumar Gupta
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- 2Blades, Evanston, IL 60201, USA
| | - Tom Wolpert
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Ryohei Terauchi
- Iwate Biotechnology Research Centre, Kitakami 024-0003, Japan
- Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kyoto 617-0001, Japan
| | - Matthew J Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
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Chakraborty A, Hussain A, Sabnam N. Uncovering the structural stability of Magnaporthe oryzae effectors: a secretome-wide in silico analysis. J Biomol Struct Dyn 2023:1-22. [PMID: 38109060 DOI: 10.1080/07391102.2023.2292795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 11/23/2023] [Indexed: 12/19/2023]
Abstract
Rice blast, caused by the ascomycete fungus Magnaporthe oryzae, is a deadly disease and a major threat to global food security. The pathogen secretes small proteinaceous effectors, virulence factors, inside the host to manipulate and perturb the host immune system, allowing the pathogen to colonize and establish a successful infection. While the molecular functions of several effectors are characterized, very little is known about the structural stability of these effectors. We analyzed a total of 554 small secretory proteins (SSPs) from the M. oryzae secretome to decipher key features of intrinsic disorder (ID) and the structural dynamics of the selected putative effectors through thorough and systematic in silico studies. Our results suggest that out of the total SSPs, 66% were predicted as effector proteins, released either into the apoplast or cytoplasm of the host cell. Of these, 68% were found to be intrinsically disordered effector proteins (IDEPs). Among the six distinct classes of disordered effectors, we observed peculiar relationships between the localization of several effectors in the apoplast or cytoplasm and the degree of disorder. We determined the degree of structural disorder and its impact on protein foldability across all the putative small secretory effector proteins from the blast pathogen, further validated by molecular dynamics simulation studies. This study provides definite clues toward unraveling the mystery behind the importance of structural distortions in effectors and their impact on plant-pathogen interactions. The study of these dynamical segments may help identify new effectors as well.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Afzal Hussain
- Department of Bioinformatics, Maulana Azad National Institute of Technology, Bhopal, India
| | - Nazmiara Sabnam
- Department of Life Sciences, Presidency University, Kolkata, India
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Peng Z, Li L, Wu S, Chen X, Shi Y, He Q, Shu F, Zhang W, Sun P, Deng H, Xing J. Frequencies and Variations of Magnaporthe oryzae Avirulence Genes in Hunan Province, China. PLANT DISEASE 2021; 105:3829-3834. [PMID: 34152208 DOI: 10.1094/pdis-01-21-0008-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rice blast caused by Magnaporthe oryzae poses significant threaten to rice production. For breeding and deploying resistant rice varieties, it is essential to understand the frequencies and genetic variations of avirulence (AVR) genes in the pathogen populations. In this study, 444 isolates were collected from Hunan Province, China in 2012, 2015, and 2016, and their pathogenicity was evaluated by testing them on monogenic rice lines carrying resistance genes Pita, Pizt, Pikm, Pib, or Pi9. The frequencies of corresponding AVR genes AVRPizt, AVRPikm, AVRPib, AVRPi9, and AVRPita were characterized by amplification and sequencing these genes in the isolates. Both Pi9 and Pikm conferred resistance to >75% of the tested isolates, while Pizt, Pita, and Pib were effective against 55.63, 15.31, and 3.15% of the isolates, respectively. AVRPikm and AVRPi9 were detected in 90% of the isolates and AVRPita, AVRPizt, and AVRPib were present in 26.12, 66.22, and 79% of the isolates, respectively. Sequencing of AVR genes showed that most mutations were single nucleotide polymorphisms, transposon insertions, and insertion mutations. The variable sites of AVRPikm and AVRPita were mainly located in the coding sequence regions (CDS), and most were synonymous mutations. A 494-bp Pot2 transposon sequence insertion was found at the 87 bp position upstream of the start codon in AVRPib. Noteworthy, although no mutations were found in CDS of AVRPi9, a GC-rich inserted sequence of ∼200 bp was found at the 1,272 bp position upstream of the start codon in three virulent isolates. As AVRPikm and AVRPi9 were widely distributed with low genetic variation in the pathogen population, Pikm and Pi9 should be promising genes for breeding rice cultivars with blast resistance in Hunan.
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Affiliation(s)
- Zhirong Peng
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Ling Li
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
- Longping Branch, Graduate School of Hunan University, Changsha, Hunan 410082, China
| | - Shenghai Wu
- Huitong County Agricultural and Rural Bureau, Huaihua, Hunan 418300, China
| | - Xiaolin Chen
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yinfeng Shi
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Qiang He
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Fu Shu
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Wuhan Zhang
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Pingyong Sun
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Huafeng Deng
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
| | - Junjie Xing
- Hunan Hybrid Rice Research Center, State Key Laboratory of Hybrid Rice, Changsha, Hunan 410125, China
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Chakraborty J. In-silico structural analysis of Pseudomonas syringae effector HopZ3 reveals ligand binding activity and virulence function. JOURNAL OF PLANT RESEARCH 2021; 134:599-611. [PMID: 33730245 DOI: 10.1007/s10265-021-01274-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Bacterial acetyltransferase effectors belonging to the Yersinia outer protein J (YopJ) group inhibit multiple immune signaling pathways in human and plants. The present study determines in-silico acetyl-coenzyme A (AcCoA) binding and Arabidopsis immune regulator RPM1-interacting protein4 (RIN4) peptide interactions to YopJ effector hypersensitivity and pathogenesis-dependent outer proteinZ3 (HopZ3) from Pseudomonas syringae. Phylogenetic analysis revealed that HopZ3 was clustered by acetyltransferase effectors from plant bacterial pathogens. Structural juxtaposition shows HopZ3 comprises topology matched closer with HopZ1a than PopP2 effectors, respectively. AcCoA binds HopZ3 at two sites i.e., substrate binding pocket and catalytic site. AcCoA interactions to substrate binding pocket was transient and dissipated upon in-silico mutation of Ser 279 residue whereas, attachment to catalytic site was found to be stable in the presence of inositol hexaphosphate (IP6) as a co-factor. Interface atoms used for measuring hydrogen bond distances, bound or accessible surface area, and root-mean-square fluctuation (RMSF) values, suggests that the HopZ3 complex stabilizes after binding to AcCoA ligand and RIN4 peptide. The few non-conserved polymorphic residues that have been displayed on HopZ3 surface presumably confer intracellular recognitions within hosts. Collectively, homology modeling and interactive docking experiments were used to substantiate Arabidopsis immune 'guardee' interactions to HopZ3.
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Soluble Expression and Catalytic Properties of Codon-Optimized Recombinant Bromelain from MD2 Pineapple in Escherichia coli. Protein J 2021; 40:406-418. [PMID: 33713245 DOI: 10.1007/s10930-021-09974-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2021] [Indexed: 01/15/2023]
Abstract
Bromelain, a member of cysteine proteases, is found abundantly in pineapple (Ananas comosus), and it has a myriad of versatile applications. However, attempts to produce recombinant bromelain for commercialization purposes are challenging due to its expressibility and solubility. This study aims to express recombinant fruit bromelain from MD2 pineapple (MD2Bro; accession no: OAY85858.1) in soluble and active forms using Escherichia coli host cell. The gene encoding MD2Bro was codon-optimized, synthesized, and subsequently ligated into pET-32b( +) for further transformation into Escherichia coli BL21-CodonPlus(DE3). Under this strategy, the expressed MD2Bro was in a fusion form with thioredoxin (Trx) tag at its N-terminal (Trx-MD2Bro). The result showed that Trx-MD2Bro was successfully expressed in fully soluble form. The protein was successfully purified using single-step Ni2+-NTA chromatography and confirmed to be in proper folds based on the circular dichroism spectroscopy analysis. The purified Trx-MD2Bro was confirmed to be catalytically active against N-carbobenzoxyglycine p-nitrophenyl ester (N-CBZ-Gly-pNP) with a specific activity of 6.13 ± 0.01 U mg-1 and inhibited by a cysteine protease inhibitor, E-64 (IC50 of 74.38 ± 1.65 nM). Furthermore, the catalytic efficiency (kcat/KM) Trx-MD2Bro was calculated to be at 5.64 ± 0.02 × 10-2 µM-1 s-1 while the optimum temperature and pH were at 50 °C and pH 6.0, respectively. Furthermore, the catalytic activity of Trx-MD2Bro was also affected by ethylenediaminetetraacetic acid (EDTA) or metal ions. Altogether it is proposed that the combination of codon optimization and the use of an appropriate vector are important in the production of a soluble and actively stable recombinant bromelain.
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Yang LN, Liu H, Duan GH, Huang YM, Liu S, Fang ZG, Wu EJ, Shang L, Zhan J. The Phytophthora infestans AVR2 Effector Escapes R2 Recognition Through Effector Disordering. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:921-931. [PMID: 32212906 DOI: 10.1094/mpmi-07-19-0179-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Intrinsic disorder is a common structural characteristic of proteins and a central player in the biochemical processes of species. However, the role of intrinsic disorder in the evolution of plant-pathogen interactions is rarely investigated. Here, we explored the role of intrinsic disorder in the development of the pathogenicity in the RXLR AVR2 effector of Phytophthora infestans. We found AVR2 exhibited high nucleotide diversity generated by point mutation, early-termination, altered start codon, deletion/insertion, and intragenic recombination and is predicted to be an intrinsically disordered protein. AVR2 amino acid sequences conferring a virulent phenotype had a higher disorder tendency in both the N- and C-terminal regions compared with sequences conferring an avirulent phenotype. In addition, we also found virulent AVR2 mutants gained one or two short linear interaction motifs, the critical components of disordered proteins required for protein-protein interactions. Furthermore, virulent AVR2 mutants were predicted to be unstable and have a short protein half-life. Taken together, these results support the notion that intrinsic disorder is important for the effector function of pathogens and demonstrate that SLiM-mediated protein-protein interaction in the C-terminal effector domain might contribute greatly to the evasion of resistance-protein detection in P. infestans.
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Affiliation(s)
- Li-Na Yang
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Hao Liu
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Guo-Hua Duan
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Yan-Mei Huang
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Shiting Liu
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Zhi-Guo Fang
- Xiangyang Academy of Agricultural Sciences, Xiangyang 441057, Hubei, China
| | - E-Jiao Wu
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Liping Shang
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China
| | - Jiasui Zhan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Graether SP. Troubleshooting Guide to Expressing Intrinsically Disordered Proteins for Use in NMR Experiments. Front Mol Biosci 2019; 5:118. [PMID: 30713842 PMCID: PMC6345686 DOI: 10.3389/fmolb.2018.00118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/23/2018] [Indexed: 12/17/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) represent a structural class of proteins that do not have a well-defined, 3D fold in solution, and often have little secondary structure. To characterize their function and molecular mechanism, it is helpful to examine their structure using nuclear magnetic resonance (NMR), which can report on properties, such as residual structure (at both the secondary and tertiary levels), ligand binding affinity, and the effect of ligand binding on IDP structure, all on a per residue basis. This brief review reports on the common problems and decisions that are involved when preparing a disordered protein for NMR studies. The paper covers gene design, expression host choice, protein purification, and the initial NMR experiments that are performed. While many of these steps are essentially identical to those for ordered proteins, a few key differences are highlighted, including the extreme sensitivity of IDPs to proteolytic cleavage, the ability to use denaturing conditions without having to refold the protein, the optimal chromatographic system choice, and the challenges of quantifying an IDP. After successful purification, characterization by NMR can be done using the standard 15N-heteronuclear single quantum coherence (15N-HSQC) experiment, or the newer CON series of experiments that are superior for disordered proteins.
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Affiliation(s)
- Steffen P Graether
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
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Kuppireddy VS, Uversky VN, Toh SS, Tsai MC, Beckerson WC, Cahill C, Carman B, Perlin MH. Identification and Initial Characterization of the Effectors of an Anther Smut Fungus and Potential Host Target Proteins. Int J Mol Sci 2017; 18:E2489. [PMID: 29165363 PMCID: PMC5713455 DOI: 10.3390/ijms18112489] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/05/2017] [Accepted: 11/16/2017] [Indexed: 12/01/2022] Open
Abstract
(1) Background: Plant pathogenic fungi often display high levels of host specificity and biotrophic fungi; in particular, they must manipulate their hosts to avoid detection and to complete their obligate pathogenic lifecycles. One important strategy of such fungi is the secretion of small proteins that serve as effectors in this process. Microbotryum violaceum is a species complex whose members infect members of the Caryophyllaceae; M. lychnidis-dioicae, a parasite on Silene latifolia, is one of the best studied interactions. We are interested in identifying and characterizing effectors of the fungus and possible corresponding host targets; (2) Methods: In silico analysis of the M. lychnidis-dioicae genome and transcriptomes allowed us to predict a pool of small secreted proteins (SSPs) with the hallmarks of effectors, including a lack of conserved protein family (PFAM) domains and also localized regions of disorder. Putative SSPs were tested for secretion using a yeast secretion trap method. We then used yeast two-hybrid analyses for candidate-secreted effectors to probe a cDNA library from a range of growth conditions of the fungus, including infected plants; (3) Results: Roughly 50 SSPs were identified by in silico analysis. Of these, 4 were studied further and shown to be secreted, as well as examined for potential host interactors. One of the putative effectors, MVLG_01732, was found to interact with Arabidopsis thaliana calcium-dependent lipid binding protein (AtCLB) and with cellulose synthase interactive protein 1 orthologues; and (4) Conclusions: The identification of a pool of putative effectors provides a resource for functional characterization of fungal proteins that mediate the delicate interaction between pathogen and host. The candidate targets of effectors, e.g., AtCLB, involved in pollen germination suggest tantalizing insights that could drive future studies.
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Affiliation(s)
- Venkata S Kuppireddy
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - Vladimir N Uversky
- Department of Molecular Biology and University of South Florida Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, Institutskaya Str., 7, Pushchino, Moscow Region 142290, Russia.
| | - Su San Toh
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - Ming-Chang Tsai
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - William C Beckerson
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - Catarina Cahill
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - Brittany Carman
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
| | - Michael H Perlin
- Department of Biology, Program on Disease Evolution, University of Louisville, Louisville, KY 40208, USA.
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Satoh Y, Miki S, Ose T, Oikawa A, Maenaka K, Terauchi R, Asano K, Sone T. Heterologous production, purification, and immunodetection of Magnaporthe oryzae avirulence protein AVR-Pia. Biosci Biotechnol Biochem 2014; 78:680-6. [PMID: 25036967 DOI: 10.1080/09168451.2014.893186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The avirulence gene AVR-Pia of Magnaporthe oryzae, which induces a hypersensitive reaction in rice cultivars containing the resistance gene Pia, was expressed in Escherichia coli. AVR-Pia protein was collected as inclusion bodies, denatured, and refolded. Finally, recombinant AVR-Pia (rAVR-Pia) protein was purified by column chromatography. Infiltration of rAVR-Pia triggered cell browning in the leaves of rice cultivar Aichiasahi (Pia), with accumulation of H2O2 and induction of PR1a expression in rice. On the other hand, these reactions were not observed in Shin-2 (pia) leaves after the same treatment. This observation indicated that rAVR-Pia had the function of an avirulence protein. rAVR-Pia was used for immunization of a rabbit, and anti-AVR-Pia antiserum was prepared. The specificity of this antibody was appraised by detecting native AVR-Pia in the inoculated leaf sheath extract using Western blotting in combination with immunoprecipitation. Native AVR-Pia was successfully detected, and its molecular weight was estimated to be 7.4 kDa, indicating signal peptide cleavage. Additionally, secreted native AVR-Pia was quantified as 3.7 ng/g rice sheath.
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Affiliation(s)
- Yuki Satoh
- a Graduate School of Agriculture, Hokkaido University , Sapporo , Japan
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Huang J, Si W, Deng Q, Li P, Yang S. Rapid evolution of avirulence genes in rice blast fungus Magnaporthe oryzae. BMC Genet 2014; 15:45. [PMID: 24725999 PMCID: PMC4021558 DOI: 10.1186/1471-2156-15-45] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 04/07/2014] [Indexed: 11/24/2022] Open
Abstract
Background Rice blast fungus Magnaporthe oryzae is one of the most devastating pathogens in rice. Avirulence genes in this fungus share a gene-for-gene relationship with the resistance genes in its host rice. Although numerous studies have shown that rice blast R-genes are extremely diverse and evolve rapidly in their host populations, little is known about the evolutionary patterns of the Avr-genes in the pathogens. Results Here, six well-characterized Avr-genes and seven randomly selected non-Avr control genes were used to investigate the genetic variations in 62 rice blast strains from different parts of China. Frequent presence/absence polymorphisms, high levels of nucleotide variation (~10-fold higher than non-Avr genes), high non-synonymous to synonymous substitution ratios, and frequent shared non-synonymous substitution were observed in the Avr-genes of these diversified blast strains. In addition, most Avr-genes are closely associated with diverse repeated sequences, which may partially explain the frequent presence/absence polymorphisms in Avr-genes. Conclusion The frequent deletion and gain of Avr-genes and rapid non-synonymous variations might be the primary mechanisms underlying rapid adaptive evolution of pathogens toward virulence to their host plants, and these features can be used as the indicators for identifying additional Avr-genes. The high number of nucleotide polymorphisms among Avr-gene alleles could also be used to distinguish genetic groups among different strains.
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Affiliation(s)
| | | | | | - Ping Li
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
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Marín M, Uversky VN, Ott T. Intrinsic disorder in pathogen effectors: protein flexibility as an evolutionary hallmark in a molecular arms race. THE PLANT CELL 2013; 25:3153-7. [PMID: 24038649 PMCID: PMC3809524 DOI: 10.1105/tpc.113.116319] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Effector proteins represent a refined mechanism of bacterial pathogens to overcome plants' innate immune systems. These modular proteins often manipulate host physiology by directly interfering with immune signaling of plant cells. Even if host cells have developed efficient strategies to perceive the presence of pathogenic microbes and to recognize intracellular effector activity, it remains an open question why only few effectors are recognized directly by plant resistance proteins. Based on in-silico genome-wide surveys and a reevaluation of published structural data, we estimated that bacterial effectors of phytopathogens are highly enriched in long-disordered regions (>50 residues). These structurally flexible segments have no secondary structure under physiological conditions but can fold in a stimulus-dependent manner (e.g., during protein-protein interactions). The high abundance of intrinsic disorder in effectors strongly suggests positive evolutionary selection of this structural feature and highlights the dynamic nature of these proteins. We postulate that such structural flexibility may be essential for (1) effector translocation, (2) evasion of the innate immune system, and (3) host function mimicry. The study of these dynamical regions will greatly complement current structural approaches to understand the molecular mechanisms of these proteins and may help in the prediction of new effectors.
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Affiliation(s)
- Macarena Marín
- Genetics Institute, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Martinsried, Germany
- Address correspondence to
| | - Vladimir N. Uversky
- Department of Molecular Medicine, University of South Florida Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Thomas Ott
- Genetics Institute, Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Martinsried, Germany
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