PMID:16952953
| Citation |
Zahrl, D, Wagner, M, Bischof, K and Koraimann, G (2006) Expression and assembly of a functional type IV secretion system elicit extracytoplasmic and cytoplasmic stress responses in Escherichia coli. J. Bacteriol. 188:6611-21 |
|---|---|
| Abstract |
Conditions perturbing protein homeostasis are known to induce cellular stress responses in prokaryotes and eukaryotes. Here we show for the first time that expression and assembly of a functional type IV secretion (T4S) machinery elicit extracytoplasmic and cytoplasmic stress responses in Escherichia coli. After induction of T4S genes by a nutritional upshift and assembly of functional DNA transporters encoded by plasmid R1-16, host cells activated the CpxAR envelope stress signaling system, as revealed by induction or repression of downstream targets of the CpxR response regulator. Furthermore, we observed elevated transcript levels of cytoplasmic stress genes, such as groESL, with a concomitant increase of sigma(32) protein levels in cells expressing T4S genes. A traA null mutant of plasmid R1-16, which lacks the functional gene encoding the major pilus protein pilin, showed distinctly reduced stress responses. These results corroborated our conclusion that the activation of bacterial stress networks was dependent on the presence of functional T4S machinery. Additionally, we detected increased transcription from the rpoHp(1) promoter in the presence of an active T4S system. Stimulation of rpoHp(1) was dependent on the presence of CpxR, suggesting a hitherto undocumented link between CpxAR and sigma(32)-regulated stress networks. |
| Links |
PubMed PMC1595493 Online version:10.1128/JB.00632-06 |
| Keywords |
Adaptation, Physiological; Bacterial Proteins; Biological Transport; Chaperonins/biosynthesis; Conjugation, Genetic; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli/physiology; Escherichia coli Proteins/biosynthesis; Escherichia coli Proteins/physiology; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genes, Bacterial; Heat-Shock Proteins/biosynthesis; Heat-Shock Proteins/genetics; Models, Biological; Mutation; Pili, Sex/genetics; Pili, Sex/metabolism; Plasmids/genetics; Protein Kinases/physiology; RNA, Bacterial/analysis; RNA, Messenger/analysis; Regulon/physiology; Sigma Factor/biosynthesis; Sigma Factor/genetics; Transcription, Genetic |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
See also
References
See Help:References for how to manage references in EcoliWiki.