Enzymatic Reactions Involved in Nucleic Acid Metabolism

P.I.计划通过HeLa核制剂研究pre - mrna的剪接。该项目将重点研究蛋白质的分离和表征以及参与该过程的富u rna。他将继续研究SnRNPs与pre-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性。他特别计划研究SnRNPs是如何从构成这些颗粒的RNA和蛋白质中合成的。为此，他计划使用从克隆的DNA序列中合成的标记rna，这些DNA序列编码富u 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，并研究它们在高级真核生物中pre- mrna剪接中的作用。P.I.还建议检查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）和蛋白质一样可以作为代谢反应的催化剂（酶）。在前一种情况下，催化的反应仅限于那些从基因中剪切出RNA片段以形成缩小尺寸的“信使”RNA的反应。申请人建议继续研究这些RNA催化剂组合在一起的机制。

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.