Systems Biology Approach to Study the Escherichia coli Two-Component Signal Transduction Interactome

所有的生物都在不断地进行调整，以适应环境的变化。单细胞微生物使用一种称为双组分调节剂的蛋白质家族来感知环境的变化并进行适应性变化。每个双组分系统由暴露于细胞外部以检测环境参数的传感器蛋白和与传感器通信并使基因表达发生适当变化的调节蛋白组成。 一个微生物可能拥有数十或数百个双组分系统，每一个都对不同的环境信号做出反应。 最近的研究表明，一些双组分系统是通过称为连接子的信号蛋白连接的。 连接器由一个双组分系统开启，并影响另一个双组分系统的信号活动。 这些连接允许形成细胞调节网络，通过整合多个双组分系统的活动，导致对给定信号的最佳适应。 在这个建议中，我假设，额外的，未被发现的连接之间存在的30个两个组件系统的良好特性的模式生物大肠杆菌。 我们将首先通过比较单个双组分通路开启时获得的基因表达谱来识别连接的双组分系统。一旦我们确定了双组分系统之间的连接，我们将使用遗传筛选来识别负责建立连接的“连接器”。 最后，我们将弄清楚这些连接器如何工作。 先前确定的连接器通过与受影响的双组分系统的传感器或调节器相互作用来改变其活动。 我们将设置实验来评估两组分系统的哪个成员受到连接器的影响，以及如何影响。 由于双组分调节剂在控制疾病病因和代谢中涉及的细菌活动中起着重要作用，因此这项工作有可能揭示有关如何治疗微生物感染以及如何利用细菌生产有用化合物的新想法。

All organisms make continual adjustments to account for changes in their environments. Single celled microbes use a family of proteins called two-component regulators to sense alterations in their environments and institute adaptive changes. Each two-component system consists of a sensor protein that is exposed to the outside of the cell to detect environmental parameters and a regulator protein that communicates with the sensor and makes appropriate changes in gene expression. A microbe may possess tens or hundreds of two-component systems, each one responsive to a different environmental cue. Recent studies indicate that some two-component systems are connected by means of signaling proteins called connectors. Connectors are turned on by one two-component system and influence the signaling activities of another two-component system. These connections allow for the formation of a cellular regulatory network that results in optimal adaptation to a given signal by integrating the activities of multiple two-component systems. In this proposal, I hypothesize that additional, undiscovered connections exist between the 30 two-component systems of the well-characterized model organism Escherichia coli. We will first identify connected two-component systems by comparing gene expression profiles obtained when individual two-component pathways are turned on. Once we have identified connections between two-component systems, we will use genetic screens to identify the "connectors" that are responsible for making the connections. Finally, we will figure out how these connectors work. Previously identified connectors work by interacting with the sensor or the regulator of the affected two-component system to alter its activity. We will set up experiments to evaluate which member of the two-component system is affected by the connector, and how. Since two-component regulators play important roles in controlling bacterial activities involved in disease causation and metabolism, this work has the potential to uncover new ideas about how to treat microbial infections and how to harness bacteria for the production of useful compounds.