An ADAM metalloprotease is a Cry3Aa Bacillus thuringiensis toxin receptor

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• 作者：Camila Ochoa-Campuzano ; M. Dolores Real ; Amparo C. Martí ; nez-Ramí ; rez ; Alej ; ra Bravo ; Carolina Rausell
• 关键词：Cry3A ; ADAM ; Metalloprotease ; Bacillus thuringiensis ; Colorado potato beetle ; Receptor ; Insecticidal toxin
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2007
• 期刊代码：159_0006291x
• 类别：bio
• 出版时间：19 October 2007
• 卷：362
• 期：2
• 页码：437-442
• 文件大小：623 K

摘要

Bacillus thuringiensis insecticidal proteins toxic action relies on the interaction with receptor molecules on insect midgut target cells. Here, we describe an ADAM metalloprotease as a novel type of B. thuringiensis toxin receptor on the basis of the following data: (i) by ligand blot and N-terminal analysis, we detected a Colorado potato beetle Cry3Aa toxin binding molecule that shares homology with an ADAM10 metalloprotease; (ii) Colorado potato beetle brush border membrane vesicles display ADAM activity since it cleaves an ADAM fluorogenic substrate; (iii) Cry3Aa acts as a competitor of the cleavage of the ADAM fluorogenic substrate; (iv) Cry3Aa sequence contains the recognition motif R₃₄₅FQPGYYGND₃₅₄ present in ADAM10 substrates. Accordingly, a peptide representative of the recognition motif localized within loop 1 of Cry3Aa domain II (Ac-F₃₄₁HTRFQPGYYGNDSFN₃₅₈-NH₂) effectively prevented Cry3Aa proteolytic processing and nearly abolished pore formation, evidencing the functional significance of the Cry3Aa–ADAM interaction in relation to this toxin mode of action.