Mechanistic Analysis of Microtubule Based Motors

基于微管的电机的机理分析

• 批准号: 7519707
• 负责人: SUSAN P. GILBERT
• 金额: $ 13.55万
• 依托单位: RENSSELAER POLYTECHNIC INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7519707
• 关键词: 7-methylguanosine; ATP phosphohydrolase; Abbreviations; Address; Amino Acids; Binding; Biochemical; Biological; Cell physiology; Cells; Chemicals; Chromosome Segregation; Collaborations; Complex; Condition; Congenital Abnormality; Coumarins; Cryoelectron Microscopy; Cytoskeleton; Disease; Dissociation; Drosophila genus; Enzymes; Exhibits; Generations; Genes; Glutathione S-Transferase; Goals; Homo sapiens; In Vitro; Kinesin; Kinetics; Malignant Neoplasms; Meiosis; Methodology; Microtubule Depolymerization; Microtubules; Minus End of the Microtubule; Mitosis; Modeling; Molecular Motors; Motion; Motor; Movement; Mutation; Nuclear Fusion; Pathway interactions; Phosphate-Binding Proteins; Plus End of the Microtubule; Proteins; Purine-Nucleoside Phosphorylase; Range; Rate; Relative (related person); Research; Role; Saccharomyces cerevisiae; Signal Transduction; Slide; Techniques; Testing; Thermodynamics; Tubulin; Vesicle; X-Ray Crystallography; alpha benzopyrone; base; cell cycle genetics; dimer; in vivo; monastrol; research study; spatial relationship; trafficking

DESCRIPTION (provided by applicant): The kinesin molecular motors are required for a wide range of cellular functions including vesicle trafficking, spindle assembly and chromosome segregation, as well as signal transduction. These ATPases can pull a cellular cargo along a microtubule, slide one microtubule relative to another, or even remodel the microtubule cytoskeleton by promoting microtubule disassembly. The goal of this proposal is to establish the kinetic and thermodynamic basis of force generation for the Eg5 and Kar3Cik1 kinesin ATPases in comparison to conventional kinesin and Ned. Eg5, Ned, and Kar3 are involved in spindle dynamics during meiosis and/or mitosis, and Kar3 is essential for karyogamy (nuclear fusion) during conjugation. Functional roles in vivo require movement of microtubules relative to each other, and Kar3 also exhibits a microtubule depolymerizing activity. Ned and Kar3 promote microtubule minus-end directed force generation, yet Eg5 and kinesin drive plus-end directed motion. Eg5 functions as a homotetramer, yet Kar3 associates with Cik1, a non-motor protein, to form a heterodimer. Kinesin is a processive motor, yet Eg5, Ned, and Kar3 are believed not to be processive. The specific aims are directed to determine the role of Cik1 for Kar3Cik1 mechanochemistry, to examine the mechanochemistry and structural transitions of Kar3Cik1 at conditions where the motor slides one microtubule relative to another in direct comparison to conditions where Kar3Cik1 promotes microtubule disassembly, and to determine the interactions of Cik1 with the microtubule independent of Kar3. For Eg5, the proposed research will define the cooperative interactions between the motor domains of a dimer and will address how the structural changes are coordinated during the ATPase cycle. A comprehensive analysis of these 4 kinesins will provide new information to begin to understand the structural and mechanistic requirements for the diverse movements occurring during the cell cycle where genetic alteration can result in birth defects and diseases such as cancer.

描述（由申请人提供）：驱动蛋白分子马达是广泛的细胞功能所必需的，包括囊泡运输、纺锤体组装和染色体分离以及信号转导。这些ATP酶可以沿着微管拉动细胞货物，使一个微管相对于另一个微管滑动，甚至通过促进微管解体来重塑微管细胞骨架。该建议的目标是建立与传统驱动蛋白和Ned相比Eg 5和Kar 3Cik 1驱动蛋白ATP酶的力产生的动力学和热力学基础。Eg 5、Ned和Kar 3参与减数分裂和/或有丝分裂期间的纺锤体动力学，并且Kar 3在接合期间对于核融合（核融合）是必需的。在体内的功能作用需要微管相对于彼此的运动，Kar 3也表现出微管解聚活性。Ned和Kar 3促进微管负端定向力的产生，而Eg 5和驱动蛋白驱动正端定向运动。Eg 5作为同源四聚体发挥作用，而Kar 3与Cik 1（一种非马达蛋白）结合形成异源二聚体。驱动蛋白是一种进行性运动，但Eg 5、Ned和Kar 3被认为不是进行性的。具体的目的是针对确定的作用Cik 1 Kar 3Cik 1机械化学，检查机械化学和结构转变的Kar 3Cik 1在电机滑动一个微管相对于另一个直接比较的条件下，Kar 3Cik 1促进微管拆卸，并确定Cik 1与微管的相互作用独立的Kar 3。对于Eg 5，拟议的研究将定义二聚体的马达结构域之间的合作相互作用，并将解决ATP酶循环期间结构变化如何协调。对这4种驱动蛋白的全面分析将为开始理解细胞周期中发生的不同运动的结构和机制要求提供新的信息，在细胞周期中遗传改变可导致出生缺陷和疾病，如癌症。