National Food Biotechnology Centre, University College Cork, Cork, Ireland.
Dueling quorum sensing systems in Pseudomonas aeruginosa control the production of the Pseudomonas quinolone signal (PQS)
Version of Record online: 9 JAN 2006
FEMS Microbiology Letters
Volume 230, Issue 1, pages 27–34, January 2004
How to Cite
McGrath, S., Wade, D. S. and Pesci, E. C. (2004), Dueling quorum sensing systems in Pseudomonas aeruginosa control the production of the Pseudomonas quinolone signal (PQS). FEMS Microbiology Letters, 230: 27–34. doi: 10.1016/S0378-1097(03)00849-8
- Issue online: 9 JAN 2006
- Version of Record online: 9 JAN 2006
- Received 27 August 2003, Revised 20 October 2003, Accepted 7 November 2003
- Pseudomonas aeruginosa;
- Quorum sensing;
The opportunistic human pathogen Pseudomonas aeruginosa regulates the production of numerous virulence factors via the action of two separate but coordinated quorum sensing systems, las and rhl. These systems control the transcription of genes in response to population density through the intercellular signals N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) and N-(butanoyl)-l-homoserine lactone (C4-HSL). A third P. aeruginosa signal, 2-heptyl-3-hydroxy-4-quinolone [Pseudomonas quinolone signal (PQS)], also plays a significant role in the transcription of multiple P. aeruginosa virulence genes. PQS is intertwined in the P. aeruginosa quorum sensing hierarchy with its production and bioactivity requiring the las and rhl quorum sensing systems, respectively. This report presents a preliminary transcriptional analysis of pqsA, the first gene of the recently discovered PQS biosynthetic gene cluster. We show that pqsA transcription required pqsR, a transcriptional activator protein encoded within the PQS biosynthetic gene cluster. It was also found that the transcription of pqsA and subsequent production of PQS was induced by the las quorum sensing system and repressed by the rhl quorum sensing system. In addition, PQS production was dependent on the ratio of 3-oxo-C12-HSL to C4-HSL, suggesting a regulatory balance between quorum sensing systems. These data are an important early step toward understanding the regulation of PQS synthesis and the role of PQS in P. aeruginosa intercellular signaling.