Dissecting Arabidopsis thaliana DICER function in small RNA processing, gene silencing and DNA methylation patterning
Dissecting Arabidopsis thaliana DICER function in small RNA processing, gene silencing and DNA methylation patterning
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DOI：
10.1038/ng1804
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发表时间：
2006-06-01
期刊：
影响因子：
30.8
通讯作者：
Jacobsen, Steven E.
中科院分区：
文献类型：
--
作者：
Henderson, Ian R.;Zhang, Xiaoyu;Jacobsen, Steven E.
小RNA有几个重要的生物学功能(1)。MicroRNAs(MiRNAs)和反式作用小干扰RNAs(TasiRNAs)调节mRNA的稳定性和翻译，siRNAs导致转座子、病毒和转基因的转录后基因沉默，并在胞嘧啶DNA甲基化的建立和维持中发挥重要作用。在这里，我们研究了四个拟南芥类基因(DCL1-DCL4)在这些过程中的作用。对dcl2 dcl3 dcl4三重突变体的小RNA测序显示，tasiRNA和siRNA的产生显著减少，这表明DCL1除了作为加工miRNAs的主要酶外，在从内源反向重复序列中产生小RNA方面具有以前未知的作用。DCL2、DCL3和DCL4在siRNA和tasiRNA的产生以及DNA甲基化的建立和维持方面表现出功能冗余。我们的研究还表明，不对称DNA甲基化可以通过不需要siRNA的途径来维持。
Small RNAs have several important biological functions(1). MicroRNAs (miRNAs) and trans-acting small interfering RNAs (tasiRNAs) regulate mRNA stability and translation, and siRNAs cause post-transcriptional gene silencing of transposons, viruses and transgenes and are important in both the establishment and maintenance of cytosine DNA methylation(2). Here, we study the role of the four Arabidopsis thaliana DICER-LIKE genes (DCL1-DCL4) in these processes. Sequencing of small RNAs from a dcl2 dcl3 dcl4 triple mutant showed markedly reduced tasiRNA and siRNA production and indicated that DCL1, in addition to its role as the major enzyme for processing miRNAs, has a previously unknown role in the production of small RNAs from endogenous inverted repeats. DCL2, DCL3 and DCL4 showed functional redundancy in siRNA and tasiRNA production and in the establishment and maintenance of DNA methylation. Our studies also suggest that asymmetric DNA methylation can be maintained by pathways that do not require siRNAs.