RNA modifications are essential for proper RNA processing, quality control, and maturation steps. In the last decade, some eukaryotic DNA repair enzymes have been shown to have an ability to recognize and process modified RNA substrates and thereby contribute to RNA surveillance. Single-strand-selective monofunctional uracil-DNA glycosylase 1 (SMUG1) is a base excision repair enzyme that not only recognizes and removes uracil and oxidized pyrimidines from DNA but is also able to process modified RNA substrates. SMUG1 interacts with the pseudouridine synthase dyskerin (DKC1), an enzyme essential for the correct assembly of small nucleolar ribonucleoproteins (snRNPs) and ribosomal RNA (rRNA) processing. Here, we review rRNA modifications and RNA quality control mechanisms in general and discuss the specific function of SMUG1 in rRNA metabolism. Cells lacking SMUG1 have elevated levels of immature rRNA molecules and accumulation of 5-hydroxymethyluridine (5hmU) in mature rRNA. SMUG1 may be required for post-transcriptional regulation and quality control of rRNAs, partly by regulating rRNA and stability.

中文翻译：

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RNA修饰指导的RNA代谢：SMUG1在rRNA质量控制中的作用

RNA修饰对于正确的RNA处理，质量控制和成熟步骤至关重要。在过去的十年中，一些真核DNA修复酶已被证明具有识别和处理修饰的RNA底物的能力，从而有助于RNA监测。单链选择性单功能尿嘧啶DNA糖基化酶1（SMUG1）是一种碱基切除修复酶，不仅可以识别和去除DNA中的尿嘧啶和氧化的嘧啶，而且还能够处理修饰的RNA底物。SMUG1与假尿苷合酶dyskerin（DKC1）相互作用，后者是正确组装小核仁核糖核蛋白（snRNPs）和核糖体RNA（rRNA）加工所必需的酶。在这里，我们综述rRNA修饰和RNA质量控制机制，并讨论SMUG1在rRNA代谢中的特定功能。缺少SMUG1的细胞具有较高水平的未成熟rRNA分子，并且在成熟rRNA中积累了5-羟甲基尿苷（5hmU）。转录后调节和rRNA的质量控制可能需要SMUG1，部分是通过调节rRNA和稳定性。