The cadherin-like protein is essential to specificity determination and cytotoxic action of the Bacillus thuringiensis insecticidal CryIAa toxin.
The Bacillus thuringiensis CryIAa toxin binds a cadherin-like protein (BtR175) on the brush-border membranes of the Bombyx mori midgut columnar cells, which are the targets. By introducing the BtR175 gene with a baculovirus, Spodoptera frugiperda Sf9 cells expressed BtR175 protein on the cell membrane and became susceptible to the CryIAa toxin. The toxin bound the cadherin repeat adjacent to the membrane and made a pore that passed inorganic ions, causing the cell to swell and burst. This was not observed with a BtR175 variant lacking the toxin-binding site. This in vitro experiment mimicked the specific insecticidal action of the toxin in vivo well.
Nagamatsu
Y
Y
Department of Applied Biochemistry, Faculty of Applied Biological Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Japan. nagamats@ipc.hiroshima-u.ac.jp
Koike
T
T
Sasaki
K
K
Yoshimoto
A
A
Furukawa
Y
Y
D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism* / Q000502:physiology; D001427:Bacterial Toxins / Q000378:metabolism; D016367:Baculoviridae / Q000378:metabolism; D015820:Cadherins / Q000502:physiology*; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004594:Electrophysiology; D004731:Endotoxins / Q000378:metabolism* / Q000502:physiology; D005786:Gene Expression Regulation; D006460:Hemolysin Proteins; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000502:physiology*; D008957:Models, Genetic; D009995:Osmosis; D013997:Time Factors
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C400621:BtR175 protein, Bacillus thuringiensis; D015820:Cadherins; D018076:DNA, Complementary; D004731:Endotoxins; D006460:Hemolysin Proteins; D008562:Membrane Glycoproteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis