Mechanism of bidirectional thermotaxis in Escherichia coli
Abstract
In bacteria various tactic responses are mediated by the same cellular pathway, but sensing of physical stimuli remains poorly understood. Here, we combine an in-vivo analysis of the pathway activity with a microfluidic taxis assay and mathematical modeling to investigate the thermotactic response of Escherichia coli. We show that in the absence of chemical attractants E. coli exhibits a steady thermophilic response, the magnitude of which decreases at higher temperatures. Adaptation of wild-type cells to high levels of chemoattractants sensed by only one of the major chemoreceptors leads to inversion of the thermotactic response at intermediate temperatures and bidirectional cell accumulation in a thermal gradient. A mathematical model can explain this behavior based on the saturation-dependent kinetics of adaptive receptor methylation. Lastly, we find that the preferred accumulation temperature corresponds to optimal growth in the presence of the chemoattractant serine, pointing to a physiological relevance of the observed thermotactic behavior.
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Author details
Funding
National Institutes of Health (R01 GM082938)
- Vladimir Jakovljevic
- Yigal Meir
- William S Ryu
- Ned S Wingreen
- Victor Sourjik
H2020 European Research Council (294761-MicRobE)
- Vladimir Jakovljevic
- Victor Sourjik
Max-Planck-Institut für Terrestrische Mikrobiologie (Open-access funding)
- Victor Sourjik
National Science Foundation (PHY-1411313)
- Alex Groisman
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Paulick et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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