Mechanism of Mitotic Checkpoint in Mammalian Cells

哺乳动物细胞有丝分裂检查点的机制

• 批准号: 6918569
• 负责人: Timothy Yen
• 金额: $ 33.84万
• 依托单位: RESEARCH INST OF FOX CHASE CAN CTR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-07 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6918569
• 关键词: aneuploidy; cell cycle; cell cycle proteins; cell line; centromere; chromosome movement; enzyme activity; laboratory rabbit; laboratory rat; microtubules; molecular assembly /self assembly; neoplasm /cancer genetics; protein kinase; protein protein interaction; tissue /cell culture; yeasts

DESCRIPTION (provided by applicant): The long-term objective of my lab is to obtain mechanistic insights into the role of aneuploidy in tumorogenesis. Our current focus on studying the key mechanical and regulatory events that specify accurate chromosome segregation in human cells is of direct importance towards understanding mechanisms that cause cancer and for the development of novel approaches to kill cancer cells. We have focused on identifying and characterizing the molecular components of the kinetochore as a major effort towards understanding the molecular requirements for accurate chromosome segregation. The goals of this proposal are to examine how some of these proteins work together to make a functional kinetochore that links kinetochore:microtubule interactions to the mitotic checkpoint pathway. We will use molecular, biochemical and microscopic approaches to accomplish our goals. This proposal will focus on the evolutionary conserved checkpoint kinases, hBUB 1 and MPS 1, and the Cdc27 subunit of the Anaphase Promoting Complex (APC). We will examine the mechanism by which hBUB 1 specifies the assembly of subdomain of the kinetochore that consists of checkpoint proteins hBUBR1, MAD1, MAD2 and Cdc20. These studies will be critical for understanding the dynamic nature of the interactions between checkpoint proteins and kinetochores. We will characterize the role of the hMPS 1 kinase in the mitotic checkpoint pathway by examining its importance at kinetochores and in transducing the signal from unattached kinetochores to the APC. Lastly, we have made the novel discovery that the Cdc27 subunit of the APC facilitates checkpoint inhibition of the APC in both humans and budding yeast. Our analysis of how Cdc27 accomplishes this provides a unique "bottoms-up" approach to study the signaling pathway that allows cells with even a single unattached chromosome from prematurely exiting mitosis.

描述（由申请人提供）：我实验室的长期目标是获得非整倍性在肿瘤发生中的作用的机制见解。我们目前的重点是研究人类细胞中精确染色体分离的关键机械和调控事件，这对于理解导致癌症的机制和开发杀死癌细胞的新方法具有直接重要意义。我们专注于识别和表征着丝粒的分子成分，作为理解准确染色体分离的分子要求的主要努力。该提案的目标是检查其中一些蛋白质如何协同工作以形成功能性着丝粒，将着丝粒：微管相互作用与有丝分裂检查点途径联系起来。我们将使用分子、生物化学和微观方法来实现我们的目标。该提案将重点关注进化保守的检查点激酶、hBUB 1 和 MPS 1，以及后期促进复合物 (APC) 的 Cdc27 亚基。我们将研究 hBUB 1 指定由检查点蛋白 hBUBR1、MAD1、MAD2 和 Cdc20 组成的动粒子域组装的机制。这些研究对于理解检查点蛋白和动粒之间相互作用的动态性质至关重要。我们将通过检查 hMPS 1 激酶在着丝粒中的重要性以及将信号从未附着的着丝粒转导到 APC 中的重要性来表征 hMPS 1 激酶在有丝分裂检查点通路中的作用。最后，我们有了新的发现，即 APC 的 Cdc27 亚基有助于人类和芽殖酵母中 APC 的检查点抑制。我们对 Cdc27 如何实现这一目标的分析提供了一种独特的“自下而上”方法来研究信号通路，该信号通路允许具有单个未附着染色体的细胞过早退出有丝分裂。