title: Bacillus thuringiensis Cry3Aa fused to a cellulase-binding peptide shows increased toxicity against the longhorned beetle.
abstract: Cry3 class toxins are used extensively for biological control of coleopteran larvae. We previously identified a peptide (PCx) from a phage display library that specifically binds Cx-cellulase from the midgut of Anoplophora glabripennis Motschulsky (Asian longhorn beetle) larvae. Here, we added a DNA fragment that encodes the peptide onto either end of the cry3Aa gene and tested the expressed PCx-Cry3Aa and Cry3Aa-PCx proteins for insecticidal activity in the longhorned beetle. An insect bioassay revealed that, compared with native Cry3Aa, the two modified Cry3Aa proteins had significantly higher lethality, with PCx-Cry3Aa exhibiting a mortality rate almost three times that of Cry3Aa. We also proposed that the increased lethality in larvae fed with PCx-Cry3Aa or Cry3Aa-PCx would be attributable to the binding of the toxin with Cx-cellulase, thereby increasing toxin retention in the midgut. The significantly enhanced insecticidal activity of Cry3Aa fused with the Cx-cellulase binding peptide provides a new strategy for increasing toxin efficacy against the longhorned beetle. These uniquely modified Cry3Aa proteins have potential use for pest control.
authors.affiliation: International Centre for Bamboo and Rattan, Beijing 100102, People's Republic of China.
authors.forename: Chang-Hua
authors.initials: CH
authors.lastname: Guo
authors.forename: Shu-Tang
authors.initials: ST
authors.lastname: Zhao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Hu
authors.forename: Xiao-Jiao
authors.initials: XJ
authors.lastname: Han
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Meng-Zhu
authors.initials: MZ
authors.lastname: Lu
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D002480:Cellulase / Q000378:metabolism*; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development; D004064:Digestive System / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D010455:Peptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D010572:Pest Control, Biological / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D002480:Cellulase