Affiliation:
1. Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
Abstract
ABSTRACT
In
Escherichia coli
, envelope stress can be overcome by three different envelope stress responses: the σ
E
stress response and the Bae and Cpx two-component systems. The Cpx envelope stress response is controlled by the sensor kinase CpxA, the response regulator CpxR, and the novel periplasmic protein CpxP. CpxP mediates feedback inhibition of the Cpx pathway through a hypothetical interaction with the sensing domain of CpxA. No informative homologues of CpxP are known, and thus it is unclear how CpxP exerts this inhibition. Here, we identified six
cpxP
loss-of-function mutations using a CpxP-β-lactamase (CpxP′-′Bla) translational fusion construct. These loss-of-function mutations identified a highly conserved, predicted α-helix in the N-terminal domain of CpxP that affects both the function and the stability of the protein. In the course of this study, we also found that CpxP′-′Bla stability is differentially controlled by the periplasmic protease DegP in response to inducing cues and that mutation of
degP
diminishes Cpx pathway activity. We propose that the N-terminal α-helix is an important functional domain for inhibition of the Cpx pathway and that CpxP is subject to DegP-dependent proteolysis.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference42 articles.
1. Ades, S. E. 2004. Control of the alternative sigma factor σE in Escherichia coli. Curr. Opin. Microbiol.7:157-162.
2. Alba, B. M., and C. A. Gross. 2004. Regulation of the Escherichia coli σE-dependent envelope stress response. Mol. Microbiol.52:613-619.
3. Bardwell, J. C., J. O. Lee, G. Jander, N. Martin, D. Belin, and J. Beckwith. 1993. A pathway for disulfide bond formation in vivo. Mol. Microbiol.90:1038-1042.
4. TcpH Influences Virulence Gene Expression in
Vibrio cholerae
by Inhibiting Degradation of the Transcription Activator TcpP
5. Casadaban, M. J. 1976. Transposition and fusion of lac genes to selected promoters in Escherichia coli using bacteriophages lambda and Mu. J. Mol. Biol.104:541-555.
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