title: Possible Insecticidal Mechanisms Mediated by Immune-Response-Related Cry-Binding Proteins in the Midgut Juice of Plutella xylostella and Spodoptera exigua.
abstract: Cry toxins are insecticidal toxin proteins produced by a spore-forming Gram-positive bacterium Bacillus thuringiensis. Interactions between the Cry toxins and the receptors from midgut brush border membrane vesicles (BBMVs), such as cadherin, alkaline phosphatase, and aminopeptidase, are key steps for the specificity and insecticidal activity of Cry proteins. However, little is known about the midgut juice proteins that may interfere with Cry binding to the receptors. To validate the hypothesis that there exist Cry-binding proteins that can interfere with the insecticidal process of Cry toxins, we applied Cry1Ab1-coupled Sepharose beads to isolate Cry-binding proteins form midgut juice of Plutella xylostella and Spodoptera exigua. Trypsin-like serine proteases and Dorsal were found to be Cry1Ab1-binding proteins in the midgut juice of P. xylostella. Peroxidase-C (POX-C) was found to be the Cry1Ab1-binding protein in the midgut juice of S. exigua. We proposed possible insecticidal mechanisms of Cry1Ab1 mediated by the two immune-related proteins: Dorsal and POX-C. Our results suggested that there exist, in the midgut juice, Cry-binding proteins, which are different from BBMV-specific receptors.
authors.affiliation: Fujian Provincial Key Laboratory of Biochemical Technology, Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University , Xiamen, Fujian 361021, People's Republic of China.
authors.forename: Keyu
authors.identifier: http://orcid.org/0000-0002-1909-3740
authors.initials: K
authors.lastname: Lu
authors.affiliation: Fujian Provincial Key Laboratory of Biochemical Technology, Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University , Xiamen, Fujian 361021, People's Republic of China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Fujian Provincial Key Laboratory of Biochemical Technology, Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University , Xiamen, Fujian 361021, People's Republic of China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Liu
authors.affiliation: Fujian Provincial Key Laboratory of Biochemical Technology, Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University , Xiamen, Fujian 361021, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City , Kansas City, Missouri 64110, United States.
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Yu
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism* / Q000494:pharmacology; D004731:Endotoxins / Q000378:metabolism* / Q000494:pharmacology; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000378:metabolism; D006460:Hemolysin Proteins / Q000378:metabolism* / Q000494:pharmacology; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism* / Q000494:pharmacology; D009036:Moths / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018411:Spodoptera / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Bacillus thuringiensis; Cry-binding proteins; Plutella xylostella; Spodoptera exigua; immune responses; midgut juice