Core Histone Tall Interactions and Function in Chromatin

核心组蛋白 Tall 在染色质中的相互作用和功能

基本信息

批准号：
7228849
负责人：
Jeffrey J Hayes
金额：
$ 26.76万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-05-01 至 2008-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7228849
关键词：
Address Affect Affinity Binding Biochemical Biological Biological Models Cell Nucleus Chemicals Chromatin Chromatin Fiber Chromatin Modeling Chromatin Structure Complex Condition DNA DNA crosslink Dependence Dinucleosome Disease Elements Enzymes Epitopes Eukaryotic Cell Fiber Fluorescein Fluoresceins Genetic Recombination Genetic Transcription Goals Grant Histone Acetylation Histones Human Individual Ionic Strengths Label Length Link Localized Malignant Neoplasms Maps Mediating Methods Modeling Modification Molecular Molecular Conformation Mono-S Mutation Nucleosomes Numbers Pattern Phase Post-Translational Protein Processing Preparation Process Property Proteins Regulation Research Personnel Signal Transduction Site Solutions Structure Tail Techniques Testing Thinking Work Xenopus chromatin remodeling crosslink follow-up novel programs research study tau Proteins

项目摘要

DESCRIPTION (provided by applicant): Within the eukaryotic cell nucleus, DNA is associated with core histones to form nucleosomes; which are further assembled with ancillary proteins into 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. In addition, elements of the chromatin complex are directly involved in the regulation of multiple processes within the nucleus that involve DNA. Indeed, a large portion of signal transduction within the cell nucleus appears to ultimately direct the post-translational modification of the core histone proteins and, in several cases, mutations in enzymes that carry out these modifications have been linked to various diseases including cancers in humans. In the last 3-5 years, much effort has been devoted to the elucidation and biochemical purification of the regulatory machinery and enzymes that mediate core histone posttranslational modifications. Interestingly, nearly all of these modifications occur within specialized regions known as the core histone tail domains. Biophysical experiments have shown that the tail domains are key components in regulating the structure and function of chromatin at multiple levels. Moreover, posttranslational modifications in these domains are thought to modulate this histone tail-directed regulation. However, the mechanism by which they define chromatin structures - and ultimately the functionality of the underlying DNA - remains unknown. The primary goal of the work described in this proposal is to elucidate the molecular details and the mechanisms by which the core histone tail domains dictate the structural and functional state of the chromatin fiber. The fiber is formed by the folding up of strings of nucleosomes and is a key structure regulated by the tail domains. However little is known regarding molecular interactions of the tail domains. Recently have shown that the tails make precise and localized interactions within nucleosomes. Using a novel site-directed chemical mapping approach, we will examine histone tail interactions in a variety of model chromatin complexes. We will focus on potential inter-nucleosomal interactions likely to be specifically involved in stabilizing the condensed chromatin fiber. Further, we will use a chemical protection approach and NMR of specifically labeled core histones to study the salt-dependent binding stability of individual histone tails within nucleosomes. In addition, we will use these same methods to examine the effects of specific patterns of histone acetylation and a chromatin remodeling activity on histone-DNA interactions.

描述（申请人提供）：在真核细胞核内，DNA与核心组蛋白结合形成核小体；它们进一步与辅助蛋白组装成多面复合物，称为染色质。这种复合体将极长的 DNA 有序地包装在细胞核的微小体积内。此外，染色质复合体的元件直接参与细胞核内涉及 DNA 的多个过程的调节。事实上，细胞核内的大部分信号转导似乎最终指导核心组蛋白的翻译后修饰，并且在某些情况下，进行这些修饰的酶的突变与包括人类癌症在内的多种疾病有关。在过去的 3-5 年中，人们致力于阐明和生化纯化介导核心组蛋白翻译后修饰的调节机制和酶。有趣的是，几乎所有这些修饰都发生在称为核心组蛋白尾结构域的特殊区域内。生物物理实验表明，尾部结构域是多层次调节染色质结构和功能的关键组成部分。此外，这些结构域中的翻译后修饰被认为可以调节这种组蛋白尾部定向调控。然而，它们定义染色质结构以及最终底层 DNA 功能的机制仍然未知。该提案中描述的工作的主要目标是阐明核心组蛋白尾结构域决定染色质纤维的结构和功能状态的分子细节和机制。纤维是由核小体串折叠形成的，是受尾部结构域调节的关键结构。然而，人们对尾部结构域的分子相互作用知之甚少。最近的研究表明，尾部在核小体内进行精确和局部的相互作用。使用新颖的定点化学作图方法，我们将检查各种模型染色质复合物中的组蛋白尾部相互作用。我们将重点关注可能专门参与稳定浓缩染色质纤维的潜在核小体间相互作用。此外，我们将使用化学保护方法和专门标记的核心组蛋白的 NMR 来研究核小体内单个组蛋白尾部的盐依赖性结合稳定性。此外，我们将使用这些相同的方法来检查组蛋白乙酰化的特定模式和染色质重塑活性对组蛋白-DNA 相互作用的影响。