PLANT INTRON PROCESSING

虽然这可能是合乎逻辑的假设，在一些分子 所有低等和高等真核生物都有一个共同的机制， 前体mRNA剪接，多种体内、体外基因转移 实验表明，关键的差异之间存在的 哺乳动物、酵母和植物RNA加工事件。 这些 差异，这可能是由于序列的变化造成的 由内含子剪接成分识别，延伸到单子叶植物， 双子叶植物群，并已阻止了有效的体内 含有内含子的单子叶植物基因在大肠杆菌中的表达 双子叶植物 尽管这些处理缺陷 存在，尚未启动内含子加工研究， 确定单子叶植物和双子叶植物之间的关键差异， 阻止单子叶植物内含子有效切除的mRNAs， 双子叶植物核。 本文提出的实验旨在 确定切除过程中形成的RNA加工中间体 植物内含子和确定的根本差异 在单子叶植物和双子叶植物RNA处理信号之间， 植物基因在异源细胞核中的表达。 具体而言，本提案中描述的研究旨在 更清楚地定义了决定 植物细胞中RNA加工的准确性和效率。 的 本项目的具体目标是：（1）识别和 表征双子叶植物前体mRNA内的核苷酸序列， 是准确和有效切除内含子所必需的， 双子叶植物细胞核;（2）鉴定snRNA和蛋白质组分 负责内含子切除的双子叶植物核提取物：（3）至 评估阻止有效的 切除双子叶植物细胞核中的单子叶植物内含子：（4）发育 单子叶植物RNA加工提取物，可用于评估 单子叶和双子叶植物前体内含子加工效率 成绩单

Although it might he logical to assume that, at some molecular level all lower and higher eukaryotes share a common mechanism for pre-mRNA splicing, a variety of in vivo and in vitro gene transfer experiments indicate that critical differences exist between the mammalian, yeast and plant RNA processing events. These differences, which may result from variations in the sequences recognized by intron splicing components, extend to the monocot and dicot groups of plants and have prevented the efficient in vivo expression of monocotyledonous genes containing introns in dicotyledonous plants. Although these processing deficiencies exist, no intron processing studies have been initiated to determine the critical differences between monocot and dicot pre- mRNAs which prevent the efficient excision of monocot introns in dicot nuclei. The experiments proposed herein are aimed at determining the RNA processing intermediates formed during excision of plant introns and at determining the fundamental differences between monocot and dicot RNA processing signals which block the expression of plant genes in heterologous nuclei. Specifically the research described in this proposal is aimed at more clearly defining the molecular parameters that determine the accuracy and efficiency of RNA processing in plant cells. The detailed objectives of this project are: (1) To identify and characterize the nucleotide sequences within dicot pre-mRNAs that are required for accurate and efficient excision of introns in dicot nuclei; (2) to identify the snRNA and protein components of dicot nuclear extracts responsible for intron excision: (3) to evaluate the nucleotide sequences which prevent the efficient excision of monocot introns in dicot nuclei: (4) to develop monocot RNA processing extracts which can be used to evaluate the intron processing efficiency of monocot and dicot precursor transcripts.