STUDIES ON THE CONTROL OF CELL DIVISION IN YEAST

细胞周期研究的最新进展导致了一个统一的 细胞周期控制假说。 这一假设的核心是 在芽殖酵母中称为Cdc28的蛋白激酶和在裂殖酵母中称为Cdc28的蛋白激酶， 动物细胞如Cdc2。 已经提出，G1至S阶段 并且G2到M相变被控制在 激活这种蛋白激酶。 的差异激活。 Cdc28蛋白激酶的不同转换似乎是介导的 通过与不同类型的正调节亚单位的结合 称为细胞周期蛋白以及其他调节元件。 该模型具有 在很大程度上被证实为芽殖和分裂酵母，它很可能是 对所有真核生物都有效。 S.酿酒酵母目前具有具有许多元件的优点， 参与G1和G2的控制，并可获得遗传 分析. 此外，还可以制备活性酵母 Cdc28蛋白激酶从纯化的组分，以促进 高分辨率的结构和功能分析， 酵母系统 我们计划继续我们过去的一些途径， 在目前的研究计划中。 具体而言，我们希望 对纯Cdc28激酶的性质进行仔细分析， 了解其功能在体内是如何调节的。 的规管及 将研究G1和有丝分裂细胞周期蛋白的性质。 一 我们将共同努力，寻找僵尸G1和有丝分裂的关键， Cdc28激酶的底物。 最后，一些其他监管 与Cdc28激酶直接或间接相互作用的元件， 调节其G1和有丝分裂功能将被表征。 这些 包括MIHI、CKS1和CDC 37。 由于高度保守的性质， 细胞周期控制，本研究过程中获得的信息 可能对所有真核生物包括人类都有意义。

Recent advances in research on the cell cycle have lead to a unifying hypothesis of cell cycle control. Central to this hypothesis is a protein kinase known in budding yeast as Cdc28 and in fission yeast and animal cells as Cdc2. It has been proposed that both the G1 to S-phase and the G2 to M-phase transitions are controlled at the level of activation of this protein kinase. The differential activation of the Cdc28 protein kinase for the different transitions appears to be mediated by association with different classes of positive regulatory subunits known as cyclins as well as by other regulatory elements. This model has largely been confirmed for budding and fission yeast and it is likely to be valid for all eukaryotes. S. cerevisiae presently has the advantage of having many of the elements involved in G1 and G2 control identified and accessible to genetic analysis. Furthermore, it has been possible to prepare active yeast Cdc28 protein kinase from purified components to facilitate high-resolution structural and functional analyses, a unique feature of the yeast system. We plan to continue a number of our past avenues of investigation in the current research plan. Specifically, we wish to perform careful analysis of the properties of pure Cdc28 kinase to better understand how its functions are regulated in vivo. The regulation and properties of both G1 and mitotic cyclins will be investigated. A concerted effort will be applied to finding bot G1 and mitotic critical substrates of the Cdc28 kinase. Finally, a number of other regulatory elements that interact directly or indirectly with the Cdc28 kinase to regulate its G1 and mitotic functions will be characterized. These include MIHI,CKS1 and CDC37. Because of the highly conserved nature of cell cycle control, the information gained in the course of this research is likely to be informative for all eukaryotic organisms, including man.