Role of ADP-ribosylation in Wnt Pathway Activation

ADP-核糖基化在 Wnt 通路激活中的作用

基本信息

批准号：
9892659
负责人：
Yasmath Ahmed
金额：
$ 12.5万
依托单位：
DARTMOUTH COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9892659
关键词：
ADP ribosylation Address Adenosine Diphosphate Ribose Animals Biochemical Biological Biological Assay Biology Cell Differentiation process Cells Collaborations Colorectal Cancer Complex Congenital Abnormality Congenital Disorders Coupled Development Disease Dissection Drosophila genus Drug Industry Effectiveness Embryonic Development Genetic Goals Heart Human In Vitro Invertebrates Investigation Knowledge Left Limb structure Malignant Neoplasms Mass Spectrum Analysis Mediating Modeling Multiprotein Complexes Mutagenesis Nature Nervous system structure Pathway interactions Physiological Play Polymerase Post-Translational Protein Processing Protein Conformation Regulation Research Retina Role Scaffolding Protein Scientist Signal Transduction Signal Transduction Pathway Site Skeleton Skin System Tankyrase Testing Therapeutic Agents Therapeutic Intervention Transcription Coactivator WNT Signaling Pathway Xenopus attenuation base beta catenin design egg experience in vivo inhibitor/antagonist innovation insight interest new therapeutic target novel novel therapeutic intervention polymerization prevent protein complex public health relevance reconstitution recruit reproductive organ response scaffold small molecule therapeutic target tool treatment strategy

项目摘要

The Wnt signal transduction pathway directs essential steps in embryonic development. Inappropriate activation of Wnt signaling triggers the development of several cancers, including the vast majority of colorectal cancers. Thus, understanding the basic mechanisms that underlie Wnt pathway activation will facilitate the design of innovative strategies for the treatment of a large number of diseases. A major goal of our research is to elucidate the regulation of two distinct multiprotein complexes - termed the “beta-catenin destruction complex” and the “signalosome”- that are fundamental for the control of Wnt signaling in the “off” and “on” states, respectively. Axin, a concentration-limiting scaffold protein, plays important roles in the assembly of both complexes. How these distinct roles of Axin are coordinated remains a mystery. Regulators of Axin, including the ADP-ribose polymerase Tankyrase (Tnks) have recently emerged as promising therapeutic targets. In the current model, the sole role of Tnks is to target Axin for proteasomal degradation, and thereby to control steady state Axin levels in the unstimulated state. However, we have found, unexpectedly, that ADP- ribosylation of Axin by Tnks also promotes Axin's critical role in activation of the pathway following Wnt stimulation. Our findings force major revision of the prevailing model for Tnks function in Wnt signaling and may underlie the effectiveness of small molecule Tnks inhibitors, which are among the most promising anti- Wnt pathway agents under development. Thus, in contrast with the prevailing model, we hypothesize that Tnks plays key roles in controlling Axin activity both in the destruction complex (in the unstimulated state) and in the signalosome (following Wnt stimulation). We propose to test this hypothesis by analyzing differences in the state of Axin ADP-ribosylation under basal and Wnt-stimulated conditions. We will determine how Axin ADP- ribosylation regulates the composition and activity of the β-catenin destruction complex and signalosome. We will address the physiological roles of ADP-ribosylation on Axin activity in the unstimulated and Wnt-stimulated states in vivo. These studies are driven by an ongoing collaboration between two scientists who have a shared interest in Wnt signaling: Yashi Ahmed, an experienced Drosophila geneticist and cell biologist, and Ethan Lee, an expert in using in vivo approaches in Xenopus and in vitro pathway reconstitution. We will combine our innovative genetic, cell biological, and biochemical approaches in vertebrate and invertebrate models to provide insight into the regulation of Wnt signaling. The proposed research has significance for the development of new therapeutic strategies for Wnt-driven diseases.

Wnt 信号转导途径指导胚胎发育的重要步骤。 Wnt 信号传导的激活会引发多种癌症的发生，包括绝大多数结直肠癌因此，了解 Wnt 通路激活的基本机制将有助于设计治疗大量疾病的创新策略是我们研究的一个主要目标。阐明两种不同的多蛋白复合物的调节——称为“β-连环蛋白破坏” 复合体”和“信号体”——对于控制 Wnt 信号传导的“关闭”和“开启”至关重要轴蛋白是一种浓度限制的支架蛋白，在组装中发挥重要作用。 Axin 的这些不同作用如何协调仍然是一个谜。包括 ADP-核糖聚合酶 Tankyrase (Tnks) 最近已成为有前景的治疗药物在当前模型中，Tnks 的唯一作用是靶向 Axin 进行蛋白酶体降解，从而控制未刺激状态下的稳态轴蛋白水平然而，我们意外地发现，ADP- Tnks 对 Axin 的核糖基化还促进 Axin 在 Wnt 之后的通路激活中发挥关键作用我们的发现迫使对 Wnt 信号传导和 Tnks 功能的流行模型进行重大修改。可能是小分子 Tnks 抑制剂有效性的基础，小分子 Tnks 抑制剂是最有前途的抗- 因此，与流行的模型相比，我们捕获了 Tnks。在破坏复合体（未刺激状态）和我们建议通过分析信号体（Wnt 刺激后）的差异来检验这一假设。我们将确定 Axin ADP-核糖基化在基础和 Wnt 刺激条件下的状态。核糖基化调节 β-连环蛋白破坏复合物和信号体的组成和活性。将解决 ADP-核糖基化对未刺激和 Wnt 刺激的 Axin 活性的生理作用这些研究是由两位拥有共同观点的科学家之间持续合作推动的。对 Wnt 信号传导感兴趣：Yashi Ahmed，一位经验丰富的果蝇遗传学家和细胞生物学家，以及 Ethan Lee，非洲爪蟾体内方法和体外途径重建方面的专家，我们将结合我们的方法。脊椎动物和无脊椎动物模型中的创新遗传、细胞生物学和生化方法所提出的研究对于Wnt信号传导的调控具有重要意义。开发针对 Wnt 驱动疾病的新治疗策略。