Enhanced exocytosis of the receptor BT-R1 induced by the Cry1Ab toxin of Bacillus thuringiensis directly correlates to the execution of cell death

Zhang, Xuebin; Griko, Natalya B.; Corona, Susan K.; Bulla, Lee A.

doi:10.1016/j.cbpb.2007.12.006

Cited by 36 publications

(22 citation statements)

References 23 publications

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“…Toxicity occurs after Bt-endotoxins are ingested, solubilized in the alkaline midgut, and then proteolytically cleaved to release the active endotoxin (Haider et al, 1986;Jaquet et al, 1987;Broderick et al, 2006). Once cleaved, the endotoxin binds to receptors on the midgut brush-border membrane vesicles (BBMV) (Hoffman et al, 1988;Zhang et al, 2005;Wang et al, 2007), which results in pore formation (Rausell et al, 2004), midgut paralysis (Gill et al, 1992;Pigott and Ellar, 2007), and cell death (Zhang et al, 2008). This midgut damage is thought to create a point of entry for enteric bacteria or B. thuringiensis to invade the hemocoel (Broderick et al, 2006).…”

Section: Introductionmentioning

confidence: 98%

Is decreased generalized immunity a cost of Bt resistance in cabbage loopers Trichoplusia ni?

Ericsson

Janmaat

Lowenberger

et al. 2009

Journal of Invertebrate Pathology

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Section: Introductionmentioning

confidence: 98%

Is decreased generalized immunity a cost of Bt resistance in cabbage loopers Trichoplusia ni?

Ericsson

Janmaat

Lowenberger

et al. 2009

Journal of Invertebrate Pathology

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“…The most extensively studied insecticidal Bt proteins are Cry-3D toxins and although their mode of action is not completely understood, it is generally accepted that involves toxin solubilization in the midgut of the susceptible larvae, membrane receptor binding and oligomerization of the toxin followed by pore formation in the brush border membrane [8]. Potential evidence for cell-death signalling pathways in insects as a result of Bt toxins activity has also been reported [9], [10]. However, the present knowledge about toxin-induced cellular phenomena lags behind our understanding of the physiological process of Bt intoxication.…”

Section: Introductionmentioning

confidence: 99%

Proteome Response of Tribolium castaneum Larvae to Bacillus thuringiensis Toxin Producing Strains

2013

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Susceptibility of Tribolium castaneum (Tc) larvae was determined against spore-crystal mixtures of five coleopteran specific and one lepidopteran specific Bacillus thuringiensis Cry toxin producing strains and those containing the structurally unrelated Cry3Ba and Cry23Aa/Cry37Aa proteins were found toxic (LC50 values 13.53 and 6.30 µg spore-crystal mixture/µL flour disc, respectively). Using iTRAQ combined with LC-MS/MS allowed the discovery of seven novel differentially expressed proteins in early response of Tc larvae to the two active spore-crystal mixtures. Proteins showing a statistically significant change in treated larvae compared to non-intoxicated larvae fell into two major categories; up-regulated proteins were involved in host defense (odorant binding protein C12, apolipophorin-III and chemosensory protein 18) and down-regulated proteins were linked to metabolic pathways affecting larval metabolism and development (pyruvate dehydrogenase Eα subunit, cuticular protein, ribosomal protein L13a and apolipoprotein LI-II). Among increased proteins, Odorant binding protein C12 showed the highest change, 4-fold increase in both toxin treatments. The protein displayed amino acid sequence and structural homology to Tenebrio molitor 12 kDa hemolymph protein b precursor, a non-olfactory odorant binding protein. Analysis of mRNA expression and mortality assays in Odorant binding protein C12 silenced larvae were consistent with a general immune defense function of non-olfactory odorant binding proteins. Regarding down-regulated proteins, at the transcriptional level, pyruvate dehydrogenase and cuticular genes were decreased in Tc larvae exposed to the Cry3Ba producing strain compared to the Cry23Aa/Cry37Aa producing strain, which may contribute to the developmental arrest that we observed with larvae fed the Cry3Ba producing strain. Results demonstrated a distinct host transcriptional regulation depending upon the Cry toxin treatment. Knowledge on how insects respond to Bt intoxication will allow designing more effective management strategies for pest control.

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“…Cry toxins fed on by insects are digested into smaller active molecules (Gill et al 1992), and these active molecules bind to receptors (cadherin-like protein or aminopeptides N-or alkaline phosphates) located on the brush-border membrane vesicles in the midgut (Gahan et al 2001, Gomez et al 2001, Pigott and Ellar 2007. There are mainly two models of Cry toxin action: formation of a pore in the membrane, resulting in cell osmosis; and induction of cell death, involved an adenylyl cyclase/PKA signaling pathway (Bravo et al 2004;Zhang et al 2005Zhang et al , 2006Zhang et al , 2008. As a bioinsecticide Þrst sprayed in the Þeld in the 1930s, formulations of B. thuringiensis have been widely applied in agricultural insect pest control (Ali et al 2010, Bravo et al 2011.…”

mentioning

confidence: 99%

Susceptibility and Selectivity of <I>Cnaphalocrocis medinalis</I> (Lepidoptera: Pyralidae) to Different Cry Toxins

Yang

Zheng

et al. 2012

jnl. econ. entom.

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Effectiveness of four Cry toxins (Cry1Ac, Cry1Aa, Cry1Ab, and Cry1C) on Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), collected from paddy fields in Jiaxing, Zhejiang Province, China, was evaluated in the laboratory. Bioassays showed that C. medinalis had different susceptibilities against four Cry toxins. The LC50 values of Cry1Ac, Cry1Ab, Cry1Aa, and Cry1C against C. medinalis were 0.405, 1.111, 1.939, and 1.246 microg/ml, respectively. Furthermore, the mortality of C. medinalis against different Cry toxins showed different results over time and LT50 values of Cry1Ac, Cry1Ab, Cry1Aa, and Cry1C against C. medinalis were 1.5, 2.3, 1.6, and 2.2 d, respectively. Preference of the larvae to Cry toxins revealed that C. medinalis larvae had no significant feeding preference on leaves without Bacillus thuringiensis (Bacillales: Bacillaceae; [Bt]) toxin compared with those containing Bt toxin. However, different Cry toxins had different attractive abilities to C. medinalis larvae. During 8 h after infestation, C. medinalis larvae preferred the leaves with Cry1Ab (22.4-27.6%) over those with Cry1Ac or Cry1C.

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Enhanced exocytosis of the receptor BT-R1 induced by the Cry1Ab toxin of Bacillus thuringiensis directly correlates to the execution of cell death

Cited by 36 publications

References 23 publications

Is decreased generalized immunity a cost of Bt resistance in cabbage loopers Trichoplusia ni?

Is decreased generalized immunity a cost of Bt resistance in cabbage loopers Trichoplusia ni?

Proteome Response of Tribolium castaneum Larvae to Bacillus thuringiensis Toxin Producing Strains

Susceptibility and Selectivity of <I>Cnaphalocrocis medinalis</I> (Lepidoptera: Pyralidae) to Different Cry Toxins

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