Negative control of RpoS synthesis by the sRNA ReaL in Pseudomonas aeruginosa

Pseudomonas aeruginosa (Pae) is an opportunistic human pathogen, able to resist host defense mechanisms and antibiotic treatment. In Pae, the master regulator of stress responses RpoS is involved in the regulation of quorum sensing and several virulence genes. Here, we report that the sRNA ReaL translationally silences rpoS mRNA. Our studies revealed that ReaL can base-pair with the Shine-Dalgarno region of rpoS mRNA, which results in a decrease of RpoS levels. These studies are underlined by a highly similar transcription profile of a rpoS deletion mutant and a PAO1 reaL over-expressing strain.