Regulation of Centromeric Chromatin

描述（由申请人提供）：细胞分裂的完美执行对所有生物体的生成和生存至关重要。在每个细胞周期中，染色体必须准确地分配给子细胞，以防止基因组不稳定和非整倍体，这是许多肿瘤和出生缺陷的标志。染色体利用它们的动粒分离，动粒是在着丝粒DNA序列上组装并介导微管附着的专门蛋白质结构。所有真核动粒的基础是一个保守的内部着丝粒结构，其特征是着丝粒染色质及其相关蛋白。着丝粒染色质的一个标志是Cenp-A，这是一种重要的组蛋白H3变体，它在表观遗传学上标记着丝粒，并且是动粒组装所需的。周围的近着丝粒染色质也对分离的保真度做出了各种贡献。为了充分理解确保染色体精确分离的机制，阐明关于着丝粒和近着丝粒染色质的功能和维持的悬而未决的问题是至关重要的。该提案将使用纯化的动粒和生物化学，生物物理，蛋白质组学和基因组学方法的组合，以解决一些悬而未决的问题，着丝粒染色质的贡献动粒功能。1)着丝粒结合蛋白如何对着丝粒的不同功能做出贡献？2)着丝粒周围染色质如何调节染色体分离？3)是什么机制导致了着丝粒的专一定位？该提案将使用芽殖酵母进行这些研究，因为它们适合于生物化学，遗传学和细胞学研究，并且酵母动粒是迄今为止最好的特征。总之，这些研究的动粒和潜在的染色质基础芽殖酵母将导致对所有真核生物的分离的基本机制的理解。这项工作不仅将阐明隔离过程的重要方面，而且将有助于设计更好的长期治疗干预措施。 公共卫生相关性：所有细胞在每次分裂时都必须继承正确数量的染色体，因为错误数量的染色体是癌症、出生缺陷和其他与细胞增殖问题有关的疾病的标志。因此，我们正在研究染色体在分裂时分配给子细胞的过程，以了解许多人类疾病的基础。

DESCRIPTION (provided by applicant): The flawless execution of cell division is essential to the generation and survival of all organisms. During every cell cycle, chromosomes must be accurately partitioned to daughter cells to prevent genomic instability and aneuploidy, a hallmark of many tumors and birth defects. Chromosomes segregate using their kinetochores, the specialized protein structures that assemble on centromeric DNA sequences and mediate attachment to microtubules. The foundation of all eukaryotic kinetochores is a conserved, inner centromere structure characterized by centromeric chromatin and its associated proteins. A hallmark of centromeric chromatin is Cenp-A, an essential histone H3 variant that epigenetically marks centromeres and is required for kinetochore assembly. The surrounding pericentromeric chromatin also makes various contributions to the fidelity of segregation. To fully understand the mechanisms that ensure accurate chromosome segregation, it is critical to elucidate outstanding questions about the functions and maintenance of centromeric and pericentromeric chromatin. This proposal will use purified kinetochores and a combination of biochemical, biophysical, proteomic and genomic approaches to address a number of outstanding questions about the contribution of centromeric chromatin to kinetochore function. 1) How do centromere-binding proteins contribute to the diverse functions of kinetochores? 2) How does pericentromeric chromatin regulate chromosome segregation? 3) What are the mechanisms that contribute to the exclusive localization of centromeres? The proposal will use budding yeast for these studies because they are amenable to biochemical, genetic and cytological studies, and the yeast kinetochore is the best characterized to date. Taken together, these studies of kinetochores and the underlying chromatin foundation in budding yeast will lead toward an understanding of the fundamental mechanisms of segregation in all eukaryotes. This work will not only elucidate important aspects about the process of segregation, but will aid in the design of better therapeutic interventions in the long-term. PUBLIC HEALTH RELEVANCE: All cells must inherit the right number of chromosomes every time they divide because the wrong number of chromosomes is a hallmark of cancer, birth defects, and other diseases related to problems in cell proliferation. We are therefore studying the process of chromosome partitioning to daughter cells when they divide to understand the basis for a number of human diseases.