title: Membrane binding and oligomer membrane insertion are necessary but insufficient for Bacillus thuringiensis Cyt1Aa toxicity.
abstract: Bacillus thuringiensis Cyt proteins are pore-forming toxins that have insecticidal activity mainly against dipteran insects. However, certain Cyt proteins have toxicity to some insect orders, but not toxicity of Cyt1Aa against lepidopteran larvae has been found. Insect specificity has been proposed to rely in specific binding to certain lipids on the brush border membrane of midgut cells since no protein receptors have been described so far. To determine the molecular basis of Cyt1Aa insect specificity we compared different steps of Cyt1Aa mode of action in a susceptible insect as the dipteran Aedes aegypti and also in the non-susceptible lepidopteran Manduca sexta. Our data shows that the lack toxicity of Cyt1Aa to M. sexta larvae does not rely on protoxin processing, membrane binding interaction, and oligomerization of Cyt1Aa since these steps were similar in the two insect species analyzed.
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico. Electronic address: emiliano@ibt.unam.mx.
authors: Pablo Emiliano
authors: PE
authors: Cantón
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico. Electronic address: jazald@ibt.unam.mx.
authors: Jazmin A
authors: JA
authors: López-Díaz
authors: Department of Cell biology and Neuroscience, University of California, Riverside, CA 92521, United States. Electronic address: sarjeet.gill@ucr.edu.
authors: Sarjeet S
authors: SS
authors: Gill
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico. Electronic address: bravo@ibt.unam.mx.
authors: Alejandra
authors: A
authors: Bravo
authors: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico. Electronic address: mario@ibt.unam.mx.
authors: Mario
authors: M
authors: Soberón
mesh_terms: D000330:Aedes / Q000378:metabolism; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism*; D004731:Endotoxins / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D018402:Manduca / Q000378:metabolism; D008871:Microvilli / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D010447:Peptide Hydrolases
keywords: Bacillus thuringiensis; Cyt toxins; Membrane binding; Mode of action; Oligomerization