STRUCTURAL ANALYSIS OF A EUKARYOTIC CENTEROMERE

真核生物染色体的着丝粒是一个特殊的区域 沿着染色质纤维， 细胞分裂时染色体的运动。 着丝粒DNA 从酵母，酿酒酵母， 使引入酵母的外源DNA能够像普通的 酵母染色体在细胞分裂过程中。 我们将研究如何 着丝粒DNA序列与染色质成分相互作用 在细胞核中，包括核蛋白和微管， 产生一个功能性的动粒。 我们将决定何时 动粒是在细胞周期中组装的， 在细胞分裂过程中维持结构。 我们会研究 动粒的生化和分子组成， 利用分子技术将这种复合物从 染色质纤维 与此相关的蛋白质 体内结构将被识别。 我们会产生抗体 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 分离着丝粒功能突变体作为替代方法 来鉴定正确染色体所需的基因产物， 种族隔离 确定所需的反式作用因子 将使我们能够确定 因子与着丝粒DNA相互作用， 参与染色体运动的功能单位。 知识 控制着丝粒结构的因素 可以提供控制分子的基本原则 细胞分裂的机制。 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一种重要的机制， 导致产生异常细胞群，包括 癌细胞 着丝粒异常，过早着丝粒 分离和染色体不稳定的情况下，已发现 Roberts' - SC短肢畸形、共济失调毛细血管扩张症和一些 其他综合征。 对细胞调控因子的认识 分离可能是进一步理解 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 the be identified. We will raise antibodies against the proteins to determine their intracellular localization, as well as to isolate the protein coding DNA sequences. 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.