A crucial role for GW182 and the DCP1:DCP2 decapping complex in miRNA-mediated gene silencing
A crucial role for GW182 and the DCP1:DCP2 decapping complex in miRNA-mediated gene silencing
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DOI：
10.1261/rna.2191905
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发表时间：
2005-11-01
期刊：
影响因子：
4.5
通讯作者：
Izaurralde, E
中科院分区：
文献类型：
--
作者：
Rehwinkel, J;Behm-Ansmant, I;Izaurralde, E
在真核细胞中，大量mRNA在5 ′至3 ′方向的降解需要去帽复合物（由DCP 1和DCP 2组成）和5 ′至3 ′核酸外切酶XRN 1的连续作用。这些酶存在于称为P体或GW体的离散细胞质病灶中（由于GW 182抗原的积累）。在其他转录后过程中起作用的蛋白质也被定位于P体。这些包括SMG5，SMG7和UPF1，它们在无义介导的mRNA衰变（NMD）中起作用，以及对RNA干扰（RNAi）和微小RNA（miRNA）途径至关重要的Argonaute蛋白。此外，XRN1是NMD和RNAL靶向mRNA降解所必需的。为了研究P体和这些转录后过程之间可能的相互作用，我们从果蝇细胞中耗尽P体或必需途径组分，并分析这些耗尽对报告构建体表达的影响，使我们能够特异性地监测NMD、RNAi或miRNA功能。我们发现，RNA结合蛋白GW182和DCPI：DCP2脱帽复合物是miRNA介导的基因沉默所必需的，揭示了P体成分在miRNA通路中的关键作用。我们的分析还表明，通过耗尽其关键效应子来抑制一种途径并不能阻止其他途径的功能，这表明果蝇缺乏相互依赖性。
in eukaryotic cells degradation of bulk mRNA in the 5' to 3' direction requires the consecutive action of the decapping complex (consisting of DCP1 and DCP2) and the 5' to 3' exonuclease XRN1. These enzymes are found in discrete cytoplasmic foci known as P-bodies or GW-bodies (because of the accumulation of the GW182 antigen). Proteins acting in other post-transcriptional processes have also been localized to P-bodies. These include SMG5, SMG7, and UPF1, which function in nonsense-mediated mRNA decay (NMD), and the Argonaute proteins that are essential for RNA interference (RNAi) and the micro-RNA (miRNA) pathway. In addition, XRN1 is required for degradation of mRNAs targeted by NMD and RNAL To investigate a possible interplay between P-bodies and these post-transcriptional processes we depleted P-body or essential pathway components from Drosophila cells and analyzed the effects of these depletions on the expression of reporter constructs, allowing us to monitor specifically NMD, RNAi, or miRNA function. We show that the RNA-binding protein GW182 and the DCPI:DCP2 decapping complex are required for miRNA-mediated gene silencing, uncovering a crucial role for P-body components in the miRNA pathway. Our analysis also revealed that inhibition of one pathway by depletion of its key effectors does not prevent the functioning of the other pathways, suggesting a lack of interdependence in Drosophila.