Maximizing Investigators' Research Award (R35 - Clinical Trial Optional)

项目概要： 进化上保守的Wnt信号通路在后生动物的发育过程中起着关键作用 和干细胞的维持。Wnt通路中的突变导致其 人类的失调已被证明有助于发育缺陷， 癌的在后一种情况下，超过90%的所有非遗传性形式的结肠直肠癌是 由Wnt通路中的突变引发，导致其不适当的激活。没有 FDA批准的抑制Wnt通路的药物，这可能是由于我们的不完全 对Wnt信号传导机制的理解和缺乏合适的药物靶点。的 我的实验室的主要重点是了解Wnt信号通路的生物学功能， 破译其分子机制并鉴定新的Wnt组分。我们的最终目标是 利用这些信息来了解Wnt通路的失调如何导致Wnt- 人类的疾病。 十多年来，我的实验室为我们的基础研究做出了重大贡献。 了解Wnt信号。这些突破是通过开发 第一生化系统（使用爪蟾卵提取物），活性纯化的重组 蛋白质，第一个数学模型（李-海因里希模型）的发展， 鉴定小分子抑制剂（CK 1 β激动剂），其中一种已被指定为 FDA将其列为治疗家族性癌前疾病（家族性腺瘤性 息肉病）。 我们目前的工作集中在确定USP 46/UAF 1/WDR 20去泛素化酶的作用 复合物调节LRP 6受体周转，APC调节Wnt的机制 受体活性，β-连环蛋白降解复合物在介导β-连环蛋白途径中的作用 行为，以及USP 47和STK 38在调节Wnt信号传导中的作用。在我们的复兴中 应用，我们现在建议1）重建LRP 6泛素化，并确定其进化 保守的E3连接酶，2）了解Wnt受体丢失后信号补偿的基础， APC突变细胞，3）为双稳态在形态发生中的作用提供了证据。 4）揭示STK 38和TRIP 12在核Wnt信号传导中的作用。

PROJECT SUMMARY: The evolutionarily conserved Wnt pathway plays a critical role during metazoan development and stem cell maintenance in the adult. Mutations in the Wnt pathway leading to its misregulation in humans have been shown to contributes to both developmental defects and cancers. In the latter case, over 90% of all non-hereditary forms of colorectal cancers are initiated by mutations in the Wnt pathway leading to its inappropriate activation. There are no FDA-approved drugs that inhibit the Wnt pathway, which is likely due to our incomplete understanding of the mechanism of Wnt signaling and the lack of suitable drug targets. The primary focus of my lab is to understand the biological function of the Wnt signaling pathway by deciphering its molecular mechanism and identifying new Wnt components. Our ultimate goal is to use this information to understand how deregulation of the Wnt pathway can lead to Wnt- driven diseases in humans. Over more than a decade, my lab has made significant contributions to our fundamental understanding of Wnt signaling. These breakthroughs were accomplished via the development of the first biochemical system (using Xenopus egg extract), the reconstitution of active purified proteins, the development of the first mathematical model (Lee-Heinrich model), and the identification of small molecule inhibitors (CK1 agonists), one of which has been designated by the FDA as an orphan drug for a familial precancerous disease (familial adenomatous polyposis). Our current work focused on determining the role of the USP46/UAF1/WDR20 deubiquitinase complex in regulating LRP6 receptor turnover, the mechanism by which APC regulates Wnt receptor activity, the role of the -catenin degradation complex in mediating bistable pathway behavior, and the roles of USP47 and STK38, in regulating Wnt signaling. In our renewal application, we now propose to 1) reconstitute LRP6 ubiquitylation and identify its evolutionarily conserved E3 ligase, 2) understand the basis for signal compensation upon Wnt receptor loss in APC mutant cells, 3) provide evidence for the role of bistability in generating morphogenetic signaling, and 4) uncover the roles of the STK38 and TRIP12 in nuclear Wnt signaling.