ReviewThe importance of regulatory RNAs in Staphylococcus aureus

•Regulatory RNAs are at the center of regulatory circuits in Staphylococcus aureus.•Small RNAs control metabolism, stress response and virulence.•Ribonucleases act as possible co-factors of sRNAs.•Deciphering sRNA regulatory pathways opens new avenues to fight S. aureus diseases.

RNA molecules with regulatory functions in pathogenic bacteria have benefited from a renewed interest these two last decades. In Staphylococcus aureus, recent genome-wide approaches have led to the discovery that almost 10-20% of genes code for RNAs with critical regulatory roles in adaptive processes. These RNAs include trans-acting RNAs, which mostly act through binding to target mRNAs, and cis-acting RNAs, which include regulatory regions of mRNAs responding to various metabolic signals. Besides recent analysis of S. aureus transcriptome has revealed an unprecedented existence of pervasive transcription generating a high number of weakly expressed antisense RNAs along the genome as well as numerous mRNAs with overlapped regions. Here, we will illustrate the diversity of trans-acting RNAs and illustrate how they are integrated into complex regulatory circuits, which link metabolism, stress response and virulence.