Molecular mechanisms of histone signaling in a chromatin relevant context

项目摘要 人类基因组以染色质的形式存在于细胞核中，染色质是DNA与组蛋白的复合物。 虽然遗传信息编码在DNA序列中，但另一层信息编码在DNA序列中。 组蛋白，特别是以翻译后修饰（PTM）的形式。这层信息是 通常被称为表观基因组学，并提供如何调控基因组的指导。染色质 和表观基因组的内容，是高度动态的，不断重组，以应对发展和 环境线索。生物学中最重要的问题之一是， 转录和其他调控复合物，导致基因调控和细胞命运。组蛋白修饰 通过调控复合物内称为阅读器结构域的小亚结构域“阅读”， 一种独特的表观基因组模式被认为是通过多种这些基因的整合活性来实现的。 阅读器域。然而，尽管关于阅读器结构域与蛋白质片段的关联已经知道很多， 组蛋白是一种与染色质相关的组蛋白结合的分子机制， 背景，或者它们如何一起作用以读出特定的表观基因组状态，还没有很好地理解。 这项研究计划解决了染色质调控中的这个基本问题。我们正在开创 使用NMR光谱学来研究阅读器结构域与染色质基本单元的缔合， 核小体我们将其与荧光显微镜、低温电子显微镜和基础 生物化学的整体多学科的方法来建立这些复杂的模型。在未来五 多年来，我们将专注于核小体的构象如何调节表观基因组签名的读出。 我们将继续研究核小体构象本身以及已知的癌症突变 这是不正常的。此外，我们将确定阅读器结构域关联的动力学和结构基础 来自PBAF染色质重塑和PRC1组蛋白修饰与核小体的复合物。通过 合作研究，我们将调查这些相互作用的功能后果。我们将继续 我们的长期目标是了解多个阅读器域如何集成， 复合物导航和响应动态染色质底物。这项研究计划的结果将 揭示染色质调节的基本机制，提供对一些疾病的病因学的见解， 人类疾病，并为靶向治疗的发展奠定基础。

Project Summary The human genome exists in the cell nucleus as chromatin, a complex of the DNA with histone proteins. Though genetic information is encoded in the DNA sequence, another layer of information, is encoded in the histone proteins, specifically in the form of post-translational modifications (PTMs). This layer of information is often referred to as epigenomics, and provides instructions on how the genome is to be regulated. Chromatin and the epigenomic content, is highly dynamic, constantly restructuring in response to developmental and environmental cues. One of the most important questions in biology is how this information is interpreted by transcriptional and other regulatory complexes, leading to gene regulation and cell fate. Histone modifications are “read” through small subdomains within the regulatory complexes called reader domains, and specificity for a unique epigenomic pattern is thought to be achieved through the integrated activity of multiples of these reader domains. However, though much is known about the association of reader domains with fragments of histones, the molecular mechanims underlying how they associate with histones in a chromatin relevent context, or how they function together to readout a specific epigenomic state, are not well understood. This research program addresses this fundamental question in chromatin regulation. We are pioneering the use of NMR spectroscopy to study the association of reader domains with the basic unit of chromatin, the nucleosome. We are combining this with fluorescence microscopy, cryo-electron microscopy, and basic biochemistry for an overall multidisciplinary approach to building models of these complexes. Over the next five years we will focus on how the conformation of the nucleosome regulates readout of epigenomic signatures. We will continue our investigation of the nucleosome conformation itself and how known cancer mutations dysregulate this. In addition, we will determine the kinetic and structural basis of association of reader domains from the PBAF chromatin remodeling and PRC1 histone modifying complexes with nucleosomes. Through collaborative studies we will investigate the functional consequence of these interactions. We will continue to build towards our long-term goal of understand of how multiple reader domains integrate to allow regulatory complexes to navigate and respond to a dynamic chromatin substrate. Results from this research program will reveal fundamental mechanisms of chromatin regulation, provide insight into the etiology of a number of human diseases, and lay the groundwork for the development of targeted therapeutics.