Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepidopteran cadherin B. thuringiensis receptors. A peptide containing the putative toxin binding region from TmCad1 bound specifically to Cry3Aa and promoted the formation of Cry3Aa toxin oligomers, proposed to be mediators of toxicity in lepidopterans. Injection of TmCad1-specific double-stranded RNA into T. molitor larvae resulted in knockdown of the TmCad1 transcript and conferred resistance to Cry3Aa toxicity. These data demonstrate the functional role of TmCad1 as a Cry3Aa receptor in T. molitor and reveal similarities between the mode of action of Cry toxins in Lepidoptera and Coleoptera.
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http://dx.doi.org/10.1074/jbc.M109.001651 | DOI Listing |
ACS Appl Mater Interfaces
September 2024
School of Life Sciences and Center of Novel Biomaterials, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China.
Anal Biochem
October 2024
Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China. Electronic address:
Using the amino acid sequences and analysis of selected known structures of Bt Cry toxins, Cry1Ab, Cry1Ac, Cry1Ah, Cry1B, Cry1C and Cry1F we specifically designed immunogens. After antibodies selection, broad-spectrum polyclonal antibodies (pAbs) and monoclonal antibody (namely 1A0-mAb) were obtained from rabbit and mouse, respectively. The produced pAbs displayed broad spectrum activity by recognizing Cry1 toxin, Cry2Aa, Cry2Ab and Cry3Aa with half maximal inhibitory concentration (IC) values of 0.
View Article and Find Full Text PDFBiomolecules
April 2024
Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei 184-8588, Tokyo, Japan.
By 2013, it had been shown that the genes cadherin-like receptor (Cad) and ATP-binding cassette transporter subfamily C2 (ABCC2) were responsible for insect resistance to several Cry1A toxins, acting as susceptibility-determining receptors, and many review articles have been published. Therefore, this review focuses on information about receptors and receptor-binding sites that have been revealed since 2014. Since 2014, studies have revealed that the receptors involved in determining susceptibility vary depending on the Cry toxin subfamily, and that binding affinity between Cry toxins and receptors plays a crucial role.
View Article and Find Full Text PDFFront Cell Infect Microbiol
March 2024
College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China.
Pine wood nematode disease is currently the most deadly forest disease in China, and the is its primary vector. Controlling the is crucial for managing pine wood nematode disease. This study, based on the selected HasA (pGHKW4) secretory expression vector, used electroporation to combine the genetically modified high-toxicity toxin Cry3Aa-T with the entomopathogenic bacterium isolated from the gut of the .
View Article and Find Full Text PDFPLoS One
December 2023
Biology Department, Faculty of Agrarian and Veterinary Sciences (Jaboticabal Campus), São Paulo State University (UNESP), São Paulo, Brazil.
Cotton crop yields are largely affected by infestations of Anthonomus grandis, which is its main pest. Although Bacillus thuringiensis (Bt) derived proteins can limit insect pest infestations, the diverse use of control methods becomes a viable alternative in order to prolong the use of technology in the field. One of the alternative methods to Bt technology has been the utilization of certain Pseudomonas species highly efficient in controlling coleopteran insects have been used to produce highly toxic insecticidal proteins.
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