Ligand specificity and affinity of BT-R1, the Bacillus thuringiensis Cry1A toxin receptor from Manduca sexta, expressed in mammalian and insect cell cultures
| Autor: | Timothy P. Keeton, Lee A. Bulla |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
animal structures
Bacterial Toxins Bacillus thuringiensis Gene Expression Heterologous Receptors Cell Surface Spodoptera Ligands Transfection Binding Competitive Applied Microbiology and Biotechnology Cell Line Hemolysin Proteins Bacterial Proteins Manduca Complementary DNA Animals Humans Bacillus thuringiensis Toxins Ecology biology Binding protein fungi biology.organism_classification Ligand (biochemistry) Molecular biology Recombinant Proteins Endotoxins Manduca sexta Cell culture COS Cells Insect Proteins Research Article Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 63:3419-3425 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.63.9.3419-3425.1997 |
| Popis: | The Manduca sexta receptor for the Bacillus thuringiensis Cry1Aa, Cry1Ab, and Cry1Ac toxins, BT-R1, has been expressed in heterologous cell culture, and its ligand binding characteristics have been determined. When transfected with the BT-R1 cDNA, insect and mammalian cell cultures produce a binding protein of approximately 195 kDa, in contrast to natural BT-R1 from M. sexia, which has an apparent molecular weight of 210 kDa. Transfection of cultured Spodoptera frugiperda cells with the BT-R1 cDNA imparts Cry1A-specific high-affinity binding activity typical of membranes prepared from larval M. sexta midguts. Competition assays with BT-R1 prepared from larval M. sexta midguts and transiently expressed in cell culture reveal virtually identical affinities for the Cry1Aa, Cry1Ab, and Cry1Ac toxins, clearly demonstrating the absolute specificity of the receptor for toxins of the lepidopteran-specific Cry1A family. BT-R1 therefore remains the only M. sexta Cry1A binding protein to be purified, cloned, and functionally expressed in heterologous cell culture, and for the first time, we are able to correlate the Cry1Aa, Cry1Ab, and Cry1Ac toxin sensitivities of M. sexta to the identity and ligand binding characteristics of a single midgut receptor molecule. |
| Databáze: | OpenAIRE |
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