Mechanisms of Telomerase RNA Processing and Formation of Ribonucleoprotein Particles in Saccharomyces cerevisiae

酿酒酵母端粒酶RNA加工和核糖核蛋白颗粒形成的机制

• 批准号: 207011783
• 负责人: Dr. Cornelia Kilchert
• 金额: --
• 依托单位: Institut für Biochemie
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/207011783?language=en
• 关键词: Mechanisms; Telomerase; RNA; Processing; Formation

Recently, several RNA-containing sub-compartments have been discovered in the cytoplasm of eukaryotic cells. It has been suggested that these compartments are liquid and behave like oil in an oil-in-water emulsion. To this day, it is not understood why RNA processing requires such compartmentalization. Evolutionarily, some components of RNA bodies are very old, and these structures have been proposed to be remnants of the early RNA world that may have represented separate reaction spaces before the rise of lipid-bilayer enclosed life. Interestingly, Sm or Sm-like proteins are found in most RNA bodies described so far. These proteins form ring-like structures; however, their molecular function remains unclear. TLC1, the telomerase RNA of S. cerevisiae, serves as a model for non-coding RNAs that associate with the Sm-ring. In many respects, TLC1 maturation resembles the generation of spliceosomal snRNPs. While snRNP assembly has been studied extensively in higher eukaryotes, the process is less well understood in yeast, and seems to differ from the metazoan pathway in several important aspects. In mammalian cells, assembly of the Sm-complex takes place in the cytoplasm, potentially in a specialized RNA compartment. Although assembly occurs spontaneously in vitro, the process is highly regulated and involves various additional factors, many of which are, however, not conserved in yeast.I will use yeast TLC1 to study Sm-ring assembly in S. cerevisiae. To identify the assembly compartment, I will combine biochemistry with high-resolution microscopy on Sm proteins and associated RNAs. In addition, purification of TLC1 will allow the identification of protein components and will help to infer processing mechanisms. Using the experimental tractability of S. cerevisiae, my research will clarify important aspects of Sm-RNA processing and will help to shed light on the role of RNA processing compartments, the ubiquity and importance of which is just beginning to emerge.

最近，在真核细胞的细胞质中发现了几个含有RNA的亚室。有人提出，这些隔室是液体，其行为就像水包油乳状液中的油。到目前为止，人们还不明白为什么RNA处理需要这样的划分。在进化上，RNA小体的一些成分非常古老，这些结构被认为是早期RNA世界的残留物，在脂质双层封闭生命兴起之前，这些结构可能代表了单独的反应空间。有趣的是，到目前为止所描述的大多数RNA小体中都发现了Sm或Sm样蛋白。这些蛋白质形成环状结构；然而，它们的分子功能尚不清楚。TLC1是酿酒酵母的端粒酶RNA，是与Sm环相关的非编码RNA的模型。在许多方面，TLC1的成熟类似于剪接体SnRNPs的产生。虽然在高等真核生物中已经对SnRNP组装进行了广泛的研究，但在酵母中对这一过程了解较少，并且似乎在几个重要方面与后生动物途径不同。在哺乳动物细胞中，Sm-复合体的组装发生在细胞质中，可能发生在一个专门的RNA隔间。虽然在体外组装是自发发生的，但这个过程是高度调控的，涉及到各种额外的因素，然而许多因素在酵母中是不保守的。我将使用酵母TLC1来研究Sm环在酿酒酵母中的组装。为了确定组装隔间，我将结合生物化学和高分辨率显微镜对Sm蛋白和相关RNA进行研究。此外，TLC1的纯化将允许鉴定蛋白质组分，并有助于推断加工机制。利用酿酒酵母的实验驯化能力，我的研究将澄清Sm-RNA加工的重要方面，并将有助于阐明RNA加工隔间的作用，它的普遍性和重要性才刚刚开始显现。