CAREER: Folding of the Core Histones: Insights into Nucleosome Folding

生物物理技术的平衡和停止流动CD和荧光（FL）光谱将被用来表征核心核小体和核小体本身的组蛋白的稳定性和折叠反应。核心组蛋白的不同形式的平衡和动力学折叠反应将由未修饰的重组组蛋白、缺乏高电荷n端尾部或包含从尾部消除一个或多个基本残基的位点定向突变的组蛋白、在n端尾部具有特定乙酰化模式的组蛋白和包含模仿atp依赖性核小体重塑复合物作用的突变取代的组蛋白决定。其活性对基因调控至关重要。这些组蛋白变体的稳定性和折叠性将在分离和与特定DNA片段（包括完整核小体）的复杂情况下进行检查。这项研究将使人们更深入地了解低聚蛋白的折叠反应，并为核小体的组装和稳定性提供见解。特别重要的是组蛋白乙酰化和atp依赖性染色质重塑复合物对组蛋白和核小体结构和稳定性的调节改变的生物物理特性。对核小体及其组成的组蛋白进行详细的生化和生物物理分析，在这些效应物存在和不存在的情况下，对于理解这些改变的本质以及它们在DNA包装和基因调控中所起的作用至关重要。教育计划包括在现有的系内课程中正式讲授生物物理学和蛋白质折叠，开发以CD和荧光光谱技术为导向的课程及其在生化实验中的实际应用，包括但不限于蛋白质折叠，在PI实验室和系内指导研究生和本科生，强调多学科方法解决生物问题。

Gloss9983831The biophysical techniques of equilibrium and stopped-flow CD and fluorescence (FL) spectroscopies will be used to characterize the stability and folding reactions of the histone proteins of the core nucleosome and the nucleosome itself. The equilibrium and kinetic folding responses of variant forms of the core histones will determined with unmodified recombinant histones, truncated histones that lack the highly charged N-terminal tails or contain site-directed mutations that eliminate one or more basic residues from the tails, histones with specific acetylation patterns on the N-terminal tails, and histones containing mutational substitutions that mimic the effects of the ATP-dependent nucleosome remodeling complexes, whose activity is essential for gene regulation. The stability and folding of these histones variants will be examined in isolation and in complex with specific DNA fragments, including in the intact nucleosome.This research will permit a deeper understanding of the folding reactions of oligomeric proteins in general and provide insights into the assembly and stability of the nucleosome. Of particular importance is the biophysical characterization of the effects of the regulatory alterations brought about by histone acetylation and ATP-dependent chromatin remodelling complexes on histone and nucleosome structure and stability. Detailed biochemical and biophysical analyses of the nucleosome and its component histones, in the presence and absence of these effectors, are essential to understanding the nature of these alterations and the role they play in DNA packaging and gene regulation. The educational plan includes formal lectures on biophysics and protein folding in existing departmental courses, development of a techniques-oriented course on CD and fluorescence spectroscopies and their practical applications to biochemical experiments, including, but not limited to, protein folding, mentoring of graduate and undergraduate students in the PI's laboratory and in the department with an emphasis on multi-disciplinary approaches to biological problems.