Requirement of a heat-labile factor(s) for in vitro expression of the amp gene of pBR322

Kuriki, Yoshitaka

doi:10.1128/jb.169.12.5856-5858.1987

Cited by 4 publications

(4 citation statements)

References 16 publications

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“…4B, p-lactamase synthesis was aisc repressed at 45°C and the repression was more pronounced in this system than that observed in the above-mentioned coupled system. As in the case of pre-p-lactamase synthesis in the coupled transcription-translation reaction (Kuriki, 1987c), the translation of p-lactamase mRNA was repressed at temperatures higher than 35''C ( Fig. 5), indicating that the repression of translation at higher temperatures is an event specific for p-lactamase mRNAs.…”

Section: Effect Of Temperature Shift-up On ^-Lactamase Mrnamentioning

confidence: 62%

“…<u Cells from wf cell extracts were prepared cells (U-S160). In contrast, the in vitro coupled transcription-translation system was pre-heated (Kuriki, 1987c) to reduce its activity in the synthesis cf pre-p-lactamase with pBR328 as template. The expression of the amp and cat genes of pBR328 in the pre-heated coupled system was then examined in the absence and presence of h-cr U-S160.…”

Section: Discussionmentioning

confidence: 99%

“…I have recently reported that exposure of E. co/; carrying pBR322 to heat shock caused a transient arrest of fi-lactamase synthesis without affecting the levels of 3-lactamase mRNAs (Kuriki, 1987a) and that the expression of the amp gene In vitro was less efficient at 45^0 than at 30°C (Kuriki, 1987c). My previous studies have also shown that the 160000 x g supernatant of E co//extracts (SI 60) contained a protein(s) that seemed to enhance the translation of fi-lactamase mRNA (Kuriki.…”

Section: Introductionmentioning

confidence: 99%

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Translational repression of TEM β‐lactamase synthesisas a response of Escherichia coli to heat shock

Kuriki

1989

Molecular Microbiology

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As a result of a temperature shift-up from 30 degrees C to 42 degrees C, beta-lactamase synthesis in Escherichia coli carrying pBR322 ceased transiently, even though the level of beta-lactamase mRNA was not altered. pBR328-directed pre-beta-lactamase synthesis in an in vitro transcription-translation coupled system was also repressed by incubation at the higher temperature. Translation of the lacZ sequence from the amp translation start signal, inserted into the open reading frame vector pORF1, was also repressed transiently upon the temperature shift-up. Pre-heating of the in vitro coupled system at 45 degrees C specifically reduced its capacity for pre-beta-lactamase synthesis. This capacity was restored by the addition of a 160,000 x g supernatant prepared from E. coli grown at 30 degrees C, but not by the supernatant from the cells incubated at 42 degrees C. These and other results indicate that (i) the 160,000 x g supernatant contains a heat-labile protein(s) that is required for efficient initiation of the translation of pre-beta-lactamase mRNA, and (ii) the heat shock-induced repression of beta-lactamase synthesis is due to inactivation of the protein(s) in the 160,000 x g supernatant.

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Section: Effect Of Temperature Shift-up On ^-Lactamase Mrnamentioning

confidence: 62%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Translational repression of TEM β‐lactamase synthesisas a response of Escherichia coli to heat shock

Kuriki

1989

Molecular Microbiology

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“…A heat-labile factor was assumed necessary for the expression of the amp-gene in pBR 322 [10], Moreover, a recent study provided evidence that Yersi nia kristensii is more resistant at 28 than at 37 °C due to enhanced P-lactamase expres sion at 28 °C [ 1 ].…”

Section: Discussionmentioning

confidence: 99%

Influence of Temperature on Beta-Lactamase Production and Outer Membrane Proteins in Gram-Negative Rods

Cullmann

Dick²

1990

Chemotherapy

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The influence of temperature (ranging from 28 to 42 °C) was studied on the phenotypic expression of chromosomally mediated β-lactamases in gram-negative clinical isolates and in their β-lactamase-derepressed resistant counterparts. The enzymes were expressed most intensely at lower temperatures (28 or 32 °C). In most strains the enzyme was barely detectable at growth temperatures of 42 °C independent of the inducer employed. The release of the enzyme into the surrounding medium was marginal even at a growth temperature of 42 °C. The major outer membrane proteins revealed discrepancies dependent on the growth temperature only for the Providencia rettgeri W 862 strain. Thus, it can be concluded that the phenotypic expression of chromosomal β-lactamase is temperature dependent to the effect that the enzymes are most expressed at 28 or 32 °C. This agrees well with the increased susceptibility to most β-lactams due to the lowered β-lactamase production at higher temperatures. This effect was pronounced most strikingly in Proteus vulgaris.

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Fermentation conditions for high‐level expression of the tac‐promoter‐controlled calf prochymosin cDNA in Escherichia coli HB101

Капралек

Ječmen

Sedláček

et al. 1991

Biotech & Bioengineering

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Escherichia coli HB101 harboring an expression plasmid that bears the calf prochymosin gene controlled by the tac promoter was cultivated under different conditions in order to find an optimal fermentation arrangement that would lead to maximal prochymosin yield. Our results indicate that it is advantageous to use lactose in the double role of inducer and carbon/energy source when foreign gene expression is controlled by the tac promoter and the gene product is only moderately toxic owing to its accumulation in the form of an intracellular body. Glucose, on the other hand, may be used when expression should be repressed. Growth temperature substantially influenced the specific rate of prochymosin and beta-lactamase gene expression and the plasmid copy number. Three phases were distinguished in the time course of the fermentation on lactose: exponential growth practically without prochymosin synthesis, linear growth with prochymosin synthesis, and prochymosin synthesis without growth of biomass. The synthesis of prochymosin in the form of intracellular inclusion body was accompanied by the loss of respiratory activity of the cell and the loss of its ability to multiply. Sixteen hours cultivation at 37 degrees C in a complex medium with lactose as inducer and carbon/energy source resulted in up to 30% of the volume and 48% of the total protein of biomass being accumulated for as prochymosin inclusion bodies. The concentration of extractable enzymatically active chymosin in the culture reached 12 mg/L.

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Requirement of a heat-labile factor(s) for in vitro expression of the amp gene of pBR322

Cited by 4 publications

References 16 publications

Translational repression of TEM β‐lactamase synthesisas a response of Escherichia coli to heat shock

Translational repression of TEM β‐lactamase synthesisas a response of Escherichia coli to heat shock

Influence of Temperature on Beta-Lactamase Production and Outer Membrane Proteins in Gram-Negative Rods

Fermentation conditions for high‐level expression of the tac‐promoter‐controlled calf prochymosin cDNA in Escherichia coli HB101

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