Publication Date:
2007-11-03
Description:
The evolution of insect resistance threatens the effectiveness of Bacillus thuringiensis (Bt) toxins that are widely used in sprays and transgenic crops. Resistance to Bt toxins in some insects is linked with mutations that disrupt a toxin-binding cadherin protein. We show that susceptibility to the Bt toxin Cry1Ab was reduced by cadherin gene silencing with RNA interference in Manduca sexta, confirming cadherin's role in Bt toxicity. Native Cry1A toxins required cadherin to form oligomers, but modified Cry1A toxins lacking one alpha-helix did not. The modified toxins killed cadherin-silenced M. sexta and Bt-resistant Pectinophora gossypiella that had cadherin deletion mutations. Our findings suggest that cadherin promotes Bt toxicity by facilitating toxin oligomerization and demonstrate that the modified Bt toxins may be useful against pests resistant to standard Bt toxins.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Soberon, Mario -- Pardo-Lopez, Liliana -- Lopez, Idalia -- Gomez, Isabel -- Tabashnik, Bruce E -- Bravo, Alejandra -- 1R01 AI066014/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 2007 Dec 7;318(5856):1640-2. Epub 2007 Nov 1.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Apartado Postal 510-3, Cuernavaca 62250, Morelos, Mexico. mario@ibt.unam.mx〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17975031" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Bacterial Proteins/chemistry/*genetics/metabolism/*toxicity
;
Bacterial Toxins/chemistry/*genetics/metabolism/*toxicity
;
Cadherins/genetics/metabolism
;
Endotoxins/chemistry/*genetics/metabolism/*toxicity
;
Genetic Engineering
;
Hemolysin Proteins/chemistry/*genetics/metabolism/*toxicity
;
*Insecticide Resistance
;
Larva
;
*Manduca/genetics/metabolism
;
*Moths/genetics/metabolism
;
Mutation
;
*Pest Control, Biological
;
RNA Interference
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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