Prevalent cytidylation and uridylation of precursor miRNAs in Arabidopsis
Prevalent cytidylation and uridylation of precursor miRNAs in Arabidopsis
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拟南芥中前体 miRNA 的普遍胞苷化和尿苷化
DOI：
10.1038/s41477-019-0562-1
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发表时间：
2019
期刊：
影响因子：
18
通讯作者：
Chen Xuemei
中科院分区：
文献类型：
--
作者：
Song Jianbo;Wang Xiaoyan;Song Bo;Gao Lei;Mo Xiaowei;Yue Luming;Yang Haiqi;Lu Jiayun;Ren Guodong;Mo Beixin;Chen Xuemei
microRNA生物合成的关键步骤是微处理器将初级前体RNA加工成前体miRNA（pre-miRNA）中间体。在植物中，对前体miRNA影响miRNA生物合成的过程知之甚少。在此，我们进行了3′快速扩增互补DNA末端测序，以分析拟南芥中的pre-miRNA 3′末端。3′端异质性普遍存在，三种微处理器组件提高了3′端精度。精确和不精确的pre-miRNA 3′末端的广泛胞苷化和尿苷化被发现。核苷酸转移酶HESO 1在体外使pre-miRNA尿苷化，并在体内负责大多数pre-miRNA尿苷化。HESO 1、NTP 6和NTP 7参与pre-miRNA胞苷酸化。前体miRNA的加尾倾向于将修剪的前体miRNA恢复至其完整长度以促进进一步加工。此外，HESO 1介导的尿苷酸化导致某些不精确加工的pre-miRNA降解。因此，我们发现了广泛的前体miRNA的胞苷化和尿苷化，并证明了前体miRNA加尾在植物中的多种功能。该研究揭示了拟南芥中pre-miRNAs的3′端普遍存在胞苷化和尿苷化。此外，核苷酸转移酶蛋白有助于pre-miRNA加尾和加尾的多样性功能被揭示。
A key step in microRNA biogenesis is the processing of a primary precursor RNA by the microprocessor into a precursor miRNA (pre-miRNA) intermediate. In plants, little is known about the processes that act on pre-miRNAs to influence miRNA biogenesis. Here, we performed 3′ rapid amplification of complementary DNA ends sequencing to profile pre-miRNA 3′ ends in Arabidopsis. 3′ end heterogeneity was prevalent, and the three microprocessor components promoted 3′ end precision. Extensive cytidylation and uridylation of precise and imprecise pre-miRNA 3′ ends were uncovered. The nucleotidyl transferase HESO1 uridylated pre-miRNAs in vitro and was responsible for most pre-miRNA uridylation in vivo. HESO1, NTP6 and NTP7 contribute to pre-miRNA cytidylation. Tailing of pre-miRNAs tended to restore trimmed pre-miRNAs to their intact length to promote further processing. In addition, HESO1-mediated uridylation led to the degradation of certain imprecisely processed pre-miRNAs. Thus, we uncovered widespread cytidylation and uridylation of pre-miRNAs and demonstrated diverse functions of pre-miRNA tailing in plants. This study revealed prevalent cytidylation and uridylation at the 3′ ends of pre-miRNAs in Arabidopsis. Moreover, the nucleotidyl transferase proteins contributing to the pre-miRNA tailing and the diverse functions of the tailing were uncovered.