State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Plant Physiol. 2013 Apr;161(4):1875-84. doi: 10.1104/pp.113.215962. Epub 2013 Feb 21.
Target mimicry is a recently identified regulatory mechanism for microRNA (miRNA) functions in plants in which the decoy RNAs bind to miRNAs via complementary sequences and therefore block the interaction between miRNAs and their authentic targets. Both endogenous decoy RNAs (miRNA target mimics) and engineered artificial RNAs can induce target mimicry effects. Yet until now, only the Induced by Phosphate Starvation1 RNA has been proven to be a functional endogenous microRNA target mimic (eTM). In this work, we developed a computational method and systematically identified intergenic or noncoding gene-originated eTMs for 20 conserved miRNAs in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa). The predicted miRNA binding sites were well conserved among eTMs of the same miRNA, whereas sequences outside of the binding sites varied a lot. We proved that the eTMs of miR160 and miR166 are functional target mimics and identified their roles in the regulation of plant development. The effectiveness of eTMs for three other miRNAs was also confirmed by transient agroinfiltration assay.
靶标模拟是一种最近在植物中发现的 miRNA 功能调控机制，其中诱饵 RNA 通过互补序列与 miRNA 结合，从而阻断 miRNA 与其真实靶标的相互作用。内源性诱饵 RNA（miRNA 靶标模拟物）和工程人工 RNA 都可以诱导靶标模拟效应。然而，到目前为止，只有磷饥饿诱导 1 号 RNA 被证明是一种功能性的内源性 miRNA 靶标模拟物（eTM）。在这项工作中，我们开发了一种计算方法，系统地鉴定了拟南芥（Arabidopsis thaliana）和水稻（Oryza sativa）中 20 个保守 miRNA 的基因间或非编码基因起源的 eTM。相同 miRNA 的 eTM 之间预测的 miRNA 结合位点高度保守，而结合位点之外的序列则变化很大。我们证明了 miR160 和 miR166 的 eTM 是功能性的靶标模拟物，并确定了它们在植物发育调控中的作用。通过瞬时农杆菌浸润实验也证实了另外三个 miRNA 的 eTM 的有效性。
