Regulation of icaR gene expression in Staphylococcus epidermidis

• Published in: FEMS microbiology letters Vol. 216; no. 2; pp. 171 - 177
• Main Authors: Conlon, Kevin M., Humphreys, Hilary, O'Gara, James P.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2002; Blackwell; Oxford University Press
• Subjects: Bacterial Proteins - genetics; Bacteriology; Biofilm; Biofilms; Biological and medical sciences; Environment; Environmental regulations; Ethanol; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Bacterial - drug effects; ica operon; icaR; LightCycler RT‐PCR; Metabolism. Enzymes; Microbiology; Mutagenesis, Insertional - physiology; Polymerase chain reaction; Post-transcription; Repressor Proteins - genetics; Reverse Transcriptase Polymerase Chain Reaction - methods; Reverse transcription; Sodium chloride; Staphylococcus epidermidis; Staphylococcus epidermidis - drug effects; Staphylococcus epidermidis - genetics; Staphylococcus epidermidis - physiology; Tetracycline - pharmacology; Transcription; Transcription activation; Transcription, Genetic - genetics; Biofilm; Transcription; operon; LightCycler RT-PCR; Virulence; Gene expression; Regulation(control); Staphylococcus epidermidis; ica operon; Bacteria; Micrococcales; Micrococcaceae; Adhesin; icaR
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2002.tb11432.x

Abstract LightCycler and conventional reverse transcription-polymerase chain reaction (RT-PCR) were used to examine regulation of icaR, which encodes a repressor of the Staphylococcus epidermidis ica operon. Varying concentrations of NaCl and ethanol activated ica but only high levels of both compounds repressed icaR transcription. Activation of ica by subinhibitory concentrations of tetracycline, which was strain-dependent, was also associated with icaR repression. In an icaR::Em mutant, NaCl but not ethanol activated ica whereas both compounds repressed icaR expression indicating that environmental regulation of the icaR gene is IcaR-independent. Apparently ethanol signals exclusively through IcaR to activate ica and regulates IcaR at the transcriptional and posttranscriptional levels. NaCl also regulates icaR expression but in addition can activate ica via an icaR-independent pathway.