A link between RNA metabolism and silencing affecting Arabidopsis development
A link between RNA metabolism and silencing affecting Arabidopsis development
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DOI：
10.1016/j.devcel.2008.04.005
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发表时间：
2008-06-01
影响因子：
11.8
通讯作者：
Ecker, Joseph R.
中科院分区：
文献类型：
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作者：
Gregory, Brian D.;O'Malley, Ronan C.;Ecker, Joseph R.
MicroRNAs （miRNAs）和小干扰rna （sirna）是丰富的内源性小rna (smrna)，通过转录后基因沉默控制转录物的表达。在这里，我们发现XRN4/EIN5（一种5-3'外核糖核酸酶）和ABH1/CBP80 （mRNA帽结合复合体的一个亚基）的缺失会导致拟南芥植物表现出无数的发育缺陷。我们发现ABH1/CBP80是获得适当成熟miRNA水平所必需的，这表明该蛋白影响miRNA介导的RNA沉默途径。此外，我们发现XRN4/ElN5影响一类smRNA的水平，该类smRNA由类似130内源性转录本的正义链和反义链加工而成，这些转录本显然转化为双链RNA （dsRNA）并随后加工。我们发现这些smRNA的亲本转录本在XRN4/EIN5缺失时以无帽的形式积累，这表明无帽的内源转录本可以成为smRNA生物发生的底物。总的来说，我们的研究结果揭示了RNA代谢和沉默途径之间意想不到的联系。
MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are abundant endogenous small RNAs (smRNAs) that control transcript expression through posttranscriptional gene silencing. Here, we show that concomitant loss of XRN4/EIN5, a 5-3'exoribonuclease, and ABH1/CBP80, a subunit of the mRNA cap binding complex, results in Arabidopsis plants manifesting myriad developmental defects. We find that ABH1/CBP80 is necessary to obtain proper mature miRNA levels, which suggests this protein affects the miRNA-mediated RNA silencing pathway. Additionally, we show that XRN4/ElN5 affects the levels of a smRNA class that is processed from both sense and antisense strands of similar to 130 endogenous transcripts that apparently are converted to double-stranded RNA (dsRNA) and subsequently processed. We find that the parent transcripts of these smRNAs accumulate in an uncapped form upon loss of XRN4/EIN5, which suggests that uncapped endogenous transcripts can become smRNA biogenesis substrates. Overall, our results reveal unexpected connections between RNA metabolism and silencing pathways.