CAREER: Characterization of Plant RNase P and Examination of its Utility as a Functional Genomics Tool

核糖核酸酶P(RNase P)是一种广泛存在的核糖核蛋白，参与tRNA的生物合成。细菌核糖核酸酶P由催化RNA亚基和蛋白质辅因子组成。虽然大多数古生物和所有真核生物的RNaseP的RNA亚基都含有细菌中存在的几个关键和保守的二级结构元件，但在缺乏多个蛋白质亚基的情况下，它们在体外不具有催化活性，蛋白质亚基的数量因来源而异，从4个到10个不等。由于RNA和蛋白质亚基对所有生物体内的功能都是必不可少的，RNaseP可以作为一个范例来理解蛋白质如何调节RNA的功能。此外，RNaseP在生命的三个领域中功能分配和亚基组成的变化为评估RNaseP是否代表着一种早期的RNA酶提供了一个独特的机会，在这种酶中，蛋白质已经篡夺了最初由RNA执行的大部分功能。还可以招募蛋白质来促进亚细胞靶向和RNaseP表达的时空控制。这方面的任何见解都将在一定程度上证明具有挑衅性的RNA世界假说的正确性。这项研究的长期目标是使用植物RNaseP作为一个模型系统来理解多细胞生物体中真核RNaseP的复杂亚基组成，并利用这一知识来利用植物RNaseP来定向降解内源mRNAs，这一应用将有助于发现基因与功能的关系。该项目将有助于建立一个学术合作网络，并加强土地授予机构的研究基础设施。在生物化学、植物分子生物学和生物技术方面促进学习和推进发现的双重目标将继续通过创新地整合本科生、研究生和博士后学者的最先进的多维研究培训和教育来实现。

Ribonuclease P (RNase P) is a ubiquitous and essential ribonucleoprotein (RNP) involved in tRNA biogenesis. Bacterial RNase P consists of a catalytic RNA subunit and a protein cofactor. While the RNA subunits of most archaeal and all eukaryal RNase P contain several of the critical and conserved secondary structural elements present in their bacterial counterpart, they are not catalytically active in vitro in the absence of their multiple protein subunits, whose number varies from four to ten depending on the source. Since both the RNA and protein subunits are essential for function in vivo in all organisms, RNase P serves as a paradigm for understanding how proteins modulate RNA function. Moreover, the variations in the functional assignment and composition of subunits in the three domains of life provide a unique opportunity to evaluate if RNase P represents an early RNA enzyme progressing through evolutionary stages to an RNA-protein enzyme in which proteins have usurped most of the functions originally carried out by the RNA. Proteins could have also been recruited to facilitate subcellular targeting and spatio-temporal control of RNase P expression. Any insight in this regard would provide some vindication of the provocative RNA world hypothesis. The long-term goal of this research is to use plant RNase P as a model system for understanding the complex subunit make-up of eukaryal RNase P in a multi-cellular organism and also employ this knowledge to exploit plant RNase P for targeted degradation of endogenous mRNAs, an application that would facilitate discovery of gene-function relationships. This project will help build a network of academic collaborations and strengthen the infrastructure for research at a land grant institution. The dual aims of fostering learning and advancing discovery in biochemistry, plant molecular biology and biotechnology will continue to be accomplished by innovatively integrating state of the art multi-dimensional research training and education for undergraduates, graduates, and postdoctoral scholars.