A Dual-Sensing Receptor Confers Robust Cellular Homeostasis.
A Dual-Sensing Receptor Confers Robust Cellular Homeostasis.
复制标题
DOI：
10.1016/j.celrep.2016.05.081
复制
发表时间：
2016-06
期刊：
影响因子：
8.8
通讯作者：
H. Schramke;Filipe Tostevin;R. Heermann;U. Gerland;K. Jung
中科院分区：
文献类型：
--
作者：
H. Schramke;Filipe Tostevin;R. Heermann;U. Gerland;K. Jung
细胞已经进化出多种机制，可以在波动的环境中维持细胞内稳态。在细菌中，控制通常由双功能受体发挥作用，既充当激酶又充当磷酸酶来调节基因表达，这种设计已知可以提供抗噪声的鲁棒性。然而，这种拮抗酶活性如何随着环境变化而平衡仍然知之甚少。我们发现，在大肠杆菌中调节 K+ 摄取的双功能受体是一种双重传感器，它响应细胞外和细胞内 K+ 浓度来调节其自激酶和磷酸酶活性。使用数学模型，我们表明，当有限资源的供应和需求波动时，双重传感是确保体内平衡的优越策略。按照工程标准，这种分子控制系统显示出惊人的高度功能集成，为大量传感策略仍难以捉摸的受体提供了参考。
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 inEscherichia coliis 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.