Document Detail


Characterization of the induction and cellular role of the BaeSR two-component envelope stress response of Escherichia coli.
MedLine Citation:
PMID:  21515766     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The bacterial cell envelope is the interface between a bacterium and its environment and is constantly exposed to environmental changes. The BaeSR two-component system regulates one of six envelope stress responses in Escherichia coli and is induced by spheroplasting, overexpression of the pilin subunit PapG, and exposure to indole. The known BaeR regulon is small, consisting of eight genes, mdtABCD-baeSR, acrD, and spy, two of which encode the BaeSR two-component system itself. In this study, we investigated the molecular nature of the BaeS-inducing cue and the cellular role of the BaeSR envelope stress response. We demonstrated that at least two flavonoids and sodium tungstate are novel inducers of the BaeSR response. Interestingly, flavonoids and sodium tungstate led to much stronger induction of the BaeSR response in an mdtA efflux pump mutant, while indole did not. These findings are consistent with the hypothesis that flavonoids and sodium tungstate are natural substrates of the MdtABC efflux pump. Indole has recently been implicated in cell-cell signaling and biofilm repression through a putative interaction with the LuxR homologue SdiA. Using genetic analyses, we found that induction of the BaeSR response by indole occurs via a pathway separate from the SdiA biofilm pathway. Further, we demonstrated that the BaeSR response does not influence biofilm formation, nor is it involved in indole-mediated inhibition of biofilm formation. We hypothesize that the main function of the Bae response is to upregulate efflux pump expression in response to specific envelope-damaging agents.
Authors:
Shannon K D Leblanc; Christopher W Oates; Tracy L Raivio
Related Documents :
19740386 - Response of macrophage toll-like receptor 4 to a sporothrix schenckii lipid extract dur...
12902506 - Lipomannans, but not lipoarabinomannans, purified from mycobacterium chelonae and mycob...
19759006 - Selective activation of the p38 mapk pathway by synthetic monophosphoryl lipid a.
15731076 - Distinct roles of pattern recognition receptors cd14 and toll-like receptor 4 in acute ...
16734496 - Antioxidants in multiple sclerosis: do they have a role in therapy?
20408896 - Dendritic cell differentiation with prostaglandin e results in selective attenuation of...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-04-22
Journal Detail:
Title:  Journal of bacteriology     Volume:  193     ISSN:  1098-5530     ISO Abbreviation:  J. Bacteriol.     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-06-15     Completed Date:  2011-08-23     Revised Date:  2012-01-02    
Medline Journal Info:
Nlm Unique ID:  2985120R     Medline TA:  J Bacteriol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3367-75     Citation Subset:  IM    
Affiliation:
Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Drug Resistance, Microbial
Escherichia coli / genetics,  metabolism,  physiology*
Escherichia coli Proteins / genetics,  metabolism*
Flavonoids / metabolism
Gene Expression Regulation, Bacterial*
Indoles / metabolism
Membrane Transport Proteins / metabolism
Multidrug Resistance-Associated Proteins / genetics,  metabolism*
Protein Kinases / genetics,  metabolism*
Signal Transduction*
Trans-Activators / genetics,  metabolism*
Transcriptional Activation
Tungsten Compounds / metabolism
Chemical
Reg. No./Substance:
0/BaeR protein, E coli; 0/Escherichia coli Proteins; 0/Flavonoids; 0/Indoles; 0/Mdt-A protein, E coli; 0/MdtB protein, E coli; 0/MdtC protein, E coli; 0/Membrane Transport Proteins; 0/Multidrug Resistance-Associated Proteins; 0/Trans-Activators; 0/Tungsten Compounds; 120-72-9/indole; 13472-45-2/sodium tungstate(VI); EC 2.7.-/Protein Kinases; EC 2.7.3.-/protein-histidine kinase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Complete Genome Sequence of the Nitrogen-fixing and Rhizosphere-associated Bacterium Pseudomonas stu...
Next Document:  Identification and characterization of CdgB, a diguanylate cyclase involved in developmental process...