Organization of the Mammalian Mitotic Spindle

准确的染色体分离对物种的繁殖和细胞的存活至关重要，而且 由一种复杂的微管结构驱动，称为纺锤体。密集的生化、遗传和 蛋白质组学工作提供了广泛的参与纺锤体组织和 依赖纺锤体的染色体运动。然而，这些努力并没有揭示出分子机制 确保在哺乳动物细胞中进行忠实的染色体分离。最近，我们展示了最多的 人类肿瘤细胞染色体错误分离的常见原因是着丝粒的持续存在。 微管(k-MT)附着错误。这表明，确保诚信的最重要机制 染色体分离是对k-MT附着稳定性的微调，但我们对k-MT如何 在有丝分裂完全不完全的过程中，附着稳定性是被调节的。我们不明白为什么 稳定部件和不稳定部件协同工作以产生一致的k-MT附着稳定性 有丝分裂的不同阶段。我们也不了解非整倍体如何影响基因组稳定性和细胞 生死存亡。根据本供资期间产生的模型，这是我们在即将到来的 资助期将生化方法和活细胞成像结合起来测试模型并确定 有丝分裂中K-MT附着调控机制的研究了解这些机制可能会导致 癌症治疗的新治疗方法。 相关性(请参阅说明)： 染色体分离的错误会导致非整倍体，从而导致出生缺陷，通常与 患有晚期癌症。这里提出的实验的目标是识别蛋白质和 确定导致人类细胞高保真染色体分离的机制。数据 这项工作产生的数据将为深入了解肿瘤细胞非整倍体的机制提供依据，并可能揭示 染色体不稳定非整倍体肿瘤的治疗策略。

Accurate chromosome segregation is essential for the propagation of species and the viability of cells, and is driven by a complex microtubule-based structure called the spindle. Intensive biochemical, genetic, and proteomic efforts provide an extensive catalogue of proteins that participate in spindle organization and spindle-dependent chromosome movement. However, these efforts don't reveal the molecular mechanisms that ensure faithful chromosome segregation in mammalian cells. Recently, we showed that the most common cause of chromosome mis-segregation in human tumor cells is the persistence of kinetochore- microtubule (k-MT) attachment errors. This indicates that the most important mechanism ensuring faithful chromosome segregation is the fine-tuning of k-MT attachment stability, yet our understanding for how k-MT attachment stability is regulated during mitosis is starkly incomplete. We don't understand how the stabilizing and destabilizing components work in concert to generate a coherent k-MT attachment stability at different phases of mitosis. We also don't understand how aneuploidy influences genome stability and cell survival. Based on models generated during the current funding period, it is our goal in the forthcoming funding period to combine biochemical methods and live cell imaging to test models and determine the mechanisms of the regulation of K-MT attachments in mitosis. Understanding these mechanisms could lead to new therapeutic approaches for cancer treatment. RELEVANCE (See instructions): Errors in chromosome segregation cause aneuploidy that causes birth defects and is commonly associated with advanced stage cancer. The goal of the experiments proposed here is to identify the proteins and determine the mechanisms responsible for high fidelity chromosome segregation in human cells. Data generated from this work will provide insight into mechanisms of aneuploidy in tumor cells and may reveal strategies for therapy of chromosomally unstable aneuploid tumors.