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

最近，在真核细胞的细胞质中发现了几个含有RNA的亚区室。有人提出，这些隔室是液体，并且表现得像水包油乳液中的油。直到今天，人们还不明白为什么RNA加工需要这样的区室化。在进化上，RNA体的某些组成部分非常古老，这些结构被认为是早期RNA世界的残余，可能代表了脂质双层封闭生命兴起之前的独立反应空间。有趣的是，Sm或Sm样蛋白在迄今为止描述的大多数RNA体中被发现。这些蛋白质形成环状结构;然而，它们的分子功能仍不清楚。TLC 1是S.酿酒酵母，作为一个模型的非编码RNA与Sm环。在许多方面，TLC 1成熟类似于剪接体snRNP的产生。虽然snRNP组装已在高等真核生物中被广泛研究，但该过程在酵母中的了解较少，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-复合物的组装发生在细胞质中，可能在专门的RNA隔室中。虽然组装在体外自发发生，但该过程受到高度调控，并涉及各种其他因素，其中许多因素在酵母中并不保守。啤酒。为了确定组装室，我将联合收割机生物化学与高分辨率显微镜对Sm蛋白和相关RNA。此外，TLC 1的纯化将允许蛋白质组分的鉴定，并将有助于推断加工机制。利用S.酿酒酵母，我的研究将澄清Sm-RNA加工的重要方面，并将有助于阐明RNA加工区室的作用，其普遍性和重要性才刚刚开始出现。

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.