Applied and Environmental Microbiology (2011) 77, 24-31

Supaporn Likitvivatanavong, Jianwu Chen, Alejandra Bravo, Mario Soberón and Sarjeet S. Gill (2011)
Cadherin, alkaline phosphatase, and aminopeptidase N as receptors of Cry11Ba toxin from Bacillus thuringiensis subsp. jegathesan in Aedes aegypti
Applied and Environmental Microbiology 77 (1), 24-31
Abstract: Cry11Ba is one of the most toxic proteins to mosquito larvae produced by Bacillus thuringiensis. It binds Aedes aegypti brush border membrane vesicles (BBMV) with high affinity, showing an apparent dissociation constant (K_d) of 8.2 nM. We previously reported that an anticadherin antibody competes with Cry11Ba binding to BBMV, suggesting a possible role of cadherin as a toxin receptor. Here we provide evidence of specific cadherin repeat regions involved in this interaction. Using cadherin fragments as competitors, a C-terminal fragment which contains cadherin repeat 7 (CR7) to CR11 competed with Cry11Ba binding to BBMV. This binding was also efficiently competed by the CR9, CR10, and CR11 peptide fragments. Moreover, we show CR11 to be an important region of interaction with Cry11Ba toxin. An alkaline phosphatase (AaeALP1) and an aminopeptidase-N (AaeAPN1) also competed with Cry11Ba binding to Ae. aegypti BBMV. Finally, we found that Cry11Ba and Cry4Ba share binding sites. Synthetic peptides corresponding to loops alpha-8, ß2-ß3 (loop 1), ß8-ß9, and ß10-ß11 (loop 3) of Cry4Ba compete with Cry11Ba binding to BBMV, suggesting Cry11Ba and Cry4Ba have common sites involved in binding Ae. aegypti BBMV. The data suggest that three different Ae. aegypti midgut proteins, i.e., cadherin, AaeALP1, and AaeAPN1, are involved in Cry11Ba binding to Ae. aegypti midgut brush border membranes.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Alejandra Bravo

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aedes aegypti
Bacillus thuringiensis var. jegathesan (entomopathogen)	Aedes aegypti
Bacillus thuringiensis Cry11B-toxin (entomopathogen)	Aedes aegypti