Biogenesis and Trafficking of snoRNPs

描述(由申请人提供)：snoRNAs(小核仁RNAs)包括一个大的反式作用RNAs家族，它引导核糖体RNAs、小核RNAs和可能的信使RNAs的修饰(在某些情况下还能被切割)。因此，snoRNAs对于产生剪接体和核糖体是必不可少的，核糖体是细胞的信使核糖核酸剪接和蛋白质翻译机制。一些snoRNAs的表达不足与神经遗传性疾病Prader-Willi综合征有关，而其他snoRNAs的缺失是致命的。该项目的目标是确定snoRNAs如何与蛋白质组装成功能复合体(SnoRNPs)并在细胞内运输。我们将采用生物化学、细胞学和遗传学相结合的方法，并将利用两个系统(非洲爪哇卵母细胞和酿酒酵母)进行体内研究。我们将在体内研究两类snoRNPs上核心snoRNP蛋白的组织结构，为理解snoRNPs的组装和功能建立必要的框架。此外，我们还将研究辅助蛋白在snoRNPs组装和运输中的作用。我们将重点关注的一种蛋白质SMN与脊髓性肌萎缩症有关，这是一种致命的隐性遗传病，发病率约为每10,000名人类新生儿中就有1名。我们的工作将研究SMN和其他蛋白质的正常细胞功能。最后，我们将对定向遗传筛选中鉴定的基因产物进行鉴定，以了解它们在snoRNP生物发生和细胞内运输中的作用。我们对RNA运输机制的洞察将为理解所有穿过细胞核的RNA的运输以及为治疗广泛的人类感染和疾病而开发的基于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.