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Regulation of Chromosome Segregation in Human Cells

人体细胞染色体分离的调控

基本信息

批准号：
7426439
负责人：
Prasad V Jallepalli
金额：
$ 34.19万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-07-01 至 2010-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7426439
关键词：
Affinity Chromatography Anaphase Aneuploidy Antimitotic Agents Biochemical C-terminal CCI-779 Cell Cycle Cell Cycle Progression Cells Chromosomal Instability Chromosome Segregation Chromosomes Cleaved cell Complement Complex Cyclin B Cysteine Protease Data Defect Drosophila polo protein Endopeptidases Eukaryota Eukaryotic Cell Genes Genetic Genome Genome Stability Health Human Human Cell Line In Vitro Kinetochores Knock-in Mouse Knock-out Laboratories Life Link Malignant - descriptor Malignant Neoplasms Mediating Metaphase Metaphase Plate Methods Microscopy Microtubules Mitosis Mitotic Mitotic Chromosome Modification Monitor Monoclonal Antibodies N-terminal Nocodazole Organism Paclitaxel Pathway interactions Pharmaceutical Preparations Phase Phenotype Phosphotransferases Play Post-Translational Protein Processing Process Proteins Rate Reaction Recombinants Regulation Research Research Personnel Role Screening procedure Signal Transduction Sister Sister Chromatid Site Somatic Cell Testing Transfection Transmission Electron Microscopy Yeasts base cancer cell cancer therapy human PTTG1 protein human STK6 protein immunoaffinity chromatography in vivo inhibitor/antagonist monastrol mutant novel separase tumorigenesis yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): Chromosome segregation is crucial to the health and survival of all organisms. Accumulating evidence indicates that the vast majority of human cancers display high rates of chromosome missegregation. This phenomenon, termed chromosomal instability (CIN), has been proposed to drive tumorigenesis by facilitating the emergence of aneuploid clones with increased malignant potential. Thus, it is imperative to obtain a better understanding of the molecules and mechanisms that regulate the process of chromosome segregation in human cells and sustain its high fidelity. We have developed novel methods for 'knocking out' genes in human somatic cells, and we have used these methods to characterize the role of a small mitosis-regulating protein termed securin. This protein forms a tight complex with a large cysteine protease termed separase, which digests the physical links that hold sister chromatids together. Based on our preliminary studies, we hypothesize that the securin-separase complex plays a central role in mitotic progression and high-fidelity chromosome segregation in humans. Precise regulation of this complex is proposed to link sister chromatid separation to upstream checkpoints and restrict it to the the appropriate phase of the cell cycle, i.e., anaphase. To test these hypotheses, we will investigate how specific post-translational modifications contribute to the function of the separase-securin complex. In Aim 1, we use a genetic approach to elucidate the in vivo role of separase auto-cleavage, to determine its relevance to mitotic progression and chromosome dynamics. In Aim 2, we test a proposed securin-independent mechanism for inhibiting premature sister chromatid separation, taking advantage of the hSecurin- 'knockout' cells developed in our earlier studies. In Aim 3, we evaluate potential mechanisms for separase-dependent regulation of processes other than sister chromatid separation. Together, these studies will significantly advance our understanding of mitotic chromosome segregation in humans. Such information is essential to developing more effective cancer therapies that attack the CIN phenotype found in most cancer cells.

描述（由申请人提供）：染色体分离对于所有生物体的健康和生存至关重要。越来越多的证据表明，绝大多数人类癌症都表现出很高的染色体错误分离率。这种现象被称为染色体不稳定性（CIN），有人提出通过促进具有增加的恶性潜力的非整倍体克隆的出现来驱动肿瘤发生。因此，必须更好地了解调节人类细胞染色体分离过程并维持其高保真度的分子和机制。我们开发了“敲除”人类体细胞中基因的新方法，并使用这些方法来表征一种称为 securin 的小型有丝分裂调节蛋白的作用。这种蛋白质与一种称为分离酶的大型半胱氨酸蛋白酶形成紧密复合物，该蛋白酶消化将姐妹染色单体结合在一起的物理连接。根据我们的初步研究，我们假设 securin-分离酶复合物在人类有丝分裂进展和高保真染色体分离中发挥核心作用。建议对该复合体进行精确调节，将姐妹染色单体分离与上游检查点联系起来，并将其限制在细胞周期的适当阶段，即后期。为了检验这些假设，我们将研究特定的翻译后修饰如何促进分离酶-securin 复合物的功能。在目标 1 中，我们使用遗传方法来阐明分离酶自动切割的体内作用，以确定其与有丝分裂进程和染色体动力学的相关性。在目标 2 中，我们利用我们早期研究中开发的 hSecurin“敲除”细胞，测试了一种拟议的 securin 独立机制，用于抑制姐妹染色单体过早分离。在目标 3 中，我们评估了除姐妹染色单体分离之外的分离酶依赖性调节过程的潜在机制。总之，这些研究将显着增进我们对人类有丝分裂染色体分离的理解。这些信息对于开发更有效的癌症疗法至关重要，这些疗法可以攻击大多数癌细胞中发现的 CIN 表型。