The Amino- and Carboxyl-Terminal Fragments of the Bacillus thuringensis Cyt1Aa Toxin Have Differential Roles in Toxin Oligomerization and Pore Formation
Por:
Rodriguez-Almazan C., de Escudero, IR, Cantón P.E., Munoz-Garay, C, Pérez C., Gill S.S., Soberón M., Bravo A.
Publicada:
25 ene 2011
Categoría:
Biochemistry
Resumen:
The Cyt toxins produced by the bacteria Bacillus thuringiensis show insecticidal activity against some insects, mainly dipteran larvae, being able to kill mosquitoes and black flies. However, they also possess a general cytolytic activity in vitro, showing hemolytic activity in red blood cells. These proteins are composed of two outer layers of alpha-helix hairpins wrapped around a beta-sheet. With regard to their mode of action, one model proposed that the two outer layers of alpha-helix hairpins swing away from the beta-sheet, allowing insertion of beta-strands into the membrane forming a pore after toxin oligomerization. The other model suggested a detergent-like mechanism of action of the toxin on the surface of the lipid bilayer. In this work, we cloned the N- and C-terminal domains form Cyt1Aa and analyzed their effects on Cyt1Aa toxin action. The N-terminal domain shows a dominant negative phenotype inhibiting the in vitro hemolytic activity of Cyt1Aa in red blood cells and the
Filiaciones:
Rodriguez-Almazan C.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Cantón P.E.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Munoz-Garay, C:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Pérez C.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Gill S.S.:
Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92506, United States
Soberón M.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Bravo A.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
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