Molecular biophysics of motility in cytoskeletal motor proteins

细胞骨架运动蛋白运动的分子生物物理学

• 批准号: 1614514
• 负责人: Claire Walczak
• 金额: $ 78.69万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1614514&HistoricalAwards=false
• 关键词: Molecular; biophysics; motility; cytoskeletal; motor

This project will investigate the structure and function of two proteins, kinesin and myosin, which belong to category of proteins that are designated as 'molecular motors'. These enzymes use the energy derived from hydrolysis of one of the most common energy storage molecules in cells, adenosine triphosphate, to drive muscle contraction, intracellular transport, cell motility, and cell division. The goal of the project is to understand how these proteins generate motion to perform cellular work. This project will utilize a 'metal-rescue' technology for controlling and modulating the activity of the motor protein by varying the ratio of metal ions that are necessary components for the proteins. This innovative technology will be useful for researchers to reversibly control the activity of multiple different enzymes. The educational aims of this project will fill a gap in the local education system to promote robust science teaching and learning for the next generation of scientists. Underrepresented minorities at the high school level will be educated and trained in STEM research.The research objective of this project is to define the nucleotide hydrolysis mechanisms of unconventional kinesin and myosin motor proteins using biochemical, structural, biophysical, and advanced mathematical analysis. Myosin and kinesin superfamily motors are cytoskeletal filament-stimulated ATPases that share structural motifs in their active sites which directly interact with the nucleotide and divalent metal cofactor, typically Mg(II). A 'metal-rescue' strategy will be used to control the enzymatic activity and motility of kinesins and myosins and by taking advantage of the differential affinities of Mg(II) and Mn(II) for serine or cysteine residues. Specifically, manipulation of the protein-metal interaction will provide a direct and experimentally reversible strategy to modulate switch-1 closure and, thus, motor motility upon its filament. The ATPase mechanism of wild type and the metal-rescue mutant kinesin-5 motors from Saccharomyces cerevisiae will be defined and the allosteric mechanochemistry of the wild type and metal-rescue mutant of myosin-II motors from Dictyostelium discoideum will be determined. This project will develop a biophysical tool to reversibly control the activity of molecular motors or other P-loop NTPases. This project is supported by the Molecular Biophysics Cluster of the Molecular and Cellular Biosciences Division in the Directorate for Biological Sciences.

该项目将研究两种蛋白质，驱动蛋白和肌球蛋白的结构和功能，这些蛋白质属于指定为“分子电机”的蛋白质类别。这些酶使用来自细胞中最常见的能量储能分子之一，三磷酸腺苷的水解产生的能量来驱动肌肉收缩，细胞内转运，细胞运动和细胞分裂。该项目的目的是了解这些蛋白质如何产生运动以执行细胞工作。该项目将利用“金属响应”技术来控制和调节运动蛋白的活性，通过改变金属离子的比率，而金属离子的比率是蛋白质的必要组件。这项创新技术对于研究人员可逆地控制多种不同酶的活性将很有用。该项目的教育目标将填补当地教育系统的空白，以促进下一代科学家的强大科学教学和学习。在STEM研究中将接受教育和培训的高中阶段的代表性不足。该项目的研究目的是使用生物化学，结构，生物物理，生物物理和先进的数学分析来定义非常规驱动蛋白和肌球蛋白运动蛋白的核苷酸水解机制。肌球蛋白和动力素超家族电动机是细胞骨架丝刺激的ATPases，它们在其活性位点共有结构基序，它们与核苷酸和二价金属辅因子直接相互作用，通常为mg（ii）。将使用一种“金属响应”策略来控制驱动蛋白和肌球蛋白的酶活性和运动性，并利用丝氨酸或半胱氨酸残基的MG（II）和MN（II）的差异亲和力。具体而言，对蛋白质 - 金属相互作用的操纵将提供直接且实验可逆的策略，以调节开关1闭合，从而在其细丝上进行运动运动。将确定野生型的ATPase机制和酿酒酵母的金属响应突变体驱动蛋白5电动机，并确定野生型和肌球蛋白-III Motors的变构机械化学的变构机械化学。该项目将开发一种生物物理工具，以可逆地控制分子电动机或其他P环NTPases的活性。该项目得到了生物科学局分子和细胞生物科学分裂的分子生物物理学簇的支持。