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与组蛋白的复合体。 虽然遗传信息在DNA序列中编码，但另一层信息在 组蛋白，特别是以翻译后修饰(PTM)的形式。这一层信息是 通常被称为表观基因组学，并提供如何调控基因组的说明。染色质 和表观基因组内容，是高度动态的，不断地重组，以响应发展和 环境线索。生物学中最重要的问题之一是这种信息是如何被 转录和其他调控复合体，导致基因调控和细胞命运。组蛋白修饰 通过调节复合体中称为读取器结构域的小的子结构域来“读”，并且特异性 一种独特的表观基因组模式被认为是通过这些基因的倍数的整合活动而实现的 读者域。然而，尽管关于读者结构域与片段之间的关联已知很多 组蛋白，它们如何与染色质相关的组蛋白相关联的分子机制 上下文，或者它们如何共同作用读出特定的表观基因组状态，还没有被很好地理解。 这项研究计划解决了染色质调节中的这个基本问题。我们正在开创 利用核磁共振波谱研究阅读器结构域与染色质的基本单位 核小体。我们将其与荧光显微镜、低温电子显微镜和BASIC相结合 生物化学为建立这些复合体的模型提供了全面的多学科方法。在接下来的五年里 几年来，我们将重点研究核小体的构象如何调节表观基因组特征的读出。 我们将继续研究核小体构象本身以及已知的癌症突变 不规范这一点。此外，我们还将确定读者领域关联的动力学和结构基础 来自PBAF的染色质重塑和组蛋白与核小体的修饰复合体。穿过 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 朝着我们的长期目标--了解多个读卡器领域如何集成以实现监管 用于导航和响应动态染色质底物的复合体。这项研究计划的结果将 揭示染色质调节的基本机制，洞察许多 人类疾病，并为靶向疗法的发展奠定了基础。

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.