Fig. 6: Model for the regulation of the natural development of competence in S. aureus.
From: The complex regulation of competence in Staphylococcus aureus under microaerobic conditions
Three central competence regulators have been identified, namely SigH, ComK1, and ComK28,14. All three regulators are essential for a complete development of the competence transcriptional program. While SigH and ComK1 are absolutely required for the expression of genetic transformation genes, ComK2 (alongside SigH and ComK1) is also essential for the induction of additional cellular functions (i.e., stress response, toxin/antitoxin systems, amino and nucleic acid metabolism, iron transport…). In addition, the development of competence is characterized by the inhibition of virulence, mainly controlled by SigH and ComK2. Finally, we have shown that the natural development of competence is induced as the oxygen concentration in the culture is drastically decreased. This oxygen rarefaction is probably sensed by the SrrAB two-component system, which in turn activates the central competence regulator SigH.
