Authors

Sévin, D. C., & Sauer, U.

Affiliations

Institute of Molecular Systems Biology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland. PhD Program on Systems Biology, Life Science Zürich, Zürich, Switzerland.

Application Area

Chemistry

General Fluorescence Microscopy

Abstract

Bacteria are thought to cope with fluctuating environmental solute concentrations primarily by adjusting the osmolality of their cytoplasm. To obtain insights into the underlying metabolic adaptations, we analyzed the global metabolic response of Escherichia coli to sustained hyperosmotic stress using nontargeted mass spectrometry. We observed that 52% of 1,071 detected metabolites, including known osmoprotectants, changed abundance with increasing salt challenge. Unexpectedly, unsupervised data analysis showed a substantial increase of most intermediates in the ubiquinone-8 (Q8) biosynthesis pathway and a 110-fold accumulation of Q8 itself, as confirmed by quantitative lipidomics. We then demonstrated that Q8 is necessary for acute and sustained osmotic-stress tolerance using Q8 mutants and tolerance rescue through feeding nonrespiratory Q8 analogs. Finally, in vitro experiments with artificial liposomes showed that mechanical membrane stabilization is a principal mechanism of Q8-mediated osmoprotection. Thus, we find that besides regulating intracellular osmolality, E. coli enhances its cytoplasmic membrane stability to withstand osmotic stress.

Extract

… “inverted epifluorescence microscope equipped with a CoolLED PrecisExcite light source and”…

Product Associated Features

pE-100: A range of compact, simple-to-use, single wavelength illumination systems for screening fluorescence.

Diascopic Technique

Bright-Field

Live Cell Issues

-

Product Type

pE-100

Journal

Nature Chemical Biology

Year of Publication

2014

Country of Publication

Switzerland