English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

KdpD and KdpE form a histidine kinase/response regulator system that senses K +  limitation and induces the  kdpFABC  operon, which encodes a high-affinity K +  uptake complex. To define the primary stimulus perceived by KdpD we focused in this study on the dynamics of the Kdp response.  Escherichia coli  cells were subjected to severe K +  limitation, and all relevant parameters of the Kdp response, i.e., levels of  kdpFABC  transcripts and KdpFABC proteins, as well as extra- and intracellular K +  concentrations, were quantitatively analysed over time (0 to 180 min). Unexpectedly, induction of  kdpFABC  was found to follow a non-monotonic time-course. To interpret this unusual behaviour, a mathematical model that adequately captures the dynamics of the Kdp system was established and used for simulations. We found a strong correlation between KdpD/KdpE activation and the intracellular K +  concentration, which is influenced by the uptake of K +  via the KdpFABC complex. Based on these results a model is proposed in which KdpD/KdpE phosphorylation is inversely correlated with the intracellular K +  concentration. To corroborate this hypothesis an isogenic mutant that produces a defective KdpFABC complex, and the  trans -complemented mutant that expresses the KtrAB high-affinity K +  uptake system of  Vibrio alginolyticus  were quantitatively analysed. Experimental data and simulations for the mutants consistently support the tight correlation between KdpD/KdpE activation and the intracellular K +  concentration. This study presents a striking example of the non-intuitive dynamics of a functional unit comprising signalling proteins and a transporter with K +  as mediator.

Dynamics of an Interactive Network Composed of a Bacterial Two-Component System, a Transporter and K+ as Mediator