Molecular Analysis of Chromosome Segregation

染色体分离的分子分析

• 批准号: 10335237
• 负责人: Trisha N. Davis
• 金额: $ 73.08万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10335237
• 关键词: Address; Affinity; Aneuploidy; Avidity; Binding Proteins; Cell Death; Cell division; Chromosome Segregation; Chromosomes; Congenital Abnormality; DNA Binding; Exhibits; Genetic Materials; Geometry; Individual; Kinetochores; Lead; Life; Longevity; Measurement; Microtubules; Mitosis; Mitotic spindle; Molecular Analysis; Molecular Machines; Morphogenesis; Organelles; Ploidies; Process; Property; Proteins; Signal Transduction; Sum; Testing; Work; base; chromosome conformation capture; daughter cell; disability; in vivo; reconstitution; repaired; response; synergism; transmission process; tumorigenesis

Project Summary Life depends on the accurate transmission of genetic material at each cell division. Errors in this process lead to aneuploidy, which is implicated in oncogenesis, birth defects and cell death. Duplicated chromosomes are captured and segregated by a microtubule-based molecular machine, the mitotic spindle. The spindle is bipolar and each spindle pole carries an exact complement of chromosomes to each daughter cell. During mitosis, microtubules nucleate from the poles and capture and organize the chromosomes. Kinetochores, large multiprotein organelles located at the centromeric DNA, bind the microtubules and anchor the chromosomes to the poles. Our work focuses on each end of the microtubule, the spindle poles and the kinetochores. Spindle morphogenesis requires spatially controlled microtubule nucleation. Using a combination of reconstitution and in vivo analysis, we will test hypotheses that address how microtubule nucleation is activated and spatially regulated. Kinetochores attach chromosomes to microtubules with a striking combination of strength and plasticity. The attachments are mobile and robust under tension, but can also rapidly destabilize in response to regulatory signals. As such, the kinetochore is at the center of an error correction mechanism that repairs incorrect attachments sensed by a lack of ‘proper’ tension. The identification of the proteins that are under tension, the measurement of the strength of the linkages and the requirements for the full strength of attachments are together the second focus of this project. We have found that individually no kinetochore protein binds the microtubule with strength or longevity. To reconstitute the full strength of microtubule attachment exhibited by native kinetochores requires synergy between proteins in contact with the microtubule with proteins within the interior of the kinetochore. We will use a reconstitution-based approach and in vivo analysis to test the contribution of affinity, avidity and geometry to this synergy. In this way we will understand how the whole achieves greater properties than the sum of the parts. In addition, by exploiting our reconstituted kinetochore, we will test hypotheses for how the tension signal that triggers error correction is transmitted from the kinetochore and received by the repair mechanisms.

项目摘要 生命取决于每个细胞分裂的遗传物质的准确传播。此过程中的错误 导致非整倍性，这在肿瘤发生，出生缺陷和细胞死亡中暗示。重复 染色体被基于微管的分子机捕获和分离有丝分裂 主轴。主轴是双极的，每个主轴杆都将染色体的精确补充到 每个女儿牢房。在有丝分裂期间，微管从极点核核捕获和组织 染色体。动力学，位于丝粒DNA的大型多蛋白细胞器，结合 微管并将染色体锚定在杆上。我们的工作重点是 微管，主轴杆和动力学。 纺锤体形态发生需要空间控制的微管成核。结合 重构和体内分析，我们将测试假设，以解决微管成核的方式 激活和空间调节。 动力学将染色体连接到具有强度和可塑性的惊人组合的微管上。 这些附件在紧张局势下是可移动和健壮的，但也可能会迅速稳定 监管信号。因此，动力学是修复误差校正机制的中心 缺乏“适当”的紧张感所感觉到的不正确依恋。鉴定蛋白质 在紧张的情况下，连接的强度的测量以及对全部强度的要求 附件是该项目的第二个重点。 我们发现，没有动力学蛋白可以单独使用强度或寿命结合微管。 重建天然动物学所暴露的微管附件的全部强度 与微管接触的蛋白质之间的协同作用与蛋白质内部内部的蛋白质 动力学。我们将使用基于重组的方法和体内分析来测试 对这种协同作用的亲和力，亲和力和几何形状。通过这种方式，我们将了解整个成就如何 比零件的总和更大。此外，通过利用我们的重组动力学，我们 将检验假设，以了解触​​发误差校正的张力信号如何从 动力学并通过修复机制接收。