Structure, Dynamics and Function of Actin

肌动蛋白的结构、动力学和功能

• 批准号: 0316269
• 负责人: Emil Reisler
• 金额: $ 84.91万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316269&HistoricalAwards=false
• 关键词: Structure; Dynamics; Function; Actin

Actin, a major cellular protein, plays a key role in motion and force generation in muscle and non-muscle cells. The regulation of actin's diverse cellular functions involves specific interactions with many actin-binding proteins. These interactions depend on the equilibration of actin monomers (G-actin) and filaments (F-actin) among different conformational states. The objective of this research is to understand the dynamics and structural states of actin and their role in the actin-based processes. The specific aims of this project include: (i) mapping the intermolecular interfaces in F-actin and the dynamic changes at these interfaces; (ii) elucidating the functional role of the interface dynamics; (iii) determining the structural basis of F-actin severing by cofilin, a major cellular actin remodeling protein; and (iv) testing the model of the ADP/ATP dependent switch between the open and closed nucleotide cleft conformations of the actin monomer. Investigations of the functional role of interface dynamics will include measurements of: (i) interface perturbation by actin binding proteins, and (ii) assays of changes in motion generation with myosin and in the interaction with other proteins due to cross-linking constraints on the interface dynamics. These aims will be pursued through multidisciplinary and collaborative studies (using wild type and mutant proteins with cysteinyl residues engineered for labeling with fluorescence and spin probes) involving cross-linking, electron microscopy, fluorescence, mass spectrometry, electron paramagnetic resonance, kinetics, and single molecule measurements.The broader impact of this project will be in advancing the discovery and understanding of basic cellular processes while providing interdisciplinary training in the chemistry/biology interface to students at all levels - including summer trainees from underrepresented groups at the local colleges - and preparing them for academic and industrial careers.

肌动蛋白是一种主要的细胞蛋白，在肌肉和非肌肉细胞的运动和力的产生中起着关键作用。 肌动蛋白的多种细胞功能的调节涉及与许多肌动蛋白结合蛋白的特异性相互作用。这些相互作用依赖于肌动蛋白单体（G-肌动蛋白）和细丝（F-肌动蛋白）在不同构象状态之间的平衡。 本研究的目的是了解肌动蛋白的动力学和结构状态及其在肌动蛋白为基础的过程中的作用。本项目的具体目标包括：（i）绘制F-肌动蛋白分子间界面及其动态变化图;（ii）阐明界面动态变化的功能作用;（iii）确定F-肌动蛋白被cofilin（一种主要的细胞肌动蛋白重塑蛋白）切断的结构基础;（iv）确定F-肌动蛋白的分子间界面及其动态变化图。和（iv）测试肌动蛋白单体的开放和闭合核苷酸裂缝构象之间的ADP/ATP依赖性转换的模型。界面动力学的功能作用的调查将包括测量：（i）接口扰动肌动蛋白结合蛋白，和（ii）测定的变化与肌球蛋白的运动生成和与其他蛋白质的相互作用，由于交联约束的接口动力学。这些目标将通过多学科和合作研究来实现（使用具有半胱氨酰残基的野生型和突变体蛋白质，所述半胱氨酰残基被工程化用于用荧光和自旋探针标记），包括交联，电子显微镜，荧光，质谱，电子顺磁共振，动力学，和单分子测量。该项目的更广泛的影响将是推进发现和理解基本的细胞过程，为各级学生提供化学/生物学交叉领域的跨学科培训-包括来自当地学院代表性不足群体的暑期学员-并为他们从事学术和工业职业做好准备。