BRCA1 function in G2-M checkpoint and mitosis

BRCA1 在 G2-M 检查点和有丝分裂中的功能

• 批准号: 7408996
• 负责人: TORU OUCHI
• 金额: $ 21.69万
• 依托单位: NORTHSHORE UNIVERSITY HEALTHSYSTEM
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-11 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7408996
• 关键词: Anaplasia; Aneuploidy; Architecture; BRCA1 gene; Binding; Biochemical; Biological; Cell Cycle; Cell Cycle Arrest; Cells; Centrosome; Chromosome Segregation; Chromosomes; Complex; Condition; Cultured Cells; Cyclins; DNA Damage; DNA Replication Damage; Depth; Development; Disease; Embryo; Employee Strikes; Enrollment; Eukaryotic Cell; Exhibits; Fibroblasts; Genetic Transcription; Goals; Human; Intervention; Investigation; Knowledge; Lead; Malignant - descriptor; Malignant Neoplasms; Mammalian Cell; Mediating; Microtubules; Mitosis; Mitotic; Mitotic Checkpoint; Molecular; Mus; Mutant Strains Mice; Mutation; Numbers; Oncogenic; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Process; Protein Kinase; Protein Overexpression; Proteins; Regulation; Research Infrastructure; Research Personnel; Role; Signal Transduction; TP53 gene; Time; Tissues; Tumor Suppression; base; cancer cell; cancer therapy; cyclin B1; human STK6 protein; insight; malignant breast neoplasm; mutant; novel; novel strategies; programs; repaired; research study; tumor

DESCRIPTION (provided by applicant): Structural centrosome abnormalities have been implicated as a potential cause of loss of cell and tissue architecture seen in cancer (i.e., anaplasia) as a result of altered centrosome function in microtubule nucleation and organization. This would result in chromosome missegregation during mitosis as a consequence of multipolar spindle formation. Previous studies of mutant mice or cell culture experiments have shown that both BRCA1 and Aurora-A are involved in the regulation of mitosis. Recently, we found that phosphorylation of BRCA1 Ser308 by Aurora-A is required for mitosis entry. The eukaryotic cell cycle is a cascade of highly complex processes that must occur with striking temporal and spatial precision. Regulatory networks called checkpoints are capable of recognizing and correcting mistakes occurring during these processes. Cells respond to DNA damage and replication blocks in two ways: They arrest the cell cycle to allow time for repair and they induce the transcription of genes that facilitate repair. In the proposed research, the infrastructure of these checkpoint circuits will be probed in mammalian cells using BRCA1 to determine how cells sense problems in mitosis. The general aim is to explore more deeply than heretofore the mechanisms of progression of mitosis regulated by BRCA1, originally uncovered by us. First, we will investigate the roles of BRCA1 phosphorylation by Aurora-A in regulation of the cyclin B1-cdk1 complex, whose activation on the centrosome is essential to enter mitosis. Second, we will study the roles of phosphorylation of BRCA1 Ser308 by Aurora-A in centrosome separation and maturation. Accumulating studies have shown that centrosome maturation in mitosis is crucial for the precise segregation of chromosomes. Biochemical and biological investigations will be formulated to understand the functional interaction of BRCA1 with Aurora-A in the centrosome cycle. Third, we will determine the mechanisms of regulation of Aurora-A by p53 and BRCA1. We plan to utilize BRCA1(-/-) mouse embryo fibroblasts (MEFs) for the proposed experiments. These studies are all aimed at a deeper understanding of both processes of oncogenic transformation and novel approaches to cancer therapy.

描述（由申请人提供）：由于微管成核和组织中中心体功能改变，结构中心体异常被认为是癌症中细胞和组织结构丧失（即退行性变）的潜在原因。由于多极纺锤体的形成，这将导致有丝分裂期间染色体错误分离。先前对突变小鼠或细胞培养实验的研究表明，BRCA1和Aurora-A都参与有丝分裂的调节。最近，我们发现 Aurora-A 磷酸化 BRCA1 Ser308 是有丝分裂进入所必需的。真核细胞周期是一系列高度复杂的过程，必须以惊人的时间和空间精度发生。称为检查点的监管网络能够识别并纠正这些过程中发生的错误。细胞以两种方式对 DNA 损伤和复制阻断做出反应：它们阻止细胞周期，为修复留出时间；它们诱导促进修复的基因转录。在拟议的研究中，将使用 BRCA1 在哺乳动物细胞中探测这些检查点电路的基础设施，以确定细胞如何感知有丝分裂中的问题。总体目标是比迄今为止更深入地探索由我们最初发现的 BRCA1 调节的有丝分裂进展机制。首先，我们将研究 Aurora-A 磷酸化 BRCA1 在细胞周期蛋白 B1-cdk1 复合物调节中的作用，该复合物在中心体上的激活对于进入有丝分裂至关重要。其次，我们将研究 Aurora-A 磷酸化 BRCA1 Ser308 在中心体分离和成熟中的作用。越来越多的研究表明，有丝分裂中中心体的成熟对于染色体的精确分离至关重要。将制定生化和生物学研究，以了解 BRCA1 与 Aurora-A 在中心体循环中的功能相互作用。第三，我们将确定p53和BRCA1对Aurora-A的调节机制。我们计划利用 BRCA1(-/-) 小鼠胚胎成纤维细胞 (MEF) 进行拟议的实验。这些研究都是为了更深入地了解致癌转化过程和癌症治疗的新方法。