REGULATION OF MRNA TURNOVER IN YEAST

基本上，对基因表达的适当调控对于ALL来说是必要的 生物过程。尽管最近的许多观察强调了 信使核糖核酸周转在转录后基因调控中的重要性 已知影响其衰变的单个mRNA的特征 速率，而且几乎对mRNA衰变的机制一无所知，或者 信使核糖核酸周转机构的组成。我们的长期目标是 工作是了解调控真核生物的分子机制。 通过利用可能的强大方法实现信使核糖核酸周转 酿酒酵母。 最近的实验表明，至少对一些哺乳动物和酵母来说 MRNAs，有离散的顺式作用序列，在 测定信使核糖核酸衰减率。这笔赠款的目标是： 1)通过缺失和点突变相结合的方式，定义 不稳定MAT/α1mRNA中的功能序列和/或结构 当转移到稳定的报告时，可以促进mRNA的快速周转 MRNAs。 2)构建遗传筛选和选择，利用这种不稳定性 在上述实验中定义的元素，以识别和表征 编码信使核糖核酸周转机制各组成部分的基因突变。 3)通过过度表达不稳定基因来确定体内mRNA衰退的途径 这样我们就可以检测到衰变过程中的中间产物。 对MAT/Alpha1mRNA成交量的分析将提供新的 关于信使核糖核酸衰变过程的信息。遗传策略 在酵母中的可能性提供了一种独特的系统来定义细胞mRNA 降解机器。鉴于信使核糖核酸衰变的基本性质，这些 这项研究很可能对更复杂的真核生物具有重要意义。

The proper regulation of gene expression is required for essentially all biological processes. Despite many recent observations that emphasize the importance of mRNA turnover in post-transcriptional gene regulation, little is known about the features of individual mRNAs which influence their decay rate, and virtually nothing is known about the mechanisms of mRNA decay, or the components of the mRNA turnover machinery. The long term goal of our work is to understand the molecular mechanisms which regulate eukaryotic mRNA turnover by exploiting the powerful approaches possible in Saccharomyces cerevisiae. Recent experiments suggest that, at least for some mammalian and yeast mRNAs, there are discrete cis-acting sequences which play a role in determining mRNa decay rate. The goals of this grant are: 1) To define, by a combination of deletion and point mutagenesis, the functional sequences and/or structures within the unstable MAT/alpha1 mRNA which can promote rapid mRNA turnover when transferred to stable reporter mRNAs. 2) To construct genetic screens and selections, exploiting the instability element defined in the above experiments, to identify and characterize mutations in genes encoding components of the mRNA turnover machinery. 3) To identify a pathway of mRNA decay in vivo by overexpressing unstable mRNAs so that we can detect intermediates in the decay pathway. Analysis of the turnover of the MAT/alpha1 mRNA will provide new information about the process of mRNA decay. The genetic strategies possible in yeast provide a unique system for defining the cellular mRNA degradation machinery. Given the fundamental nature of mRNA decay, these studies are highly likely to have significance to more complex eukaryotes.