Fig. 7: Model of the PqsS sRNA-PQS positive feedback to regulate P. aeruginosa virulence.
From: Hfq-binding small RNA PqsS regulates Pseudomonas aeruginosa pqs quorum sensing system and virulence
A novel sRNA named PqsS promotes pqs quorum sensing (QS) with the assistance of the chaperone protein Hfq. Specifically, high levels of PQS promotes PqsS expression and forms a PqsS-Hfq complex. Then, this complex decreases pqsL mRNA stability by recruiting RNase E to drive degradation, thereby enhancing PQS productions for pqs QS and MVs formation. PQS further promotes PqsS expression, thus forming a positive PqsS-PQS feedback loop. Therefore, PqsS promotes acute bacterial infections including host cell death, rhamnolipids production, and swarming motility, while reducing chronic infections, such as biofilm formation, cellular survival, and host cell ROS production.
