Biogenesis and Trafficking of snoRNPs

描述（由申请人提供）：snoRNA（小核仁RNA）包括指导核糖体RNA、小核RNA和可能的信使RNA的修饰（和在某些情况下切割）的反式作用RNA的大家族。因此，snoRNA对于剪接体和核糖体的产生是必不可少的-细胞的mRNA剪接和蛋白质翻译机制。一些snoRNA的表达缺陷与神经遗传性疾病Prader-Willi综合征有关，而其他snoRNA的缺失是致命的。该项目的目标是确定snoRNA如何与蛋白质组装成功能复合物（snoRNP）并在细胞内转运。我们将采用生物化学，细胞学和遗传学的方法相结合，并将利用两个系统（非洲爪蟾卵母细胞和酿酒酵母）的体内研究。我们将调查的核心snoRNP蛋白的组织上的两个功能类的snoRNP在体内，建立一个必要的框架，了解snoRNP的组装和功能。此外，我们将研究辅助蛋白在snoRNP组装和运输中的作用。我们将关注的一种蛋白质SMN与脊髓性肌萎缩症有关，这是一种致命的隐性遗传疾病，发病率约为1/10，000。我们的工作将研究SMN和其他蛋白质的正常细胞功能。最后，我们将表征基因产物中确定的定向遗传筛选，以了解它们在snoRNP生物合成和细胞内运输的作用。我们对RNA转运机制的深入了解将为理解所有通过细胞核的RNA的运输以及正在开发的用于治疗各种人类感染和疾病的基于RNA的治疗剂的合理靶向提供基础。

DESCRIPTION (provided by applicant): The snoRNAs (small nucleolar RNAs) comprise a large family of trans-acting RNAs that guide the modification (and in some cases cleavage) of ribosomal RNAs, small nuclear RNAs, and perhaps messenger RNAs. As such, the snoRNAs are essential for the production of spliceosomes and ribosomes - the mRNA splicing and protein translation machinery of the cell. A deficiency in the expression of some snoRNAs has been linked with the neurogenetic disease Prader-Willi Syndrome, and deletion of other snoRNAs is lethal. The goal of this project is to determine how the snoRNAs assemble with proteins into functional complexes (snoRNPs) and are transported within the cell. We will employ a combination of biochemical, cytological, and genetic approaches and will exploit two systems (Xenopus laevis oocytes and Saccharomyces cerevisiae) for in vivo studies. We will investigate the organization of core snoRNP proteins on each of two functional classes of snoRNPs in vivo, establishing a necessary framework for understanding the assembly and function of snoRNPs. In addition, we will investigate the roles of accessory proteins in the assembly and transport of snoRNPs. One protein that we will focus on, SMN, is linked to spinal muscular atrophy, a fatal recessive genetic disease with an incidence of approximately 1 in 10,000 human births. Our work will investigate the normal cellular functions of SMN and other proteins. Finally, we will characterize gene products identified in directed genetic screens in order to understand their roles in snoRNP biogenesis and intracellular trafficking. The insight that we gain into the mechanisms by which RNAs are transported will provide a foundation for understanding the trafficking of all RNAs that pass through the nucleus and for rational targeting of RNA-based therapeutic agents being developed to treat a wide range of human infections and diseases.