Abstract
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 R(345)FQPGYYGND(354) present in ADAM10 substrates. Accordingly, a peptide representative of the recognition motif localized within loop 1 of Cry3Aa domain II (Ac-F(341)HTRFQPGYYGNDSFN(358)-NH(2)) 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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ADAM Proteins / chemistry
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ADAM Proteins / metabolism*
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Amino Acid Sequence
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Animals
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Bacillus thuringiensis Toxins
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Bacterial Proteins / chemistry
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism*
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Bacterial Toxins / chemistry
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Bacterial Toxins / genetics
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Bacterial Toxins / metabolism*
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Binding Sites / genetics
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Carrier Proteins / chemistry
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Carrier Proteins / metabolism
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Cell Membrane / enzymology
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Cell Membrane / metabolism
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Coleoptera
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Electrophoresis, Gel, Two-Dimensional
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Endotoxins / chemistry
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Endotoxins / genetics
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Endotoxins / metabolism*
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Fluorescent Dyes / chemistry
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Fluorescent Dyes / metabolism
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Hemolysin Proteins / chemistry
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Hemolysin Proteins / genetics
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Hemolysin Proteins / metabolism*
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Insect Proteins / chemistry
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Insect Proteins / metabolism
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Microvilli / enzymology
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Microvilli / metabolism
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Models, Molecular
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Molecular Sequence Data
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Oligopeptides / chemistry
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Oligopeptides / metabolism
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Protein Binding
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Protein Structure, Tertiary
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Sequence Analysis, Protein
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Sequence Homology, Amino Acid
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Substrate Specificity
Substances
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Bacillus thuringiensis Toxins
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Bacterial Proteins
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Bacterial Toxins
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Carrier Proteins
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Endotoxins
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Fluorescent Dyes
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Hemolysin Proteins
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Insect Proteins
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Oligopeptides
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insecticidal crystal protein, Bacillus Thuringiensis
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ADAM Proteins