ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The Escherichia coli cspA gene, encoding the major cold-shock protein CspA, was deprived of its natural promoter and placed in an expression vector under the control of the inducible λ PL promoter. After induction of transcription by thermal inactivation of the λ ts repressor, abundant expression of the product (CspA) was obtained if the cells were subsequently incubated at 10°C, but poor expression was obtained if the cells were incubated at 37°C or 30°C. The reason for this differential temperature-dependent expression was investigated and it was found that: (i) the CspA content of the cells decreased more rapidly at 37°C compared to 10°C, regardless of whether transcription was turned off by addition of rifampicin; (ii) both the chemical and functional half-lives of the cspA transcript were substantially longer at 10°C compared to 37°C; (iii) S30 extracts as well as 70S ribosomes prepared from cold-shocked cells translated CspA mRNA (but not phage MS2 RNA) more efficiently than equivalent extracts or ribosomes obtained from control cells grown at 37°C; and (iv) purified CspA stimulated CspA mRNA translation. Overall, these results indicate that a selective modification of the cold-shocked translational apparatus favouring translation of CspA mRNA, and an increased stability of this mRNA at low temperature, may play an important role in the induction of cspA expression during cold shock.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2958.1996.362897.x
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