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 通常被称为表观遗传学，并提供了关于如何调控基因组的说明。染色质 和表观遗传的内容，是高度动态的，不断地重组，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 一种独特的修饰状态被认为是通过多种因素的综合作用而实现的。 域名。然而，尽管读者结构域与组蛋白片段的关联已知很多， 它们如何在染色质相关的上下文中与组蛋白相关联的分子机制，或如何 它们共同作用读出特定的组蛋白修饰状态，目前还不清楚。这项研究 该计划解决了染色质调节中的这一基本问题。我们正在率先使用核磁共振 光谱学研究读者结构域与染色质的基本单位--核小体的联系。我们 正在将其与X射线结晶学、荧光光谱学、生物分子层干涉测量法和Basic 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 几年后，我们将确定BAF阅读器结构域结合的热力学和结构基础 核小体染色质重塑和聚梳组蛋白修饰复合体的影响 染色质结合域，以及这些相互作用的功能结果。从长远来看，我们将建设 为了理解这些复合体中的多个读取器结构域如何整合以允许这些调节 用于导航和响应动态染色质底物的复合体。这些研究的结果将揭示 染色质调节的基本机制，提供了对许多人类 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 epigenetics, and provides instructions on how the genome is to be regulated. Chromatin and the epigenetic 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 modification state is thought to be achieved through the integrated activity of multiples of these 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 histone modification 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 X-ray crystallography, fluorescence spectroscopy, biolayer interferometry, and basic biochemistry for an overall multidisciplinary approach to building models of these complexes. Over the next five years we will determine the thermodynamic and structural basis of association of reader domains from the BAF chromatin remodeling and Polycomb histone modifying complexes with nucleosomes, the influence of adjacent chromatin binding domains, and the functional consequence of these interactions. Long-term, we will build towards an understand of how multiple reader domains in these complexes integrate to allow these regulatory complexes to navigate and respond to a dynamic chromatin substrate. The results of these studies 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.