Regulation of chromosome segregation

染色体分离的调控

• 批准号: 7944955
• 负责人: DAVID Owen MORGAN
• 金额: $ 29.36万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7944955
• 关键词: Address; Anaphase; Behavior; Biochemical; Biochemical Reaction; Cell Cycle; Cells; Centromere; Chromosome Arm; Chromosome Segregation; Chromosomes; Complex; Defect; Development; Disease; Event; Feedback; Genetic; Goals; In Vitro; Kinetics; Knowledge; Lead; Life; Link; Malignant Neoplasms; Measures; Metaphase; Microscopy; Mitosis; Mitotic spindle; Molecular; Movement; Output; Peptide Hydrolases; Phase; Phosphoric Monoester Hydrolases; Phosphorylation; Process; Protein Dephosphorylation; Protein Kinase; Regulation; Relative (related person); Research; Saccharomyces cerevisiae; Saccharomycetales; Sister; Sister Chromatid; System; Testing; Time; Work; Yeasts; anaphase-promoting complex; assay development; cohesin; daughter cell; human PLK1 protein; human PTTG1 protein; human disease; insight; protein complex; public health relevance; reconstitution; research study; separase; single cell analysis; tool; tumor progression; tumorigenesis; ubiquitin ligase

DESCRIPTION (provided by applicant): The project will explore the regulatory system that controls the initiation of chromosome separation, a critical event in the life of the cell and an event that often goes awry during tumorigenesis. Following duplication of the chromosomes in S phase of the cell cycle, the resulting sister chromatids are linked together by a protein complex called cohesin. During mitosis, the sister-chromatid pairs are oriented on the bipolar mitotic spindle. At the metaphase-anaphase transition, the cohesin linkage between sister's chromatids is abruptly dissolved by a protease called separase, resulting in synchronous separation of sister chromatids and their movement to opposite poles of the spindle. The proposed studies will explore the control of sister-chromatid separation in the budding yeast Saccharomyces cerevisiae, where much of our knowledge of this process was first uncovered. A key goal of the work will be to identify and characterize the regulatory mechanisms that generate the remarkably robust, switch-like behavior of the anaphase regulatory system. In preliminary studies with yeast cells carrying fluorescent tags on two chromosomes, the synchrony of sister-chromatid separation was found to depend in part on a positive feedback loop that governs activation of separase. These studies also led to the discovery that Chromosome IV consistently separates before Chromosome V, suggesting that chromosomes separate in a specific sequence. The first aim of the proposed studies will be to further characterize synchrony and order in the separation of multiple chromosomes in yeast, and to address the general mechanisms underlying the ordered separation of different chromosomes. The second aim will be to reconstitute the biochemical steps of sister-chromatid separation from purified components, allowing detailed studies of separase activation and cohesin cleavage in vitro. Finally, the third aim will be to use these cellular and biochemical tools to address the mechanisms governing separase activity toward cohesin, with an emphasis on the regulation of cohesin cleavage by protein kinases and phosphatases that control cohesin phosphorylation. The knowledge gained from these studies will provide new insights into the control of chromosome segregation - errors in which often contribute to developmental problems and cancer progression. PUBLIC HEALTH RELEVANCE: When a cell reproduces, the chromosomes are first duplicated and then segregated into a pair of daughter cells. Errors in this process can result in genetic damage or defects in chromosome number, which can accelerate cancer progression or cause developmental defects. The proposed studies focus on the regulatory system that controls the initiation of chromosome separation, with an emphasis on the mechanisms underlying the remarkable robustness and accuracy of this system. These studies will lead to a better understanding of how errors in chromosome segregation can arise in human disease.

描述（由申请人提供）：该项目将探索控制染色体分离开始的调节系统，细胞生命中的关键事件以及在肿瘤发生期间经常出现问题的事件。在细胞周期的S相中复制染色体后，由此产生的姐妹染色质被通过称为粘着素的蛋白质复合物将其连接在一起。在有丝分裂过程中，姊妹染色剂对在双极有丝分裂的主轴上定向。在中期 - 分子过渡时，姐妹染色单体之间的粘着蛋白链接被称为分离酶的蛋白酶突然溶解，从而导致姐妹染色单体的同步分离，并将其移动到脊柱的相对极。拟议的研究将探讨在酿酒酵母萌芽的酵母菌中姐妹 - 染色剂分离的控制，在那里我们首先发现了我们对这一过程的许多了解。这项工作的一个关键目标是识别和表征产生过后期调节系统非常健壮的类似开关行为的调节机制。在对两个染色体上携带荧光标签的酵母细胞的初步研究中，发现姐妹 - 染色剂分离的同步部分取决于控制分离酶激活的正反馈环。这些研究还导致发现，发现IV染色体在V染色体V之前始终分离，这表明染色体以特定序列分开。拟议研究的第一个目的是进一步表征酵母中多个染色体分离的同步和顺序，并解决不同染色体有序分离的一般机制。第二个目的是重新建立与纯化成分的姐妹染色剂分离的生化步骤，从而详细研究了分离酶激活和体外粘蛋白裂解的详细研究。最后，第三个目的是使用这些细胞和生化工具来解决有关分离酶活性朝着粘着蛋白的机制，重点是通过蛋白激酶和磷酸酶调节粘附酶的粘着蛋白裂解，以控制粘蛋白磷酸化。从这些研究中获得的知识将为控制染色体分离的控制提供新的见解 - 误差通常会导致发育问题和癌症的进展。 公共卫生相关性：当细胞再现时，染色体首先重复，然后隔离为一对子细胞。此过程中的错误可能导致遗传损害或染色体数量缺陷，这会加速癌症的进展或导致发育缺陷。拟议的研究集中于控制染色体分离开始的调节系统，重点是该系统的鲁棒性和准确性出色的机制。这些研究将使人们更好地了解人类疾病中染色体隔离的错误。