PMID:11179229

Citation	Krüger, E, Zühlke, D, Witt, E, Ludwig, H and Hecker, M (2001) Clp-mediated proteolysis in Gram-positive bacteria is autoregulated by the stability of a repressor. EMBO J. 20:852-63
Abstract	The heat shock proteins ClpC and ClpP are subunits of an ATP-dependent protease of Bacillus subtilis. Under non-stressed conditions, transcription of the clpC and clpP genes is negatively regulated by CtsR, the global repressor of clp gene expression. Here, CtsR was proven to be a specific substrate of the ClpCP protease under stress conditions. Two proteins of former unknown function, McsA and McsB, which are also encoded by the clpC operon, act as modulators of CtsR repression. McsA containing zinc finger motifs stabilizes CtsR under non-stressed conditions. McsB, a putative kinase, can inactivate CtsR by modification to remove the repressor from the DNA and to target CtsR for degradation by the ClpCP protease during stress. Thus, clp gene expression in Gram-positive bacteria is autoregulated by a novel mechanism of controlled proteolysis, a circuit of down-regulation by stabilization and protection of a transcription repressor, and induction by presenting the repressor to the protease. Thereby, the ClpC ATPase, a member of the Hsp100 family, was identified as a positive regulator of the heat shock response.
Links	PubMed PMC145420 Online version:10.1093/emboj/20.4.852
Keywords	Adenosine Triphosphatases/metabolism; Amino Acid Sequence; Bacterial Proteins/chemistry; Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Base Sequence; DNA Primers; Endopeptidase Clp; Genes, Bacterial; Gram-Positive Bacteria/metabolism; Heat-Shock Proteins/genetics; Heat-Shock Proteins/metabolism; Hydrolysis; Molecular Sequence Data; Operon; Protein Kinases/chemistry; Protein Kinases/genetics; Repressor Proteins/metabolism; Sequence Deletion; Sequence Homology, Amino Acid; Serine Endopeptidases/metabolism; Transcription, Genetic
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
BACSU:MCSA		GO:0006508: proteolysis	ECO:0000315:		P		McsA play a role in regulating transcription of CtsR-dependent heat shock genes. Figure 5- In the mcsA mutants, CtsR-dependent heat shock proteins under non-stressed conditions were increased when compared with the wild-type. Figure 6B- In nonstressed McsA mutant cells, the CtsR level was lower than it was in the wild type. After heat shock, CtsR levels in the mutant decreased suggestin that CtsR is less stable without McsA. The half-life of CtsR was also lower in cells lacking McsA	complete CACAO 11542
BACSU:MCSB		GO:0006508: proteolysis	ECO:0000315:		P		McsB play a role in regulating transcription of CtsR-dependent heat shock genes. Figure 5- In the mcsB mutants, CtsR-dependent heat shock proteins under non-stressed conditions were increased when compared with the wild-type. McsB influences the CtsR-mediated repression negatively. Figure 6B- The half-life of the CtsR repressor was increased in McsB mutants, suggesting that McsB destabilizes CtsR.	complete CACAO 11545
BACSU:MCSB		GO:0006508: proteolysis	ECO:0000314:		P		Through gel mobility shift experiments (Figure 6, lanes 8-10), it was shown that addition of McsB to CtsR led to a decrease in the amount of DNA retarded by CtsR. This suests that McsB can remove the DNA binding capacity of CtsR.	complete CACAO 11546

References

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