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

项目总结： 进化上保守的Wnt途径在后生动物的发育过程中起着关键作用 以及成人体内干细胞的维持。导致ITS的Wnt途径的突变 人类的错误调节已被证明是导致发育缺陷和 癌症。在后一种情况下，超过90%的非遗传性结直肠癌是 由Wnt途径的突变启动，导致其不适当的激活。没有 FDA批准的抑制Wnt途径的药物，这可能是由于我们的不完全 了解Wnt信号转导机制，缺乏合适的药物靶点。这个 我的实验室主要关注的是通过以下方式了解Wnt信号通路的生物学功能 破译其分子机制，鉴定新的Wnt组分。我们的最终目标是 为了利用这些信息来理解WNT途径的放松调控如何导致WNT- 由人类引发的疾病。 十多年来，我的实验室为我们的基础工作做出了重大贡献 了解Wnt信号。这些突破是通过发展实现的 对第一生化系统(使用非洲爪蛙卵提取液)的重组进行了活性纯化 蛋白质，第一个数学模型(Lee-Heinrich模型)的发展，以及 鉴定小分子抑制剂(CK1激动剂)，其中一种已被指定为 FDA作为一种家族性癌前疾病(家族性腺瘤)的孤儿药物 息肉病)。 我们目前的工作集中在确定USP46/UAF1/WDR20去泛素酶的作用 调节LRP6受体周转的复合体--APC调节Wnt的机制 受体活性、-连环蛋白降解复合体在介导双稳态途径中的作用 行为，以及USP47和STK38在调节Wnt信号中的作用。在我们的更新中 应用，我们现在建议：1)重建LRP6泛素化并鉴定其进化 保守的E3连接酶，2)了解Wnt受体缺失的信号补偿基础 APC突变细胞，3)为双稳在形态发生中的作用提供证据 4)揭示STK38和TRIP12在核Wnt信号转导中的作用。

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.