A Dual-Sensing Receptor Confers Robust Cellular Homeostasis

Autor: Hannah Schramke, Filipe Tostevin, Ralf Heermann, Ulrich Gerland, Kirsten Jung
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Cell Reports, Vol 16, Iss 1, Pp 213-221 (2016)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2016.05.081
Popis: Cells have evolved diverse mechanisms that maintain intracellular homeostasis in fluctuating environments. In bacteria, control is often exerted by bifunctional receptors acting as both kinase and phosphatase to regulate gene expression, a design known to provide robustness against noise. Yet how such antagonistic enzymatic activities are balanced as a function of environmental change remains poorly understood. We find that the bifunctional receptor that regulates K+ uptake in Escherichia coli is a dual sensor, which modulates its autokinase and phosphatase activities in response to both extracellular and intracellular K+ concentration. Using mathematical modeling, we show that dual sensing is a superior strategy for ensuring homeostasis when both the supply of and demand for a limiting resource fluctuate. By engineering standards, this molecular control system displays a strikingly high degree of functional integration, providing a reference for the vast numbers of receptors for which the sensing strategy remains elusive.
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