title: Bacillus thuringiensis crystal proteins CRY1Ab and CRY1Fa share a high affinity binding site in Plutella xylostella (L.).
abstract: The future success of Bacillus thuringiensis based insecticides depends in part on our ability to prevent insects from developing resistance against their insecticidal crystal proteins. Two recent papers indicated cross-resistance between Cry1A proteins and Cry1Fa in two different insect species (Tabashnik et al., 1994, Appl. Environ. Microbiol. 60, 4627-4629; Gould et al., 1995, J. Econ. Entomol. 88, 1545-1559). Brush border membrane vesicles were prepared from Plutella xylostella and used in binding assays with 125I-labeled trypsin-activated crystal proteins. Competition experiments showed that Cry1Fa competed with Cry1Ab for a same binding site, though the latter still bound to a different minor binding site with apparently the same affinity. Cry1Ca did not compete for Cry1Ab binding sites nor Cry1Fa for Cry1Ca binding sites. Based on these results, a modification of the receptor shared by Cry1Ab and Cry1Fa might confer multiple resistance to Cry1A and Cry1Fa proteins.
authors.affiliation: Departament de Genètica, Facultad de Ciències Biològiques, Universitat de València, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Granero
authors.forename: V
authors.initials: V
authors.lastname: Ballester
authors.forename: J
authors.initials: J
authors.lastname: Ferré
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D004731:Endotoxins / Q000378:metabolism*; D006460:Hemolysin Proteins; D007457:Iodine Radioisotopes; D009036:Moths / Q000378:metabolism*; D010572:Pest Control, Biological
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007457:Iodine Radioisotopes; C030956:insecticidal crystal protein, Bacillus Thuringiensis