Quorum sensing and multidrug transporters in Escherichia coli
| Autor: | Lynn Zechiedrich, Shirley Yang, Christopher R. Lopez |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Transcriptional Activation
Lipoproteins Mutant Sigma Factor Biology medicine.disease_cause Microbiology chemistry.chemical_compound Bacterial Proteins Sigma factor Drug Resistance Multiple Bacterial Escherichia coli medicine Multidisciplinary Cell growth Escherichia coli Proteins Membrane Transport Proteins Gene Expression Regulation Bacterial Biological Sciences biochemical phenomena metabolism and nutrition Autoinducer-2 Cell biology Carbon-Sulfur Lyases Quorum sensing chemistry Genes Bacterial Culture Media Conditioned Mutation bacteria Multidrug Resistance-Associated Proteins rpoS Gene Deletion Bacterial Outer Membrane Proteins |
| Zdroj: | Proceedings of the National Academy of Sciences. 103:2386-2391 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0502890102 |
| Popis: | Previously, we found that the quorum sensing transcription factor SdiA up-regulates AcrAB. Others found that a 4-quinolone was a quorum-sensing signal in Pseudomonas aeruginosa . In Escherichia coli , there are at least three multidrug transporters (AcrAB∕TolC, MdfA, and NorE) that exude fluoroquinolones. Here, we show that Δ acrAB , tolC210 , or Δ norE mutants have the same growth rate as WT cells in exponential phase but grow to higher cell density in stationary phase. Overproduction of either pump caused cells to reach lower density. mdfA had no effect. Conditioned medium (CM) from cells overexpressing acrAB represses cell growth more than CM from WT cells. CM from pump mutant cells represses cell growth less than CM from WT cells. These results were not affected by the deletion of luxS, which synthesizes the quorum-sensing signal autoinducer 2 (AI-2). Expression of the rpoS gene encoding the stationary phase σ factor is induced earlier in cells overexpressing acrAB and later in acrAB mutant cells. These results support a model in which a natural function of AcrAB∕TolC and NorE is to export signals for cell–cell communication. Drugs exported by pumps may resemble communication molecules normally exuded. |
| Databáze: | OpenAIRE |
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