GENETIC CONTROL OF MITOTIC SPINDLE ASSEMBLY AND FUNCTION

本项目的长期目标是了解 有丝分裂纺锤体的功能被整合到细胞周期中， 芽殖酵母酿酒酵母 各种抗肿瘤 化疗药物，如紫杉醇，导致人类细胞停滞， 分裂。来自各种来源的最新数据表明， 反馈控制，通过“主轴检查点”，可以检测错误 在纺锤体功能和细胞分裂中起作用。我们建议 酵母纺锤体检查点是复杂的，具有至少两个 件. 一个是着丝粒检查点， 微管在动粒上的占有状态。另 组件是一个主轴程序集检查点， 主轴装配错误。我们建议使用一些 动粒基因和动粒检查点基因的突变， 测试微管占据模型。我们还将开发一个 基于我们模型预测的体外试验。另外我们 将使用新的基因检测来更深入地了解自然 动粒信号通路的一部分。 我们提出，有一个新的纺锤体组装检查点， 在cdc2O突变体中激活，缺乏必需的微管 相关蛋白质基因和分子分析表明， cdc20 p受磷酸化和蛋白质周转调节。 我们将确定这两种情况的分子基础 现象。我们将使用cdc2O来识别小说中的突变体， 纺锤体组装检查点。许多酵母纺锤体检查点基因 在高等真核生物中是保守的，这表明纺锤体 检查点是进化保守的。我们的实验将 确定一些重要的监管机制， 在多种细胞类型中的基因组稳定性。纺锤体检查点 基因可以识别化学治疗的分子靶点 对某些癌症和出生缺陷进行干预。

The long term goals of this project are to understand how the function of the mitotic spindle is integrated into the cell cycle in the budding yeast Saccharomyces cerevisiae. Various anti-tumor chemotherapeutic agents, like taxol, cause human cells to arrest in mitosis. Recent data from a variety of sources suggest that there is feedback control, by a "spindle checkpoint", that can detect errors in spindle function and arrest cell division. We propose that the yeast spindle checkpoint is complex, having at least two components. One is a kinetochore checkpoint that is sensitive to the state of microtubule occupancy at kinetochores. The other component is a spindle assembly checkpoint that is activated when the spindle is mis-assembled. We propose to use a number of mutations in kinetochore genes and kinetochore checkpoint genes to test the model of microtubule occupancy. We will also develop an in vitro assay based on predictions from our model. In addition, we will use novel genetic assays to gain greater insight into the nature of the kinetochore signalling pathway. We propose that there is a novel spindle assembly checkpoint is activated in cdc2O mutants, lacking an essential microtubule associated protein. Genetic and molecular analyses suggest that Cdc20p is regulated by phosphorylation and by protein turnover. We will determine the molecular basis for both of those phenomena. We will use cdc2O to identify mutants in the novel spindle assembly checkpoint. Many yeast spindle checkpoint genes are conserved among higher eucaryots, suggesting that the spindle checkpoint is evolutionarily conserved. Our experiments will identify some of the important regulatory mechanisms that control genomic stability in a variety of cell types. The spindle checkpoint genes may identify molecular targets for chemotherapeutic intervention in some cancers and birth defects.