Enzymatic Reactions Involved in Nucleic Acid Metabolism

P.I.计划研究HeLa核制剂进行的前mRNAs剪接。该项目将侧重于蛋白质的分离和特性，以及参与这一过程的富铀RNA。他将继续研究SnRNPs与前mRNA的相互作用，以及直接参与剪接或有助于该系统特异性的辅助活动。他特别计划研究由构成这些颗粒的RNA和蛋白质合成SnRNPs的过程。为此，他计划使用从克隆的DNA序列中提取的标记RNA，这些DNA序列编码富含U的RNA。与这些RNA相互作用的蛋白质也将从HeLa细胞中分离出来。该方法的目的是重建SNRNPs，并研究它们在高等真核生物中前-mRNAs剪接中的作用。P.I.还建议研究牛乳头瘤病毒的复制，目的是确定宿主细胞周期如何调节这种DNA的复制。他已经开始研究通过从携带BPV质粒的小鼠细胞中提取无细胞提取物来复制这种DNA。意义：近年来，人们了解到核糖核酸(RNA)和蛋白质都可以作为代谢反应的催化剂(酶)。在前一种情况下，催化的反应仅限于从基因中拼接出RNA转运体片段，形成尺寸较小的“信使”RNA。申请人建议继续研究这些RNA催化酶结合在一起的机制。

The P.I. plans to study the splicing of pre mRNAs carried out by HeLa nuclear preparations. This project will focus on the separation and charaterization of proteins and the U-rich RNAs that are involved in this process. He will continue to study the interaction of SnRNPs with pre-mRNA as well as auxiliary activities that are directly involved in splicing or contribute to the specificity of this system. He specifically plans to examine the synthesis of SnRNPs from RNA and proteins that constitute these particles. For this purpose, he plans to use labeled RNAs snythesized from cloned DNA sequences that code for the U-rich RNAs. The proteins that interact with these RNAs will also be isolated from HeLa cells. The goal of this approach is to reconstitute SnRNPs and to study their role in the splicing of pre-mRNAs in higher eukaryotes. The P.I. also proposes to examine the replication of bovine papilloma virus with the goal of determining how the replication of this DNA is regulated by the host cell cycle. He has initiated studies on the replication of this DNA by cell-free extracts from mouse cells carrrying a BPV plasmid. Significance: In recent years it has been learned that ribonucleic acid (RNA) as well as proteins can act as catalysts (enzymes) of metabolic reactions. In the former case the reactions catalyzed have been restricted to those splicing out pieces of the RNA transcipts from gene to form a "messenger" RNA of reduced size. The applicant proposes to continue his studies of the mechanism by which these RNA catalyzst are put together.