The Pseudomonas aeruginosa quinolone signal (PQS) has an iron-chelating activity.
Virulence factor production and the development of biofilms in Pseudomonas aeruginosa have been shown to be regulated by two hierarchically organized quorum-sensing systems activated by two types of small acyl-homoserine lactone signal molecules. Recently, a third type of bacterial signal molecule, the Pseudomonas quinolone signal (PQS), has been identified, which positively regulates a subset of genes dependent on the quorum-sensing systems. However, the molecular mechanism underlying PQS signalling has remained poorly understood. In this study the global transcriptional profile of P. aeruginosa in response to PQS revealed a marked upregulation of genes belonging to the tightly interdependent functional groups of the iron acquisition and the oxidative stress response. Remarkably, most of the differentially regulated genes, as well as the induction of rhlR, could be traced back to an iron-chelating effect of PQS. Our results amount to the elucidation of how PQS affects P. aeruginosa and have important implications for the understanding of the complex regulatory circuits involved in P. aeruginosa gene regulation.
Bredenbruch
Florian
F
Department of Cell Biology, German Research Centre for Biotechnology, Braunschweig, Germany.
Geffers
Robert
R
Nimtz
Manfred
M
Buer
Jan
J
Häussler
Susanne
S
D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D046228:Microarray Analysis; D018384:Oxidative Stress / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000378:metabolism; D015363:Quinolones / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D021241:Spectrometry, Mass, Electrospray Ionization; D014157:Transcription Factors / Q000378:metabolism*; D037521:Virulence Factors / Q000235:genetics
C407944:2-heptyl-3-hydroxy-4-quinolone; D015363:Quinolones; D014157:Transcription Factors; D037521:Virulence Factors; D007501:Iron