Journal article
ClpE from Lactococcus lactis promotes repression of CtsR-dependent gene expression
The heat shock response in bacterial cells is characterized by rapid induction of heat shock protein expression, followed by an adaptation period during which heat shock protein synthesis decreases to a new steady-state level. In this study we found that after a shift to a high temperature the Clp ATPase (ClpE) in Lactococcus lactis is required for such a decrease in expression of a gene negatively regulated by the heat shock regulator (CtsR).
Northern blot analysis showed that while a shift to a high temperature in wild-type cells resulted in a temporal increase followed by a decrease in expression of clpP encoding the proteolytic component of the Clp protease complex, this decrease was delayed in the absence of ClpE. Site-directed mutagenesis of the zinc-binding motif conserved in ClpE ATPases interfered with the ability to repress CtsR-dependent expression.
Quantification of ClpE by Western blot analysis revealed that at a high temperature CIpE is subjected to ClpP-dependent processing and that disruption of the zinc finger domain renders GpE more susceptible. Interestingly, this domain resembles the N-terminal region of McsA, which was recently reported to interact with the CtsR homologue in Bacillus subtilis.
Thus, our data point to a regulatory role of ClpE in turning off clpP gene expression following temporal heat shock induction, and we propose that this effect is mediated through CtsR.
Language: | English |
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Publisher: | American Society for Microbiology |
Year: | 2003 |
Pages: | 5117-5124 |
ISSN: | 10985530 , 00219193 and 10678832 |
Types: | Journal article |
DOI: | 10.1128/JB.185.17.5117-5124.2003 |
ORCIDs: | 0000-0003-2151-7802 and 0000-0002-8350-5631 |
Adenosine Triphosphatases Amino Acid Sequence Bacterial Proteins ClpE protein, bacteria CtsR protein, bacteria Endopeptidase Clp Gene Expression Regulation, Bacterial Heat-Shock Proteins Heat-Shock Response Hot Temperature Lactococcus lactis Molecular Sequence Data Mutagenesis, Site-Directed Mutation Repressor Proteins Serine Endopeptidases