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: 6342846
• 负责人: Sharyn A. Endow
• 金额: $ 30.86万
• 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 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6342846
• 关键词: Drosophilidae; X ray crystallography; adenosinetriphosphatase; cell cycle; chromosome movement; conformation; cryoelectron microscopy; green fluorescent proteins; growth /development; intermolecular interaction; kinesin; laboratory rabbit; meiosis; microtubule associated protein; microtubules; mitotic spindle apparatus; polymerase chain reaction; protein structure function; tubulin; video microscopy; western blottings

The long-term objectives of this project are to identify and characterize the forces that underlie chromosome movement in meiosis and mitosis, including interactions of chromosomes with the spindle and microtubule dynamics involved in spindle assembly and function. The proposed studies focus on Ncd, a kinesin family microtubule motor protein in Drosophila. Ncd is a minus end-directed motor that plays an essential role in spindle assembly and function in meiosis and mitosis. The proposed studies focus on 1) the mechanism by which the 'neck', the region of the protein adjacent to the conserved motor domain, functions to determine motor directionality, 2) conformational changes in the motor that occur during motor function, and 3) the effects of minus-end motility and motor uncoupling on Ncd function in the cell. The specific aims of the proposed studies are to: 1. Determine the mechanism of neck function in motor directionality. Functional tests of the neck in determining motor polarity will be performed by constructing mutant motors and analyzing polarity in vitro. 2. Identify regions of the motor involved in changes of conformation during motor function. Mutants that uncouple ATP hydrolysis from force generation or trap the motor in different states of ATP hydrolysis will be selected or designed, and tested in vitro to identify structural elements that move during motor function. 3. Determine the effect of minus-end polarity and motor uncoupling on Ncd function in vivo. Truncated mutants and motor uncoupling mutants will be introduced into Drosophila as gfp gene fusions to determine the effects of the mutated motors on Ncd function and dynamics in live cells. These studies address the molecular basis of force generation in the spindle and the role of microtubule motors in chromosome movement during cell division. Defective chromosome distribution causes aneuploidy and genetic abnormalities, and is associated with malignancies in humans.

该项目的长期目标是识别和表征减数分裂和有丝分裂中染色体运动的力，包括染色体与纺锤体组装和功能所涉及的纺锤体和微管动力学的相互作用。拟议的研究集中于果蝇中的动力蛋白家族微管运动蛋白NCD。 NCD是一个减去端导向的电动机，在纺锤体组装和功能中起重要作用在减数分裂和有丝分裂中。拟议的研究重点是1）“颈部”，蛋白质的区域，与保守运动结构域相邻的蛋白质区域，确定运动方向性的功能，2）运动过程中发生的电动机发生的构象变化，以及3）减去细胞中NCD功能的负末端运动性和运动的影响。拟议研究的具体目的是：1。确定运动方向性中颈部功能的机理。颈部在确定运动极性方面的功能测试将通过构建突变体电动机和分析体外分析来进行。 2。确定运动功能期间构象变化的电动机区域。将选择或设计在不同状态的ATP水解状态下，将ATP水解从力产生或捕获电动机的突变体将被选择或设计，并在体外进行测试以鉴定在运动功能期间移动的结构元素。 3。确定负端极性和运动解偶联对体内NCD功能的影响。截短的突变体和运动解偶联突变体将作为GFP基因融合引入果蝇中，以确定突变电机对活细胞中NCD功能和动力学的影响。这些研究介绍了力在纺锤体中产生力的分子基础以及微管电动机在细胞分裂过程中染色体运动中的作用。有缺陷的染色体分布会导致非整倍性和遗传异常，并且与人类的恶性肿瘤有关。