Histone Tail Interactions and Functions in Chromatin

染色质中组蛋白尾部的相互作用和功能

• 批准号: 7936640
• 负责人: Jeffrey J Hayes
• 金额: $ 11.86万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7936640
• 关键词: Acetylation; Address; Affect; Affinity; Binding; Biological Assay; Cell Nucleus; Cells; Chemicals; Chromatin; Chromatin Fiber; Chromatin Modeling; Chromatin Remodeling Factor; Chromatin Structure; Complex; DNA; Disease; Elements; Enzymes; Eukaryotic Cell; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Glutamine; Goals; Grant; HMGN Proteins; HMGN1 gene; Hereditary Disease; Higher Order Chromatin Structure; Histone Acetylation; Histone H1; Histone H1(s); Histone H3; Histones; Human; Individual; Label; Lasers; Lead; Length; Life; Link; Location; Lysine; Malignant Neoplasms; Maps; Methods; Modeling; Modification; Molecular; Mutation; Nuclear; Nucleosome Core Particle; Nucleosomes; Physical condensation; Play; Post-Translational Protein Processing; Process; Proteins; Role; Secondary to; Signal Transduction; Site; Structure; Tail; Techniques; Testing; Tetrahymena; Work; base; cancer genetics; chromatin remodeling; crosslink; novel; novel strategies; public health relevance; reconstitution; research study; transcription factor

DESCRIPTION (provided by applicant): DNA within the eukaryotic cell nucleus is assembled with histones and other proteins to form a complicated, multifaceted complex known as chromatin. Chromatin not only serves to package the genome but elements of chromatin structure have been intimately integrated into gene control mechanisms. The core histone tail domains are essential for the formation of multiple levels of structure within chromatin and a large portion of signal transduction within the nucleus ultimately directs posttranslational modification of these domains in order to facilitate nuclear processes such as transcription. In several cases, mutations in enzymes that carry out these modifications have been linked to various diseases including cancers in humans. However, the molecular mechanisms by which the tail domains define chromatin structures - and ultimately the functionality of the underlying DNA - remain poorly understood. The primary goal of the work described in this proposal is to elucidate the molecular mechanisms by which the core histone tail domains dictate the formation of higher order chromatin structures and how acetylation of specific lysines within these domains alters tail structures and interactions to allow for gene expression. Our aims are to 1) characterize short-range and long-range inter- nucleosomal interactions of the H3 and H4 tail domains in model nucleosomes and nucleosome arrays, 2) Determine whether linker histone H1, the architectural transcription factor HMGN or a chromatin remodeling activity specifically alters interactions of the tail domains and to 3) quantitatively assess binding of selected tail domains and the effect of acetylation on these interactions in reconstituted and native chromatin. We will use several novel approaches including site-directed chemical mapping of tail-DNA interactions, a UV laser crosslinking approach, and other chemical probing approaches to investigate structures and interactions of the tail domains. Further, we will use a chemical protection approach and NMR of specifically labeled core histones to quantitatively assess the salt-dependent binding stability of individual histone tails within nucleosomes. This work will advance our understanding of critical molecular mechanisms that impinge upon control of gene expression and ultimately diseases such as cancer. PUBLIC HEALTH RELEVANCE Within the eukaryotic cell nucleus, DNA is associated with core histones and other proteins to form a multi-faceted complex known as chromatin. This complex brings about the orderly packaging of the immense length of DNA within the tiny volume of the nucleus and is directly integrated into multiple processes including regulation of gene expression. The results of this project will illuminate the molecular mechanisms by which critical elements known as the histone tail domains define and regulate chromatin structure and gene expression and thus allow a greater understanding of fundamental processes related to cancer and genetic diseases.

描述（由申请人提供）：真核细胞核中的DNA与组蛋白和其他蛋白质组装在一起，形成一种复杂的，多面的复合物，称为染色质。染色质不仅可以包装基因组，而且染色质结构的元素已与基因控制机制紧密整合在一起。核心组蛋白尾域对于形成染色质内部多个结构的必不可少，而细胞核内的大部分信号转导最终会导致这些结构域的翻译后修饰，以促进诸如转录之类的核过程。在某些情况下，进行这些修饰的酶的突变与包括人类的癌症在内的各种疾病有关。然而，尾部结构域定义染色质结构的分子机制以及最终的基础DNA的功能仍然知之甚少。本提案中描述的工作的主要目标是阐明核心组蛋白尾域决定高阶染色质结构的形成以及这些结构域内特定赖氨酸的乙酰化如何改变尾巴结构和相互作用以允许基因表达的相互作用的分子机制。我们的目的是1）表征模型核小体和核小体阵列中H3和H4尾域的短距离和远距离核小体相互作用，2）确定连接器H1，结构转录因子HMGN HMGN HMGN或染色质重塑活性是否特定于尾巴相互作用和尾巴相互作用，并评估尾巴相互作用的尾巴相互作用和3）的尾巴相互作用。在重构和天然染色质中的相互作用。我们将使用几种新型方法，包括尾-DNA相互作用的位置定向化学图，紫外线激光交联方法以及其他化学探测方法，以研究尾域的结构和相互作用。此外，我们将使用一种化学保护方法和特异性标记的核心组蛋白的NMR来定量评估核小体内各个组蛋白尾巴的盐依赖性结合稳定性。这项工作将促进我们对控制基因表达和最终疾病（例如癌症）的关键分子机制的理解。 真核细胞核中的公共卫生相关性，DNA与核心组蛋白和其他蛋白质相关，形成了一种称为染色质的多面络合物。这种复合物带来了细胞核体积很小的DNA长度的有序包装，并直接整合到多个过程中，包括调节基因表达。该项目的结果将阐明分子机制，通过这些机制，被称为组蛋白尾巴结构域的关键元素定义并调节染色质结构和基因表达，从而可以更深入地了解与癌症和遗传疾病有关的基本过程。