Structural and functional basis for protein-based eukaryotic RNA processing

 描述（由申请人提供）：转移RNA（tRNA）是连接mRNA与蛋白质合成的重要生物衔接分子。鉴于其重要的生物学作用，tRNA的正确成熟和修饰是细胞健康和活力的严格要求。这在线粒体中特别突出，其中线粒体tRNA基因突变是线粒体疾病的普遍原因。在细胞器基因组中，tRNA“打断”rRNA和蛋白质编码基因，使得tRNA转录物的5'端加工不仅对于tRNA成熟是必需的，而且对于前面序列的3'端加工也是必需的。在生命的所有领域中，tRNA 5'端成熟由必需的核糖核酸酶P（RNase P）催化。直到最近，所有已知的RNase P酶都被认为包括催化RNA组分。然而，在人类线粒体和A.拟南芥叶绿体、线粒体和细胞核改变了这一模式。通过PRORP进行正确的tRNA成熟对人类健康至关重要; PRORP及其底物中破坏tRNA 5'端加工的突变与包括母系遗传性原发性高血压、线粒体肌病、MELAS和HSD 10疾病在内的疾病有关。我们的工作将使用生物物理，生物化学和细胞生物学技术来确定PRORP的结构和机制，以及开发用于评估PRORP生理作用的体内模型系统。这些研究将为理解一系列线粒体疾病的分子基础并最终治疗这些疾病建立一个框架。总之，我们高度跨学科的工作将提供关于高等真核生物线粒体tRNA 5'端加工的第一个结构和机制信息。

 DESCRIPTION (provided by applicant): Transfer RNAs (tRNAs) are essential biological adaptor molecules connecting mRNA to protein synthesis. Given their important biological role, correct maturation and modification of tRNAs is strictly required for cell health and viability. Ths is particularly salient in mitochondria, where mitochondrial tRNA gene mutations are the prevalent cause of mitochondrial disease. In organellar genomes, tRNAs "punctuate" rRNA and protein coding genes, making 5' end processing of tRNA transcripts essential not only for tRNA maturation, but also for the 3' end processing of the preceding sequences. Across all domains of life, tRNA 5' end maturation is catalyzed by the essential enzyme ribonuclease P (RNase P). Until recently all known RNase P enzymes were thought to include a catalytic RNA component. However, the discovery of Protein Only RNase P (PRORP) in human mitochondria and A. thaliana chloroplasts, mitochondria, and nuclei has shifted this paradigm. Correct tRNA maturation by PRORP is essential for human health; mutations in PRORP and its substrates that disrupt tRNA 5' end processing are linked to diseases including maternally inherited essential hypertension, mitochondrial myopathy, MELAS, and HSD10- disease. Our work will use biophysical, biochemical and cell- biological techniques to determine the structure and mechanism of PRORPs, as well as develop an in vivo model system for assessing the physiological role of PRORPs. These studies will establish a framework for understanding the molecular basis of, and ultimately treating, a range of mitochondrial diseases. Together, our highly interdisciplinary work will provide the first structural and mechanistic information on mitochondrial tRNA 5' end processing in higher eukaryotes.