Mechanisms of Kinetochore Assembly

着丝粒组装机制

• 批准号: 9352348
• 负责人: Aaron F Straight
• 金额: $ 33.29万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9352348
• 关键词: Alpha Cell; Anaphase; Aneuploidy; Binding; Binding Proteins; Biochemical; Cell Cycle; Cell-Free System; Cells; Cellular biology; Centromere; Chromatin; Chromatin Structure; Chromosome Segregation; Chromosomes; Complex; DNA; DNA Sequence; Defect; Development; Dimerization; Disease; Down Syndrome; Ensure; Epigenetic Process; Functional disorder; Genetic; Genome; Genomic Instability; Goals; Hereditary Disease; Histone H3; Histones; Human; Human Genetics; In Vitro; Interphase; Kinetochores; Lead; Malignant Neoplasms; Metaphase; Microtubules; Mitosis; Mitotic; Mitotic Checkpoint; Modeling; Monitor; Mutation; Nucleosome Binding Domain; Nucleosomes; Organism; Process; Property; Proteins; Recruitment Activity; Rest; Role; Site; Structure; System; Testing; Variant; Work; cancer type; centromere protein A; centromere protein C; chromosome movement; crosslink; dimer; experimental study; insight; novel; prevent; public health relevance; reconstitution; segregation; telophase

DESCRIPTION (provided by applicant): Accurate genome segregation is essential for the survival and development of all organisms. Mistakes in chromosome segregation result in cellular aneuploidies that give rise to human genetic diseases such as Down syndrome and that characterize most human cancer types. A major question in cell biology is what are the cellular mechanisms that ensure high fidelity chromosome segregation to avoid genetic instability and the resulting aneuploidy. Our studies focus on the formation and function of human centromeres and kinetochores. The functions of the kinetochore are to bind microtubules, to monitor proper chromosome attachment via the mitotic checkpoint and to segregate chromosomes in anaphase. Defects in any of these processes result in chromosome segregation errors. The centromere is sole the assembly site for the mitotic kinetochore on the chromosome. Centromere function is determined by a specialized histone variant called centromere protein A (CENP-A) and mutation or loss of CENP-A causes centromere and kinetochore dysfunction. Our first objective in this proposal is to identify the mechanisms that assemble CENP-A into chromatin. We propose to do this by identifying how two of the key proteins required for CENP-A assembly, HJURP and M18BP1, are targeted to centromeres to assemble CENP-A nucleosomes during telophase and G1. Second, we propose to characterize the mechanisms by which the essential centromere protein CENP-C interacts with arrays of centromeric chromatin. Using insights from biochemical experiments, we will test models for CENP-C function in human cells in organizing and reinforcing centromere and kinetochore structure. Third, we propose to use a novel in vitro centromere and kinetochore assembly system to understand the role of chromatin structure in promoting centromere and kinetochore function. Together our aims should provide new insight into the assembly and function of vertebrate centromeres and how their activities ensure faithful chromosome segregation.

描述（由申请人提供）：准确的基因组分离对于所有生物的生存和发展至关重要。染色体隔离的错误导致细胞性非整倍性引起人类遗传疾病，例如唐氏综合症，而大多数人类癌症的特征。细胞生物学的一个主要问题是哪些细胞机制是确保高富达染色体隔离以避免遗传不稳定性和产生的非整倍性的。我们的研究集中于人类丝粒和动力学的形成和功能。动力学的功能是结合微管，以通过有丝分裂检查点监测适当的染色体附着，并在后期中隔离染色体。这些过程中的任何一个缺陷都会导致染色体分离错误。丝粒是染色体上有丝分裂动物学的唯一组装位点。 Centromere功能由称为Centromere蛋白A（CENP-A）的专门组蛋白变体以及CENP-A的突变或丢失导致Centromere和Kinetochore功能障碍。该提案中我们的第一个目标是确定将CENP-A组装成染色质的机制。我们建议通过确定CENP-A组装所需的两个关键蛋白Hjurp和M18BP1的目标是如何靶向centromeres，以在凝固片和G1期间组装CENP-A核小体。其次，我们建议表征必需的Centromere蛋白CENP-C与丝粒染色质阵列相互作用的机制。利用来自生化实验的见解，我们将在组织和增强Centromere和Kinetochore结构中测试人类细胞中CENP-C功能的模型。第三，我们建议使用一种新型的体外丝粒和动元组装系统来了解染色质结构在促进Centromere和Kinetochore功能中的作用。我们的目标共同提供了有关脊椎动物centromeres的组装和功能的新见解，以及它们的活动如何确保忠实的染色体隔离。