MOLECULAR ANALYSIS OF CHROMOSOME SEGREGATION IN YEAST

完整的染色体被忠实地传递给子细胞 在细胞分裂期间。 这一过程背后的分子机制是 没有很好地理解。 该项目的目标是获得一个 对染色体组成部分的分子理解 分离在酵母酿酒酵母。 使用一组新的 鉴定了在染色体分离中有缺陷的IPL突变体， 遗传学和生物化学方法将用于解决以下问题 问题. 1. IPL 1蛋白激酶在有丝分裂中的作用是什么？ 预测 将证明新鉴定的IPL 1蛋白的激酶活性 生物化学 这种激酶的内源性底物将是 IPL1蛋白在动粒中的可能作用 功能将通过生物化学和遗传学方法进行研究。 2. 其他IPL蛋白的作用是什么？ 其他四种IPL 将研究由突变体定义的蛋白质，以了解 它们在染色体分离中的作用 这将涉及表型 IPL突变体的表征、分子克隆和表征 IPL基因的表达及其基因产物的亚细胞定位。 的 这些研究的结果将允许特定分子的制剂 进行生化测试的模型。 3. 还有哪些蛋白质参与染色体分离？ 额外 有丝分裂所需的蛋白质将通过遗传方法鉴定， 还将提供有关可能的物理相互作用的信息 这些蛋白质之间。 对整个染色体的详细了解 分离机制将最终从这些研究中出现， proteins. 由于染色体中许多成分的保守性， 分离，什么是从这些研究中了解到酵母可能适用 到更高的细胞，不适当的染色体分离会导致各种各样的 遗传性疾病，如唐氏综合症和自然流产。 它也可能在促进肿瘤形成中发挥作用。

Complete sets of chromosomes are faithfully transmitted to daughter cells during cell division. The molecular mechanism underlying this process is not well understood. The goal of this proposed project is to gain a molecular understanding of the components responsible for chromosome segregation in the yeast Saccharomyces cerevisiae. Using a set of newly identified ipl mutants that are defective in chromosome segregation, genetic and biochemical approaches will be used to address the following questions. 1. What is the role of the IPL1 protein kinase in mitosis? The predicted kinase activity of the newly identified IPL1 protein will be demonstrated biochemically. The endogenous substrates of this kinase will be identified, and the possible role of the IPL1 protein in kinetochore function will be studied by biochemical and genetic methods. 2. What are the roles of the other IPL proteins? The other four IPL proteins defined by mutants will be studied to gain an understanding of their roles in chromosome segregation. This will involve phenotypic characterization of the ipl mutants, molecular cloning and characterization of the IPL genes, and subcellular localization of their gene products. The results from these studies will allow the formulation of specific molecular models to be tested biochemically. 3. What other proteins are involved in chromosome segregation? Additional proteins required for mitosis will be identified by genetic methods, which will also provide information about the possible physical interaction between these proteins. A detailed understanding of the entire chromosome segregation machinery will eventually emerge from the study of these proteins. Because of the conserved nature of many components involved in chromosome segregation, what is learn from these studies in yeast is likely to apply to higher cells where improper chromosome segregation causes a variety of genetic disorders, such as Down's syndrome and spontaneous fetal abortion. It may also play a role in the promotion of neoplasia.