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）：运动蛋白分子电动机需要广泛的细胞功能，包括囊泡运输，主轴组件和染色体分离以及信号转导。这些ATPase可以沿着微管拉一个细胞货物，相对于另一个微管滑动一个微管，甚至通过促进微管拆卸来重塑微管细胞骨架。该提案的目的是与传统的驱动蛋白和NED相比，为EG5和KAR3CIK1驱动蛋白ATPases建立力的动力学基础和热力学基础。 EG5，NED和KAR3参与减数分裂和/或有丝分裂期间的纺锤体动力学，而Kar3对于共轭过程中的核果（核融合）至关重要。体内功能作用需要微管相对于彼此的运动，而Kar3也表现出微管解聚活性。 NED和KAR3促进了微管负向力产生，但EG5和动力蛋白驱动器加端的定向运动。 EG5充当同二聚体，但Kar3与非运动蛋白Cik1相关联，以形成异二聚体。动力蛋白是一种过程，但是EG5，NED和KAR3被认为不是造物的。具体目的旨在确定CIK1对于KAR3CIK1机械化学的作用，以检查KAR3CIK1在与KAR3CIK1相对于另一个微管在另一个微管中滑动一个微管的条件下Kar3Cik1的机械化学和结构过渡，在该条件下，KAR3CIK1在KAR3CIK1的情况下直接比较了Microtule upassembles，并确定与CIK1的相互作用，并确定与CIK1的相互作用，以确定Micrub的相互作用。对于EG5，拟议的研究将定义二聚体运动域之间的合作相互作用，并将解决在ATPase周期中如何协调结构变化。对这4种驱动蛋白的全面分析将提供新的信息，以开始了解在细胞周期中发生的各种运动的结构和机械要求，在这种细胞周期中，遗传改变会导致出生缺陷和疾病，例如癌症。