title: Bacillus thuringiensis crystal proteins that target nematodes.
abstract: Bacillus thuringiensis (Bt) crystal proteins are pore-forming toxins used as insecticides around the world. Previously, the extent to which these proteins might also target the invertebrate phylum Nematoda has been mostly ignored. We have expressed seven different crystal toxin proteins from two largely unstudied Bt crystal protein subfamilies. By assaying their toxicity on diverse free-living nematode species, we demonstrate that four of these crystal proteins are active against multiple nematode species and that each nematode species tested is susceptible to at least one toxin. We also demonstrate that a rat intestinal nematode is susceptible to some of the nematicidal crystal proteins, indicating these may hold promise in controlling vertebrate-parasitic nematodes. Toxicity in nematodes correlates with damage to the intestine, consistent with the mechanism of crystal toxin action in insects. Structure-function analyses indicate that one novel nematicidal crystal protein can be engineered to a small 43-kDa active core. These data demonstrate that at least two Bt crystal protein subfamilies contain nematicidal toxins.
authors.affiliation: Section of Cell and Developmental Biology, University of California, San Diego, CA 92093-0349, USA.
authors.forename: Jun-Zhi
authors.initials: JZ
authors.lastname: Wei
authors.forename: Kristina
authors.initials: K
authors.lastname: Hale
authors.forename: Lynn
authors.initials: L
authors.lastname: Carta
authors.forename: Edward
authors.initials: E
authors.lastname: Platzer
authors.forename: Cynthie
authors.initials: C
authors.lastname: Wong
authors.forename: Su-Chiung
authors.initials: SC
authors.lastname: Fang
authors.forename: Raffi V
authors.initials: RV
authors.lastname: Aroian
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000494:pharmacology; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000737:chemistry; D017173:Caenorhabditis elegans; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005822:Genetic Vectors; D006460:Hemolysin Proteins; D009154:Mutation; D009348:Nematoda; D009559:Nippostrongylus; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D000969:Antinematodal Agents; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis