Curation Information

Role of the Pseudomonas aeruginosa las and rhl quorum-sensing systems in rhlI regulation.;de Kievit TR, Kakai Y, Register JK, Pesci EC, Iglewski BH;FEMS microbiology letters 2002 Jun 18; 212(1):101-6 [12076794]
LasR [P25084, view regulon]
Reported TF sp.
Pseudomonas aeruginosa PAO1
Reported site sp.
Pseudomonas aeruginosa PAO1
Created by
Matthew Coveyou
Curation notes

Experimental Process

Investigation of the quorum-sensing regulation of P. aeruginoas PAO1 gene rhlI began with identification of the transcriptional start site via primer extension. The same assay showed reduced transcription in a lasR-mutant strain. A putative las-box was identified from comparison with lux-box sequences. Beta-gal assay was applied to five mutant strains for comparison with wild-type expression: lasR-, lasI-, rhlR-, rhlI-, and lasI-/rhlI-. Mutant strains lasR-, lasI-, and lasI-/rhlI- showed dramatic loss of expression, while levels in rhlR- and rhlI- strains did not fall below 75% of the wild-type, indicating primary regulation by the lasR/lasI system. Addition of respective autoinducers restored expression in lasI- and rhlI- mutants. Assays were repeated with partial las-box deletions in all strains, and expression fell dramatically in all five and the wild-type.

Transcription Factor Binding Sites


Gene Regulation

Regulated genes for each binding site are displayed below. Gene regulation diagrams show binding sites, positively-regulated genes, negatively-regulated genes, both positively and negatively regulated genes, genes with unspecified type of regulation. For each indvidual site, experimental techniques used to determine the site are also given.

Site sequence Regulated genes Gene diagram Experimental techniques TF function TF type
... ... rhlI
Experimental technique details Beta-gal reporter assay - Experimental technique details Consensus search (ECO:0005624) - Experimental technique details Multiple sequence alignment (MSA) (ECO:0005556) - Experimental technique details Primer Extension assay (ECO:0005657) - activator not specified