Regulation of a maize HD-ZIP IV transcription factor by a non-conventional RDR2-dependent small RNA
Regulation of a maize HD-ZIP IV transcription factor by a non-conventional RDR2-dependent small RNA
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DOI：
10.1111/tpj.12771
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发表时间：
2015-03-01
期刊：
影响因子：
7.2
通讯作者：
Vernoud, Vanessa
中科院分区：
文献类型：
--
作者：
Klein-Cosson, Catherine;Chambrier, Pierre;Vernoud, Vanessa
小分子非编码RNA是一种多功能的核糖核酸调节因子，在转录或转录后水平控制基因表达，调控植物发育的许多方面。在这里，我们提出了一个24 nt的小RNA（命名为small 1），是互补的3 UTR的OCL 1（外细胞层1），玉米HD-ZIPIV基因家族的创始成员编码植物特异性转录因子，主要参与表皮分化和专业化的存在的证据。small 1的生物发生依赖于DICER样3（DCL 3），RNA依赖性RNA聚合酶2（RDR 2）和RNA聚合酶IV，这些组分通常是RNA依赖性DNA甲基化所需的。出乎意料的是，在瞬时和稳定的转化系统中的GFP传感器实验显示，small 1可以在转录后水平上调节其目标，主要通过翻译抑制。这种翻译抑制在small 1不积累的rdr 2突变体背景中减弱。我们的实验进一步表明，可能参与的二级茎环结构存在于3 UTR的OCL 1的有效的目标阻遏，这表明存在的几个调节机制影响OCL 1 mRNA的稳定性和translation.Significance StatementThis工作解决了问题的调节植物特异性HD-ZIP IV转录因子的非典型非编码小RNA。虽然这种小RNA的生物发生依赖于转录基因沉默机制的组成部分，如DCL 3 RDR 2和Pol IV，但我们的研究结果强烈表明，它主要通过翻译抑制在转录后水平调节其靶点。
Small non-coding RNAs are versatile riboregulators that control gene expression at the transcriptional or post-transcriptional level, governing many facets of plant development. Here we present evidence for the existence of a 24 nt small RNA (named small1) that is complementary to the 3 UTR of OCL1 (Outer Cell Layer1), the founding member of the maize HD-ZIPIV gene family encoding plant-specific transcription factors that are mainly involved in epidermis differentiation and specialization. The biogenesis of small1 depends on DICER-like3 (DCL3), RNA-dependent RNA polymerase2 (RDR2) and RNA polymeraseIV, components that are usually required for RNA-dependent DNA-methylation. Unexpectedly, GFP sensor experiments in transient and stable transformation systems revealed that small1 may regulate its target at the post-transcriptional level, mainly through translational repression. This translational repression is attenuated in an rdr2 mutant background in which small1 does not accumulate. Our experiments further showed the possible involvement of a secondary stem-loop structure present in the 3 UTR of OCL1 for efficient target repression, suggesting the existence of several regulatory mechanisms affecting OCL1 mRNA stability and translation.Significance StatementThis work addresses the question of the regulation of the plant specific HD-ZIP IV transcription factors by an atypical non coding small RNA. Although the biogenesis of this small RNA depends on components of the transcriptional gene silencing machinery such as DCL3 RDR2 and Pol IV, our results strongly suggest that it regulates its target at the post-transcriptional level, mainly through translational repression.