Structure and Function of RNase MRP

核糖体是所有细胞的蛋白质合成机器，对细胞的生长和生存是必不可少的。核糖体的生物发生与生长速度、发育，甚至疾病和衰老有关。因此，了解核糖体的形成过程非常重要。这些复杂细胞器的合成需要一系列的活动，包括前体rRNA转录本的加工，特定核苷酸的修饰，以及rRNA与50-80个蛋白质的组装。核糖体生物发生的关键特征在从酵母到人类的所有真核生物中都是相同的，这使得人们能够根据在模式生物研究中所学到的知识进行概括。在本项目中，酿酒酵母被选为实验有机体，因为它拥有完善的遗传操作系统。这些研究将集中在RNase MRP的结构和功能上，RNase MRP是一种酶，它将内部转录间隔区中的前体rRNA切割在核糖体小亚基和大核糖体亚基的序列之间。这种核仁酶含有一个RNA亚基和九种蛋白质。核糖核酸酶MRP的结构和作用机制尚不清楚。PI将使用系统发育序列比较、突变分析、免疫沉淀和蛋白质标记来分析每个蛋白质亚基和RNA亚基的区域如何对酶结构和底物专一性做出贡献。遗传方法将得到RNA结构探测和对RNA结构和蛋白质-RNA相互作用的计算机分析的补充。最终目标是为RNaseMRP的结构和功能提供一个模型。

0077949LindahlRibosomes, the protein-synthesizing machines of all cells, are essential for cellular growth and survival. The biogenesis of ribosomes has been related to growth rate, development, and even disease and aging. Therefore, it is important to understand the process of ribosome formation. The synthesis of these complex organelles requires a series of activities, including processing of the precursor rRNA transcript, modification of specific nucleotides, and assembly of rRNA with 50-80 proteins. The key features of ribosome biogenesis are shared in all eukaryotes from yeast to humans, allowing one to make generalizations from what has been learned in studies of model organisms. In this project, Saccharomyces cerevisiae has been chosen as the experimental organism because of its well-developed systems for genetic manipulation. These studies will focus on the structure and function of RNase MRP, an enzyme that cleaves the precursor rRNA in the Internal Transcribed Spacer between the sequences destined for small and large ribosomal subunits. This nucleolar enzyme contains one RNA subunit and nine proteins. The architecture and mechanism of action of RNase MRP are poorly understood. The PI will use phylogenetic sequence comparisons, mutant analysis, immunoprecipitation and protein tagging to analyze how each protein subunit and territories of the RNA subunit contribute to enzyme structure and substrate specificity. The genetic approach will be complemented with RNA structure probing and computer analysis of RNA structure and protein-RNA interactions. The final goal is to provide a model for the structure and function of RNase MRP.