Defining the logic and function of the AMPK-mTORC1 signaling axis

项目总结 在后生动物中，器官的动态平衡需要增殖信号和能量状态的协调， 然而，分子反馈系统如何平衡单个细胞内的能量消耗并不是很好。 明白了。这项研究的目的是明确细胞生长是如何通过代谢反馈控制在单个- 细胞水平。为了实现这一目标，我将结合延时成像和新陈代谢方法来构建 信号动力学和代谢通量之间的定量关系。一个行之有效的机制 协调细胞生长和动态平衡的是AMPK信号轴。在能量有限的州， AMPK直接抑制高能量消耗的生长过程，同时促进分解代谢 小路。AMPK活性的净效果是增加了还原剂、生物合成 前体和三磷酸腺苷。这项工作将建立在最近的发现基础上，在正常生长条件下，AMPK 在个体中，活性是动态的，并且与主要的增殖途径的活性呈强烈的反相关 细胞。要定义AMPK活性如何直接限制合成代谢的主调节因子mTORC1的信号整合 过程中，我将多路荧光记者同时测量AMPK和mTORC1活性 在活细胞内。然后将使用活细胞成像方法来定义动态输入/输出关系 AMPK活性、mTORC1信号和下游过程之间的关系，包括蛋白质速率 翻译和DNA合成。接下来，代谢组学特征将定义精确的适应功能 以及AMPK-mTORC1控制环支持的代谢配置。最终，这项研究将界定 如何整合基于信号和代谢物的控制机制来协调新陈代谢 增殖细胞的动态平衡。动态了解AMPK-mTORC1控制回路对于 了解能量平衡是如何在单细胞水平上实现的。这项研究的发现可能 支持开发针对许多人类疾病的新的治疗方法 由于生长和能量过程的失调。

PROJECT SUMMARY Across metazoans, organ homeostasis requires the coordination of proliferative signals and energetic states, yet how molecular feedback systems balance energy expenditure within an individual cell is not well understood. This study aims to define how cell growth is regulated by metabolic feedback control at the single- cell level. To achieve this goal, I will couple time-lapse imaging and metabolomic approaches to construct quantitative relationships between signaling dynamics and metabolic flux. One well-established mechanism which coordinates cellular growth and homeostasis is the AMPK signaling axis. In energetically limited states, AMPK directly inhibits energetically expensive growth processes and simultaneously promotes catabolic pathways. The net effect of AMPK activity is to increase the availability of reducing agents, biosynthetic precursors, and ATP. This work will build upon the recent finding that under normal growth conditions, AMPK activity is dynamic and strongly anti-correlated with the activities of major proliferative pathways in individual cells. To define how AMPK activity directly limits signal integration by mTORC1, a master regulator of anabolic processes, I will multiplex fluorescent reporters to simultaneously measure AMPK and mTORC1 activities within living cells. Live cell imaging approaches will then be used to define dynamic input/output relationships between AMPK activity, mTORC1 signaling, and downstream processes including the rates of protein translation and DNA synthesis. Next, metabolomic characterization will define the precise adaptive function and metabolic configurations supported by the AMPK-mTORC1 control loop. Ultimately, this study will define how signaling-based and metabolite-based control mechanisms are integrated to coordinate metabolic homeostasis in proliferating cells. A dynamic understanding of the AMPK-mTORC1 control loop is essential for understanding how energetic homeostasis is achieved at a single cell level. Findings from this study may support the development of novel therapeutic approaches that target the many human diseases characterized by the dysregulation of growth and energetic processes.