Notch Signaling in Cancer

项目摘要 我的研究计划的动机是了解致癌信号如何促进人类的免疫反应。 癌我们工作的一个重要方面使我们的贡献有别于其他方面， 已经集中在关于正常和异常信号传导的分子机制的基本问题上， 强调结构，生物化学，分子和细胞为基础的方法。我的首要研究目标是 该奖项的颁发期建立在我们近二十年来在Notch领域的持续贡献之上，并且将 重点回答以下关键问题： i）ADAM家族蛋白酶激活正常和致病性Notch的分子机制是什么？ 配体通常将Notch受体从休眠状态转化为信号活性状态，使其易受 ADAM家族金属蛋白酶在细胞膜外直接进行蛋白水解，但我们的 对ADAM介导的Notch受体的蛋白水解的理解仍然非常基本。我们将 阐明完整的ADAM 10和ADAM 17胞外域的结构，并确定 亚当斯的调节和催化结构域在正常和致癌细胞中执行Notch蛋白水解， 发信号。然后，可以使用区分ADAM 10活性位点与ADAM 17活性位点的结构特征来 指导开发高选择性的ADAM 10或ADAM 17抑制剂。 ii）Notch核转录机制的分子机制是什么？ 情结？细胞内Notch（ICN）与细胞核中RBPJ转录因子的结合导致MAML 募集，但如何与Notch-RBPJ复合物合作，以诱导 转录仍然是该领域中未解决的基本问题。通过定义事件的顺序 通过将Notch 1信号传导和MAML 1募集与基因表达变化联系起来，我们将阐明Notch 1信号传导和MAML 1募集在基因表达变化中的作用。 MAML在癌细胞对Notch活化的反应中。 iii）Notch转录靶点反馈调节的分子机制是什么？作为核心 NRARP是Notch信号的一个组成部分，在不同的细胞类型中，NRARP是Notch调控的转录靶点 转导电路，通过与核心Notch结合作为信号传导的负反馈调节器 转录复合体我们的目标将是阐明NRARP招募到Notch的结构基础 转录复合物，揭示NRARP抑制复合物组装的分子机制， 阐明NRARP抑制的分子机制。总之，这些研究将揭示一个 Notch信号调节的中心机制，并为开发新的调节剂创造机会， 陷波信号。

Project Summary The motivation for my research program has been to understand how oncogenic signaling promotes human cancer. An important facet of our work, which distinguishes our contributions from those of others, is that we have focused on fundamental questions about molecular mechanisms of both normal and aberrant signaling, emphasizing structural, biochemical, molecular, and cell-based approaches. My overarching research goals over the award period build from our sustained contributions over almost two decades in the Notch field, and will emphasize answering the following key questions: i) What is the molecular mechanism of normal and pathogenic Notch activation by ADAM-family proteases? Ligands normally convert Notch receptors from a dormant to signaling-active state by rendering them susceptible to proteolysis by ADAM-family metalloproteases at a site immediately external to the cell membrane, yet our understanding of ADAM-mediated proteolysis of Notch receptors remains remarkably rudimentary. We will elucidate the structures of the full ADAM10 and ADAM17 ectodomains, and determine how interplay between the regulatory and catalytic domains of the ADAMs executes Notch proteolysis in normal and oncogenic signaling. Structural features that distinguish the ADAM10 active site from that of ADAM17 can then be used to guide development of highly selective ADAM10 or ADAM17 inhibitors. ii) What is the molecular mechanism of engagement of the transcriptional machinery by Notch nuclear complexes? Binding of intracellular Notch (ICN) to the RBPJ transcription factor in the nucleus leads to MAML recruitment, but how Mastermind-like proteins (MAMLs) cooperate with Notch-RBPJ complexes to induce transcription remains a fundamental unresolved question in the field. By defining the sequence of events connecting Notch1 signaling and MAML1 recruitment to gene expression changes, we will illuminate the role of MAML in the response of cancer cells to Notch activation. iii) What is the molecular mechanism of feedback regulation by Notch transcriptional targets? As a core transcriptional target regulated by Notch in diverse cell types, NRARP is an integral part of the Notch signal transduction circuitry, acting as a negative feedback regulator of signaling by binding to the core Notch transcription complex. Our goals will be to elucidate the structural basis for NRARP recruitment to the Notch transcription complex, uncover the molecular mechanism underlying assembly of NRARP inhibitory complexes, and elucidate the molecular mechanism underlying NRARP inhibition. Together, these studies will uncover a central mechanism of Notch signal modulation, and create opportunities for development of novel regulators of Notch signaling.