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CAPRRESI: Chimera Assembly by Plasmid Recovery and Restriction Enzyme Site Insertion
Published on: June 25, 2017
Periplasmic stress and ECF sigma factors.
1Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9; Canada. traivio@ualberta.ca
Annual Review of Microbiology
|September 7, 2001
Summary
Bacteria use envelope stress responses to maintain cell health. The sigma(E) pathway manages outer-membrane protein assembly, while the Cpx system handles pilus assembly in Escherichia coli.
Area of Science:
- Microbiology
- Molecular Biology
- Cell Biology
Background:
- Envelope stress responses are crucial for bacterial physiology, including protein folding and cell wall biosynthesis.
- Extracytoplasmic function (ECF) sigma factors regulate many stress responses, often involving membrane-localized anti-sigma factors.
- The sigma(E) pathway in Escherichia coli controls outer-membrane protein (OMP) assembly and degradation in response to envelope stress.
Purpose of the Study:
- To elucidate the mechanisms of envelope stress responses in bacteria.
- To understand the roles of sigma(E) and Cpx pathways in maintaining cellular homeostasis.
- To investigate how Escherichia coli manages outer-membrane protein and pilus assembly.
Main Methods:
- The study focuses on the sigma(E) and Cpx two-component systems in Escherichia coli.
- Analysis involves understanding signal transduction pathways involving sensor kinases and response regulators.
- Gene expression control related to protein folding, degradation, and assembly is examined.
Main Results:
- The sigma(E) pathway is essential for proper assembly of outer-membrane proteins (OMPs).
- The Cpx two-component system regulates pilus assembly by sensing misfolded periplasmic proteins.
- CpxA sensor kinase and CpxR response regulator are key components of the pilus assembly stress response.
Conclusions:
- Escherichia coli employs distinct envelope stress response pathways, sigma(E) and Cpx, to maintain cellular integrity.
- The sigma(E) pathway ensures correct OMP folding and degradation.
- The Cpx system is vital for proper pilus assembly, responding to misfolded periplasmic proteins.
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