DICER-LIKE2 plays a primary role in transitive silencing of transgenes in Arabidopsis.
DICER-LIKE2 plays a primary role in transitive silencing of transgenes in Arabidopsis.
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DICER LIKE2在拟南芥中转基因的传递沉默中起主要作用。
DOI：
10.1371/journal.pone.0001755
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发表时间：
2008-03-12
期刊：
影响因子：
3.7
通讯作者：
Vance V
中科院分区：
文献类型：
--
作者：
Mlotshwa S;Pruss GJ;Peragine A;Endres MW;Li J;Chen X;Poethig RS;Bowman LH;Vance V
DCL酶在植物RNA沉默中起着关键作用，它将长的双链RNA（dsRNA）加工成介导RNA沉默的一级短的干扰RNA（siRNAs）。siRNA的数量可以通过传递性（transitivity）来增加和沉默放大，这是一种依赖于RNA聚合酶（RDR）的途径，它以靶RNA为底物产生二级siRNA。在这里，我们报告说，拟南芥DCL 2-而不是DCL 4-所需的细胞自主，转录后沉默的转基因的传递性。DCL 2中的插入突变阻断了正义转基因诱导的沉默，并消除了相关的RDR依赖性siRNA的积累。在发夹转基因诱导的沉默中，dcl 2突变同样消除了次级siRNA的积累并阻断了传递性沉默，但不阻断初级siRNA介导的沉默。引人注目的是，在所有情况下，dcl 2突变消除了所有二级siRNA的积累，包括由其他DCL酶产生的那些。相比之下，DCL 4中的突变在发夹转基因的情况下促进了向传递性沉默的急剧转变，并且增强了由有义转基因诱导的沉默。P1/HC-Pro和P38病毒抑制子对发夹和正义转基因沉默的抑制与次级siRNA积累的消除相关，但抑制子并不阻断发夹转录物的茎加工成初级siRNA。因此，这些病毒抑制子在它们对siRNA生物发生的影响方面类似于dcl 2突变。我们的结论是，DCL 2起着重要的，而不是多余的，在传递沉默的转基因的作用，并可能发挥更重要的作用，沉默的病毒比目前认为的。
Dicer-like (DCL) enzymes play a pivotal role in RNA silencing in plants, processing the long double-stranded RNA (dsRNA) that triggers silencing into the primary short interfering RNAs (siRNAs) that mediate it. The siRNA population can be augmented and silencing amplified via transitivity, an RNA-dependent RNA polymerase (RDR)-dependent pathway that uses the target RNA as substrate to generate secondary siRNAs. Here we report that Arabidopsis DCL2–but not DCL4-is required for transitivity in cell-autonomous, post-transcriptional silencing of transgenes. An insertion mutation in DCL2 blocked sense transgene-induced silencing and eliminated accumulation of the associated RDR-dependent siRNAs. In hairpin transgene-induced silencing, the dcl2 mutation likewise eliminated accumulation of secondary siRNAs and blocked transitive silencing, but did not block silencing mediated by primary siRNAs. Strikingly, in all cases, the dcl2 mutation eliminated accumulation of all secondary siRNAs, including those generated by other DCL enzymes. In contrast, mutations in DCL4 promoted a dramatic shift to transitive silencing in the case of the hairpin transgene and enhanced silencing induced by the sense transgene. Suppression of hairpin and sense transgene silencing by the P1/HC-Pro and P38 viral suppressors was associated with elimination of secondary siRNA accumulation, but the suppressors did not block processing of the stem of the hairpin transcript into primary siRNAs. Thus, these viral suppressors resemble the dcl2 mutation in their effects on siRNA biogenesis. We conclude that DCL2 plays an essential, as opposed to redundant, role in transitive silencing of transgenes and may play a more important role in silencing of viruses than currently thought.
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影响因子：
30.8
作者：
Dunoyer, Patrice;Himber, Christophe;Voinnet, Olivier
通讯作者：
Voinnet, Olivier
影响因子：
56.9
作者：
Alonso, JM;Stepanova, AN;Ecker, JR
通讯作者：
Ecker, JR
影响因子：
9.2
作者：
Finnegan, EJ;Margis, R;Waterhouse, PM
通讯作者：
Waterhouse, PM
DOI：
10.1073/pnas.232434999
发表时间：
2002-11-12
影响因子：
11.1
作者：
Mallory, AC;Reinhart, BJ;Bowman, LH
通讯作者：
Bowman, LH
影响因子：
11.4
作者：
Bouche, Nicolas;Lauressergues, Dominique;Vaucheret, Herve
通讯作者：
Vaucheret, Herve