RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
Optical Microscopy and Analysis Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
Nucleic Acids Res. 2020 Jul 9;48(12):6919-6930. doi: 10.1093/nar/gkaa414.
Noncoding Y RNAs are abundant in animal cells and present in many bacteria. These RNAs are bound and stabilized by Ro60, a ring-shaped protein that is a target of autoantibodies in patients with systemic lupus erythematosus. Studies in bacteria revealed that Y RNA tethers Ro60 to a ring-shaped exoribonuclease, forming a double-ringed RNP machine specialized for structured RNA degradation. In addition to functioning as a tether, the bacterial RNA gates access of substrates to the Ro60 cavity. To identify roles for Y RNAs in mammals, we used CRISPR to generate mouse embryonic stem cells lacking one or both of the two murine Y RNAs. Despite reports that animal cell Y RNAs are essential for DNA replication, cells lacking these RNAs divide normally. However, Ro60 levels are reduced, revealing that Y RNA binding is required for Ro60 to accumulate to wild-type levels. Y RNAs regulate the subcellular location of Ro60, since Ro60 is reduced in the cytoplasm and increased in nucleoli when Y RNAs are absent. Last, we show that Y RNAs tether Ro60 to diverse effector proteins to generate specialized RNPs. Together, our data demonstrate that the roles of Y RNAs are intimately connected to that of their Ro60 partner.
非编码 Y RNA 在动物细胞中大量存在，并且在许多细菌中也存在。这些 RNA 被 Ro60 结合和稳定，Ro60 是一种环形蛋白，是红斑狼疮患者自身抗体的靶标。在细菌中的研究表明，Y RNA 将 Ro60 束缚在一个环形核糖核酸外切酶上，形成一种专门用于降解结构 RNA 的双环 RNP 机器。除了作为一种束缚物外，细菌 RNA 还控制底物进入 Ro60 腔的通道。为了确定 Y RNA 在哺乳动物中的作用，我们使用 CRISPR 技术生成了缺乏两种鼠类 Y RNA 之一或两者的小鼠胚胎干细胞。尽管有报道称动物细胞 Y RNA 对 DNA 复制至关重要，但缺乏这些 RNA 的细胞仍能正常分裂。然而，Ro60 水平降低，表明 Y RNA 结合对于 Ro60 积累到野生型水平是必需的。Y RNA 调节 Ro60 的亚细胞定位，因为当 Y RNA 不存在时，Ro60 在细胞质中减少，在核仁中增加。最后，我们表明 Y RNA 将 Ro60 束缚到多种效应蛋白上，以产生专门的 RNP。总之，我们的数据表明，Y RNA 的作用与其 Ro60 伴侣的作用密切相关。
