Plant virus-mediated induction of miR168 is associated with repression of ARGONAUTE1 accumulation
Plant virus-mediated induction of miR168 is associated with repression of ARGONAUTE1 accumulation
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DOI：
10.1038/emboj.2010.215
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发表时间：
2010-10-20
期刊：
影响因子：
11.4
通讯作者：
Havelda, Zoltan
中科院分区：
文献类型：
--
作者：
Varallyay, Eva;Valoczi, Anna;Havelda, Zoltan
病毒感染诱导ARGONAUTE1(Ago1)基因的表达，同时促进MIR168(Ago1的调节因子)基因的积累。在这里，我们表明，在感染病毒的植物中，Ago1mRNA的增强表达并不伴随着Ago1蛋白积累的增加。我们还表明，Ago1 mRNA水平的诱导是宿主防御反应的一部分，而MIR168的诱导主要由Tombus病毒p19 RNA沉默抑制子介导，MIR168与病毒占据的扇区在空间上重叠。P19的缺失导致MIR168的诱导消失，并伴随着Ago1蛋白的增强积累。在瞬时表达研究中，p19介导了MIR168的诱导和内源性Ago1水平的下调。在感染病毒的植物中，p19不能有效地结合MIR168，这表明这一活性与p19的小RNA结合能力无关。我们的结果表明，植物病毒可以通过调节内源MIR168水平来抑制Ago1蛋白的翻译能力，从而减轻Ago1蛋白的抗病毒功能。EMBO期刊(2010)29,3507-3519。DOI：10.1038/Intemj.2010.215；2010年9月7日在线出版主题类别：核糖核酸；植物生物学
Virus infections induce the expression of ARGONAUTE1 (AGO1) mRNA and in parallel enhance the accumulation of miR168 (regulator of AGO1) mRNA). Here, we show that in virus-infected plants the enhanced expression of AGO1 mRNA is not accompanied by increased AGO1 protein accumulation. We also show that the induction of AGO1 mRNA level is a part of the host defence reaction, whereas the induction of miR168, which overlaps spatially with virus-occupied sectors, is mediated mainly by the Tombusvirus p19 RNA-silencing suppressor. The absence of p19 results in the elimination of miR168 induction and accompanied with the enhanced accumulation of AGO1 protein. In transient expression study, p19 mediates the induction of miR168 and the down-regulation of endogenous AGO1 level. P19 is not able to efficiently bind miR168 in virus-infected plants, indicating that this activity is uncoupled from the small RNA-binding capacity of p19. Our results imply that plant viruses can inhibit the translational capacity of AGO1 mRNA by modulating the endogenous miR168 level to alleviate the anti-viral function of AGO1 protein. The EMBO Journal (2010) 29, 3507-3519. doi:10.1038/emboj.2010.215; Published online 7 September 2010 Subject Categories: RNA; plant biology