Microtubule Dynamics and Chromosome Segregation

项目摘要 这个项目的主要目标是了解力的机械贡献 驱动蛋白相关马达和动态微管对染色体的产生 种族隔离微管和马达都是抗癌的极好靶点 药物，但为了做出明智的选择，开发治疗方法，有必要了解 它们对细胞分裂的贡献我们发现了两个相对未被研究的 驱动蛋白相关的马达，Kif25和Kif9，它们有助于促进正常的 有丝分裂纺锤体功能我们将使用高分辨率活细胞成像，基因编辑， 雷帕霉素依赖性敲除侧向方法和体外单分子测定 研究Kif25如何抑制过早的中心体分离，以及它如何发挥 有丝分裂纺锤体上的向内力足以激活纺锤体组装检查点。 我们将使用类似的技术来了解Kif9如何使分裂细胞绕过 主轴装配检查点。这些活动的基础是 作为驱动蛋白活性底物的微管。我们开发了一系列 让我们能够量化微管动力学的细微变化。稳定 微管组装动力学的改变通常是由于微管的丢失或 驱动蛋白样调节剂或其他肿瘤发生驱动因素的过度表达。我们将使用 基于细胞的分析和活体成像，以确定改变的机制， 微管组装速率影响长期染色体不稳定性。

Project Summary The broad goal of this project is to understand the mechanistic contribution of force generation by kinesin-related motors and dynamic microtubules to chromosome segregation. Both microtubules and motors represent excellent targets for anti-cancer drugs but to make wise choices for developing therapeutics it is necessary to understand their contribution to cell division in detail. We have identified two relatively unstudied kinesin-related motors, Kif25 and Kif9 that contribute key activities to facilitate proper mitotic spindle function. We will use high resolution live cell imaging, gene editing, Rapamycin-dependent knock-sideways approaches and single molecule assays in vitro to investigate how Kif25 suppresses premature centrosome separation and how it exerts inward force on the mitotic spindle sufficient to activate the spindle assembly checkpoint. We will use similar techniques to understand how Kif9 enables dividing cells to bypass the spindle assembly checkpoint. Underlying these activities are the dynamic microtubules that serve as substrates for kinesin activity. We have developed a number of assays that allow us to quantify subtle changes in microtubule dynamics. Stable alterations in microtubule assembly dynamics are often result from loss or overexpression of kinesin-like modulators, or other drivers of tumorigenesis. We will use cell-based assays and live imaging to determine the mechanism by which altered microtubule assembly rates impact long-term chromosome instability.