Gene expression can be post-transcriptionally regulated via dynamic and reversible RNA modifications. N¹-methyladenosine (m¹A) is a recently identified mRNA modification; however, little is known about its precise location and biogenesis. Here, we develop a base-resolution m¹A profiling method, based on m¹A-induced misincorporation during reverse transcription, and report distinct classes of m¹A methylome in the human transcriptome. m¹A in 5′ UTR, particularly those at the mRNA cap, associate with increased translation efficiency. A different, small subset of m¹A exhibit a GUUCRA tRNA-like motif, are evenly distributed in the transcriptome, and are dependent on the methyltransferase TRMT6/61A. Additionally, we show that m¹A is prevalent in the mitochondrial-encoded transcripts. Manipulation of m¹A level via TRMT61B, a mitochondria-localizing m¹A methyltransferase, demonstrates that m¹A in mitochondrial mRNA interferes with translation. Collectively, our approaches reveal distinct classes of m¹A methylome and provide a resource for functional studies of m¹A-mediated epitranscriptomic regulation.

可以通过动态和可逆的RNA修饰在转录后调节基因表达。N ^1-甲基腺苷（m ¹ A）是最近发现的mRNA修饰；然而，对其确切的位置和生物发生知之甚少。在这里，我们开发了一个基本分辨率米¹廓线的方法，基于米¹逆转录期间A诱导的错误掺入，并报告不同的类米的¹在人转录甲甲基化。5'UTR中的m ¹ A，特别是在mRNA帽处的m ¹ A与提高的翻译效率相关。m ^1的另一个小子集一个展示出GUUCRA tRNA样基序的蛋白，均匀地分布在转录组中，并且依赖于甲基转移酶TRMT6 / 61A。此外，我们显示m ¹ A在线粒体编码的转录物中普遍存在。通过线粒体定位的m ¹ A甲基转移酶TRMT61B操纵m ¹ A的水平，表明线粒体mRNA中的m ¹ A干扰翻译。总的来说，我们的方法揭示了不同类别的M ¹一甲基化组和M的功能研究提供了资源¹ A-介导epitranscriptomic调节。