STRUCTURE AND EXPRESSION OF EUCARYOTIC GENES

我们建议继续研究有关架构， 小杆线虫肌动蛋白基因的表达 优雅 我们现在将重点放在肌动蛋白信使RNA（mRNA） 处理和扩展工作，包括处理其他 mRNA。 在研究肌动蛋白基因时，我们最近发现 四个基因中有三个编码的mRNA经历了 不寻常的反应，其中mRNA的5' 22个核苷酸被 来自一个单独的RNA分子。 C. 秀丽线虫也经历这种反式剪接反应。 我们将研究 这一现象及其生物学意义。 我们将阐明肌动蛋白反式剪接的机制 C.优雅 我们将描述肌动蛋白mRNA 前体，剪接前导RNA前体，和分子 中间体的 我们将使用体外剪接反应来鉴定 反应的组分，确定是否单独的反式和 存在顺式元件（snRNP和剪接体），顺式剪接是 与反式剪接分开，我们将鉴定其他MRNA 进行相同的转剪接反应。 我们将调查 剪接前导序列是否赋予mRNA稳定性，增强 翻译或定位mRNA。 我们将进行实验 以确定是否通过以下方式获得相似的拼接前导 其他真核生物中的反式剪接。

We propose to continue our studies on the structure and expression of the actin genes of the nematode Caenorhabditis elegans. We will now focus on actin messenger RNA (mRNA) processing and extend the work to include processing of other mRNAs. While studying the actin genes, we recently discovered that three of the four genes encode mRNAs that undergo an unusual reaction in which the 5' 22 nucleotides of the mRNAs are derived from a separate RNA molecule. Other mRNAs in C. elegans also undergo this trans-splicing reaction. We will study this phenomenon and its biological implications. We will elucidate the mechanism of trans-splicing of the actin mRNAs in C. elegans. We will characterize the actin mRNA precursors, the splice leader RNA precursor, and molecular intermediates. We will use in vitro splicing reactions to identify the components of the reaction, determine if separate trans-and cis- elements (snRNPs and spliceosomes) exist and cis-splicing is kept separate from trans-splicing we will identify other MRNAs that undergo the same transplicing reaction. We will investigate whether the splice leader confers mRNA stability, enhances translation, or localizes mRNAs. We will carry out experiments to determine whether similar splice leaders are acquired through trans-splicing in other eukaryotes.