STRUCTURAL ANALYSIS OF AN EUKARYOTIC CENTROMERE

真核生物染色体的着丝粒是染色体沿着 染色质纤维在染色体运动中起着重要作用， 细胞分裂 从酵母中分离的着丝粒DNA序列， 酿酒酵母，使外源DNA引入酵母， 在细胞分裂过程中起着普通酵母染色体的作用。 我们将 研究着丝粒DNA序列如何与染色质成分相互作用 在细胞核中，包括核蛋白和微管， 成为一个有功能的动粒。 我们将确定动粒 是在细胞周期中组装的，以及这种结构是如何维持的 在细胞分裂期间。 我们将检查生物化学和分子 用分子技术分离动粒 这个复合物来自染色质纤维。 这些蛋白质与 与该结构在体内的关系将被识别。 我们就立起 针对蛋白质的抗体，以确定它们的细胞内 定位，以及分离蛋白质编码DNA序列。 我们 将分离着丝粒功能的突变体作为替代方法， 鉴定正确染色体分离所需的基因产物。 的 染色体移动所需反式作用因子的鉴定 将使我们能够确定这些因素如何与着丝粒相互作用 DNA产生参与染色体运动的功能单位。 控制着丝粒组织的因素的知识 可以提供基本的原则，管理分子机制， 细胞分裂 细胞分裂是生物体的一个中心过程。 变化 细胞分裂的控制可能是导致细胞分裂的重要机制。 产生异常细胞群，包括癌细胞。 着丝粒异常、着丝粒过早分离与染色体 在Roberts '-SC短肢畸形、共济失调 毛细血管扩张症和其他一些综合征。 的理解 控制细胞分裂的因素可能是进一步的基础。 了解这些功能障碍。

Centromeres of eukaryotic chromosomes are specific regions along the chromatin fiber that play a fundamental role in chromosome movement during cell division. Centromere DNA sequences isolated from the yeast, Saccharomyces cerevisiae, enable foreign DNA introduced into yeast to function as ordinary yeast chromosomes during cell division. We will examine how the centromere DNA sequence interacts with chromatin components in the cell nucleus, including nuclear proteins and microtubules, to give rise to a functional kinetochore. We will determine when the kinetochore is assembled during the cell cycle, and how this structure is maintained during cell division. We will examine the biochemical and molecular constitution of the kinetochore by using molecular techniques to detach this complex from the chromatin fiber. The proteins that are associated with this structure in vivo will then be identified. We will raise antibodies against the proteins to determine their intracellular localization, as well as to isolate the protein coding DNA sequence. We will isolate mutants in centromere function as an alternative method to identify gene products required for proper chromosome segregation. The identification of trans-acting factors required for chromosome movement will enable us to determine how these factors interact with the centromere DNA to give rise to a functional unit involved in chromosome locomotion. Knowledge of the factors that control the organization of the centromere may provide fundamental principles governing the molecular mechanism of cell division. Cell division is a central process of living organisms. Changes in the control of cell division may be an important mechanism that results in the production of aberrant cell populations, including cancer cells. Centromeric abnormalities, premature centromere separation and chromosome instability have been found in cases of Roberts'- SC phocomelia, ataxia telangiectasia, and a number of other syndromes. An understanding of the factors controlling cell division may be fundamental for the further understanding of these dysfunctions.