Mapping the Architecture of Cancer Signaling Pathways

描述(由申请人提供)：了解细胞如何迁移、建立极性和采用细胞形状是理解癌症生物学的基础。几乎百分之一的人类蛋白质组致力于Rho GTPase信号，它调节每个过程的关键方面。众所周知，Rho GTP酶是一种“信号开关”，它由鸟嘌呤核苷酸交换因子和GAP(GTP酶激活蛋白)蛋白“开启”或“关闭”。目前尚不清楚的是决定Rho全环和GAP特异性的分子机制。由于GEF和GAP在特定的细胞环境中调节Rho-GTP酶，它们有望成为未来治疗干预的候选对象，以调节不同类型癌症的GTP酶活性。这一建议开发了一种创新和集成的方法来绘制体内Rho GTP酶信号的结构图。将使用多种独立的方法，包括使用含有非天然氨基酸的细胞蛋白质的新型蛋白质组筛选，以及高通量结合分析和基于信息学的实验。我们最近在我们的实验室建立了这种方法，我们的初步数据证实了我们的基本原理，即这种方法将揭示Rho GTPase信号和癌症生物学之间的新联系。在这个试点项目结束时，我们希望证明这种方法可以在更大的范围内工作，为这一途径的调节者绘制相互作用网络。这些结果将从根本上促进我们对Rho GTP酶如何调控过程的理解，如迁移、极性和细胞形态。它还有望为改变癌症预后的治疗策略的未来发展提供必要的基本信息。

DESCRIPTION (provided by applicant): To appreciate how cells migrate, establish polarity, and adopt cell shape is fundamental to understanding cancer biology. Almost one percent of the human proteome is dedicated to Rho GTPase signaling, which regulates key aspects of each of these processes. It is well known that Rho GTPases are "signaling switches" that are turned "on" or "off" by GEF (Guanine nucleotide Exchange Factors) and GAP (GTPase Activating Proteins) proteins. What is not known are the molecular mechanisms that determine Rho GEF and GAP specificity. Because GEFs and GAPs regulate Rho-GTPases in specific cellular contexts, they are promising candidates for future therapeutic interventions to modulate GTPase activity in different types of cancers. This proposal develops an innovative and integrated approach to map the architecture of Rho GTPase signaling in vivo. Multiple independent methods will be used, including novel proteomic screens using cellular proteins with unnatural amino acids as well as high throughput binding assays and informatics- based experiments. We have recently established this approach in our laboratory and our preliminary data validates our rationale that this approach will uncover novel links between Rho GTPase signaling and cancer biology. At the conclusion of this pilot project we expect to demonstrate that this approach can work on a larger scale to map interaction networks for regulators of this pathway. These results will fundamentally advance our understanding of how Rho GTPases are modulated to regulate processes such as migration, polarity, and cell morphology. It can also be expected to provide the basic information necessary for the future development of therapeutic strategies to alter cancer outcomes.