mascRNA is a small cytoplasmic RNA derived from the lncRNA MALAT1. After being processed by the tRNA processing enzymes RNase P and RNase Z, mascRNA undergoes CCA addition like tRNAs and folds into a tRNA‐like cloverleaf structure. While MALAT1 functions in multiple cellular processes, the role of mascRNA was largely unknown. Here, we show that mascRNA binds directly to the multi‐tRNA synthetase complex (MSC) component glutaminyl‐tRNA synthetase (QARS). mascRNA promotes global protein translation and cell proliferation by positively regulating QARS protein levels. Our results uncover a role of mascRNA that is independent of MALAT1, but could be part of the molecular mechanism of MALAT1's function in cancer, and provide a paradigm for understanding tRNA‐like structures in mammalian cells.

中文翻译：

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tRNA 样小非编码 RNA mascRNA 促进整体蛋白质翻译

mascRNA 是一种来源于 lncRNA MALAT1的小细胞质 RNA 。在被 tRNA 加工酶 RNase P 和 RNase Z 加工后，mascRNA 像 tRNA 一样经历 CCA 添加并折叠成类似 tRNA 的三叶草结构。虽然MALAT1在多个细胞过程中起作用，但 mascRNA 的作用在很大程度上是未知的。在这里，我们展示了 mascRNA 直接与多 tRNA 合成酶复合物 (MSC) 组分谷氨酰胺酰-tRNA 合成酶 (QARS) 结合。mascRNA 通过正向调节 QARS 蛋白水平促进整体蛋白翻译和细胞增殖。我们的研究结果揭示了与MALAT1无关的 mascRNA 的作用，但可能是MALAT1分子机制的一部分其在癌症中的作用，并为理解哺乳动物细胞中的 tRNA 样结构提供了一个范例。