Regulation of Centromere Protein Stability and Impact on Cancer Progression

 描述（由申请人提供）：染色体复制和传递对于遗传性状的遗传至关重要，但在多细胞真核生物中对这些过程的机制仍知之甚少。着丝粒是形成动粒所必需的，在有丝分裂和减数分裂期间，动粒是连接纺锤体的关键位点。着丝粒或动粒功能的缺陷导致非整倍性，这是人类癌症的标志，并导致许多出生缺陷。在着丝粒领域的一个紧迫的问题，今天是如何在多细胞真核生物中的着丝粒身份是从一代到下一代传播。我们已发表和未发表的结果表明，着丝粒染色质蛋白及其调节因子的水平受到基因表达和蛋白水解机制的严格调控，以确保忠实的着丝粒和染色体繁殖。本研究综合了遗传学、分子生物学、细胞生物学和生物化学等方法，利用果蝇细胞培养和动物组织，研究调控着丝粒染色质蛋白水平的分子和机制，并探讨其促进着丝粒染色质组装和增殖的机制。进入着丝粒染色质的入口点是一种保守的组蛋白H3样蛋白（CENP-A，在苍蝇中的CID），其仅定位于功能性着丝粒。我们以前确定了CENP定位和组装的关键调控因子，以及细胞周期调控和着丝粒形成之间的联系，这为提出的目标提供了知识和技术基础。本提案的具体重点是阐明 本研究通过研究以下三个方面来探讨着丝粒蛋白稳定性的细胞周期调控以及调控错误的后果：1）相互保护和其他机制如何调控CID及其伴侣CAL 1的稳定性; 2）着丝粒蛋白调控错误对细胞、组织和生物体的影响; 3）着丝粒蛋白调控错误如何在果蝇胶质母细胞瘤模型中促进癌症的发生和发展。通过这些研究产生的着丝粒组装的正常调节的更深入的理解将提供关于这一基本生物过程的基本信息，洞察与癌症和出生缺陷相关的非整倍体病因学的机制，并最终将导致诊断和治疗与着丝粒缺陷相关的人类疾病，如癌症的工具的发展。

 DESCRIPTION (provided by applicant): Chromosome replication and transmission are essential for the inheritance of genetic traits, but the mechanisms responsible for these processes remain poorly understood in multicellular eukaryotes. The centromere is required for kinetochore formation, which serves as the key attachment site to the spindle during mitosis and meiosis. Defects in centromere or kinetochore function result in aneuploidy, which is a hallmark of human cancers and is responsible for many birth defects. A pressing question in the centromere field today is how centromere identity is propagated from one generation to the next in multicellular eukaryotes. Our published and unpublished results demonstrate that the levels of centromeric chromatin proteins and their regulators are tightly regulated by gene expression and proteolytic mechanisms to ensure faithful centromere and chromosome propagation. This proposal integrates genetic, molecular, cell biological and biochemical approaches to identify the molecules and mechanisms that regulate the levels of centromeric chromatin proteins, and promote the assembly and propagation of centromeric chromatin, using Drosophila cell culture and animal tissues. The entry point into centromeric chromatin is a conserved histone H3-like protein (CENP-A, CID in flies) that localizes exclusively to functional centromeres. We previously identified key regulators of CENP-localization and assembly, as well as a link between cell cycle regulation and centromere formation, which provide an intellectual and technical foundation for the proposed aims. The specific focus of this proposal is to elucidate the cell cycle regulation of centromeric protein stability and the consequences of misregulation by investigating: 1) how mutual protection and other mechanisms regulate the stability of CID and its chaperone CAL1, 2) the impact of centromere protein misregulation on cells, tissues and the organism, and 3) how centromere protein misregulation contributes to cancer initiation and progression in Drosophila model of glioblastoma. The deeper understanding of the normal regulation of centromere assembly generated by these studies will provide basic information about this essential biological process, insights into mechanisms responsible for the etiology of aneuploidy associated with cancer and birth defects, and ultimately will lead to the development of tools for diagnosis and treatment of human diseases associated with centromere defects, such as cancer.