Non-canonical functions of chromatin insulators and Polycomb-group proteins

基因转录的变化在癌症的进展中是重要的，在大多数其他人类疾病中， 在衰老过程中，以及在多细胞生物体发育的各个阶段。全 了解这些变化是如何调节的，是诊断工具和干预战略的基础。 进一步的进步有望产生新的方法，并提高目前的有效性。 接近。在果蝇中可用的工具使研究基因调控机制成为可能， 在真实的体内环境中。该提案旨在研究基于染色质的基因调控机制 涉及Polycomb响应元件（PRE）和绝缘体（包括一种名为homie的绝缘体）， 果蝇的基因甚至跳过了这些研究将解决如何解决的基本问题 调节DNA介导转录记忆和染色体组织， 原子核中的三维空间。他们将提供一个更清晰的理解表观遗传机制如何 传播替代转录状态，以及染色体结构域组织如何影响基因 表情这些研究的一个独特贡献是将这些机制与那些介导 增强子-启动子的相互作用。在哺乳动物中，多梳组蛋白和 绝缘子参与维持干细胞身份，发育决策和剂量 补偿，以及肿瘤发生和遗传性人类疾病。具体目标是： 目标1。确定保守的DNA结合多梳组（PcG）蛋白多同源异型（Pho） 维持果蝇的活性和抑制状态，甚至跳过（eve）基因表达。 确定调控夏娃的新表观遗传机制如何在全基因组范围内展开。 这些研究的结果将推动表观遗传基因调控领域进入新的领域， 对发育和成体组织维持的全新影响。 目标二。确定通读转录如何抑制增强子功能，以及这种抑制是如何 受Polycomb结构域的影响，在前夕和整个基因组。 这里的研究将探索一种新的方式，在这种方式中，转录的行为调节基因，从而导致 适用于全基因组的机械见解。 目标3：确定一些启动子启动高度进行性转录的机制， 通过势垒，例如poly（A）加成信号，而其他则不。 进行性转录对基因表达和染色体结构有很大的影响， 沿着沿着的距离。它的规则和影响才刚刚开始被理解。我们有 开发了一种灵敏的分析系统，使我们能够快速地朝着机械的方向发展。 认识

Changes in gene transcription are important in the progression of cancer, in most other human diseases, and in the aging process, as well as in the development of multicellular organisms at all stages. A full understanding of how such changes are regulated is the basis of diagnostic tools and intervention strategies. Further advancement holds the promise of novel approaches, and of increased effectiveness of current approaches. Tools available in Drosophila make it possible to study gene regulatory mechanisms in great detail, in a true in vivo context. This proposal is to study mechanisms of chromatin-based gene regulation involving Polycomb-response elements (PREs) and insulators (including one named homie) that are found in the well-characterized Drosophila gene even skipped. These studies will address basic questions of how regulatory DNA that mediates transcriptional memory and chromosome organization carries out its function in 3 dimensions in the nucleus. They will provide a clearer understanding of how epigenetic mechanisms propagate alternative transcriptional states, and how chromosomal domain organization affects gene expression. A unique contribution of these studies is to integrate these mechanisms with those mediating enhancer-promoter interactions in a developmental context. In mammals, Polycomb-group proteins and insulators are involved in the maintenance of stem cell identity, developmental decisions, and dosage compensation, as well as in oncogenesis and inherited human disorders. The Specific Aims are: Aim 1. Determine how the conserved, DNA binding Polycomb-group (PcG) protein Pleiohomeotic (Pho) maintains both the active and the repressed state of Drosophila even skipped (eve) gene expression. Determine how novel epigenetic mechanisms that regulate eve are deployed genome-wide. Results from these studies will propel the field of epigenetic gene regulation into novel territory, uncovering entirely new influences on both development and adult tissue maintenance. Aim 2. Determine how read-through transcription represses enhancer function and how this repression is influenced by Polycomb domains, at eve and throughout the genome. Studies here will explore a new way in which the very act of transcription regulates genes, leading to mechanistic insights that apply genome-wide. Aim 3. Determine mechanisms whereby some promoters initiate highly processive transcription that reads through barriers, such as poly(A) addition signals, while others do not. Processive transcription has the power to influence gene expression and chromosome architecture over great distances along a chromosome. Its regulation and influence are just beginning to be understood. We have developed a sensitive assay system that will allow us to make rapid progress toward a mechanistic understanding.