A Molecular Genetic Analysis of Transcription Termination in Yeast

9604295 Hyman真核mRNA3‘端的形成是通过一种复杂的机制发生的，该机制包括前mRNA3’端的切割和随后的多个腺苷残基的酶促添加以产生PolyA尾巴。指导多聚腺苷化的RNA序列的突变也会导致转录终止的缺陷，这表明这两个过程可能以一种尚未确定的机制耦合在一起。RNA聚合酶II终止转录很可能是一个涉及一个或多个辅助因子的复杂过程。本研究旨在了解mRNA多聚腺苷化和转录终止的机制是如何聚合形成一个功能性的mRNA3‘端。酵母模型系统将利用分子遗传学和生物化学相结合的方法来确定反式作用因子和相应的基因，这是形成mRNA3‘端所需的，并确定它们的功能。真核信使RNA的合成需要形成成熟的mRNA3‘端，这是通过一个复杂的机制发生的。引导3‘端形成的RNA序列的突变也会导致转录终止的缺陷，这表明这两个过程可能以一种尚未确定的机制耦合在一起。本研究旨在了解酵母模型系统中mRNA 3‘端的形成和转录终止之间的机制关系。

9604295 Hyman Eukaryotic mRNA 3'-end formation occurs by a complex mechanism involving pre-mRNA cleavage and subsequent enzymatic addition of multiple adenosine residues to create a poly(A) tail. Mutations in RNA sequences that direct polyadenylation also result in defects in termination of transcription suggesting that these two processes may be coupled in an as yet undetermined mechanism. Termination of transcription by RNA polymerase II is most likely a complex process involving one or more accessory factors. This research is aimed at understanding how the mechanisms of mRNA polyadenylation and transcription termination converge to form a functional mRNA 3'-end. A yeast model system will take advantage of combined molecular genetic and biochemical approaches to identify trans-acting factors and corresponding genes required for mRNA 3'-end formation and determine their function. The synthesis of a functional eukaryotic messenger RNA requires the formation of a mature mRNA 3'-end, which occurs by a complex mechanism. Mutations in RNA sequences that direct 3'-end formation also result in defects in the termination of transcription suggesting that the two processes may be coupled in an as yet undetermined mechanism. This research is aimed at understanding the mechanistic relationship between mRNA 3'-end formation and transcription termination in a yeast model system.