title: Cry4Ba and Cyt1Aa proteins from Bacillus thuringiensis israelensis: Interactions and toxicity mechanism against Aedes aegypti.
abstract: Individual crystal proteins from Bacillus thuringiensis israelensis exhibit variable levels of insecticidal activities against mosquito larvae. In all cases, they are much less active compared to the whole crystal proteins due to described complex synergistic interactions among them. In the present study we investigated the effects of Cyt1A98 (a Cyt1Aa type protein) on Cry4BLB (a Cry4Ba type toxin) insecticidal activity toward the dengue vector Aedes aegypti. The bioassay analyses demonstrated the ability of Cyt1A98 protein to enhance Cry4BLB toxin larvicidal activity even at a low proportion in the mixture (1%). In vitro interaction assays showed that Cyt1A98 provides supplementary binding sites for Cry4BLB in A. aegypti BBMVs. Moreover, it enhances the formation of Cry4BLB oligomeric structure. These results support that Cyt1A98 protein could act as a membrane-bound receptor fixing Cry4BLB δ-endotoxins and promoting its oligomerization.
authors.affiliation: Biopesticides Team [L.P.I.P.], Center of Biotechnology of Sfax, University of Sfax, P.O. Box 1177, 3018 Sfax, Tunisia.
authors.forename: Jihen
authors.initials: J
authors.lastname: Elleuch
authors.affiliation: Department of Biological & Environmental Sciences, Qatar University, P.O. Box 2713, Doha, Qatar.
authors.forename: Samir
authors.initials: S
authors.lastname: Jaoua
authors.affiliation: Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1-UM2-CNRS 5290-IRD 224), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Laboratoire de Lutte contre les Insectes Nuisibles (LIN), Montpellier, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Darriet
authors.affiliation: Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1-UM2-CNRS 5290-IRD 224), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Laboratoire de Lutte contre les Insectes Nuisibles (LIN), Montpellier, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chandre
authors.affiliation: Biopesticides Team [L.P.I.P.], Center of Biotechnology of Sfax, University of Sfax, P.O. Box 1177, 3018 Sfax, Tunisia.
authors.forename: Slim
authors.initials: S
authors.lastname: Tounsi
authors.affiliation: Biopesticides Team [L.P.I.P.], Center of Biotechnology of Sfax, University of Sfax, P.O. Box 1177, 3018 Sfax, Tunisia. Electronic address: raida_zz@yahoo.fr.
authors.forename: Raida Zribi
authors.initials: RZ
authors.lastname: Zghal
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000494:pharmacology*; D001681:Biological Assay; D004357:Drug Synergism; D004731:Endotoxins / Q000737:chemistry / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000737:chemistry / Q000494:pharmacology*; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology; D007814:Larva / Q000187:drug effects; D008871:Microvilli / Q000187:drug effects
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Aedes aegypti; Bacillus thuringiensis israelensis; Cry4BLB toxin; Cytolytic protein Cyt1A98; Synergism