Release of outer membrane vesicles by Gram-negative bacteria is a novel envelope stress response.
Abstract
Conditions that impair protein folding in the Gram-negative bacterial envelope cause
stress. The destabilizing effects of stress in this compartment are recognized and
countered by a number of signal transduction mechanisms. Data presented here reveal
another facet of the complex bacterial stress response, release of outer membrane
vesicles. Native vesicles are composed of outer membrane and periplasmic material,
and they are released from the bacterial surface without loss of membrane integrity.
Here we demonstrate that the quantity of vesicle release correlates directly with
the level of protein accumulation in the cell envelope. Accumulation of material occurs
under stress, and is exacerbated upon impairment of the normal housekeeping and stress-responsive
mechanisms of the cell. Mutations that cause increased vesiculation enhance bacterial
survival upon challenge with stressing agents or accumulation of toxic misfolded proteins.
Preferential packaging of a misfolded protein mimic into vesicles for removal indicates
that the vesiculation process can act to selectively eliminate unwanted material.
Our results demonstrate that production of bacterial outer membrane vesicles is a
fully independent, general envelope stress response. In addition to identifying a
novel mechanism for alleviating stress, this work provides physiological relevance
for vesicle production as a protective mechanism.
Type
Journal articleSubject
Adaptation, PhysiologicalAnti-Bacterial Agents
Bacterial Outer Membrane Proteins
Cell Wall
DNA Transposable Elements
Electrophoresis, Polyacrylamide Gel
Escherichia coli
Escherichia coli Proteins
Gram-Negative Bacteria
Microbial Viability
Microscopy, Electron, Scanning
Microscopy, Electron, Transmission
Mutagenesis, Insertional
Polymyxin B
Protein Transport
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https://hdl.handle.net/10161/10658Published Version (Please cite this version)
10.1111/j.1365-2958.2006.05522.xPublication Info
McBroom, Amanda J; & Kuehn, Meta J (2007). Release of outer membrane vesicles by Gram-negative bacteria is a novel envelope stress
response. Mol Microbiol, 63(2). pp. 545-558. 10.1111/j.1365-2958.2006.05522.x. Retrieved from https://hdl.handle.net/10161/10658.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Margarethe Joanna Kuehn
Associate Professor of Biochemistry
Enterotoxigenic E. coli (ETEC) causes traveler's diarrhea and infant mortality in
underdeveloped countries, and Pseudomonas aeruginosa is an opportunistic pathogen
for immunocompromised patients. Like all gram negative bacteria studied to date, ETEC
and P. aeruginosa produce small outer membrane vesicles that can serve as delivery
"bombs" to host tissues. Vesicles contain a subset of outer membrane and
soluble periplasmic proteins and lipids. In tissues and sera of infected hosts,

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