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Pacheco S, Gallegos AS, Peláez-Aguilar ÁE, Sánchez J, Gómez I, Soberón M, Bravo A. CRISPR-Cas9 knockout of membrane-bound alkaline phosphatase or cadherin does not confer resistance to Cry toxins in Aedes aegypti. PLoS Negl Trop Dis 2024; 18:e0012256. [PMID: 38870209 DOI: 10.1371/journal.pntd.0012256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/30/2024] [Indexed: 06/15/2024] Open
Abstract
The Aedes aegypti cadherin-like protein (Aae-Cad) and the membrane-bound alkaline phosphatase (Aae-mALP) are membrane proteins identified as putative receptors for the larvicidal Cry toxins produced by Bacillus thuringiensis subsp. israelensis bacteria. Cry toxins are the most used toxins in the control of different agricultural pest and mosquitos. Despite the relevance of Aae-Cad and Aae-mALP as possible toxin-receptors in mosquitoes, previous efforts to establish a clear functional connection among them and Cry toxins activity have been relatively limited. In this study, we used CRISPR-Cas9 to generate knockout (KO) mutations of Aae-Cad and Aae-mALP. The Aae-mALP KO was successfully generated, in contrast to the Aae-Cad KO which was obtained only in females. The female-linked genotype was due to the proximity of aae-cad gene to the sex-determining loci (M:m). Both A. aegypti KO mutant populations were viable and their insect-development was not affected, although a tendency on lower egg hatching rate was observed. Bioassays were performed to assess the effects of these KO mutations on the susceptibility of A. aegypti to Cry toxins, showing that the Aae-Cad female KO or Aae-mALP KO mutations did not significantly alter the susceptibility of A. aegypti larvae to the mosquitocidal Cry toxins, including Cry11Aa, Cry11Ba, Cry4Ba, and Cry4Aa. These findings suggest that besides the potential participation of Aae-Cad and Aae-mALP as Cry toxin receptors in A. aegypti, additional midgut membrane proteins are involved in the mode of action of these insecticidal toxins.
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Affiliation(s)
- Sabino Pacheco
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Adrián S Gallegos
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Ángel E Peláez-Aguilar
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Jorge Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Isabel Gómez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Mario Soberón
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Alejandra Bravo
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
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Kinkar OU, Prashar A, Yadav B, Kumar A, Hadapad AB, Hire RS, Makde RD. Purification, characterization and proteolytic processing of mosquito larvicidal protein Cry11Aa from Bacillus thuringensis subsp. isralensis ISPC-12. Int J Biol Macromol 2023:124979. [PMID: 37245748 DOI: 10.1016/j.ijbiomac.2023.124979] [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: 02/23/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/30/2023]
Abstract
Cry11Aa is the most potent mosquito larvicidal protein of Bacillus thuringiensis subsp. israelensis (Bti). Development of resistance against insecticidal proteins including Cry11Aa is known but no field resistance was observed with Bti. The phenomenon of increasing resistance in insect pests necessitates the development of new strategies and techniques to enhance efficacy of insecticidal proteins. Recombinant technology offers better control over the molecule and allows modification of protein to achieve maximal effect against target pests. In this study, we standardised protocol for recombinant purification of Cry11Aa. Recombinant Cry11Aa found active against larvae of Aedes and Culex mosquito species and LC50 were estimated. Detailed biophysical characterization provides crucial insights into stability and in-vitro behaviour of the recombinant Cry11Aa. Moreover, trypsin hydrolysis doesn't improve overall toxicity of recombinant Cry11Aa. Proteolytic processing suggests domain I and II are more prone to proteolysis in comparison to domain III. Significance of structural features for proteolysis of Cry11Aa was observed after performing molecular dynamics simulations. Findings reported here are contributing significantly in method for purification, understanding in-vitro behaviour and proteolytic processing of Cry11Aa which could facilitate in efficient utilisation of Bti for insect pests and vectors control.
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Affiliation(s)
- Omkar U Kinkar
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Arpit Prashar
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Beena Yadav
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Ashwani Kumar
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ashok B Hadapad
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ramesh S Hire
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ravindra D Makde
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
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Complete structure elucidation of a functional form of the Bacillus thuringiensis Cry4Ba δ-endotoxin: Insights into toxin-induced transmembrane pore architecture. Biochem Biophys Res Commun 2022; 620:158-164. [DOI: 10.1016/j.bbrc.2022.06.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 06/21/2022] [Indexed: 11/24/2022]
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Li Q, Li M, Zhu M, Zhong J, Wen L, Zhang J, Zhang R, Gao Q, Yu XQ, Lu Y. Genome-wide identification and comparative analysis of Cry toxin receptor families in 7 insect species with a focus on Spodoptera litura. INSECT SCIENCE 2022; 29:783-800. [PMID: 34405540 DOI: 10.1111/1744-7917.12961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/30/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Cadherin, aminopeptidase N (APN) and alkaline phosphatase (ALP) have been characterized as Cry receptors. In this study, comparative genomic analysis of the 3 receptor families was performed in 7 insects. ALPs and APNs are divided into three and eight clades in phylogenetic trees, respectively. ALPs in clade 3 and APNs in clade 1 contain multiple paralogs within each species and most paralogs are located closely in chromosomes. Drosophila melanogaster has expanded APNs in clade 5 and were lowly expressed in midgut. Cadherins are divided into 16 clades; they may diverge before holometabolous insect speciation except for BtR and Cad89D-like clades. Eight insects from different orders containing BtR orthologs are sensitive to Cry1A or Cry3A, while five species without BtR are insensitive to both toxins. Most APNs in clade 1, several ALPs in clade 3, BtR and Cad89D-like genes were highly or moderately expressed in larval midgut of Spodoptera litura and the other six species, and several members in these clades have been identified as Cry receptors. Expressions of putative S. litura Cry receptors in the midgut after exposing to Bt toxins were also analyzed.
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Affiliation(s)
- Qilin Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Mengge Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Mengyao Zhu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jielai Zhong
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Liang Wen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jie Zhang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Ruonan Zhang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Qiang Gao
- College of Biology, Hunan University, Changsha, 410082, China
| | - Xiao-Qiang Yu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Yuzhen Lu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
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Alam I, Batool K, Idris AL, Tan W, Guan X, Zhang L. Role of Lectin in the Response of Aedes aegypti Against Bt Toxin. Front Immunol 2022; 13:898198. [PMID: 35634312 PMCID: PMC9136036 DOI: 10.3389/fimmu.2022.898198] [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: 03/17/2022] [Accepted: 04/19/2022] [Indexed: 12/05/2022] Open
Abstract
Aedes aegypti is one of the world’s most dangerous mosquitoes, and a vector of diseases such as dengue fever, chikungunya virus, yellow fever, and Zika virus disease. Currently, a major global challenge is the scarcity of antiviral medicine and vaccine for arboviruses. Bacillus thuringiensis var israelensis (Bti) toxins are used as biological mosquito control agents. Endotoxins, including Cry4Aa, Cry4Ba, Cry10Aa, Cry11Aa, and Cyt1Aa, are toxic to mosquitoes. Insect eradication by Cry toxin relies primarily on the interaction of cry toxins with key toxin receptors, such as aminopeptidase (APN), alkaline phosphatase (ALP), cadherin (CAD), and ATP-binding cassette transporters. The carbohydrate recognition domains (CRDs) of lectins and domains II and III of Cry toxins share similar structural folds, suggesting that midgut proteins, such as C-type lectins (CTLs), may interfere with interactions among Cry toxins and receptors by binding to both and alter Cry toxicity. In the present review, we summarize the functional role of C-type lectins in Ae. aegypti mosquitoes and the mechanism underlying the alteration of Cry toxin activity by CTLs. Furthermore, we outline future research directions on elucidating the Bti resistance mechanism. This study provides a basis for understanding Bti resistance, which can be used to develop novel insecticides.
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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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Banerjee R, Flores-Escobar B, Chougule NP, Cantón PE, Dumitru R, Bonning BC. Peptide mediated, enhanced toxicity of a bacterial pesticidal protein against southern green stink bug. Microb Biotechnol 2022; 15:2071-2082. [PMID: 35315236 PMCID: PMC9249324 DOI: 10.1111/1751-7915.14030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 01/23/2023] Open
Abstract
The damage caused by stink bugs that feed on agricultural crops accounts for such significant losses that transgenic plant resistance to stink bugs would be highly desirable. As the level of toxicity of the Bacillus thuringiensis‐derived, ETX/Mtx2 pesticidal protein Mpp83Aa1 is insufficient for practical use against the southern green stink bug Nezara viridula, we employed two disparate approaches to isolate peptides NvBP1 and ABP5 that bind to specific proteins (alpha amylase and aminopeptidase N respectively) on the surface of the N. viridula gut. Incorporation of these peptides into Mpp83Aa1 provided artificial anchors resulting in increased gut binding, and enhanced toxicity. These peptide‐modified pesticidal proteins with increased toxicity provide a key advance for potential future use against N. viridula when delivered by transgenic plants to mitigate economic loss associated with this important pest.
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Affiliation(s)
- Rahul Banerjee
- Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL, 32611, USA
| | - Biviana Flores-Escobar
- Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL, 32611, USA
| | - Nanasaheb P Chougule
- Innovation Center, BASF Corporation, 3500 Paramount Parkway, Morrisville, NC, 27560, USA
| | - Pablo Emiliano Cantón
- Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL, 32611, USA
| | - Razvan Dumitru
- Innovation Center, BASF Corporation, 3500 Paramount Parkway, Morrisville, NC, 27560, USA
| | - Bryony C Bonning
- Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL, 32611, USA
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7
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Batool K, Alam I, Liu P, Shu Z, Zhao S, Yang W, Jie X, Gu J, Chen XG. Recombinant Mosquito Densovirus with Bti Toxins Significantly Improves Pathogenicity against Aedes albopictus. Toxins (Basel) 2022; 14:toxins14020147. [PMID: 35202174 PMCID: PMC8879223 DOI: 10.3390/toxins14020147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/12/2022] [Accepted: 02/14/2022] [Indexed: 12/12/2022] Open
Abstract
Mosquito densoviruses (MDVs) are mosquito-specific viruses that are recommended as mosquito bio-control agents. The MDV Aedes aegypti densovirus (AeDNV) is a good candidate for controlling mosquitoes. However, the slow activity restricts their widespread use for vector control. In this study, we introduced the Bacillus thuringiensis (Bti) toxin Cry11Aa domain II loop α8 and Cyt1Aa loop β6-αE peptides into the AeDNV genome to improve its mosquitocidal efficiency; protein expression was confirmed using nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). Recombinant plasmids were transfected into mosquito C6/36 cell lines, and the expression of specific peptides was detected through RT-PCR. A toxicity bioassay against the first instar Aedes albopictus larvae revealed that the pathogenic activity of recombinant AeDNV was significantly higher and faster than the wild-type (wt) viruses, and mortality increased in a dose-dependent manner. The recombinant viruses were genetically stable and displayed growth phenotype and virus proliferation ability, similar to wild-type AeDNV. Our novel results offer further insights by combining two mosquitocidal pathogens to improve viral toxicity for mosquito control.
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Affiliation(s)
- Khadija Batool
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Intikhab Alam
- College of Life Sciences, South China Agricultural University, Guangzhou 510515, China;
| | - Peiwen Liu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Zeng Shu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Siyu Zhao
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Wenqiang Yang
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Xiao Jie
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Jinbao Gu
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; (K.B.); (P.L.); (Z.S.); (S.Z.); (W.Y.); (X.J.); (J.G.)
- Correspondence: ; Tel.: +86-186-6486-7266
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Zhong J, Fang S, Gao M, Lu L, Zhang X, Zhu Q, Liu Y, Jurat-Fuentes JL, Liu X. Evidence of a shared binding site for Bacillus thuringiensis Cry1Ac and Cry2Aa toxins in Cnaphalocrocis medinalis cadherin. INSECT MOLECULAR BIOLOGY 2022; 31:101-114. [PMID: 34637177 DOI: 10.1111/imb.12741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 08/26/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Insect midgut cadherins function as receptors and play critical roles as protein receptors of insecticidal Bacillus thuringiensis (Bt) toxins used as biopesticides and in Bt transgenic crops worldwide. Here, we cloned and characterized the full-length midgut cadherin (CmCad) cDNA from the rice leaffolder (Cnaphalocrocis medinalis), a destructive pest of rice in many Asian countries. Expression of recombinant proteins corresponding to the extracellular domain of CmCad allowed testing binding of Cry proteins. Results from in vitro ligand blotting and enzyme-linked immunosorbent assays supported that the extracellular domain of CmCad contains regions recognized by both Cry1Ac and Cry2Aa. Molecular modelling and docking simulations indicated that binding to both Cry1Ac and Cry2Aa is localized primarily within a CmCad motif corresponding to residues T1417-D1435. A recombinant CmCad protein produced without residues T1417-D1435 lacked binding to Cry1Ac and Cry2Aa, confirmed our modelling predictions that CmCad has a shared Cry1Ac and Cry2Aa binding site. The potential existence of a shared binding region in CmCad suggests that caution should be taken when using combinations of Cry1Ac and Cry2Aa in pyramided transgenic rice, as their combined use could speed the evolution of resistance to both toxins.
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Affiliation(s)
- J Zhong
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - S Fang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - M Gao
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - L Lu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - X Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Q Zhu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Y Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - J L Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, USA
| | - X Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
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9
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Genome-wide analysis of V-ATPase genes in Plutella xylostella (L.) and the potential role of PxVHA-G1 in resistance to Bacillus thuringiensis Cry1Ac toxin. Int J Biol Macromol 2022; 194:74-83. [PMID: 34861270 DOI: 10.1016/j.ijbiomac.2021.11.169] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 02/06/2023]
Abstract
The rapid development of insecticide resistance has hampered the use of Bacillus thuringiensis (Bt), a widely used bio-pesticide. Plutella xylostella (L.) is a globally distributed lepidopteran pest of cruciferous vegetables and has developed severe field resistance to the Bt toxin. Vacuolar H+-ATPases (VHA) are multi-subunit complexes and participate in multiple physiological processes. However, the characterization and functional studies of VHA genes are lacking in insects. This study performed a genome-wide analysis and identified 35 VHA gene family members divided into 15 subfamilies in P. xylostella. We cloned a V-ATPase subunit G gene, PxVHA-G1, in our previous midgut transcriptome profiles. Quantitative reverse transcriptase-polymerase chain reaction results showed that PxVHA-G1 was upregulated in the Cry1S1000-resistant strain than in the G88-susceptible strain, and its expression profile revealed that the midgut, Malpighian tubules, and larva stages generally showed high expression levels. RNAi-mediated knockdown of the PxVHA-G1 gene increased the susceptibility of P. xylostella (G88 and Cry1S1000) to Cry1Ac toxin. Our study is the first to explore the role of PxVHA-G1 on regulating Cry1Ac toxicity in P. xylostella, thus, providing new insights into the role of VHAs in the development of Cry1Ac resistance and sustainable development of pest management.
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Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance. Toxins (Basel) 2021; 13:toxins13080523. [PMID: 34437394 PMCID: PMC8402332 DOI: 10.3390/toxins13080523] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022] Open
Abstract
Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.
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Bourchookarn W, Bourchookarn A, Imtong C, Li HC, Angsuthanasombat C. His 180 in the pore-lining α4 of the Bacillus thuringiensis Cry4Aa δ-endotoxin is crucial for structural arrangements of the α4-α5 transmembrane hairpin and hence biotoxicity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140634. [PMID: 33636413 DOI: 10.1016/j.bbapap.2021.140634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/15/2021] [Accepted: 02/19/2021] [Indexed: 10/22/2022]
Abstract
One proposed toxic mechanism of Bacillus thuringiensis Cry δ-endotoxins involves pore formation in target membranes by the α4-α5 transmembrane hairpin constituting their pore-forming domain. Here, nine selected charged and uncharged polar residues in the pore-lining α4 of the Cry4Aa mosquito-active toxin were substituted with Ala. All mutant toxins, i.e., D169A, R171A, Q173A, H178A, Y179A, H180A, Q182A, N183A and E187A, were over-expressed in Escherichia coli as 130-kDa protoxin inclusions at levels comparable to the wild-type toxin. Bioassays against Aedes aegypti larvae revealed that only H178A and H180A mutants displayed a drastic reduction in biotoxicity, albeit almost complete insolubility observed for H178A, but not for H180A inclusions. Further mutagenic analysis showed that replacements of His180 with charged (Arg, Lys, Asp, Glu), small uncharged polar (Ser, Cys) or small non-polar (Gly, Val) residues severely impaired the biotoxicity, unlike substitutions with relatively large uncharged (Asn, Gln, Leu) or aromatic (Phe, Tyr, Trp) residues. Similar to the trypsin-activated wild-type toxin, both bio-active and -inactive H180 mutants were still capable of releasing entrapped calcein from lipid vesicles and producing cation-selective channels with ~130-pS maximum conductance. Analysis of the Cry4Aa structure revealed the existence of a hydrophobic cavity near the critical His180 side-chain. Analysis of simulated structures revealed that His180-to-smaller residue conversions create a gap disrupting such cavity's hydrophobicity and hence structural arrangements of the α4-α5 hairpin. Altogether, our data disclose a critical involvement in Cry4Aa-biotoxicity of His180 exclusively present in the lumen-facing α4 for providing proper environment for the α4-α5 hairpin prior to membrane-inserted pore formation.
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Affiliation(s)
- Walairat Bourchookarn
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand
| | - Apichai Bourchookarn
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand.
| | - Chompounoot Imtong
- Faculty of Science and Technology, Prince of Songkla University, Pattani 94000, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Chanan Angsuthanasombat
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan; Laboratory of Synthetic Biophysics and Chemical Biology, Biophysics Institute for Research and Development (BIRD), Chiang Mai 50230, Thailand; Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand.
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12
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Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance. Toxins (Basel) 2020; 12:toxins12120773. [PMID: 33291447 PMCID: PMC7762171 DOI: 10.3390/toxins12120773] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/24/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.
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13
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da Silva WJ, Pilz-Júnior HL, Heermann R, da Silva OS. The great potential of entomopathogenic bacteria Xenorhabdus and Photorhabdus for mosquito control: a review. Parasit Vectors 2020; 13:376. [PMID: 32727530 PMCID: PMC7391577 DOI: 10.1186/s13071-020-04236-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/15/2020] [Indexed: 12/13/2022] Open
Abstract
The control of insects of medical importance, such as Aedes aegypti and Aedes albopictus are still the only effective way to prevent the transmission of diseases, such as dengue, chikungunya and Zika. Their control is performed mainly using chemical products; however, they often have low specificity to non-target organisms, including humans. Also, studies have reported resistance to the most commonly used insecticides, such as the organophosphate and pyrethroids. Biological control is an ecological and sustainable method since it has a slow rate of insect resistance development. Bacterial species of the genera Xenorhabdus and Photorhabdus have been the target of several research groups worldwide, aiming at their use in agricultural, pharmaceutical and industrial products. This review highlights articles referring to the use of Xenorhabdus and Photorhabdus for insects and especially for mosquito control proposing future ways for their biotechnological applicability. Approximately 24 species of Xenorhabdus and five species of Photorhabdus have been described to have insecticidal properties. These studies have shown genes that are capable of encoding low molecular weight proteins, secondary toxin complexes and metabolites with insecticide activities, as well as antibiotic, fungicidal and antiparasitic molecules. In addition, several species of Xenorhabdus and Photorhabdus showed insecticidal properties against mosquitoes. Therefore, these biological agents can be used in new control methods, and must be, urgently considered in short term, in studies and applications, especially in mosquito control.![]()
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Affiliation(s)
- Wellington Junior da Silva
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS, 90050-170, Brazil
| | - Harry Luiz Pilz-Júnior
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS, 90050-170, Brazil
| | - Ralf Heermann
- Institut für Molekulare Physiologie, Mikrobiologie und Weinforschung, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 13, 55128, Mainz, Germany.
| | - Onilda Santos da Silva
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS, 90050-170, Brazil.
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14
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Chen J, Aimanova KG, Gill SS. Aedes cadherin receptor that mediates Bacillus thuringiensis Cry11A toxicity is essential for mosquito development. PLoS Negl Trop Dis 2020; 14:e0007948. [PMID: 32012156 PMCID: PMC7018227 DOI: 10.1371/journal.pntd.0007948] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 02/13/2020] [Accepted: 11/25/2019] [Indexed: 11/20/2022] Open
Abstract
Aedes cadherin (AaeCad, AAEL024535) has been characterized as a receptor for Bacillus thuringiensis subsp. israelensis (Bti) Cry11A toxins. However, its role in development is still unknown. In this study, we modified the cadherin gene using ZFN and TALEN. Even though we obtained heterozygous deletions, no homozygous mutants were viable. Because ZFN and TALEN have lower off-targets than CRISPR/Cas9, we conclude the cadherin gene is essential for Aedes development. In contrast, in lepidopteran insects loss of a homologous cadherin does not appear to be lethal, since homozygous mutants are viable. To analyze the role of AaeCad in vivo, we tagged this protein with EGFP using CRISPR-Cas9-mediated homologous recombination and obtained a homozygous AaeCad-EGFP line. Addition of Aedes Rad51 mRNA enhanced the rate of recombination. We then examined AaeCad protein expression in most tissues and protein dynamics during mosquito development. We observe that AaeCad is expressed in larval and adult midgut-specific manner and its expression pattern changed during the mosquito development. Confocal images showed AaeCad has high expression in larval caecae and posterior midgut, and also in adult midgut. Expression of AaeCad is observed primarily in the apical membranes of epithelial cells, and not in cell-cell junctions. The expression pattern observed suggests AaeCad does not appear to play a role in these junctions. However, we cannot exclude its role beyond cell-cell adhesion in the midgut. We also observed that Cry11A bound to the apical side of larval gastric caecae and posterior midgut cells exactly where AaeCad-EGFP was expressed. Their co-localization suggests that AaeCad is indeed a receptor for the Cry11A toxin. Using this mosquito line we also observed that low doses of Cry11A toxin caused the cells to slough off membranes, which likely represents a defense mechanism, to limit cell damage from Cry11A toxin pores formed in the cell membrane. A number of receptors for Bt Cry toxins, have been identified and characterized, including cadherin proteins. However, the role of these proteins in the insect is unknown and there have been few efforts to elucidate their function. First, in this study we show that in the mosquito, Aedes aegypti, the cadherin protein is essential for development. Secondly, we provide evidence that AaeCad plays a role in the apical membrane and the maintenance of midgut integrity by gene tagging using CRISPR/Cas9, which overcomes the limitation of receptor localization using antibodies in previous studies. These investigations are helpful to further investigate the physiological function of AaeCad. Moreover, this study demonstrated successful tagging of an essential gene with fluorescence protein in a non-model insect. In addition, this study showed that epithelium thinning is possibly a conserved mechanism for host defense against pore-forming toxins, like Cry11A.
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Affiliation(s)
- Jianwu Chen
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
| | - Karly G. Aimanova
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
| | - Sarjeet S. Gill
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, United States of America
- * E-mail:
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15
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Hu X, Chen H, Xu J, Zhao G, Huang X, Liu J, Batool K, Wu C, Wu S, Huang E, Wu J, Chowhury M, Zhang J, Guan X, Yu XQ, Zhang L. Function of Aedes aegypti galectin-6 in modulation of Cry11Aa toxicity. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 162:96-104. [PMID: 31836060 DOI: 10.1016/j.pestbp.2019.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 07/09/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Galectins are a family of β-galactoside binding proteins, and insect galectins play a role in immune responses and may also affect Cry toxin activity. In this study, we aimed to further understand the function and molecular mechanism of Aedes aegypti galectin-6 in modulation of Cry11Aa toxicity. A. aegypti galectin-6 was cloned, and the recombinant galectin-6 was expressed and purified. Bioassays indicated that galectin-6 could reduce the toxicity of Cry11Aa, protecting A. aegypti larvae. To determine interactions among galectin-6, Cry11Aa and putative toxin receptors, Octet Red System, western blotting, far-western blotting and ELISA assays were performed. Octet Red System showed that galectin-6 bound to BBMVs of A. aegypti larvae with lower affinity than that of Cry11Aa. Western blotting and far-western blotting analyses demonstrated that galectin-6 bound to A. aegypti ALP1 and APN2 as well as to BBMVs, consistent with the results of ELISA and protein docking simulations. However, galectin-6 did not bind to Cadherin in far-western blotting or ELISA assay, though the protein docking simulations suggested their binding potential. These findings support the conclusion that galectin-6 may block Cry11Aa from binding to ALP1 and APN2 due to structural similarity, which might decrease the mosquitocidal toxicity of Cry11Aa.
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Affiliation(s)
- Xiaohua Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Hong Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jin Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Guohui Zhao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xianhui Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiannan Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Chenxu Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Songqing Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Enjiong Huang
- Fujian International Travel Healthcare Center, Fuzhou 350001, China
| | - Juan Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Munmun Chowhury
- Division of Cell Biology and Biophysics, University of Missouri, Kansas City, MO 64110, USA
| | - Jie Zhang
- Division of Cell Biology and Biophysics, University of Missouri, Kansas City, MO 64110, USA
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiao-Qiang Yu
- Division of Cell Biology and Biophysics, University of Missouri, Kansas City, MO 64110, USA.
| | - Lingling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Division of Cell Biology and Biophysics, University of Missouri, Kansas City, MO 64110, USA.
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16
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Batool K, Alam I, Jin L, Xu J, Wu C, Wang J, Huang E, Guan X, Yu XQ, Zhang L. CTLGA9 Interacts with ALP1 and APN Receptors To Modulate Cry11Aa Toxicity in Aedes aegypti. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:8896-8904. [PMID: 31339308 DOI: 10.1021/acs.jafc.9b01840] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The mosquito Aedes aegypti is associated with the spread of many viral diseases in humans, including Dengue virus (DENVs), Yellow fever virus (YFV), Zika virus (ZIKV), and Chikungunya virus (CHIKV). Bacillus thuringiensis (Bt) is widely used as a biopesticide, which produces Cry toxins for mosquito control. The Cry toxins bind mainly to important receptors, including alkaline phosphatase (ALP) and aminopeptidase-N (APN). This work investigated the function of a C-type lectin, CTLGA9, in A. aegypti in response to Cry toxins. Our results showed by far-western blot and ELISA methods that the CTLTGA9 protein interacted with brush border membrane vesicles (BBMVs) of A. aegypti larvae and with ALP1, APN, and Cry11Aa proteins. Furthermore, molecular docking showed overlapping binding sites in ALP1 and APN for binding to Cry11Aa and CTLGA9. The toxicity assays further demonstrated that CTLGA9 inhibited the larvicidal activity of Cry toxins. According to the results of molecular docking, CTLGA9 may compete with Cry11Aa for binding to ALP1 and APN receptors and thus decreases the mosquitocidal toxicity of Cry11Aa. Our results provide further insights into better understanding the mechanism of Cry toxins and help improve the Cry toxicity for mosquito control.
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Affiliation(s)
- Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Intikhab Alam
- Key Laboratory of Genetics, Breeding and Comprehensive Utilization of Crops, Ministry of Education, College of Crop Science , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , People's Republic of China
| | - Liang Jin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Jin Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Chenxu Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Junxiang Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Enjiong Huang
- Fujian International Travel Healthcare Center , 350001 Fuzhou , Fujian , People's Republic of China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
| | - Xiao-Qiang Yu
- Division of Cell Biology and Biophysics , University of Missouri , Kansas City , Missouri 64110 , United States
| | - Lingling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Key Lab of Biopesticides and Chemical Biology, MOE , Fujian Agriculture and Forestry University , 350002 Fuzhou , Fujian , PR China
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17
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Qiu L, Sun Y, Jiang Z, Yang P, Liu H, Zhou H, Wang X, Zhang W, Lin Y, Ma W. The midgut V-ATPase subunit A gene is associated with toxicity to crystal 2Aa and crystal 1Ca-expressing transgenic rice in Chilo suppressalis. INSECT MOLECULAR BIOLOGY 2019; 28:520-527. [PMID: 30719783 DOI: 10.1111/imb.12570] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Insecticidal crystal (Cry) proteins produced by the bacterium Bacillus thuringiensis (Bt) are toxic to a diverse range of insects. Transgenic rice expressing Cry1A, Cry2A and Cry1C toxins have been developed that are lethal to Chilo suppressalis, a devastating insect pest of rice in China. Identifying the mechanisms underlying the interactions of Cry toxins with susceptible hosts will improve both our understanding of Cry protein toxicology and long-term efficacy of Bt crops. In this study, we tested the hypothesis that V-ATPase subunit A contributes to the action of Cry1Ab/1Ac, Cry2Aa and Cry1Ca toxins in C. suppressalis. The full-length V-ATPase subunit A transcript was initially cloned from the C. suppressalis larval midgut and then used to generate double-stranded RNA (dsRNA)-producing bacteria. Toxicity assays using transgenic rice lines TT51 (Cry1Ab and Cry1Ac fusion genes), T2A-1 (Cry2Aa), and T1C-19 (Cry1Ca) in conjunction with V-ATPase subunit A dsRNA-treated C. suppressalis larvae revealed significantly reduced larval susceptibility to T2A-1 and T1C-19 transgenic rice, but not to TT51 rice. These results suggest that the V-ATPase subunit A plays a crucial role in mediating Cry2Aa and Cry1Ca toxicity in C. suppressalis. These findings will have significant implications on the development of future resistance management tools.
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Affiliation(s)
- L Qiu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Wuhan, Hubei, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Y Sun
- 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
| | - Z Jiang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - P Yang
- 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
| | - H Liu
- 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
| | - 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
| | - X Wang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 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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18
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Zhang LL, Hu XH, Wu SQ, Batool K, Chowdhury M, Lin Y, Zhang J, Gill SS, Guan X, Yu XQ. Aedes aegypti Galectin Competes with Cry11Aa for Binding to ALP1 To Modulate Cry Toxicity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:13435-13443. [PMID: 30556692 DOI: 10.1021/acs.jafc.8b04665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The key step for the toxicity of Bacillus thuringiensis subsp. israelensis (Bti) is the interaction between toxins and putative receptors; thus, many studies focus on identification of new toxin receptors and engineering of toxins with higher affinity/specificity for receptors. In the larvae of Aedes aegypti, galectin-14 was one of the genes upregulated by Bti treatment. RNAi knockdown expression of galectin-14 and feeding recombinant galectin-14-thioredoxin fusion protein significantly affected survival of Ae. aegypti larvae treated with Bti toxins. Recombinant galectin-14 protein bound to brush border membrane vesicles (BBMVs) of Ae. aegypti larvae, ALP1 and APN2, and galectin-14 and Cry11Aa bound to BBMVs with a similarly high affinity. Competitive binding results showed that galectin-14 competed with Cry11Aa for binding to BBMVs and ALP1 to prevent effective binding of toxin to receptors. These novel findings demonstrated that midgut proteins other than receptors play an important role in modulating the toxicity of Cry toxins.
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Affiliation(s)
- Ling-Ling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and School of Life Science , Fujian Agriculture and Forestry University , Fuzhou 350002 , China
- Division of Cell Biology and Biophysics , University of Missouri - Kansas City , Kansas City , Missouri 64110 , United States
| | - Xiao-Hua Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and School of Life Science , Fujian Agriculture and Forestry University , Fuzhou 350002 , China
| | - Song-Qing Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and School of Life Science , Fujian Agriculture and Forestry University , Fuzhou 350002 , China
| | - Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and School of Life Science , Fujian Agriculture and Forestry University , Fuzhou 350002 , China
| | - Munmun Chowdhury
- Division of Cell Biology and Biophysics , University of Missouri - Kansas City , Kansas City , Missouri 64110 , United States
| | - Yi Lin
- Department of Bioengineering & Biotechnology, College of Chemical Engineering , Huaqiao University , Xiamen 361021 , China
| | - Jie Zhang
- Division of Cell Biology and Biophysics , University of Missouri - Kansas City , Kansas City , Missouri 64110 , United States
| | - Sarjeet S Gill
- Department of Molecular, Cell and Systems Biology , University of California , Riverside , California 92521 , United States
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and School of Life Science , Fujian Agriculture and Forestry University , Fuzhou 350002 , China
| | - Xiao-Qiang Yu
- Division of Cell Biology and Biophysics , University of Missouri - Kansas City , Kansas City , Missouri 64110 , United States
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, and School of Life Sciences , South China Normal University , Guangzhou 510631 , China
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19
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Rao W, Zhan Y, Chen S, Xu Z, Huang T, Hong X, Zheng Y, Pan X, Guan X. Flowerlike Mg(OH) 2 Cross-Nanosheets for Controlling Cry1Ac Protein Loss: Evaluation of Insecticidal Activity and Biosecurity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:3651-3657. [PMID: 29584428 DOI: 10.1021/acs.jafc.8b00575] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bacillus thuringiensis (Bt) can produce Cry proteins during the sporulation phase, and Cry protein is effective against lepidopteran, coleopteran, and dipteran insects and nematodes. However, Cry protein tends to be discharged into soil and nontarget plants through rainwater runoff, leading to reduced effective period toward target insects. In the present study, nano-Mg(OH)2 (magnesium hydroxide nanoparticles, MHNPs) were synthesized to control the loss of Cry1Ac protein and deliver protein to Helicoverpa armigera (Lepidoptera: Noctuidae). The results showed that Cry1Ac protein could be loaded onto MHNPs through electrostatic adsorption, and both MHNPs and Cry protein were stable during the adsorption process. Meanwhile, the Cry1Ac-loaded MHNPs could remain on the surface of cotton leaves, resulting in enhanced adhesion of Cry1Ac protein by 59.50% and increased pest mortality by 75.00%. Additionally, MHNPs could be slowly decomposed by acid medium and MHNPs showed no obvious influence on cotton, Bt, Escherichia coli, and H. armigera. Therefore, MHNPs could serve as an efficient nanocarrier for delivery of Cry1Ac protein and be used as a potential adjuvant for biopesticide in agricultural applications.
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Affiliation(s)
- Wenhua Rao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Yating Zhan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Saili Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Zhangyan Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Tengzhou Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Xianxian Hong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Yilin Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Xiaohong Pan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection & Key Lab of Biopesticide and Chemical Biology, Ministry of Education , Fujian Agriculture and Forestry University , Fuzhou , Fujian 350002 , People's Republic of China
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Peng D, Wan D, Cheng C, Ye X, Sun M. Nematode-specific cadherin CDH-8 acts as a receptor for Cry5B toxin in Caenorhabditis elegans. Appl Microbiol Biotechnol 2018; 102:3663-3673. [PMID: 29502179 DOI: 10.1007/s00253-018-8868-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/22/2018] [Accepted: 02/10/2018] [Indexed: 10/17/2022]
Abstract
Parasitic nematodes of animals and plants cause worldwide devastating impacts on people's lives and agricultural crops. The crystal protein Cry5B produced by Bacillus thuringiensis has efficient and specific activity against a wide range of nematodes. However, the action mode of this toxin has not yet been thoroughly determined. Here, a nematode-specific cadherin CDH-8 was demonstrated to be a receptor for Cry5B toxin by using Caenorhabditis elegans as a model, providing evidence that the cadherin mutant worm cdh-8(RB815) possesses significant resistance to Cry5B, and the CDH-8 fragments bind specifically to Cry5B. Furthermore, CDH-8 was identified to be required for the oligomerization of Cry5B toxin in vivo and contribute to the internalization and pore formation of Cry5B in nematode cells. This study will facilitate a better understanding of the action mode of nematicidal Cry toxins and help the design of Cry toxin-based products for the control of plant or animal parasitic nematodes.
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Affiliation(s)
- Donghai Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Danfeng Wan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Chunsheng Cheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiaobo Ye
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
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Shao E, Lin L, Liu S, Zhang J, Chen X, Sha L, Huang Z, Huang B, Guan X. Analysis of Homologs of Cry-toxin Receptor-Related Proteins in the Midgut of a Non-Bt Target, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2018; 18:4839024. [PMID: 29415259 PMCID: PMC5804751 DOI: 10.1093/jisesa/iex102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Indexed: 05/13/2023]
Abstract
The brown planthopper (BPH) Nilaparvata lugens is one of the most destructive insect pests in the rice fields of Asia. Like other hemipteran insects, BPH is not susceptible to Cry toxins of Bacillus thuringiensis (Bt) or transgenic rice carrying Bt cry genes. Lack of Cry receptors in the midgut is one of the main reasons that BPH is not susceptible to the Cry toxins. The main Cry-binding proteins (CBPs) of the susceptible insects are cadherin, aminopeptidase N (APN), and alkaline phosphatase (ALP). In this study, we analyzed and validated de novo assembled transcripts from transcriptome sequencing data of BPH to identify and characterize homologs of cadherin, APN, and ALP. We then compared the cadherin-, APN-, and ALP-like proteins of BPH to previously reported CBPs to identify their homologs in BPH. The sequence analysis revealed that at least one cadherin, one APN, and two ALPs of BPH contained homologous functional domains identified from the Cry-binding cadherin, APN, and ALP, respectively. Quantitative real-time polymerase chain reaction used to verify the expression level of each putative Cry receptor homolog in the BPH midgut indicated that the CBPs homologous APN and ALP were expressed at high or medium-high levels while the cadherin was expressed at a low level. These results suggest that homologs of CBPs exist in the midgut of BPH. However, differences in key motifs of CBPs, which are functional in interacting with Cry toxins, may be responsible for insusceptibility of BPH to Cry toxins.
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Affiliation(s)
- Ensi Shao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
- China National Engineering Research Center of JUNCAO Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Li Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Sijun Liu
- Department of Entomology, Iowa State University, Ames, IA, 50011
| | - Jiao Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Xuelin Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Li Sha
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Zhipeng Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Biwang Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
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22
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Chen J, Aimanova K, Gill SS. Functional characterization of Aedes aegypti alkaline phosphatase ALP1 involved in the toxicity of Cry toxins from Bacillus thuringiensis subsp. israelensis and jegathesan. Peptides 2017; 98:78-85. [PMID: 28587836 PMCID: PMC5705450 DOI: 10.1016/j.peptides.2017.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/24/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
Abstract
Presently three major groups of proteins from Aedes aegypti, cadherin, alkaline phosphatases (ALP) and aminopeptidases N (APN), have been identified as Cry11Aa toxin receptors. To further characterize their role on toxicity, transgenic mosquitoes with silenced Aedes cadherin expression were previously generated and the role of cadherin in mediating the toxicity of four different mosquitocidal toxins (Cry11Aa, Cry11Ba, Cry4Aa and Cry4Ba) was demonstrated. Here, we investigated the role of another reported Cry11Aa receptor, ALP1. As with Aedes cadherin, this protein is localized in the apical cell membrane of distal and proximal gastric caecae and the posterior midgut. We also successfully generated transgenic mosquitoes that knockdowned ALP1 transcript levels using an inducible Aedes heat shock promoter, Hsp70A driving dsALP1RNA. Four different mosquitocidal toxins were used for larval bioassays against this transgenic mosquito. Bioassay results show thatCry11Aa toxicity to these transgenic larvae following a heat shock decreased (4.4 fold) and Cry11Ba toxicity is slightly attenuated. But Cry4Aa and Cry4Ba toxicity to ALP1 silenced larvae is unchanged. Without heat shock, toxicity of all four toxins does not change, suggesting this heat shock promoter is heat-inducible. Notably, transgenic mosquitoes with ALP1 knockdown are about 3.7 times less resistant to Cry11Aa toxin than those with Aedes cadherin knockdown. These results demonstrate that the ALP1 is an important secondary receptor for Cry11Aa and Cry11Ba, but it might not be involved in Cry4Aa and Cry4Ba toxicity.
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Affiliation(s)
- Jianwu Chen
- Departmentof Cell Biology and Neurosciences, University of California, Riverside, CA 92521, United States.
| | - Karly Aimanova
- Departmentof Cell Biology and Neurosciences, University of California, Riverside, CA 92521, United States
| | - Sarjeet S Gill
- Departmentof Cell Biology and Neurosciences, University of California, Riverside, CA 92521, United States
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Identification and Characterization of Hyphantria cunea Aminopeptidase N as a Binding Protein of Bacillus thuringiensis Cry1Ab35 Toxin. Int J Mol Sci 2017; 18:ijms18122575. [PMID: 29189732 PMCID: PMC5751178 DOI: 10.3390/ijms18122575] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 11/22/2022] Open
Abstract
The fall webworm, Hyphantria cunea (Drury) is a major invasive pest in China. Aminopeptidase N (APN) isoforms in lepidopteran larvae midguts are known for their involvement in the mode of action of insecticidal crystal (Cry) proteins from Bacillus thuringiensis. In the present work, we identified a putative Cry1Ab toxin-binding protein, an APN isoform designated HcAPN3, in the midgut of H. cunea by ligand blot and mass spectrometry. HcAPN3 was highly expressed throughout all larval developmental stages and was abundant in the midgut and hindgut tissues. HcAPN3 was down-regulated at 6 h, then was up-regulated significantly at 12 h and 24 h after Cry1Ab toxin treatment. We expressed HcAPN3 in insect cells and detected its interaction with Cry1Ab toxin by ligand blot assays. Furthermore, RNA interference (RNAi) against HcAPN3 using oral delivery and injection of double-stranded RNA (dsRNA) resulted in a 61–66% decrease in transcript level. Down-regulating of the expression of HcAPN3 was closely associated with reduced susceptibility of H. cunea to Cry1Ab. In addition, the HcAPN3E fragment peptide expressed in Escherichia coli enhanced Cry1Ab toxicity against H. cunea larvae. This work represents the first evidence to suggest that an APN in H. cunea is a putative binding protein involved in Cry1Ab susceptibility.
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Pan X, Xu Z, Li L, Shao E, Chen S, Huang T, Chen Z, Rao W, Huang T, Zhang L, Wu S, Guan X. Adsorption of Insecticidal Crystal Protein Cry11Aa onto Nano-Mg(OH) 2: Effects on Bioactivity and Anti-Ultraviolet Ability. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:9428-9434. [PMID: 29019656 DOI: 10.1021/acs.jafc.7b03410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The traditional Bacillus thuringiensis (Bt) formulations for field applications are not resistant to harsh environmental conditions. Hence, the active ingredients of the Bt bioinsecticides could degrade quickly and has low anti-ultraviolet ability in the field, which significantly limits its practical application. In the present study, we developed an efficient and stable delivery system for Bt Cry11Aa toxins. We coated Cry11Aa proteins with Mg(OH)2 nanoparticles (MHNPs), and then assessed the effects of MHNPs on bioactivity and anti-ultraviolet ability of the Cry11Aa proteins. Our results indicated that MHNPs, like "coating clothes", could effectively protect the Cry protein and enhance the insecticidal bioactivity after UV radiation (the degradation rate was decreased from 64.29% to 16.67%). In addtion, MHNPs could improve the proteolysis of Cry11Aa in the midgut and aggravate the damage of the Cry protein to the gut epithelial cells, leading to increased insecticidal activity against Culex quinquefasciatus. Our results revealed that MHNPs, as an excellent nanocarrier, could substantially improve the insecticidal bioactivity and anti-ultraviolet ability of Cry11Aa.
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Affiliation(s)
- Xiaohong Pan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
| | - Zhangyan Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Lan Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Enshi Shao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
| | - Saili Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Tengzhou Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Zhi Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Wenhua Rao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
| | - Tianpei Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
| | - Lingling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
| | - Songqing Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Lab of Biopesticide and Chemical Biology, Ministry of Education & College of Plant Protection & College of Resources and Environmental Sciences & College of Life Sciences & Forestry College, Fujian Agriculture and Forestry University , Fuzhou, Fujian 350002, P. R. China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests , Fuzhou, Fujian 350002, P. R. China
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25
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Zhang Q, Hua G, Adang MJ. Effects and mechanisms of Bacillus thuringiensis crystal toxins for mosquito larvae. INSECT SCIENCE 2017; 24:714-729. [PMID: 27628909 DOI: 10.1111/1744-7917.12401] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/15/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Bacillus thuringiensis is a Gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. The virulence factor, known as parasporal crystals, is composed of Cry and Cyt toxins. Most Cry toxins display a common 3-domain topology. Cry toxins exert intoxication through toxin activation, receptor binding and pore formation in a suitable larval gut environment. The mosquitocidal toxins of Bt subsp. israelensis (Bti) were found to be highly active against mosquito larvae and are widely used for vector control. Bt subsp. jegathesan is another strain which possesses high potency against broad range of mosquito larvae. The present review summarizes characterized receptors for Cry toxins in mosquito larvae, and will also discuss the diversity and effects of 3-D mosquitocidal Cry toxin and the ongoing research for Cry toxin mechanisms generated from investigations of lepidopteran and dipteran larvae.
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Affiliation(s)
- Qi Zhang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - Gang Hua
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - Michael J Adang
- Department of Entomology, University of Georgia, Athens, GA, USA
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA, USA
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An Intramolecular Salt Bridge in Bacillus thuringiensis Cry4Ba Toxin Is Involved in the Stability of Helix α-3, Which Is Needed for Oligomerization and Insecticidal Activity. Appl Environ Microbiol 2017; 83:AEM.01515-17. [PMID: 28802270 DOI: 10.1128/aem.01515-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 08/04/2017] [Indexed: 01/30/2023] Open
Abstract
Bacillus thuringiensis three-domain Cry toxins kill insects by forming pores in the apical membrane of larval midgut cells. Oligomerization of the toxin is an important step for pore formation. Domain I helix α-3 participates in toxin oligomerization. Here we identify an intramolecular salt bridge within helix α-3 of Cry4Ba (D111-K115) that is conserved in many members of the family of three-domain Cry toxins. Single point mutations such as D111K or K115D resulted in proteins severely affected in toxicity. These mutants were also altered in oligomerization, and the mutant K115D was more sensitive to protease digestion. The double point mutant with reversed charges, D111K-K115D, recovered both oligomerization and toxicity, suggesting that this salt bridge is highly important for conservation of the structure of helix α-3 and necessary to promote the correct oligomerization of the toxin.IMPORTANCE Domain I has been shown to be involved in oligomerization through helix α-3 in different Cry toxins, and mutations affecting oligomerization also elicit changes in toxicity. The three-dimensional structure of the Cry4Ba toxin reveals an intramolecular salt bridge in helix α-3 of domain I. Mutations that disrupt this salt bridge resulted in changes in Cry4Ba oligomerization and toxicity, while a double point reciprocal mutation that restored the salt bridge resulted in recovery of toxin oligomerization and toxicity. These data highlight the role of oligomer formation as a key step in Cry4Ba toxicity.
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Rezende TMT, Romão TP, Batista M, Berry C, Adang MJ, Silva-Filha MHNL. Identification of Cry48Aa/Cry49Aa toxin ligands in the midgut of Culex quinquefasciatus larvae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 88:63-70. [PMID: 28780070 DOI: 10.1016/j.ibmb.2017.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/15/2017] [Accepted: 08/01/2017] [Indexed: 06/07/2023]
Abstract
A binary mosquitocidal toxin composed of a three-domain Cry-like toxin (Cry48Aa) and a binary-like toxin (Cry49Aa) was identified in Lysinibacillus sphaericus. Cry48Aa/Cry49Aa has action on Culex quinquefasciatus larvae, in particular, to those that are resistant to the Bin Binary toxin, which is the major insecticidal factor from L. sphaericus-based biolarvicides, indicating that Cry48Aa/Cry49Aa interacts with distinct target sites in the midgut and can overcome Bin toxin resistance. This study aimed to identify Cry48Aa/Cry49Aa ligands in C. quinquefasciatus midgut through binding assays and mass spectrometry. Several proteins, mostly from 50 to 120 kDa, bound to the Cry48Aa/Cry49Aa toxin were revealed by toxin overlay and pull-down assays. These proteins were identified against the C. quinquefasciatus genome and after analysis a set of 49 proteins were selected which includes midgut bound proteins such as aminopeptidases, amylases, alkaline phosphatases in addition to molecules from other classes that can be potentially involved in this toxin's mode of action. Among these, some proteins are orthologs of Cry receptors previously identified in mosquito larvae, as candidate receptors for Cry48Aa/Cry49Aa toxin. Further investigation is needed to evaluate the specificity of their interactions and their possible role as receptors.
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Affiliation(s)
| | | | - Michel Batista
- Instituto Carlos Chagas-FIOCRUZ, Curitiba, PR 81350-010, Brazil
| | - Colin Berry
- Cardiff School of Biosciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom
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28
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Kim IH, Ensign J, Kim DY, Jung HY, Kim NR, Choi BH, Park SM, Lan Q, Goodman WG. Specificity and putative mode of action of a mosquito larvicidal toxin from the bacterium Xenorhabdus innexi. J Invertebr Pathol 2017; 149:21-28. [PMID: 28712711 DOI: 10.1016/j.jip.2017.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 07/01/2017] [Accepted: 07/10/2017] [Indexed: 11/17/2022]
Abstract
Reduction of mosquito-borne diseases relies, in part, on the use of synthetic pesticides to control pest mosquitoes. This reliance has led to genetic resistance, environmental contamination and the nondiscriminatory elimination of both pest and non-pest species. To expand our options for control, we screened entomopathogenic bacteria for potential larvicidal activity. A lipopeptide from the bacterium, Xenorhabdus innexi, was discovered that displayed potent larvicidal activity. The LC50s of the lipopeptide towards Aedes aegypti, Culex pipiens and Anopheles gambiae larvae were 1.81, 1.25 and 1.86 parts-per-million, respectively. No mortality was observed in other insect species tested. The putative mode of action of the lipopeptide suggested that after orally ingestion, it bound to the apical membrane of anterior midgut cells and created pores in the cellular membranes. The rapid neutralization of midgut pH suggested the pores disabled the H+-V-ATPase on the basal membrane and led to epithelial cell death. Specificity and toxicity towards mosquito larvae and the unique mode of action makes this lipopeptide a potentially attractive bacterial insecticide for control of mosquitoes.
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Affiliation(s)
- Il-Hwan Kim
- Vector Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA; Department of Entomology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Jerald Ensign
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Do-Young Kim
- Advanced Bio Convergence Center, Pohang Technopark, Jigok-dong, Pohang, Republic of Korea
| | - Hoe-Yune Jung
- Advanced Bio Convergence Center, Pohang Technopark, Jigok-dong, Pohang, Republic of Korea; R&D Center, NovMetaPharma Co., Ltd., Jigok-dong, Pohang, Republic of Korea
| | - Na-Ri Kim
- Advanced Bio Convergence Center, Pohang Technopark, Jigok-dong, Pohang, Republic of Korea
| | - Bo-Hwa Choi
- Advanced Bio Convergence Center, Pohang Technopark, Jigok-dong, Pohang, Republic of Korea
| | - Sun-Min Park
- Advanced Bio Convergence Center, Pohang Technopark, Jigok-dong, Pohang, Republic of Korea
| | - Que Lan
- Department of Entomology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Walter G Goodman
- Department of Entomology, University of Wisconsin-Madison, Madison, WI 53706, USA
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Stalinski R, Laporte F, Després L, Tetreau G. Alkaline phosphatases are involved in the response ofAedes aegyptilarvae to intoxication withBacillus thuringiensissubsp.israelensis Cry toxins. Environ Microbiol 2016; 18:1022-36. [DOI: 10.1111/1462-2920.13186] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Renaud Stalinski
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Frédéric Laporte
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Laurence Després
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Guillaume Tetreau
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
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30
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Peng D, Lin J, Huang Q, Zheng W, Liu G, Zheng J, Zhu L, Sun M. A novel metalloproteinase virulence factor is involved in Bacillus thuringiensis pathogenesis in nematodes and insects. Environ Microbiol 2015; 18:846-62. [PMID: 26995589 DOI: 10.1111/1462-2920.13069] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/25/2015] [Indexed: 11/29/2022]
Abstract
The Gram-positive soil bacterium Bacillus thuringiensis has been developed as the leading microbial insecticide for years. The pathogenesis of B. thuringiensis requires common extracellular factors that depend on the PlcR regulon, which regulates a large number of virulence factors; however, the precise role of many of these proteins is not known. In this study, we describe the complete lifecycle of a nematicidal B. thuringiensis strain in the free living nematode Caenorhabditis elegans using in vitro and in vivo molecular techniques to follow host and bacterial effectors during the infection process. We then focus on the metalloproteinase ColB, a collagenase, which was found highly important for destruction of the intestine thereby facilitates the adaptation and colonization of B. thuringiensis in C. elegans. In vivo green fluorescent protein (GFP) reporter-gene studies showed that ColB expression is highly induced and regulated by the global activator PlcR. Finally, we demonstrated that ColB also takes part in B. thuringiensis virulence in an insect model following injection and oral infection. Indeed, addition of purified ColB accelerates the action of Cry toxin proteins in insects, too. These results give novel insights into host adaptation for B. thuringiensis and other B. cereus group bacteria and highlight the role of collagenase metalloproteases to synergize infection process.
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Affiliation(s)
- Donghai Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jian Lin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Qiong Huang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Wen Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Guoqiang Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Lei Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
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31
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Atkinson SC, Armistead JS, Mathias DK, Sandeu MM, Tao D, Borhani-Dizaji N, Tarimo BB, Morlais I, Dinglasan RR, Borg NA. The Anopheles-midgut APN1 structure reveals a new malaria transmission-blocking vaccine epitope. Nat Struct Mol Biol 2015; 22:532-9. [PMID: 26075520 PMCID: PMC4547048 DOI: 10.1038/nsmb.3048] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 05/18/2015] [Indexed: 12/31/2022]
Abstract
Mosquito-based malaria transmission-blocking vaccines (mTBVs) target midgut-surface antigens of the Plasmodium parasite's obligate vector, the Anopheles mosquito. The alanyl aminopeptidase N (AnAPN1) is the leading mTBV immunogen; however, AnAPN1's role in Plasmodium infection of the mosquito and how anti-AnAPN1 antibodies functionally block parasite transmission have remained elusive. Here we present the 2.65-Å crystal structure of AnAPN1 and the immunoreactivity and transmission-blocking profiles of three monoclonal antibodies (mAbs) to AnAPN1, including mAb 4H5B7, which effectively blocks transmission of natural strains of Plasmodium falciparum. Using the AnAPN1 structure, we map the conformation-dependent 4H5B7 neoepitope to a previously uncharacterized region on domain 1 and further demonstrate that nonhuman-primate neoepitope-specific IgG also blocks parasite transmission. We discuss the prospect of a new biological function of AnAPN1 as a receptor for Plasmodium in the mosquito midgut and the implications for redesigning the AnAPN1 mTBV.
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Affiliation(s)
- Sarah C Atkinson
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Jennifer S Armistead
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Derrick K Mathias
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Maurice M Sandeu
- Laboratoire de Recherche sur le Paludisme, Institut de Recherche pour le Développement-Organisation de Coordination et de Coopération pour la Lutte Contre les Grandes Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Dingyin Tao
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Nahid Borhani-Dizaji
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Brian B Tarimo
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [3] Nelson Mandela African Institute for Science and Technology, Arusha, Tanzania. [4] Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Isabelle Morlais
- Laboratoire de Recherche sur le Paludisme, Institut de Recherche pour le Développement-Organisation de Coordination et de Coopération pour la Lutte Contre les Grandes Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Rhoel R Dinglasan
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Natalie A Borg
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Lee SB, Chen J, Aimanova KG, Gill SS. Aedes cadherin mediates the in vivo toxicity of the Cry11Aa toxin to Aedes aegypti. Peptides 2015; 68:140-147. [PMID: 25064814 PMCID: PMC4305047 DOI: 10.1016/j.peptides.2014.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/07/2014] [Accepted: 07/07/2014] [Indexed: 12/16/2022]
Abstract
Cadherin plays an important role in the toxicity of Bacillus thuringiensis Cry proteins. We previously cloned a full-length cadherin from Aedes aegypti larvae and reported this protein binds Cry11Aa toxin from B. thuringiensis subsp. israelensis with high affinity, ≈16.7nM. Based on these results, we investigated if Aedes cadherin is involved in the in vivo toxicity of Cry11Aa toxin to Ae. aegypti. We established a mosquito cell line stably expressing the full-length Aedes cadherin and transgenic mosquitoes with silenced Aedes cadherin expression. Cells expressing the Aedes cadherin showed increased sensitivity to Cry11Aa toxin. Cry11Aa toxin at 400nM killed approximately 37% of the cells in 3h. Otherwise, transgenic mosquitoes with silenced Aedes cadherin expression showed increased tolerance to Cry11Aa toxin. Furthermore, cells expressing Aedes cadherin triggered Cry11Aa oligomerization. These results show the Aedes cadherin plays a pivotal role in Cry11Aa toxicity to Ae. aegypti larvae by mediating Cry11Aa oligomerization. However, since high toxicity was not obtained in cadherin-expressing cells, an additional receptor may be needed for manifestation of full toxicity. Moreover, cells expressing Aedes cadherin were sensitive to Cry4Aa and Cry11Ba, but not Cry4Ba. However transgenic mosquitoes with silenced Aedes cadherin expression showed no tolerance to Cry4Aa, Cry4Ba, and Cry11Ba toxins. These results suggest that while Aedes cadherin may mediate Cry4Aa and Cry11Ba toxicity, this cadherin but is not the main receptor of Cry4Aa, Cry4Ba and Cry11Ba toxin in Ae. aegypti.
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Affiliation(s)
- Su-Bum Lee
- Environmental Toxicology graduate program, University of California, Riverside, CA, 92521, USA
| | - Jianwu Chen
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, 92521, USA
| | - Karlygash G. Aimanova
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, 92521, USA
| | - Sarjeet S. Gill
- Environmental Toxicology graduate program, University of California, Riverside, CA, 92521, USA
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA, 92521, USA
- Corresponding author: . Tel: 951-827-4621/3547
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Qiu L, Hou L, Zhang B, Liu L, Li B, Deng P, Ma W, Wang X, Fabrick JA, Chen L, Lei C. Cadherin is involved in the action of Bacillus thuringiensis toxins Cry1Ac and Cry2Aa in the beet armyworm, Spodoptera exigua. J Invertebr Pathol 2015; 127:47-53. [DOI: 10.1016/j.jip.2015.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 02/20/2015] [Accepted: 02/27/2015] [Indexed: 12/23/2022]
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Zhang Q, Hua G, Adang MJ. Chitosan/DsiRNA nanoparticle targeting identifies AgCad1 cadherin in Anopheles gambiae larvae as an in vivo receptor of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 60:33-38. [PMID: 25758367 DOI: 10.1016/j.ibmb.2015.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/18/2015] [Accepted: 03/01/2015] [Indexed: 06/04/2023]
Abstract
The Cry11Ba protein of Bacillus thuringiensis subsp. jegathesan crystals has uniquely high toxicity against a spectrum of mosquito species. The high potency of Cry11Ba against Anopheles gambiae is caused by recognition of multiple midgut proteins including glycosyl phosphatidylinositol-anchored alkaline phosphatase AgALP1, aminopeptidase AgAPN2, α-amylase AgAmy1 and α-glucosidase Agm3 that bind Cry11Ba with high affinity and function as putative receptors. The cadherin AgCad2 in An. gambiae larvae also binds Cry11Ba with high affinity (Kd = 12 nM) and is considered a putative receptor, while cadherin AgCad1 bound Cry11Ba with low affinity (Kd = 766 nM), a property not supportive for a Cry11Ba receptor role. Here, we show the in vivo involvement of AgCad1 in Cry11Ba toxicity in An. gambiae larvae using chitosan/DsiRNA nanoparticles to inhibit AgCad expression in larvae. Cry11Ba was significantly less toxic to AgCad1-silenced larvae than to control larvae. Because AgCad1 was co-suppressed by AgCad2 DsRNAi, the involvement of AgCad2 in Cry11Ba toxicity could not be ascertained. The ratio of AgCad1:AgCad2 transcript level is 36:1 for gut tissue in 4th instar larvae. Silencing AgCad expression had no effect on transcript levels of other binding receptors of Cry11Ba. We conclude that AgCad1 and possibly AgCad2 in An. gambiae larvae are functional receptors of Cry11Ba toxin in vivo.
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Affiliation(s)
- Qi Zhang
- Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA
| | - Gang Hua
- Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA
| | - Michael J Adang
- Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602-2603, USA.
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Aroonkesorn A, Pootanakit K, Katzenmeier G, Angsuthanasombat C. Two specific membrane-bound aminopeptidase N isoforms from Aedes aegypti larvae serve as functional receptors for the Bacillus thuringiensis Cry4Ba toxin implicating counterpart specificity. Biochem Biophys Res Commun 2015; 461:300-6. [PMID: 25871797 PMCID: PMC7124302 DOI: 10.1016/j.bbrc.2015.04.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 04/05/2015] [Indexed: 12/28/2022]
Abstract
The interaction between Bacillus thuringiensis Cry toxins and their receptors on midgut cells of susceptible insect larvae is the critical determinant in toxin specificity. Besides GPI-linked alkaline phosphatase in Aedes aegypti mosquito-larval midguts, membrane-bound aminopeptidase N (AaeAPN) is widely thought to serve as a Cry4Ba receptor. Here, two full-length AaeAPN isoforms, AaeAPN2778 and AaeAPN2783, predicted to be GPI-linked were cloned and successfully expressed in Spodoptera frugiperda (Sf9) cells as 112- and 107-kDa membrane-bound proteins, respectively. In the cytotoxicity assay, Sf9 cells expressing each of the two AaeAPN isoforms showed increased sensitivity to the Cry4Ba mosquito-active toxin. Double immunolocalization revealed specific binding of Cry4Ba to each individual AaeAPN expressed on the cell membrane surface. Sequence analysis and homology-based modeling placed these two AaeAPNs to the M1 aminopeptidase family as they showed similar four-domain structures, with the most conserved domain II being the catalytic component. Additionally, the most variable domain IV containing negatively charged surface patches observed only in dipteran APNs could be involved in insect specificity. Overall results demonstrated that these two membrane-bound APN isoforms were responsible for mediating Cry4Ba toxicity against AaeAPN-expressed Sf9 cells, suggesting their important role as functional receptors for the toxin counterpart in A. aegypti mosquito larvae. Two novel Aedes GPI-APN isoforms were functionally expressed in Sf9 cells. Cells expressing each AaeAPN were more sensitive to Cry4Ba toxin cytolysis. Specific binding of Cry4Ba to individual AaeAPN-expressing Sf9 cells was demonstrated. These two AaeAPNs mediating Cry4Ba cytotoxicity serve as receptors in Aedes larvae. AaeAPN models reveal four-domain organization with implications for toxin-counterpart specificity.
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Affiliation(s)
- Aratee Aroonkesorn
- Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand
| | - Kusol Pootanakit
- Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand
| | - Gerd Katzenmeier
- Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand
| | - Chanan Angsuthanasombat
- Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand; Laboratory of Molecular Biophysics and Structural Biochemistry, Biophysics Institute for Research and Development (BIRD), Bangkok 10160, Thailand.
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Chen Z, He F, Xiao Y, Liu C, Li J, Yang Y, Ai H, Peng J, Hong H, Liu K. Endogenous expression of a Bt toxin receptor in the Cry1Ac-susceptible insect cell line and its synergistic effect with cadherin on cytotoxicity of activated Cry1Ac. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 59:1-17. [PMID: 25662100 DOI: 10.1016/j.ibmb.2015.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/18/2015] [Accepted: 01/23/2015] [Indexed: 06/04/2023]
Abstract
Although many insect cell lines derived from various tissues are available, it is unclear whether endogenous receptors of Bacillus thuringiensis (Bt) crystal toxins are expressed in these cell lines. In the present study, we demonstrated that the ovaries-derived Spodoptera litura Sl-HP cell line was susceptible to activated Cry1Ac although larvae of S. litura are not susceptible to the toxin. Assays of the transcriptome revealed that thirteen ATP-binding cassette transporter genes (ABC) were expressed at different levels in this cell line. Of these, the SlABCC3 shared 52-55% amino acid sequence identity with the known Bt toxin receptor ABCC2. RNAi-mediated knockdown targeting SlABCC3 significantly decreased the susceptibility of Sl-HP cells to activated Cry1Ac. Over-expression of the gene strongly increased the susceptibility of Trichoplusia ni Hi5 cells to the toxin. Not only was SlABCC3 comparable to the heterologously expressed Helicoverpa armigera Hacadherin on the receptor-mediated cytotoxicity of activated Cry1Ac to Hi5 cells, but also SlABCC3 and Hacadherin had a strong synergistic effect on cytotoxicity of activated Cry1Ac. These results suggested that Bt toxin receptors-expressing insect cell lines can be used as an alternative model for evaluating cytotoxicity of Bt toxins and studying their mechanisms of action.
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Affiliation(s)
- Zuwen Chen
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Fei He
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Yutao Xiao
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Chenxi Liu
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Jianghuai Li
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Yongbo Yang
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Hui Ai
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Jianxin Peng
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Huazhu Hong
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Kaiyu Liu
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China.
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Lee SB, Aimanova KG, Gill SS. Alkaline phosphatases and aminopeptidases are altered in a Cry11Aa resistant strain of Aedes aegypti. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 54:112-121. [PMID: 25242559 PMCID: PMC4254116 DOI: 10.1016/j.ibmb.2014.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/10/2014] [Accepted: 09/13/2014] [Indexed: 06/01/2023]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) is widely used for the biological control of mosquito populations. However, the mechanism of Bti toxins is still not fully understood. To further elucidate the mechanism of Bti toxins, we developed an Aedes aegypti resistant strain that shows high-level resistance to Cry11Aa toxin. After 27 selections with Cry11Aa toxin, the larvae showed a 124-fold resistance ratio for Cry11Aa (strain G30). G30 larvae showed cross-resistance to Cry4Aa (66-fold resistance), less to Cry4Ba (13-fold), but not to Cry11Ba (2-fold). Midguts from these resistant larvae did not show detectable difference in the processing of the Cry11Aa toxin compared to that in susceptible larvae (WT). Brush border membrane vesicles (BBMV) from resistant larvae bound slightly less Cry11Aa compared to WT BBMV. To identify potential proteins associated with Cry11A resistance, not only transcript changes in the larval midgut were analyzed using Illumina sequencing and qPCR, but alterations of previously identified receptor proteins were investigated using immunoblots. The transcripts of 375 genes were significantly increased and those of 208 genes were down regulated in the resistant larvae midgut compared to the WT. None of the transcripts for previously identified receptors of Cry11Aa (Aedes cadherin, ALP1, APN1, and APN2) were altered in these analyses. The genes for the identified functional receptors in resistant larvae midgut did not contain any mutation in their sequences nor was there any change in their transcript expression levels compared to WT. However, ALP proteins were expressed at reduced levels (∼ 40%) in the resistant strain BBMV. APN proteins and their activity were also slightly reduced in resistance strain. The transcript levels of ALPs (AAEL013330 and AAEL015070) and APNs (AAEL008158, AAEL008162) were significantly reduced. These results strongly suggest that ALPs and APNs could be associated with Cry11Aa resistance in Ae. aegypti.
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Affiliation(s)
- Su-Bum Lee
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA; Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA
| | - Karlygash G Aimanova
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA
| | - Sarjeet S Gill
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA; Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA.
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Després L, Stalinski R, Tetreau G, Paris M, Bonin A, Navratil V, Reynaud S, David JP. Gene expression patterns and sequence polymorphisms associated with mosquito resistance to Bacillus thuringiensis israelensis toxins. BMC Genomics 2014; 15:926. [PMID: 25341495 PMCID: PMC4223840 DOI: 10.1186/1471-2164-15-926] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/16/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Despite the intensive use of Bacillus thuringiensis israelensis (Bti) toxins for mosquito control, little is known about the long term effect of exposure to this cocktail of toxins on target mosquito populations. In contrast to the many cases of resistance to Bacillus thuringiensis Cry toxins observed in other insects, there is no evidence so far for Bti resistance evolution in field mosquito populations. High fitness costs measured in a Bti selected mosquito laboratory strain suggest that evolving resistance to Bti is costly. The aim of the present study was to identify transcription level and polymorphism variations associated with resistance to Bti toxins in the dengue vector Aedes aegypti. We used RNA sequencing (RNA-seq) for comparing a laboratory-selected strain showing elevated resistance to Bti toxins and its parental non-selected susceptible strain. As the resistant strain displayed two marked larval development phenotypes (slow and normal), each phenotype was analyzed separately in order to evidence potential links between resistance mechanisms and mosquito life-history traits. RESULTS A total of 12,458 genes were detected of which 844 were differentially transcribed between the resistant and susceptible strains. Polymorphism analysis revealed a total of 68,541 SNPs of which 12,571 SNPs exhibited more than 40% frequency difference between the resistant and susceptible strains, affecting 2,953 genes. Bti resistance is associated with changes in the transcription level of enzymes involved in detoxification and chitin metabolism. Among previously described Bti-toxin receptors, four alkaline phosphatases (ALPs) were differentially transcribed between resistant and susceptible larvae, and non-synonymous changes affected the protein sequence of one cadherin, six aminopeptidases (APNs) and four α-amylases. Other putative Cry receptors located in lipid rafts, such as flotillin and glycoside hydrolases, were under-transcribed and/or contained non-synonymous substitutions. Finally, immunity-related genes showed contrasted transcription and polymorphisms patterns between the two developmental resistant phenotypes, suggesting the existence of trade-offs between Bti-resistance, life-history traits and immunity. CONCLUSIONS The present study is the first to analyze the whole transcriptome of Bti-resistant mosquitoes by RNA-seq, shedding light on the importance of studying both transcription levels and sequence polymorphism variations to get a comprehensive view of insecticide resistance.
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Affiliation(s)
- Laurence Després
- Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, Grenoble, France.
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Devillers J, Lagneau C, Lattes A, Garrigues J, Clémenté M, Yébakima A. In silico models for predicting vector control chemicals targeting Aedes aegypti. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2014; 25:805-835. [PMID: 25275884 PMCID: PMC4200584 DOI: 10.1080/1062936x.2014.958291] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/30/2014] [Indexed: 05/31/2023]
Abstract
Human arboviral diseases have emerged or re-emerged in numerous countries worldwide due to a number of factors including the lack of progress in vaccine development, lack of drugs, insecticide resistance in mosquitoes, climate changes, societal behaviours, and economical constraints. Thus, Aedes aegypti is the main vector of the yellow fever and dengue fever flaviviruses and is also responsible for several recent outbreaks of the chikungunya alphavirus. As for the other mosquito species, the A. aegypti control relies heavily on the use of insecticides. However, because of increasing resistance to the different families of insecticides, reduction of Aedes populations is becoming increasingly difficult. Despite the unquestionable utility of insecticides in fighting mosquito populations, there are very few new insecticides developed and commercialized for vector control. This is because the high cost of the discovery of an insecticide is not counterbalanced by the 'low profitability' of the vector control market. Fortunately, the use of quantitative structure-activity relationship (QSAR) modelling allows the reduction of time and cost in the discovery of new chemical structures potentially active against mosquitoes. In this context, the goal of the present study was to review all the existing QSAR models on A. aegypti. The homology and pharmacophore models were also reviewed. Specific attention was paid to show the variety of targets investigated in Aedes in relation to the physiology and ecology of the mosquito as well as the diversity of the chemical structures which have been proposed, encompassing man-made and natural substances.
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Affiliation(s)
| | | | - A. Lattes
- Laboratoire I.M.R.C.P., Université Paul Sabatier, Toulouse, France
| | - J.C. Garrigues
- Laboratoire I.M.R.C.P., Université Paul Sabatier, Toulouse, France
| | - M.M. Clémenté
- Centre de Démoustication/LAV (ARS-Conseil Général) de la Martinique, Martinique, France
| | - A. Yébakima
- Centre de Démoustication/LAV (ARS-Conseil Général) de la Martinique, Martinique, France
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40
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Melo ALDA, Soccol VT, Soccol CR. Bacillus thuringiensis: mechanism of action, resistance, and new applications: a review. Crit Rev Biotechnol 2014; 36:317-26. [DOI: 10.3109/07388551.2014.960793] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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41
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Monnerat R, Pereira E, Teles B, Martins E, Praça L, Queiroz P, Soberon M, Bravo A, Ramos F, Soares CM. Synergistic activity of Bacillus thuringiensis toxins against Simulium spp. larvae. J Invertebr Pathol 2014; 121:70-3. [PMID: 25051392 DOI: 10.1016/j.jip.2014.07.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 07/10/2014] [Accepted: 07/11/2014] [Indexed: 11/15/2022]
Abstract
Species of Simulium spread diseases in humans and animals such as onchocerciasis and mansonelosis, causing health problems and economic loses. One alternative for controlling these insects is the use of Bacillus thuringiensis serovar israelensis (Bti). This bacterium produces different dipteran-active Cry and Cyt toxins and has been widely used in blackfly biological control programs worldwide. Studies on other insect targets have revealed the role of individual Cry and Cyt proteins in toxicity and demonstrated a synergistic effect among them. However, the insecticidal activity and interactions of these proteins against Simulium larvae have not been reported. In this study we demonstrate that Cry4Ba is the most effective toxin followed by Cry4Aa and Cry11Aa. Cry10Aa and Cyt1Aa were not toxic when administered alone but both were able to synergise the activity of Cry4B and Cry11Aa toxins. Cyt1Aa is also able to synergise with Cry4Aa. The mixture of all toxin-producing strains showed the greatest level of synergism, but still lower than the Bti parental strain.
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Affiliation(s)
- Rose Monnerat
- Embrapa Recursos Genéticos e Biotecnologia, Caixa Postal 02372, CEP 70849-970 Brasília, DF, Brazil.
| | - Eleny Pereira
- Universidade de Brasília, Departamento de Biologia Animal, Caixa Postal 4508, CEP 70910-900 Brasília, DF, Brazil
| | - Beatriz Teles
- Instituto Nacional de Pesquisas da Amazônia, INPA, Coordenação de Pesquisas em Entomologia, Manaus, AM, Brazil
| | - Erica Martins
- Instituto Mato-Grossense do Algodão, Cuiabá, MT, Brazil
| | - Lilian Praça
- Embrapa Recursos Genéticos e Biotecnologia, Caixa Postal 02372, CEP 70849-970 Brasília, DF, Brazil
| | - Paulo Queiroz
- Instituto Mato-Grossense do Algodão, Cuiabá, MT, Brazil
| | - Mario Soberon
- Instituto de Biotecnologia, Universidad Nacional Autonoma de México, Cuernavaca, Mexico, DF, Mexico
| | - Alejandra Bravo
- Instituto de Biotecnologia, Universidad Nacional Autonoma de México, Cuernavaca, Mexico, DF, Mexico
| | - Felipe Ramos
- Embrapa Recursos Genéticos e Biotecnologia, Caixa Postal 02372, CEP 70849-970 Brasília, DF, Brazil
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42
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Bacillus thuringiensis subsp. israelensis and its dipteran-specific toxins. Toxins (Basel) 2014; 6:1222-43. [PMID: 24686769 PMCID: PMC4014730 DOI: 10.3390/toxins6041222] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/10/2014] [Accepted: 03/14/2014] [Indexed: 01/05/2023] Open
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) is the first Bacillus thuringiensis to be found and used as an effective biological control agent against larvae of many mosquito and black fly species around the world. Its larvicidal activity resides in four major (of 134, 128, 72 and 27 kDa) and at least two minor (of 78 and 29 kDa) polypeptides encoded respectively by cry4Aa, cry4Ba, cry11Aa, cyt1Aa, cry10Aa and cyt2Ba, all mapped on the 128 kb plasmid known as pBtoxis. These six δ-endotoxins form a complex parasporal crystalline body with remarkably high, specific and different toxicities to Aedes, Culex and Anopheles larvae. Cry toxins are composed of three domains (perforating domain I and receptor binding II and III) and create cation-selective channels, whereas Cyts are composed of one domain that acts as well as a detergent-like membrane perforator. Despite the low toxicities of Cyt1Aa and Cyt2Ba alone against exposed larvae, they are highly synergistic with the Cry toxins and hence their combinations prevent emergence of resistance in the targets. The lack of significant levels of resistance in field mosquito populations treated for decades with Bti-bioinsecticide suggests that this bacterium will be an effective biocontrol agent for years to come.
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Vega-Cabrera A, Cancino-Rodezno A, Porta H, Pardo-Lopez L. Aedes aegypti Mos20 cells internalizes cry toxins by endocytosis, and actin has a role in the defense against Cry11Aa toxin. Toxins (Basel) 2014; 6:464-87. [PMID: 24476709 PMCID: PMC3942746 DOI: 10.3390/toxins6020464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/11/2014] [Accepted: 01/16/2014] [Indexed: 11/16/2022] Open
Abstract
Bacillus thuringiensis (Bt) Cry toxins are used to control Aedes aegypti, an important vector of dengue fever and yellow fever. Bt Cry toxin forms pores in the gut cells, provoking larvae death by osmotic shock. Little is known, however, about the endocytic and/or degradative cell processes that may counteract the toxin action at low doses. The purpose of this work is to describe the mechanisms of internalization and detoxification of Cry toxins, at low doses, into Mos20 cells from A. aegypti, following endocytotic and cytoskeletal markers or specific chemical inhibitors. Here, we show that both clathrin-dependent and clathrin-independent endocytosis are involved in the internalization into Mos20 cells of Cry11Aa, a toxin specific for Dipteran, and Cry1Ab, a toxin specific for Lepidoptera. Cry11Aa and Cry1Ab are not directed to secretory lysosomes. Instead, Mos20 cells use the Rab5 and Rab11 pathways as a common mechanism, most probably for the expulsion of Cry11Aa and Cry1Ab toxins. In conclusion, we propose that endocytosis is a mechanism induced by Cry toxins independently of specificity, probably as part of a basal immune response. We found, however, that actin is necessary for defense-specific response to Cry11Aa, because actin-silenced Mos20 cells become more sensitive to the toxic action of Cry11A toxin. Cry toxin internalization analysis in insect cell lines may contribute to a better understanding to Cry resistance in mosquitoes.
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Affiliation(s)
- Adriana Vega-Cabrera
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Angeles Cancino-Rodezno
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, Distrito Federal 04510, Mexico;.
| | - Helena Porta
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Liliana Pardo-Lopez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
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Chen J, Likitvivatanavong S, Aimanova KG, Gill SS. A 104 kDa Aedes aegypti aminopeptidase N is a putative receptor for the Cry11Aa toxin from Bacillus thuringiensis subsp. israelensis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:1201-8. [PMID: 24128608 PMCID: PMC3872109 DOI: 10.1016/j.ibmb.2013.09.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/20/2013] [Accepted: 09/27/2013] [Indexed: 05/25/2023]
Abstract
The Cry11Aa protein produced in Bacillus thuringiensis subsp. israelensis, a bacterial strain used worldwide for the control of Aedes aegypti larvae, binds midgut brush border membrane vesicles (BBMV) with an apparent K(d) of 29.8 nM. Previously an aminopeptidase N (APN), named AaeAPN2, was identified as a putative Cry11Aa toxin binding protein by pull-down assays using biotinylated Cry11Aa toxin (Chen et al., 2009. Insect Biochem. Mol. Biol. 39, 688-696). Here we show this protein localizes to the apical membrane of epithelial cells in proximal and distal regions of larval caeca. The AaeAPN2 protein binds Cry11Aa with high affinity, 8.6 nM. The full-length and fragments of AaeAPN2 were cloned and expressed in Escherichia coli. The toxin-binding region was identified and further competitive assays demonstrated that Cry11Aa binding to BBMV was efficiently competed by the full-length AaeAPN2 and the fragments of AaeAPN2b and AaeAPN2e. In bioassays against Ae. aegypti larvae, the presence of full-length and a partial fragment (AaeAPN2b) of AaeAPN2 enhanced Cry11Aa larval mortality. Taken together, we conclude that AaeAPN2 is a binding protein and plays a role in Cry11Aa toxicity.
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Affiliation(s)
| | | | | | - Sarjeet S. Gill
- Corresponding author: Sarjeet Gill, . Tel: 951-827-4621/3547
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A Spodoptera exigua cadherin serves as a putative receptor for Bacillus thuringiensis Cry1Ca toxin and shows differential enhancement of Cry1Ca and Cry1Ac toxicity. Appl Environ Microbiol 2013; 79:5576-83. [PMID: 23835184 DOI: 10.1128/aem.01519-13] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Crystal toxin Cry1Ca from Bacillus thuringiensis has an insecticidal spectrum encompassing lepidopteran insects that are tolerant to current commercially used B. thuringiensis crops (Bt crops) expressing Cry1A toxins and may be useful as a potential bioinsecticide. The mode of action of Cry1A is fairly well understood. However, whether Cry1Ca interacts with the same receptor proteins as Cry1A remains unproven. In the present paper, we first cloned a cadherin-like gene, SeCad1b, from Spodoptera exigua (relatively susceptible to Cry1Ca). SeCad1b was highly expressed in the larval gut but scarcely detected in fat body, Malpighian tubules, and remaining carcass. Second, we bacterially expressed truncated cadherin rSeCad1bp and its interspecific homologue rHaBtRp from Helicoverpa armigera (more sensitive to Cry1Ac) containing the putative toxin-binding regions. Competitive binding assays showed that both Cry1Ca and Cry1Ac could bind to rSeCad1bp and rHaBtRp, and they did not compete with each other. Third, Cry1Ca ingestion killed larvae and decreased the weight of surviving larvae. Dietary introduction of SeCad1b double-stranded RNA (dsRNA) reduced approximately 80% of the target mRNA and partially alleviated the negative effect of Cry1Ca on larval survival and growth. Lastly, rSeCad1bp and rHaBtRp differentially enhanced the negative effects of Cry1Ca and Cry1Ac on the larval mortalities and growth of S. exigua and H. armigera. Thus, we provide the first lines of evidence to suggest that SeCad1b from S. exigua is a functional receptor of Cry1Ca.
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46
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Contreras E, Schoppmeier M, Real MD, Rausell C. Sodium solute symporter and cadherin proteins act as Bacillus thuringiensis Cry3Ba toxin functional receptors in Tribolium castaneum. J Biol Chem 2013; 288:18013-21. [PMID: 23645668 DOI: 10.1074/jbc.m113.474445] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding how Bacillus thuringiensis (Bt) toxins interact with proteins in the midgut of susceptible coleopteran insects is crucial to fully explain the molecular bases of Bt specificity and insecticidal action. In this work, aminopeptidase N (TcAPN-I), E-cadherin (TcCad1), and sodium solute symporter (TcSSS) have been identified by ligand blot as putative Cry3Ba toxin-binding proteins in Tribolium castaneum (Tc) larvae. RNA interference knockdown of TcCad1 or TcSSS proteins resulted in decreased susceptibility to Cry3Ba toxin, demonstrating the Cry toxin receptor functionality for these proteins. In contrast, TcAPN-I silencing had no effect on Cry3Ba larval toxicity, suggesting that this protein is not relevant in the Cry3Ba toxin mode of action in Tc. Remarkable features of TcSSS protein were the presence of cadherin repeats in its amino acid sequence and that a TcSSS peptide fragment containing a sequence homologous to a binding epitope found in Manduca sexta and Tenebrio molitor Bt cadherin functional receptors enhanced Cry3Ba toxicity. This is the first time that the involvement of a sodium solute symporter protein as a Bt functional receptor has been demonstrated. The role of this novel receptor in Bt toxicity against coleopteran insects together with the lack of receptor functionality of aminopeptidase N proteins might account for some of the differences in toxin specificity between Lepidoptera and Coleoptera insect orders.
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Affiliation(s)
- Estefanía Contreras
- Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot 46100, Valencia, Spain
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47
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Zúñiga-Navarrete F, Gómez I, Peña G, Bravo A, Soberón M. A Tenebrio molitor GPI-anchored alkaline phosphatase is involved in binding of Bacillus thuringiensis Cry3Aa to brush border membrane vesicles. Peptides 2013; 41:81-6. [PMID: 22743140 DOI: 10.1016/j.peptides.2012.05.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 05/23/2012] [Accepted: 05/30/2012] [Indexed: 01/02/2023]
Abstract
Bacillus thuringiensis Cry toxins recognizes their target cells in part by the binding to glycosyl-phosphatidyl-inositol (GPI) anchored proteins such as aminopeptidase-N (APN) or alkaline phosphatases (ALP). Treatment of Tenebrio molitor brush border membrane vesicles (BBMV) with phospholipase C that cleaves out GPI-anchored proteins from the membranes, showed that GPI-anchored proteins are involved in binding of Cry3Aa toxin to BBMV. A 68 kDa GPI-anchored ALP was shown to bind Cry3Aa by toxin overlay assays. The 68 kDa GPI-anchored ALP was preferentially expressed in early instar larvae in comparison to late instar larvae. Our work shows for the first time that GPI-anchored ALP is important for Cry3Aa binding to T. molitor BBMV suggesting that the mode of action of Cry toxins is conserved in different insect orders.
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Affiliation(s)
- Fernando Zúñiga-Navarrete
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62250, Morelos, Mexico
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48
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Hua G, Zhang Q, Zhang R, Abdullah AM, Linser PJ, Adang MJ. AgCad2 cadherin in Anopheles gambiae larvae is a putative receptor of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:153-161. [PMID: 23231770 DOI: 10.1016/j.ibmb.2012.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/22/2012] [Accepted: 11/30/2012] [Indexed: 06/01/2023]
Abstract
In an effort to study the mode of action of Cry11Ba, we identified toxin binding proteins in Anopheles gambiae larval midgut and investigated their receptor roles. Previously, an aminopeptidase (AgAPN2) and an alkaline phosphatase (AgALP1) were identified as receptors for Cry11Ba toxin in A. gambiae. However, an A. gambiae cadherin (AgCad1) that bound Cry11Ba with low affinity (K(d) = 766 nM) did not support a receptor role of AgCad1 for Cry11Ba. Here, we studied a second A. gambiae cadherin (AgCad2) that shares 14% identity to AgCad1. Immunohistochemical study showed that the protein is localized on A. gambiae larval midgut apical membranes. Its cDNA was cloned and the protein was analyzed as a transmembrane protein containing 14 cadherin repeats. An Escherichia coli expressed CR14MPED fragment of AgCad2 bound Cry11Ba with high affinity (K(d) = 11.8 nM), blocked Cry11Ba binding to A. gambiae brush border vesicles and reduced Cry11Ba toxicity in bioassays. Its binding to Cry11Ba could be completely competed off by AgCad1, but only partially competed by AgALP1. The results are evidence that AgCad2 may function as a receptor for Cry11Ba in A. gambiae larvae.
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Affiliation(s)
- Gang Hua
- Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA
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49
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Bayyareddy K, Zhu X, Orlando R, Adang MJ. Proteome analysis of Cry4Ba toxin-interacting Aedes aegypti lipid rafts using geLC-MS/MS. J Proteome Res 2012; 11:5843-55. [PMID: 23153095 DOI: 10.1021/pr3006167] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Lipid rafts are microdomains in the plasma membrane of eukaryotic cells. Among their many functions, lipid rafts are involved in cell toxicity caused by pore forming bacterial toxins including Bacillus thuringiensis (Bt) Cry toxins. We isolated lipid rafts from brush border membrane vesicles (BBMV) of Aedes aegypti larvae as a detergent resistant membrane (DRM) fraction on density gradients. Cholesterol, aminopeptidase (APN), alkaline phosphatase (ALP) and the raft marker flotillin were preferentially partitioned into the lipid raft fraction. When mosquitocidal Cry4Ba toxin was preincubated with BBMV, Cry4Ba localized to lipid rafts. A proteomic approach based on one-dimensional gel electrophoresis, in-gel trypsin digestion, followed by liquid chromatography-mass spectrometry (geLC-MS/MS) identified a total of 386 proteins. Of which many are typical lipid raft marker proteins including flotillins and glycosylphosphatidylinositol (GPI)-anchored proteins. Identified raft proteins were annotated in silico for functional and physicochemical characteristics. Parameters such as distribution of isoelectric point, molecular mass, and predicted post-translational modifications relevant to lipid raft proteins (GPI anchorage and myristoylation or palmitoylation) were analyzed for identified proteins in the DRM fraction. From a functional point of view, this study identified proteins implicated in Cry toxin interactions as well as membrane-associated proteins expressed in the mosquito midgut that have potential relevance to mosquito biology and vector management.
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Affiliation(s)
- Krishnareddy Bayyareddy
- Department of Entomology, Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, United States
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50
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Jiménez AI, Reyes EZ, Cancino-Rodezno A, Bedoya-Pérez LP, Caballero-Flores GG, Muriel-Millan LF, Likitvivatanavong S, Gill SS, Bravo A, Soberón M. Aedes aegypti alkaline phosphatase ALP1 is a functional receptor of Bacillus thuringiensis Cry4Ba and Cry11Aa toxins. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:683-9. [PMID: 22728570 PMCID: PMC3416946 DOI: 10.1016/j.ibmb.2012.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 05/26/2023]
Abstract
Bacillus thuringiensis subs. israelensis produces at least three Cry toxins (Cry4Aa, Cry4Ba, and Cry11Aa) that are active against Aedes aegypti larvae. Previous work characterized a GPI-anchored alkaline phosphatase (ALP1) as a Cry11Aa binding molecule from the gut of A. aegypti larvae. We show here that Cry4Ba binds ALP1, and that the binding and toxicity of Cry4Ba mutants located in loop 2 of domain II is correlated. Also, we analyzed the contribution of ALP1 toward the toxicity of Cry4Ba and Cry11Aa toxins by silencing the expression of this protein though RNAi. Efficient silencing of ALP1 was demonstrated by real-time quantitative PCR (qPCR) and Western blot. ALP1 silenced larvae showed tolerance to both Cry4Ba and Cry11Aa although the silenced larvae were more tolerant to Cry11Aa in comparison to Cry4Ba. Our results demonstrate that ALP1 is a functional receptor that plays an important role in the toxicity of the Cry4Ba and Cry11Aa proteins.
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Affiliation(s)
- Alan I. Jiménez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Esmeralda Z. Reyes
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Angeles Cancino-Rodezno
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Leidy P. Bedoya-Pérez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Gustavo G. Caballero-Flores
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Luis F. Muriel-Millan
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | | | - Sarjeet S. Gill
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92506
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico
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