Publication Date:
2015-04-29
Description:
The DegS-DegU two-component regulatory system regulates many cellular events in Bacillus subtilis . Genes for DegSU constitutes an operon directed by the P1 promoter and downstream degU is autoregulated via the P3 promoter activated by phosphorylated DegU. In the Gram-positive bacteria, Spx plays a major role in the protection system against oxidative stresses as a transcriptional regulator. Spx is a substrate of the ATP-dependent ClpXP protease. It regulates diamide-stress regulon in addition to many genes with unknown functions. We have found that null mutations for clpX and clpP , which encode the subunits for the protease ClpXP, enhanced the DegU level through activation of the P1 promoter. We isolated four suppressors for the clpP -enhancing effect. Whole-genome sequencing of the suppressors revealed that two have a point mutation in spx and the rest have a deletion of spx . The clpP -enhancing effect on degS-lacZ expression was abolished in the spx disruptant . These results show that the degSU operon is a new target of Spx-mediated positive regulation. Furthermore, we found that the P1 promoter was induced by glucose and that this induction was greatly reduced in the spx mutant. These results suggested that Spx-mediated glucose induction at the P1 promoter.
Print ISSN:
0021-924X
Electronic ISSN:
1756-2651
Topics:
Biology
,
Chemistry and Pharmacology
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