A novel two-component system controls the expression of Pseudomonas aeruginosa fimbrial cup genes
Article first published online: 25 NOV 2004
Volume 55, Issue 2, pages 368–380, January 2005
How to Cite
Kulasekara, H. D., Ventre, I., Kulasekara, B. R., Lazdunski, A., Filloux, A. and Lory, S. (2005), A novel two-component system controls the expression of Pseudomonas aeruginosa fimbrial cup genes. Molecular Microbiology, 55: 368–380. doi: 10.1111/j.1365-2958.2004.04402.x
- Issue published online: 25 NOV 2004
- Article first published online: 25 NOV 2004
- Accepted 20 September, 2004.
Biofilm formation by the opportunistic pathogen Pseudomonas aeruginosa requires the expression of a number of surface adhesive components. The expression of surface organelles facilitating biofilm formation is controlled by environmental signals acting through transcriptional regulatory networks. We analysed the expression of a family of P. aeruginosa adhesins encoded by three distinct fimbrial gene clusters (cupA, cupB and cupC). Using transposon mutagenesis, we have identified several regulatory loci that upregulated cupB and cupC transcription. One such locus contains three components, RocS1, RocR and RocA1, which represent a variant of a classical two-component signal transduction pathway. RocS1 is a sensor kinase, RocA1 is a DNA binding response regulator that activates cup genes, and RocR is an antagonist of RocA1 activity. Using a two-hybrid assay, we have shown that RocS1 interacts with receiver domains of both RocA1 and RocR. Expression of the Cup system in response to environmental stimuli is accomplished by a novel mechanism in which the sensor kinase activates its cognate response regulator through a phosphorelay pathway, while an additional repressor protein modulates this interaction.