Effect of a 20-kilodalton protein from Bacillus thuringiensis subsp. israelensis on production of the CytA protein by Escherichia coli

Visick, Jonathan E.; Whiteley, H. R.

doi:10.1128/jb.173.5.1748-1756.1991

Cited by 58 publications

(66 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This requirement for the 20 kDa protein could be bypassed by the use of E. coli host strains deficient in intracellular proteolysis (Visick and Whiteley, 1991). Similarly, the 20 kDa protein was reported to enhance the production of CrylVA (Yoshisue et aL, 1992) and CrylVD (Visick and Whiteley, 1991) in E. coli. Extending these observations, recent studies have reported that the 20 kDa protein enhances the production of the CytA protein in the acrystalliferous B.…”

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

“…The mechanisms by which the cryllA orf2 protein and the crylVD 20 kDa protein exert their effect on crystal formation in B. thuringiensis are not well understood, although evidence provided by Visick and Whiteley (1991) suggests that the 20 kDa protein protects the nascent CytA peptide from proteolysis. Whether protecting the protoxin molecule from proteolysis, assisting in proper folding of the nascent protoxin molecule to allow its deposition in the crystalline inclusion, or serving as a scaffolding protein for crystal formation, an absence of function would probably result in increased proteolytic degradation of the protoxin and reduced protoxin yield.…”

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

“…2). Early studies of the expression of the cytA gene in E. coil indicated that the 20kDa protein encoded by the third orf in the crylVD operon is required for efficient CytA production (Adams et aL, 1989;McLean and Whiteley, 1987;Visick and Whiteley, 1991). This requirement for the 20 kDa protein could be bypassed by the use of E. coli host strains deficient in intracellular proteolysis (Visick and Whiteley, 1991).…”

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

See 2 more Smart Citations

Regulation of insecticidal crystal protein production in Bacillus thuringiensis

Baum¹,

Malvar

1995

Molecular Microbiology

147

116

View full text Add to dashboard Cite

SummaryThe production of insecticidal crystal proteins (ICPs) in Bacillus thuringiensis normally coincides with sporulation, resulting in the appearance of parasporal crystalline inclusions within the mother cell. In most instances, the temporal and spatial regulation of ICP gene expression is determined at the transcriptional level by mother-cell-specific sigma factors that share homology with cr E and eK from Bacillus subtilis. The crylll ICP genes are a notable exception; these genes are transcribed from eA-like promoters during vegetative growth, are induced or derepressed at the onset of stationary phase, and are overexpressed in sporulation mutants of B. thuringiensis blocked in the phosphorylation of Spo0A, a key regulator of sporulation initiation. Transcription alone, however, cannot account for the impressive ability of this bacterium to accumulate insecticidal proteins. A variety of post-transcriptional and post-translational mechanisms also contribute to the efficient production of ICPs in B. thuringiensis, thus making this bacterium a cost-effective biological control agent.

show abstract

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

Section: Protein Stability and Crystal Formationmentioning

confidence: 99%

See 1 more Smart Citation

Regulation of insecticidal crystal protein production in Bacillus thuringiensis

Baum¹,

Malvar

1995

Molecular Microbiology

147

116

View full text Add to dashboard Cite

show abstract

“…The level of mosquito larvicidal activity of Cyt1Aa by itself is low, but it raises synergistically the activity of Cry4Aa, Cry4Ba or Cry11Aa, to a greater extent than the synergism obtained by combination of the three Cry polypeptides themselves (Crickmore et al, 1995; Khasdan et al, 2001 (Wu & Federici, 1993; Manasherob et al, 2001) and stabilizes Cyt1Aa post-translationally (Adams et al, 1989;Visick & Whiteley, 1991).…”

Section: Introductionmentioning

confidence: 99%

“…kyushuensis has recently been found to have a single pore-forming domain, composed of two outer layers of a-helix hairpins wrapped around mixed b-sheets (Li et al, 1996). Due to high similarity (70 %) in its amino acid sequence to Cyt2Aa, Cyt1Aa is supposed to show a similar folding pattern to Cyt2Aa (Li et al, 1996;Gazit et al, 1997).The level of mosquito larvicidal activity of Cyt1Aa by itself is low, but it raises synergistically the activity of Cry4Aa, Cry4Ba or Cry11Aa, to a greater extent than the synergism obtained by combination of the three Cry polypeptides themselves (Crickmore et al, 1995; Khasdan et al, 2001 (Wu & Federici, 1993; Manasherob et al, 2001) and stabilizes Cyt1Aa post-translationally (Adams et al, 1989;Visick & Whiteley, 1991).The hypothesis that recombinant E. coli cells expressing the cyt1Aa gene die by inhibition of DNA synthesis (Douek et al, 1992) is consistent with the high affinity of Cyt1Aa for phosphatidylethanolamine (Thomas & Ellar, 1983b), the major DNA-bound E. coli phospholipid (Ballesta et al, 1972). This hypothesis predicts that the target is the chromosome replication complex (Douek et al, 1992).…”

mentioning

confidence: 99%

Compaction of the Escherichia coli nucleoid caused by Cyt1Aa

et al. 2003

View full text Add to dashboard Cite

Compaction of the Escherichia coli nucleoid in the cell's centre was associated with the loss of colony-forming ability; these effects were caused by induction of Cyt1Aa, the cytotoxic 27 kDa protein from Bacillus thuringiensis subsp. israelensis. Cyt1Aa-affected compaction of the nucleoids was delayed but eventually more intense than compaction caused by chloramphenicol. The possibility that small, compact nucleoids in Cyt1Aa-expressing cells resulted in DNA replication run-out and segregation following cell division was ruled out by measuring relative nucleoid length. Treatments with membrane-perforating substances other than Cyt1Aa did not cause such compaction of the nucleoids, but rather the nucleoids overexpanded to occupy nearly all of the cell volume. These findings support the suggestion that, in addition to its perforating ability, Cyt1Aa causes specific disruption of nucleoid associations with the cytoplasmic membrane. In situ immunofluorescence labelling with Alexa did not demonstrate a great amount of Cyt1Aa associated with the membrane. Clear separation between Alexa-labelled Cyt1Aa and 49,6-diamidino-2-phenylindole (DAPI)-stained DNA indicates that the nucleoid does not bind Cyt1Aa. Around 2 h after induction, nucleoids in Cyt1Aa-expressing cells started to decompact and expanded to fill the whole cell volume, most likely due to partial cell lysis without massive peptidoglycan destruction. INTRODUCTIONDuring sporulation, various subspecies of the Grampositive soil bacterium Bacillus thuringiensis produce large amounts of insecticidal crystal proteins (ICP), the so-called d-endotoxins , each toxic against larvae of a different group of insects. The ICP of B. thuringiensis subsp. israelensis is specific against the larvae of mosquitoes and black flies (Goldberg & Margalit, 1977;Margalith & Ben-Dov, 2000), vectors of many human infectious diseases (Service, 1986). The crystal is composed of four major polypeptides, Cry4Aa, Cry4Ba, Cry11Aa and Cyt1Aa (of 125, 135, 68 and 28 kDa, respectively), which are encoded by genes carried on the~130 kDa plasmid nicknamed pBtoxis (Ben-Dov et al., 1999). Cyt1Aa, which is not homologous to any of the known Cry toxins , is the most prominent of the four polypeptides, but it is less specific than Cry4Aa, Cry4Ba and Cry11Aa, haemolytic and cytotoxic in vitro (Thomas & Ellar, 1983b;Drobniewski & Ellar, 1988;Hofte & Whiteley, 1989). The broad cytolytic activity of Cyt1Aa has been attributed to its hydrophobicity and ability to bind zwitterionic phospholipids (Thomas & Ellar, 1983a, b). Cyt1Aa is inserted into the membrane to create cation-selective single channels of 1-2 nm in diameter, leading to colloid-osmotic lysis (Knowles & Ellar, 1987;Knowles et al., 1989), and induces leakage of low-molecular-mass substances from lipid vesicles (Drobniewski & Ellar, 1988.Seven cytolytic, mosquitocidal-specific toxins are currently known (Earp & Ellar, 1987;Drobniewski & Ellar, 1989;Yu et al., 1991;Koni & Ellar, 1993;Cheong & Gill, 1997;Guerchicoff et al., 1997;Thiery et al., 199...

show abstract

Bacillus Thuringiensisand Its Use as a Biological Insecticide

Aronson

1994

Plant Breeding Reviews

View full text Add to dashboard Cite

Effect of a 20-kilodalton protein from Bacillus thuringiensis subsp. israelensis on production of the CytA protein by Escherichia coli

Cited by 58 publications

References 43 publications

Regulation of insecticidal crystal protein production in Bacillus thuringiensis

Regulation of insecticidal crystal protein production in Bacillus thuringiensis

Compaction of the Escherichia coli nucleoid caused by Cyt1Aa

Bacillus Thuringiensisand Its Use as a Biological Insecticide

Contact Info

Product

Resources

About