PMID:10972835
| Citation |
Raivio, TL, Laird, MW, Joly, JC and Silhavy, TJ (2000) Tethering of CpxP to the inner membrane prevents spheroplast induction of the cpx envelope stress response. Mol. Microbiol. 37:1186-97 |
|---|---|
| Abstract |
The Cpx envelope stress response of Escherichia coli is controlled by a two-component regulatory system that senses misfolded proteins in extracytoplasmic compartments and responds by inducing the expression of envelope protein folding and degrading factors. We have proposed that in the absence of envelope stress the pathway is maintained in a downregulated state, in part through interactions between the periplasmic inhibitor molecule CpxP and the sensing domain of the histidine kinase CpxA. In this study, we show that depletion of the periplasmic contents of the cell by spheroplast formation does indeed lead to induction of the Cpx envelope stress response. Further, removal of CpxP is an important component of this induction because tethering an MBP-CpxP fusion protein to the spheroplast inner membranes prevents full activation by this treatment. Spheroplast formation has previously been demonstrated to induce the expression of a periplasmic protein of unknown function, Spy. Analysis of spy expression in response to spheroplast formation by Western blot analysis and by lacZ operon fusion in various cpx mutant backgrounds demonstrated that spy is a member of the Cpx regulon. Interestingly, although the only known spy homologue is cpxP, Spy does not appear to perform the same function as CpxP as it is not involved in inhibiting the Cpx envelope stress response. Rather, deletion of spy leads to activation of the sigmaE stress response. Because the sigmaE response is specifically affected by alterations in outer membrane protein biogenesis, we think it possible that Spy may be involved in this process. |
| Links | |
| Keywords |
Amino Acid Sequence; Bacterial Outer Membrane Proteins/metabolism; Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Carrier Proteins/genetics; Carrier Proteins/metabolism; Cell Membrane/metabolism; Collectins; Escherichia coli/growth & development; Escherichia coli/physiology; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Membrane Proteins/genetics; Membrane Proteins/metabolism; Molecular Sequence Data; Periplasmic Proteins; Regulon; Sigma Factor/metabolism; Transcription Factors/metabolism |
| 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)
References
See Help:References for how to manage references in EcoliWiki.