3′-Terminal 2′-O-methylation of lung cancer miR-21-5p enhances its stability and association with Argonaute 2
3′-Terminal 2′-O-methylation of lung cancer miR-21-5p enhances its stability and association with Argonaute 2
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DOI：
10.1093/nar/gkaa504
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发表时间：
2020-07-27
影响因子：
14.9
通讯作者：
Zen, Ke
中科院分区：
文献类型：
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作者：
Liang, Hongwei;Jiao, Zichen;Zen, Ke
在植物和果蝇中，miRNA在3 '端核糖上的2'-羟基基团处的甲基化（2 '-O-甲基化，2' Ome）对于miRNA功能至关重要。这种甲基化现象是否存在于哺乳动物的miRNA中仍然未知。通过LC-MS/MS分析，我们发现从人非小细胞肺癌（NSCLC）组织中分离的大多数miR-215 p具有3 '-末端2' Ome。在氧化/β-消除程序后，通过qRT-PCR和北方印迹证实癌组织中miR-21- 5 p的优势3 '-末端2' Ome。癌组织和配对的非癌肺组织miRNAs显示不同的3 '-末端2' Ome模式。我们进一步鉴定了HENMT 1作为负责哺乳动物miRNA的3 '-末端2' Ome的甲基转移酶。与未甲基化的miR-21- 5 p相比，甲基化的miR-21- 5 p对3 '-> 5'核糖核酸外切酶多核苷酸核苷酸转移酶1（PNPT 1）的酶切具有更强的抵抗力，对Argonaute-2的亲和力也更高，这可能分别是其稳定性更高和对程序性细胞死亡蛋白4（PDCD 4）翻译抑制作用更强的原因。我们的发现揭示了HENMT 1介导的哺乳动物miRNA的3 '-末端2' Ome，并强调了其在增强miRNA的稳定性和功能中的作用。
Methylation of miRNAs at the 2'-hydroxyl group on the ribose at 3'-end (2'-O-methylation, 2'Ome) is critical for miRNA function in plants and Drosophila. Whether this methylation phenomenon exists for mammalian miRNA remains unknown. Through LC-MS/MS analysis, we discover that majority of miR-215p isolated from human non-small cell lung cancer (NSCLC) tissue possesses 3'-terminal 2'Ome. Predominant 3'-terminal 2'Ome of miR-21-5p in cancer tissue is confirmed by qRT-PCR and northern blot after oxidation/beta-elimination procedure. Cancerous and the paired non-cancerous lung tissue miRNAs display different pattern of 3'-terminal 2' Ome. We further identify HENMT1 as the methyltransferase responsible for 3'-terminal 2' Ome of mammalian miRNAs. Compared to non-methylated miR-21-5p, methylated miR-21-5p is more resistant to digestion by 3'-> 5' exoribonuclease polyribonucleotide nucleotidyltransferase 1 (PNPT1) and has higher affinity to Argonaute-2, whichmay contribute to its higher stability and stronger inhibition on programmed cell death protein 4 (PDCD4) translation, respectively. Our findings reveal HENMT1-mediated 3'-terminal 2' Ome of mammalian miRNAs and highlight its role in enhancing miRNA's stability and function.