Systems biology of MAPK signaling in early drosophila embryo

描述（由申请人提供）：丝裂原激活蛋白激酶（MAPK）信号通路是成体和发育组织中细胞过程的关键调节因子。 MAPK 信号传导失调与多种疾病相关，这使其成为多个治疗领域的关键药物靶点。鉴于这一重要途径内有大量的成分和调节水平，如果没有定量实验、数学建模和计算分析，理解和控制其功能基本上是不可能的。早期果蝇胚胎中的末端模式系统非常适合此目的，因为它的解剖学相对简单，并且可以使用大量遗传工具来操纵 MAPK 调节剂和底物。我们开发了用于体内分析末端模式系统中 MAPK 磷酸化和信号传导的定量测定方法。基于这些测定，在我们最近发表的工作中，我们制定了一个模型，根据该模型，早期胚胎中 MAPK 信号传导的空间模式是由酶底物竞争网络控制的。具体来说，我们提出 MAPK 底物相互竞争并与 MAPK 磷酸酶竞争与激活的 MAPK 的结合。此外，我们提出 MAPK 底物竞争不仅影响 MAPK 通路，还影响其与其他信号系统的相互作用。本申请中描述的工作将提供底物竞争机制的分子和功能表征。我们提案的主要创新在于综合了发育信号转导的建模、遗传和生化方法。通过结合我们在建模、遗传学和生物化学方面的优势，我们在制定和实验测试 MAPK 信号传导的系统级描述方面处于独特的地位。超越早期果蝇胚胎和 MAPK 途径，我们提出底物竞争在生物分子网络中提供了一种通用的信号整合策略，其中酶（例如 MAPK）与其多种调节剂和底物相互作用。

DESCRIPTION (provided by applicant): The Mitogen Activated Protein Kinase (MAPK) signaling pathway is a critical regulator of cellular processes in adult and developing tissues. Deregulated MAPK signaling is associated with a number of diseases, which makes it a key drug target in multiple therapeutic areas. Given a large number of components and levels of regulation within this important pathway, understanding and controlling its function is essentially impossible without quantitative experiments, mathematical modeling, and computational analysis. The terminal patterning system in the early Drosophila embryo is ideally suited for this purpose because of its relative anatomical simplicity and the availability of a large number of genetic tools for the manipulation of MAPK regulators and substrates. We have developed quantitative assays for the in vivo analysis of MAPK phosphorylation and signaling in the terminal patterning system. Based on these assays, in our recently published work we formulated a model according to which the spatial pattern of MAPK signaling in the early embryo is controlled by an enzyme-substrate competition network. Specifically, we proposed that MAPK substrates compete among themselves and with the MAPK phosphatase for binding to the activated MAPK. In addition, we proposed that MAPK substrate competition influences not only the MAPK pathway, but also its interaction with other signaling systems. The work described in this application will provide molecular and functional characterization of the substrate competition mechanism. The main innovation of our proposal is in synthesizing modeling, genetic, and biochemical approaches to developmental signal transduction. By combining our strengths in modeling, genetics, and biochemistry, we are uniquely positioned to formulate and experimentally test systems-level descriptions of MAPK signaling. Going beyond the early Drosophila embryo and MAPK pathway, we propose that substrate competition provides a general signal integration strategy in biomolecular networks where enzymes, such as MAPK, interact with their multiple regulators and substrates.