Proteolytic processing of δ-endotoxin of Bacillus thuringiensis var. kurstaki HD-1 in insensitive insect, Spodoptera litura: Unusual proteolysis in the presence of sodium dodecyl sulfate

Inagaki, Soichi; Miyasono, Minoru; Ishiguro, Takeo; Takeda, Reiji; Hayashi, Yoshiyuki

doi:10.1016/0022-2011(92)90155-w

Cited by 25 publications

(19 citation statements)

References 14 publications

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“…It has been reported that variations in gut protease expression patterns have severe consequences on the appearance of insect resistance to Cry toxins either because of a lower protoxin activation or a complete toxin degradation (Inagaki et al, 1992;Oppert et al, 1994). Forcada et al (1998) demonstrated that changes in midgut proteolytic activity explain the emergence of resistance observed in the case of Heliothis virescens with more quickly processing of the active form of Cry1Ab compared to the susceptible strain.…”

Section: Vip3aa16 Toxin Activationmentioning

confidence: 98%

Investigation of the steps involved in the difference of susceptibility of Ephestia kuehniella and Spodoptera littoralis to the Bacillus thuringiensis Vip3Aa16 toxin

Abdelkefi-Mesrati

Boukedi

Chakroun

et al. 2011

Journal of Invertebrate Pathology

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Section: Vip3aa16 Toxin Activationmentioning

confidence: 98%

Investigation of the steps involved in the difference of susceptibility of Ephestia kuehniella and Spodoptera littoralis to the Bacillus thuringiensis Vip3Aa16 toxin

Abdelkefi-Mesrati

Boukedi

Chakroun

et al. 2011

Journal of Invertebrate Pathology

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“…Production of a stable toxin core has been shown to determine or significantly contribute to specificity in multiple cases. For instance, comparison of processing in Cry1A susceptible (Pieris brassicae, Bombyx mori) and tolerant (Mamestra brassicae, Spdoptera litura) hosts identified reduced production of the toxin form associated with susceptibility in the tolerant larvae (Inagaki et al, 1992;Lightwood et al, 2000).…”

Section: Specificity Level Iii: Toxin Processing and Stabilitymentioning

confidence: 99%

Specificity determinants for Cry insecticidal proteins: Insights from their mode of action

Jurat-Fuentes

Crickmore

2017

Journal of Invertebrate Pathology

149

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“…entomocidus HD-198 exhibited a lower protoxin activation rate than susceptible insects exhibited due to a decrease in the total proteolytic activity of the gut extract (32,33). Ingaki et al (18) found the reverse to be true for Spodoptera litura processing of B. thuringiensis subsp. kurstaki HD-1.…”

mentioning

confidence: 99%

Role of Proteolysis in Determining Potency of Bacillus thuringiensis Cry1Ac δ-Endotoxin

Lightwood

Ellar

Jarrett³

2000

Appl Environ Microbiol

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Bacillus thuringiensis protein ␦-endotoxins are toxic to a variety of different insect species. Larvicidal potency depends on the completion of a number of steps in the mode of action of the toxin. Here, we investigated the role of proteolytic processing in determining the potency of the B. thuringiensis Cry1Ac ␦-endotoxin towards Pieris brassicae (family: Pieridae) and Mamestra brassicae (family: Noctuidae). In bioassays, Cry1Ac was over 2,000 times more active against P. brassicae than against M. brassicae larvae. Using gut juice purified from both insects, we processed Cry1Ac to soluble forms that had the same N terminus and the same apparent molecular weight. However, extended proteolysis of Cry1Ac in vitro with proteases from both insects resulted in the formation of an insoluble aggregate. With proteases from P. brassicae, the Cry1Ac-susceptible insect, Cry1Ac was processed to an insoluble product with a molecular mass of ϳ56 kDa, whereas proteases from M. brassicae, the non-susceptible insect, generated products with molecular masses of ϳ58, ϳ40, and ϳ20 kDa. N-terminal sequencing of the insoluble products revealed that both insects cleaved Cry1Ac within domain I, but M. brassicae proteases also cleaved the toxin at Arg423 in domain II. A similar pattern of processing was observed in vivo. When Arg423 was replaced with Gln or Ser, the resulting mutant toxins resisted degradation by M. brassicae proteases. However, this mutation had little effect on toxicity to M. brassicae. Differential processing of membrane-bound Cry1Ac was also observed in qualitative binding experiments performed with brush border membrane vesicles from the two insects and in midguts isolated from toxin-treated insects.

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Proteolytic processing of δ-endotoxin of Bacillus thuringiensis var. kurstaki HD-1 in insensitive insect, Spodoptera litura: Unusual proteolysis in the presence of sodium dodecyl sulfate

Cited by 25 publications

References 14 publications

Investigation of the steps involved in the difference of susceptibility of Ephestia kuehniella and Spodoptera littoralis to the Bacillus thuringiensis Vip3Aa16 toxin

Investigation of the steps involved in the difference of susceptibility of Ephestia kuehniella and Spodoptera littoralis to the Bacillus thuringiensis Vip3Aa16 toxin

Specificity determinants for Cry insecticidal proteins: Insights from their mode of action

Role of Proteolysis in Determining Potency of Bacillus thuringiensis Cry1Ac δ-Endotoxin

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