title: Cytotoxic activity of Bacillus thuringiensis Cry proteins on mammalian cells transfected with cadherin-like Cry receptor gene of Bombyx mori (silkworm).
abstract: Cry1Aa, an insecticidal protein produced by Bacillus thuringiensis, has been shown to bind to cadherin-like protein, BtR175, in Bombyx mori (silkworm) midgut. We previously reported three variant alleles of BtR175 (BtR175a, b and c). When transiently expressed in COS7 cells, all the three BtR175 variants bound to Cry1Aa. We stably expressed BtR175b in HEK293 cells. These BtR175b-expressing cells swelled and died in the presence of activated Cry1Aa in a dose- and time-dependent manner, showing that BtR175b itself can impart Cry1Aa-susceptibility to mammalian cells. These cells were more susceptible to Cry1Aa than to Cry1Ab and Cry1Ac. Since dispersed B. mori midgut cells were reported to be highly susceptible to Cry1Ac, this result suggested that other Cry1Ac-specific receptor(s) were simultaneously working with BtR175 in the midgut cells. Advantages are also discussed of applying these transfected mammalian cells to toxicity assays of mutant Cry proteins.
authors.affiliation: Laboratory of Applied Molecular Biology, Division of Applied Biochemistry, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka, 599-8531, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tsuda
authors.forename: Fumiki
authors.initials: F
authors.lastname: Nakatani
authors.forename: Keiko
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikawa
authors.forename: Chikako
authors.initials: C
authors.lastname: Matsuura
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukada
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Michio
authors.initials: M
authors.lastname: Himeno
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism / Q000494:pharmacology*; D001427:Bacterial Toxins; D012831:Bombyx / Q000235:genetics*; D002478:Cells, Cultured / Q000187:drug effects; D004731:Endotoxins / Q000378:metabolism / Q000494:pharmacology*; D006460:Hemolysin Proteins; D006801:Humans; D008322:Mammals; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D020033:Protein Isoforms; D018675:Toxicity Tests; D014162:Transfection
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C400621:BtR175 protein, Bacillus thuringiensis; D004731:Endotoxins; D006460:Hemolysin Proteins; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; C030956:insecticidal crystal protein, Bacillus Thuringiensis