Biogenesis, Function and Turnover of Noncoding RNAs

我们实验室的长期目标是了解非编码rna的功能，细胞如何识别和降解有缺陷和不需要的rna，以及无法降解这些rna如何影响细胞功能并导致人类疾病。我们工作的一个重点是一类丰富的核糖核蛋白（RNPs），被称为Ro60 RNPs，广泛存在于动物细胞和许多细菌中。发现其主要蛋白成分环状ro60kda自身抗原，是因为它是系统性红斑狼疮和干燥综合征患者自身抗体的重要临床靶点。在所有被检测的生物体中，Ro60结合被称为Y rna的非编码rna。通过研究细菌中的Ro60 RNPs，我们发现了ncRNA的一个新作用，即将蛋白质辅助因子拴在效应蛋白上以改变其功能。具体来说，我们发现细菌Ro60同源物被Y RNA拴在一个环状核糖核酸酶上，形成一个新的双环RNA降解机器。我们目前正在努力确定Ro60 RNPs在哺乳动物细胞中的功能。作为这项工作的一部分，我们使用CRISPR生成了缺乏Ro60和Y rna的小鼠胚胎干细胞系。我们的研究表明，就像在细菌中一样，Y rna的一个作用是将Ro60连接到不同的蛋白质上，以产生专门的RNPs。在第二个重点中，我们描述了RNA监测途径在哺乳动物和细菌细胞生理学中的作用。最近的一项成就是我们发现了一个长期神秘的细菌RNA修复操纵子是通过将受损的trna与转录激活蛋白结合来调节的。这些研究发现了一个涉及缺陷tRNA的新的信号通路，并暗示操纵子参与tRNA修复。

The long-term goals of our laboratory are to understand how noncoding RNAs function, how cells recognize and degrade defective and unneeded RNAs, and how failure to degrade these RNAs affects cell function and contributes to human disease. One focus of our work is an abundant class of ribonucleoproteins (RNPs), known as Ro60 RNPs, which are widespread in animal cells and present in many bacteria. The major protein component, the ring-shaped Ro 60 kDa autoantigen, was discovered because it is a clinically important target of autoantibodies in patients with systemic lupus erythematosus and Sjogren's syndrome. In all organisms examined, Ro60 binds noncoding RNAs called Y RNAs. By studying Ro60 RNPs in bacteria, we uncovered a novel role for ncRNA, that of tethering a protein cofactor to an effector protein to alter its function. Specifically, we discovered that a bacterial Ro60 ortholog was tethered by Y RNA to a ring-shaped ribonuclease, forming a new double-ringed RNA degradation machine. We are currently working to define the functions of Ro60 RNPs in mammalian cells. As part of this effort, we used CRISPR to generate mouse embryonic stem cell lines lacking Ro60 and Y RNAs. Our studies revealed that, as in bacteria, one role of Y RNAs is to tether Ro60 to diverse proteins to create specialized RNPs. In a second focus, we are characterizing the roles of RNA surveillance pathways in mammalian and bacterial cell physiology. A recent accomplishment was our discovery that a long mysterious bacterial RNA repair operon is regulated by binding of damaged tRNAs to a transcriptional activator protein. These studies identified a new signaling pathway involving defective tRNAs and implicate the operon in tRNA repair.