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 通常被称为表观遗传学，并提供如何调控基因组的指导。染色质 和表观遗传的内容，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”， 一种独特的改性状态被认为是通过多个这些物质的综合活动来实现的。 域.然而，尽管我们对阅读器结构域与组蛋白片段的关联了解很多， 在染色质相关的背景下，它们如何与组蛋白结合的分子机制， 它们一起起作用以读出特定的组蛋白修饰状态，这一点还没有很好地理解。本研究 该计划解决了染色质调节中的这一基本问题。我们是核磁共振技术的先驱 使用荧光光谱来研究阅读器结构域与染色质的基本单位核小体的关联。我们 将其与X射线晶体学、荧光光谱学、生物层干涉测量学和基本的 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 年，我们将确定从BAF的阅读器域协会的热力学和结构基础 染色质重塑和多梳组蛋白修饰复合物与核小体，相邻的影响 染色质结合结构域，以及这些相互作用的功能后果。长期来看，我们将 为了理解这些复合物中的多个阅读器结构域如何整合以允许这些调节性的功能， 复合物导航和响应动态染色质底物。这些研究的结果将揭示 染色质调节的基本机制，提供了一些人类肿瘤的病因学的见解。 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 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.