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Lin M, Liu Y, Shen C, Meng M, Zhang X, Xu C, Jin J, Hu X, Zhu Q, Xie Y, Chen W, Liu X, Lin J. Generation of anti-idiotypic antibodies mimicking Cry2Aa toxin from an immunized mouse phage display library as potential insecticidal agents against Plutella xylostella. Biochem Biophys Res Commun 2024; 691:149308. [PMID: 38029542 DOI: 10.1016/j.bbrc.2023.149308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/18/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023]
Abstract
This study tried to generate anti-idiotypic antibodies (Ab2s) which mimic Cry2Aa toxin using a phage-display antibody library (2.8 × 107 CFU/mL). The latter was constructed from a mouse immunized with F (ab')2 fragments digested from anti-Cry2Aa polyclonal antibodies. The F (ab')2 fragments and Plutella xylostella (P. xylostella) brush border membrane vesicles (BBMV) were utilized as targets for selection. Eight mouse phage-display single-chain variable fragments (scFvs) were isolated and identified by enzyme-linked immunoassay (ELISA), PCR and DNA sequencing after four rounds of biopanning. Among them, M3 exhibited the highest binding affinity with F (ab')2, while M4 bound the best with the toxin binding region of cadherin of P. xylostella (PxCad-TBR). Both of these two fragments were chosen for prokaryotic expression. The expressed M3 and M4 proteins with molecular weights of 30 kDa were purified. The M4 showed a binding affinity of 29.9 ± 2.4 nM with the PxCad-TBR and resulted in 27.8 ± 4.3 % larvae mortality against P. xylostella. Computer-assisted molecular modeling and docking analysis showed that mouse scFv M4 mimicked some Cry2Aa toxin binding sites when interacting with PxCad-TBR. Therefore, anti-idiotypic antibodies generated by BBMV-based screening could be useful for the development of new bio-insecticides as an alternative to Cry2Aa toxin for pest control.
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Affiliation(s)
- Manman Lin
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Yuan Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
| | - Cheng Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Meng Meng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Xiao Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Chongxin Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Jiafeng Jin
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Xiaodan Hu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Qing Zhu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Yajing Xie
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Wei Chen
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Xianjin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
| | - Johnson Lin
- School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa.
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Xiong L, Liu Z, Li J, Yao S, Li Z, Chen X, Shen L, Zhang Z, Li Y, Hou Q, Zhang Y, You M, Yuchi Z, You S. Analysis of the Effect of Plutella xylostella Polycalin and ABCC2 Transporter on Cry1Ac Susceptibility by CRISPR/Cas9-Mediated Knockout. Toxins (Basel) 2023; 15:toxins15040273. [PMID: 37104211 PMCID: PMC10145054 DOI: 10.3390/toxins15040273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/28/2023] [Accepted: 04/04/2023] [Indexed: 04/28/2023] Open
Abstract
Many insects, including the Plutella xylostella (L.), have developed varying degrees of resistance to many insecticides, including Bacillus thuringiensis (Bt) toxins, the bioinsecticides derived from Bt. The polycalin protein is one of the potential receptors for Bt toxins, and previous studies have confirmed that the Cry1Ac toxin can bind to the polycalin protein of P. xylostella, but whether polycalin is associated with the resistance of Bt toxins remains controversial. In this study, we compared the midgut of larvae from Cry1Ac-susceptible and -resistant strains, and found that the expression of the Pxpolycalin gene was largely reduced in the midgut of the resistant strains. Moreover, the spatial and temporal expression patterns of Pxpolycalin showed that it was mainly expressed in the larval stage and midgut tissue. However, genetic linkage experiments showed that the Pxpolycalin gene and its transcript level were not linked to Cry1Ac resistance, whereas both the PxABCC2 gene and its transcript levels were linked to Cry1Ac resistance. The larvae fed on a diet containing the Cry1Ac toxin showed no significant change in the expression of the Pxpolycalin gene in a short term. Furthermore, the knockout of polycalin and ATP-binding cassette transporter subfamily C2 (ABCC2) genes separately by CRISPR/Cas9 technology resulted in resistance to decreased susceptibility to Cry1Ac toxin. Our results provide new insights into the potential role of polycalin and ABCC2 proteins in Cry1Ac resistance and the mechanism underlying the resistance of insects to Bt toxins.
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Affiliation(s)
- Lei Xiong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Zhaoxia Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou 362000, China
| | - Jingge Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Shuyuan Yao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Zeyun Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Xuanhao Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Lingling Shen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Zhen Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Yongbin Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Qing Hou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Yuhang Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
| | - Zhiguang Yuchi
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Shijun You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
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Dechkla M, Charoenjotivadhanakul S, Imtong C, Visitsattapongse S, Li HC, Angsuthanasombat C. Cry4Aa and Cry4Ba Mosquito-Active Toxins Utilize Different Domains in Binding to a Particular Culex ALP Isoform: A Functional Toxin Receptor Implicating Differential Actions on Target Larvae. Toxins (Basel) 2022; 14:toxins14100652. [PMID: 36287921 PMCID: PMC9607545 DOI: 10.3390/toxins14100652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
The three-domain Cry4Aa toxin produced from Bacillus thuringiensis subsp. israelensis was previously shown to be much more toxic to Culex mosquito larvae than its closely related toxin—Cry4Ba. The interaction of these two individual toxins with target receptors on susceptible larval midgut cells is likely to be the critical determinant in their differential toxicity. Here, two full-length membrane-bound alkaline phosphatase (mALP) isoforms from Culex quinquefasciatus larvae, Cq-mALP1263and Cq-mALP1264, predicted to be GPI-linked was cloned and functionally expressed in Spodoptera frugiperda (Sf9) cells as 57- and 61-kDa membrane-bound proteins, respectively. Bioinformatics analysis disclosed that both Cq-mALP isoforms share significant sequence similarity to Aedes aegypti-mALP—a Cry4Ba toxin receptor. In cytotoxicity assays, Sf9 cells expressing Cq-mALP1264, but not Cq-mALP1263, showed remarkably greater susceptibility to Cry4Aa than Cry4Ba, while immunolocalization studies revealed that both toxins were capable of binding to each Cq-mALP expressed on the cell membrane surface. Molecular docking of the Cq-mALP1264-modeled structure with individual Cry4 toxins revealed that Cry4Aa could bind to Cq-mALP1264 primarily through particular residues on three surface-exposed loops in the receptor-binding domain—DII, including Thr512, Tyr513 and Lys514 in the β10-β11loop. Dissimilarly, Cry4Ba appeared to utilize only certain residues in its C-terminal domain—DIII to interact with such a Culex counterpart receptor. Ala-substitutions of selected β10-β11loop residues (T512A, Y513A and K514A) revealed that only the K514A mutant displayed a drastic decrease in biotoxicity against C. quinquefasciatus larvae. Further substitution of Lys514 with Asp (K514D) revealed a further decrease in larval toxicity. Furthermore, in silico calculation of the binding affinity change (ΔΔGbind) in Cry4Aa-Cq-mALP1264 interactions upon these single-substitutions revealed that the K514D mutation displayed the largest ΔΔGbind value as compared to three other mutations, signifying an adverse impact of a negative charge at this critical receptor-binding position. Altogether, our present study has disclosed that these two related-Cry4 mosquito-active toxins conceivably exploited different domains in functional binding to the same Culex membrane-bound ALP isoform—Cq-mALP1264 for mediating differential toxicity against Culex target larvae.
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Affiliation(s)
- Manussawee Dechkla
- Department of Environmental Biology, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand
- Correspondence: (M.D.); (C.A.)
| | - Sathapat Charoenjotivadhanakul
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
| | - Chompounoot Imtong
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
| | - Sarinporn Visitsattapongse
- Department of Biomedical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Ladkrabang, Bangkok 10520, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Chanan Angsuthanasombat
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Correspondence: (M.D.); (C.A.)
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Hu X, Zhang X, Liu Y, Gao M, Lin M, Xie Y, Zhu Q, Xu C, Liu X, Vosloo D, Pooe OJ. Generation of Human Domain Antibody Fragments as Potential Insecticidal Agents against Helicoverpa armigera by Cadherin-Based Screening. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:11510-11519. [PMID: 35944165 DOI: 10.1021/acs.jafc.2c02000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
New insecticidal genes and approaches for pest control are a hot research area. In the present study, we explored a novel strategy for the generation of insecticidal proteins. The midgut cadherin of Helicoverpa armigera (H. armigera) was used as a target to screen materials that have insecticidal activity. After three rounds of panning, the phage-displayed human domain antibody B1F6, which not only binds to the H. armigera cadherin CR9-CR11 but also significantly inhibits Cry1Ac toxins from binding to CR9-CR11, was obtained from a phage-displayed human domain antibody (DAb) library. To better analyze the relevant activity of B1F6, soluble B1F6 protein was expressed by Escherichia coli BL21 (DE3). The cytotoxicity assays demonstrated that soluble B1F6 induced Sf9 cell death when expressing H. armigera cadherin on the cell membrane. The insect bioassay results showed that soluble B1F6 protein (90 μg/cm2) caused 49.5 ± 3.3% H. armigera larvae mortality. The midgut histological results showed that soluble B1F6 caused damage to the midgut epithelium of H. armigera larvae. The present study explored a new strategy and provided a basic material for the generation of new insecticidal materials.
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Affiliation(s)
- Xiaodan Hu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Xiao Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yuan Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Meijing Gao
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Manman Lin
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Yajing Xie
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Qing Zhu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Chongxin Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xianjin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Dalene Vosloo
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Ofentse Jacob Pooe
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
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Alam I, Batool K, Idris AL, Tan W, Guan X, Zhang L. Function of CTLGA9 Amino Acid Residue Leucine-6 in Modulating Cry Toxicity. Front Immunol 2022; 13:906259. [PMID: 35865517 PMCID: PMC9294448 DOI: 10.3389/fimmu.2022.906259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/06/2022] [Indexed: 12/02/2022] Open
Abstract
Aedes aegypti is a crucial vector for many arboviral diseases that cause millions of deaths worldwide and thus is of major public health concern. Crystal (Cry) proteins, which are toxins produced by Bacillus thuringiensis, are structurally organized into three-domains, of which domain II is the most variable in terms of binding towards various toxin receptors. The binding of Cry11Aa to putative receptor such as aminopeptidase-N (APN) is explicitly inhibited by midgut C-type lectins (CTLs). The similarity between the domain II fold of Cry11Aa toxin and the carbohydrate recognition domain in the CTLs is a possible structural basis for the involvement of Cry domain II in the recognition of carbohydrates on toxin receptors. In this study, a site-directed point mutation was introduced into the A. aegypti CTLGA9 gene on the basis of molecular docking findings, leading to substitution of the Leucine-6 (Leu-6) residue in the protein with alanine. Subsequently, functional monitoring of the mutated protein was carried out. Unlike the amino acid residues of wild-type CTLGA9, none of the residues of mutant (m) CTLGA9 were competed with Cry11Aa for binding to the APN receptor interface. Additionally, ligand blot analysis showed that both wild-type and mutant CTLGA9 had similar abilities to bind to APN and Cry11Aa. Furthermore, in the competitive ELISA in which labeled mutant CTLGA9 (10 nM) was mixed with increasing concentrations of unlabeled Cry11Aa (0–500 nM), the mutant showed no competition with Cry11Aa for binding to APN., By contrast, in the positive control sample of labeled wild type CTLGA9 mixed with same concentrations of Cry11Aa competition between the two ligands for binding to the APN was evident. These results suggest that Leucine-6 may be the key site involved in the competitive receptor binding between CTLGA9 and Cry11Aa. Moreover, according to the bioassay results, mutant CTLGA9 could in fact enhance the toxicity of Cry11Aa. Our novel findings provide further insights into the mechanism of Cry toxicity as well as a theoretical basis for enhancing the mosquitocidal activity of these toxin through molecular modification strategies.
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Affiliation(s)
- Intikhab Alam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Aisha Lawan Idris
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Weilong Tan
- Nanjing Bioengineering (Gene) Technology Center for Medicines, Nanjing, China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lingling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
- *Correspondence: Lingling Zhang,
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Cheng Q, Yu X, Xiong Z, Wan Z, Li Y, Ma W, Tan W, Liu M, Shea KJ. Abiotic Synthetic Antibodies to Target a Specific Protein Domain and Inhibit Its Function. ACS APPLIED MATERIALS & INTERFACES 2022; 14:19178-19191. [PMID: 35442625 DOI: 10.1021/acsami.2c02287] [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: 06/14/2023]
Abstract
The Bacillus thuringiensis (Bt) Cry proteins are widely used in insect pest control. Despite their economic benefits, remaining concerns over potential ecological and health risks warrant their ongoing surveillance. Affinity reagents, most often antibodies, protein scaffolds, and aptamers, are the traditional tools used for protein binding and detection. We report a synthetic antibody (SA) alternative to traditional biological affinity reagents for binding Bt Cry proteins. Analysis of hotspots of the Bt Cry protein-insect midgut cadherin-like receptor complexes was used for the design of the SA. The SA was selected from a small focused library of hydrogel copolymers containing functional monomers complementary to key exposed hotspots of Bt Cry proteins. A directed chemical evolution identified a SA, APhe-NP23, with affinity and selectivity for Bt Cry1Ab/Ac proteins. The putative intermolecular polymer-protein interfaces were identified by the SA's uptake of Bt Cry1Ac pepsin hydrolysates, binding epitope mutation studies, and protein-protein inhibition studies of the toxin binding to its native insect receptor binding domains. The SA inhibitor binds to the same protein domains as the insect's cadherin-like receptors, Bt-R1 and SeCad1b. The SA binds rapidly to Bt Cry1Ab/Ac with high capacity, is pH-responsive, and is synthesized reproducibly. We believe that a hotspot-directed approach is general for creation of abiotic protein affinity reagents that target functional protein domains. Affinity ligands are typically high-information content biologicals. Their structure and function are determined from their amino acid or oligo sequence. In contract, the SA described in this work is a statistical copolymer that lacks sequence specificity. These results are an important contribution to the concept that randomness and biospecificity are not mutually exclusive.
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Affiliation(s)
- Qiaolian Cheng
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Xiaoyang Yu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Zhouxuan Xiong
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Zihao Wan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Yuxin Li
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Mingming Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Kenneth J Shea
- Department of Chemistry, University of California-Irvine, Irvine, California 92697, United States
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7
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Lin M, Liu Y, Zhang X, Zhong J, Hu X, Xu C, Xie Y, Zhang C, Liang Y, Liu X, Lin J. Anti-idiotypic single-chain variable fragment antibody partially mimic the functionally spatial structure of Cry2Aa toxin. Anal Biochem 2021; 625:114222. [PMID: 33932355 DOI: 10.1016/j.ab.2021.114222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/16/2021] [Accepted: 04/22/2021] [Indexed: 01/12/2023]
Abstract
The anti-idiotypic antibody is widely used in the field of immunology to simulate structural features or even induce the biological activity of antigens. In this study, we obtained seven anti-idiotypic single-chain variable fragments (scFv) antibodies of Cry2Aa toxin from a phage-displayed mutant library constructed using error-prone PCR technique. A mutant designated 2-12B showed the best binding ability amongst all anti-idiotypic scFv isolates to Plutella xylostella brush border membrane vesicles (BBMVs). 2-12B and Cry2Aa toxin shared a potential receptor of polycalin in P. xylostella BBMVs. Homology modeling and molecular docking demonstrated that 2-12B and Cry2Aa toxin have seven common binding amino acid residues in polycalin. Insect bioassay results suggested that 2-12 had insecticidal efficacy against P. xylostella larvae. These results indicated that the Cry2Aa anti-idiotypic scFv antibody 2-12B partially mimicked the structure and function of Cry2Aa toxin. The anti-idiotypic scFv antibody provides the basic material for the future study of surrogate molecules or new insecticidal materials.
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Affiliation(s)
- Manman Lin
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Yuan Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
| | - Xiao Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Jianfeng Zhong
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Xiaodan Hu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Chongxin Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Yajing Xie
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Cunzheng Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Ying Liang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Xianjin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
| | - Johnson Lin
- School of Life Sciences, Discipline of Microbiology, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa.
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8
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The Tripartite Interaction of Host Immunity- Bacillus thuringiensis Infection-Gut Microbiota. Toxins (Basel) 2020; 12:toxins12080514. [PMID: 32806491 PMCID: PMC7472377 DOI: 10.3390/toxins12080514] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/12/2022] Open
Abstract
Bacillus thuringiensis (Bt) is an important cosmopolitan bacterial entomopathogen, which produces various protein toxins that have been expressed in transgenic crops. The evolved molecular interaction between the insect immune system and gut microbiota is changed during the Bt infection process. The host immune response, such as the expression of induced antimicrobial peptides (AMPs), the melanization response, and the production of reactive oxygen species (ROS), varies with different doses of Bt infection. Moreover, B. thuringiensis infection changes the abundance and structural composition of the intestinal bacteria community. The activated immune response, together with dysbiosis of the gut microbiota, also has an important effect on Bt pathogenicity and insect resistance to Bt. In this review, we attempt to clarify this tripartite interaction of host immunity, Bt infection, and gut microbiota, especially the important role of key immune regulators and symbiotic bacteria in the Bt killing activity. Increasing the effectiveness of biocontrol agents by interfering with insect resistance and controlling symbiotic bacteria can be important steps for the successful application of microbial biopesticides.
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9
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Wang J, Ding MY, Wang J, Liu RM, Li HT, Gao JG. In silico Structure-Based Investigation of Key Residues of Insecticidal Activity of Sip1Aa Protein. Front Microbiol 2020; 11:984. [PMID: 32547509 PMCID: PMC7273025 DOI: 10.3389/fmicb.2020.00984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/23/2020] [Indexed: 01/16/2023] Open
Abstract
Colaphellus bowringi Baly mainly damages cruciferous vegetables, leading to huge economic losses. The secretory insecticidal protein (Sip) of Bacillus thuringiensis (Bt) has high insecticidal activity against C. bowringi Baly. The tertiary structure of Sip1Aa protein was analyzed by homologous modeling and other bioinformatics methods to predict the conserved domain of Sip1Aa protein. Acidic and basic amino acids in the conserved domain were selected, and alanine was used to replace these amino acids by site-directed mutation. The difference between the insecticidal activities of mutant protein and Sip1Aa protein was analyzed. The insecticidal activities of H99A, K109A, K128A, and E130A against C. bowringi Baly were significantly increased, among which that of K128A was the most obviously changed, and the LC50 value was decreased by about 10 times compared with that of Sip1Aa protein. The LC50 value of mutant E130A was 0.286 μg/mL, which was about six times less than that of Sip1Aa. K128 and E130 were both in the β9–β10 loop. The toxicity of D290A, H242A, and H303A to C. bowringi Baly was significantly reduced, and their LC50 value increased by about six, eight, and three times compared with that of Sip1Aa protein, respectively. This study showed that acidic and basic amino acid residues played a certain role in the toxicity of Sip1Aa protein, and the loss of side chains in key residues had a significant impact on the insecticidal activity of the protein. This study provides the theoretical basis for revealing the relationship between the structure and function of Sip1Aa protein and also provides a new method for the subsequent study of sip gene.
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Affiliation(s)
- Jing Wang
- College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Ming-Yue Ding
- College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Jian Wang
- College of Life Sciences, Northeast Agricultural University, Harbin, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Rong-Mei Liu
- College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Hai-Tao Li
- College of Life Sciences, Northeast Agricultural University, Harbin, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ji-Guo Gao
- College of Life Sciences, Northeast Agricultural University, Harbin, China
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10
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The Cadherin Protein Is Not Involved in Susceptibility to Bacillus thuringiensis Cry1Ab or Cry1Fa Toxins in Spodoptera frugiperda. Toxins (Basel) 2020; 12:toxins12060375. [PMID: 32517191 PMCID: PMC7354596 DOI: 10.3390/toxins12060375] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 11/17/2022] Open
Abstract
It is well known that insect larval midgut cadherin protein serves as a receptor of Bacillus thuringiensis (Bt) crystal Cry1Ac or Cry1Ab toxins, since structural mutations and downregulation of cad gene expression are linked with resistance to Cry1Ac toxin in several lepidopteran insects. However, the role of Spodoptera frugiperda cadherin protein (SfCad) in the mode of action of Bt toxins remains elusive. Here, we investigated whether SfCad is involved in susceptibility to Cry1Ab or Cry1Fa toxins. In vivo, knockout of the SfCad gene by CRISPR/Cas 9 did not increase tolerance to either of these toxins in S. frugiperda larvae. In vitro cytotoxicity assays demonstrated that cultured insect TnHi5 cells expressing GFP-tagged SfCad did not increase susceptibility to activated Cry1Ab or Cry1Fa toxins. In contrast, expression of another well recognized Cry1A receptor in this cell line, the ABCC2 transporter, increased the toxicity of both Cry1Ab and Cry1Fa toxins, suggesting that SfABCC2 functions as a receptor of these toxins. Finally, we showed that the toxin-binding region of SfCad did not bind to activated Cry1Ab, Cry1Ac, nor Cry1Fa. All these results support that SfCad is not involved in the mode of action of Cry1Ab or Cry1Fa toxins in S. frugiperda.
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11
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Zhou H, Hu W, Huang Q, Abouzaid M, Jin H, Sun Y, Qiu L, Zhang W, Lin Y, Ma W. Knockdown of cadherin genes decreases susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis produced Crystal toxins. INSECT MOLECULAR BIOLOGY 2020; 29:301-308. [PMID: 31908051 DOI: 10.1111/imb.12634] [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] [Received: 08/12/2019] [Revised: 12/24/2019] [Accepted: 12/31/2019] [Indexed: 06/10/2023]
Abstract
The striped rice stem borer, Chilo suppressalis Walker, is one of the most destructive rice pests in Asia. Insecticidal crystal proteins (Cry toxins) produced by Bacillus thuringiensis are widely used as biopesticides or in developing transgenic crops for pest management. In this study, we tested the involvement of two newly cloned C. suppressalis cadherins (CsCAD3 and CsCAD4) in the toxicity of Cry1Ab/Ac, Cry2Aa and Cry1Ca. Our results showed that CsCAD4 was expressed highest in the midgut, whereas CsCAD3 was expressed highest in the epidermis. The feeding of double-stranded RNA specific to CsCAD3 and CsCAD4 respectively significantly suppressed the expressions of target gene. The knockdown of CsCAD3 significantly reduced the mortality of larvae to Cry1Ab/Ac, whereas knockdown of CsCAD4 significantly decreased the larval susceptibility to Cry2Aa. In contrast, reduced expressions of CsCAD3 or CsCAD4 were not interacted with larval susceptibility to Cry1Ca. Our results suggest that CsCAD3 and CsCAD4 function in Cry toxin toxicity and these findings will help us to better understand the action mechanism of Cry toxins in C. suppressalis.
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Affiliation(s)
- H Zhou
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - W Hu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Q Huang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - M Abouzaid
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - H Jin
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Y Sun
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - L Qiu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - W Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, Hubei, China
| | - Y Lin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, Hubei, China
| | - W Ma
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
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12
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Gao M, Hu X, Zhang X, Zhong J, Lu L, Liu Y, Dong S, Wang Y, Liu X. Identification of a Cry1Fa binding site of cadherin in Plutella xylostella through fragment exchanging and molecular docking methods. Int J Biol Macromol 2020; 146:62-69. [PMID: 31836394 DOI: 10.1016/j.ijbiomac.2019.12.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/05/2019] [Accepted: 12/08/2019] [Indexed: 11/19/2022]
Abstract
Binding to the cadherin in target pests is the primary step in the action mechanism of Cry toxins, but little is known regarding the interaction of Cry1Fa with cadherin. Our previous study suggested that a Plutella xylostella cadherin fragment (PxCad-TBR) can bind to Cry1Fa, while its homologous fragment (HaCad-TBR) in Helicoverpa armigera cannot. In this study, we expressed two cadherin fragments that combine parts of PxCad-TBR and HaCad-TBR in Escherichia coli and tested their binding to the Cry1Fa. The results showed that the fragment containing amino acids T1202-A1341 of P. xylostella cadherin showed binding ability to Cry1Fa. Furthermore, two regions (V1219-E1233 and D1326-F1337) were predicted as hot spot regions that are involved in the interaction of Cry1Fa and PxCad-TBR with computer-aided molecular docking. We then constructed two PxCad-TBR mutations by fragment exchanging based on the molecular docking results and verified the mutations' binding abilities to the Cry1Fa. The results showed that the region that contains amino acids D1326-F1337 was one important binding site to Cry1Fa in P. xylostella cadherin. These results suggested that a combination of computer-aided molecular docking and fragment exchanging is an effective way to locate the key binding sites of Bt toxins in receptors.
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Affiliation(s)
- Meijing Gao
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xiaodan Hu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xiao Zhang
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Jianfeng Zhong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Lina Lu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yuan Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Sa Dong
- School of Horticulture and Plant Protection, Yangzhou University, China
| | - Yun Wang
- Horticulture Dept, Jinling Institute of Technology, Nanjing, China
| | - Xianjin Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
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13
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Gao M, Dong S, Hu X, Zhang X, Liu Y, Zhong J, Lu L, Wang Y, Chen L, Liu X. Roles of Midgut Cadherin from Two Moths in Different Bacillus thuringiensis Action Mechanisms: Correlation among Toxin Binding, Cellular Toxicity, and Synergism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:13237-13246. [PMID: 31671945 DOI: 10.1021/acs.jafc.9b04563] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The midgut cadherin has been described as one of the main functional receptors for Bacillus thuringiensis (Bt) toxins. Plutella xylostella (P. xylostella) and Helicoverpa armigera (H. armigera) are two major target pests of Bt toxins in China, and the roles of their cadherins in the action of Bt toxins have been only partially studied. Here, we expressed the two cadherins in Sf9 cells and their partial extracellular domains in Escherichia coli and tested them for Bt toxin binding, cellular toxicity, and synergism with toxins. Our results suggested that PxCad might function as a Cry1Ac receptor, although it showed lower binding levels to Cry1Ac and reduced cytotoxicity compared with HaCad. PxCad and HaCad are not receptors for Cry2A, Cry1B, Cry1C, and Cry1F toxins, although some of them can bind to the cadherins. The PxCad-TBR exhibits higher enhancement of Cry1Ac and weak enhancement of Cry1F toxicity in P. xylostella larvae, although it is not the receptor of Cry1F.
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Affiliation(s)
- Meijing Gao
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Sa Dong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
- School of Horticulture and Plant Protection , Yangzhou University , Yangzhou 225009 , China
| | - Xiaodan Hu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
- Discipline of Biology, School of Life Sciences , University of KwaZulu-Natal, Westville Campus , Private Bag X54001, Durban 4000 , South Africa
| | - Xiao Zhang
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Yuan Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Jianfeng Zhong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Lina Lu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Yun Wang
- Horticulture Department , Jinling Institute of Technology , Nanjing 210038 , China
| | - Limen Chen
- Lishui Academy of Agricultural Sciences , Lishui 323000 , China
| | - Xianjin Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
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14
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Wang Y, Zhang X, Xie Y, Wu A, Zai X, Liu X. High-affinity phage-displayed peptide as a recognition probe for the detection of Cry2Ad2-3. Int J Biol Macromol 2019; 137:562-567. [PMID: 31238073 DOI: 10.1016/j.ijbiomac.2019.06.164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 11/25/2022]
Abstract
Cry2A is widely used in transgenic crops in combination with Cry1A toxins. The sensitive and robust detection of Cry2A toxin in food and the environment is necessary to monitor the safety of biopesticides. Here, we describe an approach that involves the use of phage-displayed peptide for the detection of Cry2Ad2-3-the main area of Cry2Ad2 insecticidal activity. After four rounds of panning, six positive monoclonal phage particles were obtained. Pep5 with a sequence of ACSYNHNSKCGGG displayed low cross-reactivity with other Cry toxins. The working range of detection for Cry2Ad2-3 toxin standards in the brush border membrane vesicle (BBMV)-peptide sandwich ELISA was 10-50.625 ng mL-1 and the detection limit (LOD) was 8 ng mL-1. Molecular insight into the interaction of pep5 with Cry2Ad2-3 was gleaned using homology modeling and docking. Molecular docking results showed that high-affinity peptide tended to dock in the groove between the two domains of Cry2Ad2-3. The interactions within the toxin-pep5 complex were due to hydrogen bond and hydrophobic interaction. Pep5 also lead us to trap the binding region. Therefore, peptides may be a cost-efficient alternative for detecting Cry toxins and studying their mechanisms.
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Affiliation(s)
- Yun Wang
- College of Horticulture, Jinling Institute of Technology, 210038 Nanjing, PR China
| | - Xiao Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, PR China
| | - Yajing Xie
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, PR China
| | - Aihua Wu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, PR China
| | - Xueming Zai
- College of Horticulture, Jinling Institute of Technology, 210038 Nanjing, PR China
| | - Xianjin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, PR China.
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