Structural and Functional Analysis of the CHD1 Chromatin Remodeler

CHD1 染色质重塑蛋白的结构和功能分析

• 批准号: 8043586
• 负责人: GREGORY DEAN BOWMAN
• 金额: $ 27.91万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8043586
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Architecture; Binding; Biochemical; C-terminal; Cells; Chromatin; Chromatin Remodeling Factor; Chromatin Structure; Chromosome Structures; Chromosomes; Communication; Complex; Congenital Abnormality; Coupling; DNA; DNA Binding; DNA Footprint; Disease; Docking; Elements; Enzymes; Future; Gene Expression; Gene Expression Regulation; Gene Silencing; Genes; Genome; Goals; Health; Histones; Human body; Hydrolysis; Individual; Inherited; Knowledge; Link; Malignant Neoplasms; Measurement; Modeling; Modification; Molecular; Molecular Profiling; Motion; Movement; N-terminal; Nucleosomes; Pattern; Play; Positioning Attribute; Process; Proteins; Reaction; Relative (related person); Resolution; Roentgen Rays; Role; Site-Directed Mutagenesis; Slide; Staging; Structure; Surface; Techniques; Therapeutic; Tissues; Variant; Work; X-Ray Crystallography; chromatin remodeling; combat; design; developmental disease; genome-wide; human disease

DESCRIPTION (provided by applicant): The physical organization of chromosomes is intimately tied to gene regulation. Chromatin remodeling refers to the dynamic compaction and decondensation of eukaryotic chromosomes through the covalent modification and physical movement of nucleosomes. Knowledge of the processes that drive remodeling are essential for gaining a more insightful understanding of human diseases that result from disruptions of normal gene regulation, such as cancer and inherited developmental disorders. Relatively little is known regarding the mechanism by which ATP-dependent remodeling factors alter nucleosome structure, with no understanding of how distinct remodeler domains functionally interact to promote remodeling, how key remodeler domains are positioned in space with respect to one another, nor how remodelers embrace the nucleosome substrate. The long-term objective of this proposal is to establish a biochemical and biophysical framework necessary for describing and understanding the process of chromatin remodeling. This proposal focuses on the CHD1 chromatin remodeling factor, with specific aims to (1) dissect the CHD1 remodeling cycle by characterizing partially dysfunctional variants, (2) determine the architecture of the CHD1 remodeler using X-ray crystallography, and (3) determine the organization of a CHD1:nucleosome complex using small angle X-ray scattering (SAXS) and DNA footprinting. By coupling functional studies of CHD1 with structural information gained through X-ray crystallography, SAXS, and DNA footprinting, we expect to elucidate key steps of the remodeling reaction. In the future, a deeper understanding of chromatin remodeling will be essential for developing therapeutics that manipulate genome-wide gene expression for treatment of human disease. PUBLIC HEALTH RELEVANCE Nearly all cells in the human body possess the same set of genes, yet only a subset of these genes are turned "on" in any particular tissue. The "on" and "off" states of genes are regulated in a complex and ill-defined manner that directly correlates with the physical packaging of chromosomes, called the chromatin structure. Understanding the process by which chromosomes can be unpackaged and repackaged by so-called chromatin remodeling factors is necessary for understanding and therefore combatting many diseases such as cancer where there are imbalances in gene expression.

描述（由申请人提供）：染色体的物理组织与基因调控密切相关。染色质重塑是指真核生物通过核小体的共价修饰和物理运动对染色体进行动态压缩和去致密化。了解驱动重塑的过程对于更深刻地理解由正常基因调控中断导致的人类疾病（如癌症和遗传性发育障碍）至关重要。相对而言，我们对依赖atp的重塑因子改变核小体结构的机制知之甚少，不了解不同的重塑结构域如何在功能上相互作用以促进重塑，不了解关键的重塑结构域如何在空间中相互定位，也不了解重塑结构域如何拥抱核小体底物。本提案的长期目标是建立描述和理解染色质重塑过程所必需的生化和生物物理框架。本研究的重点是CHD1染色质重塑因子，其具体目标是：(1)通过表征部分功能异常的变异来解剖CHD1重塑周期，(2)使用x射线晶体学确定CHD1重塑器的结构，以及(3)使用小角x射线散射（SAXS）和DNA足迹确定CHD1：核小体复合物的组织。通过将CHD1的功能研究与通过x射线晶体学、SAXS和DNA足迹获得的结构信息相结合，我们希望阐明重塑反应的关键步骤。在未来，对染色质重塑的更深入了解将是开发治疗人类疾病的治疗方法所必需的，这些治疗方法可以操纵全基因组基因表达。人体中几乎所有的细胞都拥有相同的一组基因，然而在任何特定的组织中只有这些基因的一个子集被“打开”。基因的“开”和“关”状态是以一种复杂而不明确的方式调节的，这种方式与染色体的物理包装直接相关，称为染色质结构。了解染色体被所谓的染色质重塑因子拆解和重新包装的过程，对于理解并因此对抗许多疾病是必要的，例如癌症，其中存在基因表达不平衡。