A third envelope stress signal transduction pathway in Escherichia coli
Summary Escherichia coli uses overlapping envelope stress responses to adapt to insults to the bacterial envelope that cause protein misfolding. The σ E and Cpx envelope stress responses are activated by both common and distinct envelope stresses and respond by increasing the expression of the perip...
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Published in: | Molecular microbiology Vol. 45; no. 6; pp. 1599 - 1611 |
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Main Authors: | , |
Format: | Journal Article |
Language: | English |
Published: |
Oxford, UK
Blackwell Science Ltd
01-09-2002
Blackwell Publishing Ltd |
Subjects: | |
Online Access: | Get full text |
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Summary: | Summary
Escherichia coli
uses overlapping envelope stress responses to adapt to insults to the bacterial envelope that cause protein misfolding. The σ
E
and Cpx envelope stress responses are activated by both common and distinct envelope stresses and respond by increasing the expression of the periplasmic protease DegP as well as target genes unique to each response. The σ
E
pathway is involved in outer membrane protein (OMP) folding quality control whereas the Cpx pathway plays an important role in the assembly of at least one pilus. Previously, we identified the
spy
gene as a new Cpx regulon member of unknown function. Interestingly, induction of
spy
expression by severe envelope stresses such as spheroplasting is only partially dependent on an intact Cpx signalling pathway, unlike other Cpx‐regulated genes. Here we show that the BaeS sensor kinase and BaeR response regulator also control expression of
spy
in response to envelope stress. BaeS and BaeR do not affect expression of other known Cpx‐regulated genes, however,
baeR cpxR
double mutants show increased sensitivity to envelope stresses relative to either single mutant alone. We propose that the Bae signal transduction pathway controls a third envelope stress response in
E. coli that induces expression of a distinct set of adaptive genes. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0950-382X 1365-2958 |
DOI: | 10.1046/j.1365-2958.2002.03112.x |