Abstract
Although the list of proteins that localize to the bacterial cell poles is constantly growing, little is known about their temporal behavior. EI, a major protein of the phosphotransferase system (PTS) that regulates sugar uptake and metabolism in bacteria, was shown to form clusters at the Escherichia coli cell poles. We monitored the localization of EI clusters, as well as diffuse molecules, in space and time during the lifetime of E. coli cells. We show that EI distribution and cluster dynamics varies among cells in a population, and that the cluster speed inversely correlates with cluster size. In growing cells, EI is not assembled into clusters in almost 40% of the cells, and the clusters in most remaining cells dynamically relocate within the pole region or between the poles. In non-growing cells, the fraction of cells that contain EI clusters is significantly higher, and dispersal of these clusters is often observed shortly after exiting quiescence. Later, during growth, EI clusters stochastically re-form by assembly of pre-existing dispersed molecules at random time points. Using a fluorescent glucose analog, we found that EI function inversely correlates with clustering and with cluster size. Thus, activity is exerted by dispersed EI molecules, whereas the polar clusters serve as a reservoir of molecules ready to act when needed. Taken together our findings highlight the spatiotemporal distribution of EI as a novel layer of regulation that contributes to the population phenotypic heterogeneity with regard to sugar metabolism, seemingly conferring a survival benefit.
Original language | English |
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Article number | 2695 |
Journal | Frontiers in Microbiology |
Volume | 8 |
Issue number | JAN |
DOIs | |
State | Published - 17 Jan 2018 |
Bibliographical note
Funding Information:This research was supported by the Israel Science Foundation founded by the Israel Academy of Sciences and Humanities and the Deutsch-Israeli Project Cooperation (DIP). We thank Zakhariya Manevitch from the Core Research Facility of the Faculty of Medicine at The Hebrew University for help with FRAP microscopy. We acknowledge Thomas G. Bernhardt (Harvard Medical School) for gifts of strains. We thank members of Orna Amster-Choder's lab for fruitful discussions.
Publisher Copyright:
© 2018 Govindarajan, Albocher, Szoke, Nussbaum-Shochat and Amster-Choder.
Keywords
- Bacterial polarity
- Cell poles
- Dynamic localization
- General PTS proteins
- PTS system
- Phenotypic heterogeneity
- Proteins localization