Multiple sources of slow activity fluctuations in a bacterial chemosensory network
| Autor: | Victor Sourjik, Ady Vaknin, Remy Colin, Christelle Rosazza |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Chemoreceptor
QH301-705.5 Science Systems biology Thermal fluctuations Receptors Cell Surface fluctuation dissipation relation Methylation 01 natural sciences Quantitative Biology::Cell Behavior Quantitative Biology::Subcellular Processes 03 medical and health sciences 0103 physical sciences Escherichia coli Fluorescence Resonance Energy Transfer out-of-equilibrium Biology (General) 010306 general physics Receptor 030304 developmental biology Microbiology and Infectious Disease 0303 health sciences Chemistry Quantitative Biology::Molecular Networks Chemotaxis E. coli Gene Expression Regulation Bacterial single-cell FRET bacterial chemotaxis Förster resonance energy transfer Biological Variation Population Levy walks cell networks dynamics Biophysics Medicine Single-Cell Analysis Protein Processing Post-Translational Noise (radio) Research Article Computational and Systems Biology |
| Zdroj: | eLife eLife, Vol 6 (2017) |
| DOI: | 10.1101/123935 |
| Popis: | Cellular networks are intrinsically subject to stochastic fluctuations, but analysis of the resulting noise remained largely limited to gene expression. The pathway controlling chemotaxis ofEscherichia coliprovides one example where posttranslational signaling noise has been deduced from cellular behavior. This noise was proposed to result from stochasticity in chemoreceptor methylation, and it is believed to enhance environment exploration by bacteria. Here we combined single-cell FRET measurements with analysis based on the fluctuation-dissipation theorem (FDT) to characterize origins of activity fluctuations within the chemotaxis pathway. We observed surprisingly large methylation-independent thermal fluctuations of receptor activity, which contribute to noise comparably to the energy-consuming methylation dynamics. Interactions between clustered receptors involved in amplification of chemotactic signals are also necessary to produce the observed large activity fluctuations. Our work thus shows that the high response sensitivity of this cellular pathway also increases its susceptibility to noise, from thermal and out-of-equilibrium processes. |
| Databáze: | OpenAIRE |
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