Regulated proteolysis of the alternative sigma factor SigX in Streptococcus mutans: implication in the escape from competence.

ABSTRACT:

Background

SigX (σX), the alternative sigma factor of Streptococcus mutans, is the key regulator for transcriptional activation of late competence genes essential for taking up exogenous DNA. Recent studies reveal that adaptor protein MecA and the protease ClpC act as negative regulators of competence by a mechanism that involves MecA-mediated proteolysis of SigX by the ClpC in S. mutans. However, the molecular detail how MecA and ClpC negatively regulate competence in this species remains to be determined. Here, we provide evidence that adaptor protein MecA targets SigX for degradation by the protease complex ClpC/ClpP when S. mutans is grown in a complex medium.

Results

By analyzing the cellular levels of SigX, we demonstrate that the synthesis of SigX is transiently induc

SUBMITTER: Dong G 

PROVIDER: S-EPMC4109385 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature