Since the early days of foundational studies of nucleic acids, many chemical moieties have been discovered to decorate RNA and DNA in diverse organisms. In mammalian cells, one of these chemical modifications, N6-methyl adenosine (m6A), is unique in a way that it is highly abundant not only on RNA polymerase II (RNAPII) transcribed, protein-coding transcripts but also on non-coding RNAs, such as ribosomal RNAs and snRNAs, mediated by distinct, evolutionarily conserved enzymes. Here, we review RNA m6A modification in the light of the recent appreciation of nuclear roles for m6A in regulating chromatin states and gene expression, as well as the recent discoveries of the evolutionarily conserved methyltransferases, which catalyze methylation of adenosine on diverse sets of RNAs. Considering that the substrates of these enzymes are involved in many important biological processes, this modification warrants further research to understand the molecular mechanisms and functions of m6A in health and disease.

自核酸基础研究初期以来，已发现许多化学基团用于装饰不同生物体中的 RNA 和 DNA。在哺乳动物细胞中，这些化学修饰之一 N6-甲基腺苷 (m6A) 在某种程度上是独一无二的，它不仅在 RNA 聚合酶 II (RNAPII) 转录的蛋白质编码转录本上而且在非编码 RNA 上都非常丰富，例如核糖体 RNA 和 snRNA，由不同的、进化上保守的酶介导。在这里，我们根据最近对 m6A 在调节染色质状态和基因表达中的核作用的认识，以及最近发现的进化保守的甲基转移酶（催化不同组 RNA 上的腺苷甲基化）来回顾 RNA m6A 修饰。