Mode of action of mosquitocidal Bacillus thuringiensis toxins.
Cry toxins from Bacillus thuringiensis (Bt) are used for insect control. Their primary action is to lyse midgut epithelial cells. In lepidopteran insects, Cry1A monomeric toxins interact with a first receptor and this interaction triggers toxin oligomerization. The oligomeric structure interacts then with a second GPI-anchored receptor that induces insertion into membrane microdomains and larvae death. In the case of mosquitocidal Bt strains, two different toxins participate, Cry and Cyt. These toxins have a synergistic effect and Cyt1Aa overcomes Cry toxin-resistance. We will summarize recent findings on the identification of Cry receptors in mosquitoes and the mechanism of synergism: Cyt1Aa synergizes or suppresses resistance to Cry toxins by functioning as a Cry membrane-bound receptor.
Soberón
Mario
M
Departamento de Microbiologia Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. postal 510-3, Cuernavaca 62250, Morelos, Mexico.
Fernández
Luisa E
LE
Pérez
Claudia
C
Gill
Sarjeet S
SS
Bravo
Alejandra
A
D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry* / Q000633:toxicity*; D009033:Culicidae / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000187:drug effects; D008954:Models, Biological; D008958:Models, Molecular
D001427:Bacterial Toxins