Chromosome Movement in Meiosis and Mitosis

减数分裂和有丝分裂中的染色体运动

• 批准号: 7872868
• 负责人: Sharyn A. Endow
• 金额: $ 30.89万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7872868
• 关键词: ATP phosphohydrolase; Address; Affect; Aneuploidy; Appearance; Binding; Binding Proteins; Biological Assay; Cell division; Cells; Centrosome; Chromosomes; Defect; Drosophila Proteins; Drosophila genus; Elements; Embryo; Fiber; Fluorescence; Generations; Genetic Nondisjunction; Goals; Green Fluorescent Proteins; Head; Homologous Gene; Human; Hydrolysis; In Vitro; Kinesin; Laboratories; Lasers; Life; Mediating; Meiosis; Microtubules; Minus End of the Microtubule; Mitosis; Molecular; Molecular Abnormality; Motor; Movement; Mus; Mutate; Neck; Nucleotides; Oocytes; Organism; Pathway interactions; Play; Production; Property; Protein Binding; Proteins; Reporting; Research; Resolution; Role; Rotation; Stroke; Structure; Testing; Tubulin; Work; base; chromosome movement; design; driving force; melting; mutant; tumorigenesis

DESCRIPTION (provided by applicant): The long-term objective of this project is to identify and characterize the forces that drive chromosome movement in meiosis and mitosis. These forces are essential for normal chromosome distribution and arise primarily from microtubule dynamics and microtubule motors. A major goal is to understand the role of microtubule motor proteins in spindle and chromosome dynamics in cell division, including the molecular basis of motor directionality and force generation, and the role of motor directionality and force production in division. The proposed studies focus on Ncd, a minus-end microtubule motor protein of Drosophila. The Ncd motor plays an essential role in spindle assembly and function in meiosis and mitosis. The proposed studies are to examine basic motor properties with the objective of understanding how motors work in the cell. Specific aims of the proposed studies are to 1. Determine the step of nucleotide hydrolysis at which the Ncd stalk/neck rotates. The stalk rotation represents a potential force-producing stroke that drives movement of the motor to the microtubule minus end. We will test the hypothesis that the stalk rotates when the motor binds to microtubules and releases ADP, producing the large displacement we observed in laser trap assays. 2. Define the molecular basis of motor structural changes essential for force generation and transduction. We will test the hypothesis, based on our recent cryoEM results, that switch II helix melting and distortion of the central 2-sheet are essential for motor function by mutating key residues and assaying the mutated motors for ATPase activity and gliding velocity in vitro. Structural analysis of selected mutants will be performed to obtain information regarding the changes the elements undergo. 3. Determine the role of motors in microtubule nucleation in anastral meiosis I spindles and their effects on microtubule dynamics in the spindle. Mature and assembling spindles will be analyzed in live oocytes to determine whether 3tubulin is present and the polarity of microtubules in the anastral meiosis I spindle. Newly designed ncd mutants that affect the ability of the motor to produce force will be examined for their effects on microtubule dynamics in the meiosis I spindle and findings will be correlated with effects of the mutant motors on spindle assembly.

描述（由申请人提供）：该项目的长期目标是识别和表征驱动减数分裂和有丝分裂中染色体运动的力。这些力对于正常的染色体分布至关重要，主要来自微管动力学和微管电机。一个主要目标是了解微管运动蛋白在纺锤体和染色体动力学中的作用，包括运动方向性和力产生的分子基础，以及运动方向性和力在分裂中的作用。拟议的研究集中于果蝇的减去末端微管运动蛋白NCD。 NCD电动机在减数分裂和有丝分裂中的主轴组件和功能中起着至关重要的作用。拟议的研究旨在检查基本运动性能，目的是了解电动机在细胞中的工作方式。 拟议研究的具体目的是 1。确定NCD茎/颈部旋转的核苷酸水解步骤。茎的旋转代表了潜在的产生力的中风，可将电动机移至微管负端的运动。我们将检验以下假设：当电动机与微管结合并释放ADP时，茎旋转，从而产生我们在激光陷阱测定中观察到的大型位移。 2。定义运动结构变化的分子基础，对于产生力和转导至关重要。我们将根据我们最近的冷冻结果来检验该假设，即通过突变关键残基并测定突变的电动机以使ATPase活性和体外滑道速度通过突变的电动机进行突变，对运动功能的转换II螺旋熔化和变形对于运动功能至关重要。将对选定的突变体进行结构分析，以获取有关元素发生的变化的信息。 3。确定电动机在微管成核中的作用在叠层减数分裂中I纺锤体及其对纺锤体中微管动力学的影响。将在活卵母细胞中分析成熟和组装的纺锤体，以确定是否存在3tubulin，以及在叠层减数分裂中纺锤体中微管的极性。新设计的NCD突变体影响电动机产生力的能力的新CD突变体将检查其对减数分裂I主轴中微管动力学的影响，并且发现将与突变器电动机对纺锤体组件的影响有关。