Distinct and cooperative activities of HESO1 and URT1 nucleotidyl transferases in microRNA turnover in Arabidopsis.
Distinct and cooperative activities of HESO1 and URT1 nucleotidyl transferases in microRNA turnover in Arabidopsis.
复制标题
HESO1 和 URT1 核苷酸转移酶在拟南芥中 microRNA 周转中的独特和协同活性。
DOI：
10.1371/journal.pgen.1005119
复制
发表时间：
2015-04
期刊：
影响因子：
4.5
通讯作者：
Chen X
中科院分区：
文献类型：
--
作者：
Tu B;Liu L;Xu C;Zhai J;Li S;Lopez MA;Zhao Y;Yu Y;Ramachandran V;Ren G;Yu B;Li S;Meyers BC;Mo B;Chen X
3’尿苷化越来越被认为是与真核生物中 RNA 周转相关的保守 RNA 修饰过程。在拟南芥中，3' 末端核糖上的 2'-O-甲基化可保护 micro(mi)RNA 免受 3' 截短和 3' 尿苷化。此前，我们确定 HESO1 是体内尿苷酸化大多数未甲基化 miRNA 的核苷酸转移酶，但在 heso1 功能丧失突变体中仍然保留了大量 miRNA 的 3' 尾部。在这项研究中，我们发现在其他九种潜在的核苷酸转移酶中，UTP:RNA 尿苷酰转移酶 1 (URT1) 是尾随 miRNA 的最主要的单一核苷酸转移酶。 URT1 和 HESO1 在体外更喜欢具有不同 3' 末端核苷酸的底物，并在体内协同作用以尾随不同形式的相同 miRNA。此外，HESO1 和 URT1 都对 AGO1 结合的 miRNA 表现出核苷酸转移酶活性。尽管这些酶能够向 AGO1 结合的 miRNA 添加长尾，但带尾的 miRNA 仍然与 AGO1 相关。此外，AGO1 结合的 miRNA165/6 的拖尾显着降低了 AGO1-miR165/6 的切片活性，表明拖尾降低了 miRNA 活性。然而，URT1 对 miR171a 的单尿苷化赋予 miRNA 触发次级 siRNA 生物发生的能力。因此，3’加尾除了导致 miRNA 降解之外，还可能影响 miRNA 的活性。 RNA 上带有非模板尿苷的尾部（称为尿苷化）通常与 RNA 降解有关。我们之前将 HESO1 鉴定为一种核苷酸转移酶，可对 microRNA (miRNA) 进行尿苷酸化，从而导致其在拟南芥中降解。但 HESO1 不能解释体内所有 miRNA 尿苷化活性。在这里，我们发现 UTP:RNA 尿苷酰转移酶 1 (URT1) 是另一种尿苷酰化 miRNA 的核苷酸转移酶。 HESO1 和 URT1 具有不同的底物偏好，并且协同作用来尾部 miRNA。我们发现这两种酶都能够作用于 ARGONAUTE1 (AGO1) 结合的 miRNA，并且带尾的 miRNA 仍与 AGO1 结合。我们发现 URT1 介导的拖尾对 miR165/6 和 miR171a 的活性有不同的影响。这项研究揭示了复杂的 miRNA 尿苷化过程以及 miRNA 尿苷化的功能结果。
3’ uridylation is increasingly recognized as a conserved RNA modification process associated with RNA turnover in eukaryotes. 2’-O-methylation on the 3’ terminal ribose protects micro(mi)RNAs from 3’ truncation and 3’ uridylation in Arabidopsis. Previously, we identified HESO1 as the nucleotidyl transferase that uridylates most unmethylated miRNAs in vivo, but substantial 3’ tailing of miRNAs still remains in heso1 loss-of-function mutants. In this study, we found that among nine other potential nucleotidyl transferases, UTP:RNA URIDYLYLTRANSFERASE 1 (URT1) is the single most predominant nucleotidyl transferase that tails miRNAs. URT1 and HESO1 prefer substrates with different 3’ end nucleotides in vitro and act cooperatively to tail different forms of the same miRNAs in vivo. Moreover, both HESO1 and URT1 exhibit nucleotidyl transferase activity on AGO1-bound miRNAs. Although these enzymes are able to add long tails to AGO1-bound miRNAs, the tailed miRNAs remain associated with AGO1. Moreover, tailing of AGO1-bound miRNA165/6 drastically reduces the slicing activity of AGO1-miR165/6, suggesting that tailing reduces miRNA activity. However, monouridylation of miR171a by URT1 endows the miRNA the ability to trigger the biogenesis of secondary siRNAs. Therefore, 3’ tailing could affect the activities of miRNAs in addition to leading to miRNA degradation. The tailing of RNAs with non-templated uridines, known as uridylation, is often associated with RNA degradation. We previously identified HESO1 as a nucleotidyl transferase that uridylates microRNAs (miRNAs) to lead to their degradation in Arabidopsis. But HESO1 cannot account for all the miRNA uridylation activity in vivo. Here, we have uncovered UTP:RNA URIDYLYLTRANSFERASE 1 (URT1) as another nucleotidyl transferase that uridylates miRNAs. HESO1 and URT1 have different substrate preferences and act cooperatively to tail miRNAs. We show that both enzymes are able to act on ARGONAUTE1 (AGO1)-bound miRNAs and that the tailed miRNAs stay bound by AGO1. We show that URT1-mediated tailing affects the activities of miR165/6 and miR171a differently. This study reveals intricate miRNA uridylation processes as well as functional outcomes of miRNA uridylation.
登录
查看更多内容
影响因子：
16
作者：
Qi, Y;Denli, AM;Hannon, GJ
通讯作者：
Hannon, GJ
影响因子：
9.2
作者：
Park, W;Li, JJ;Chen, XM
通讯作者：
Chen, XM
Mirbase：MicroRNA基因组学的工具。
影响因子：
14.9
作者：
Griffiths-Jones, Sam;Saini, Harpreet Kaur;van Dongen, Stijn;Enright, Anton J.
通讯作者：
Enright, Anton J.
影响因子：
14.9
作者：
Yu B;Bi L;Zhai J;Agarwal M;Li S;Wu Q;Ding SW;Meyers BC;Vaucheret H;Chen X
通讯作者：
Chen X
影响因子：
9.2
作者：
Horwich, Michael D.;Li, Chengjian;Zamore, Phillip D.
通讯作者：
Zamore, Phillip D.