Domain II Loop 3 of Bacillus thuringiensis Cry1Ab Toxin Is Involved in a "Ping Pong" Binding Mechanism with Manduca sexta Aminopeptidase-N and Cadherin Receptors
Por:
Pacheco S., Gómez I., Arenas I., Saab-Rincon G., Rodríguez-Almazán C., Gill S.S., Bravo A., Soberón M.
Publicada:
20 nov 2009
Resumen:
Bacillus thuringiensis Cry toxins are used worldwide as insecticides in agriculture, in forestry, and in the control of disease transmission vectors. In the lepidopteran Manduca sexta, cadherin (Bt-R(1)) and aminopeptidase-N (APN) function as Cry1A toxin receptors. The interaction with Bt-R(1) promotes cleavage of the amino-terminal end, including helix alpha-1 and formation of prepore oligomer that binds to APN, leading to membrane insertion and pore formation. Loops of domain II of Cry1Ab toxin are involved in receptor interaction. Here we show that Cry1Ab mutants located in domain II loop 3 are affected in binding to both receptors and toxicity against Manduca sexta larvae. Interaction with both receptors depends on the oligomeric state of the toxin. Monomers of loop 3 mutants were affected in binding to APN and to a cadherin fragment corresponding to cadherin repeat 12 but not with a fragment comprising cadherin repeats 7-12. In contrast, the oligomers of loop 3 mutants were affect
Filiaciones:
Pacheco S.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Gómez I.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Arenas I.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Saab-Rincon G.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Rodríguez-Almazán 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
Bravo A.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Soberón M.:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico
Bronze
|