Pumilio 2 controls translation by competing with eIF4E for 7-methyl guanosine cap recognition
Pumilio 2 controls translation by competing with eIF4E for 7-methyl guanosine cap recognition
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DOI：
10.1261/rna.1884610
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发表时间：
2010-01-01
期刊：
影响因子：
4.5
通讯作者：
Richter, Joel D.
中科院分区：
文献类型：
--
作者：
Cao, Quiping;Padmanabhan, Kiran;Richter, Joel D.
Pumilio 2（Pum 2）与RINGO/SPY mRNA的39 UTR pumilio结合元件（PBE）相互作用，抑制爪蟾卵母细胞的翻译。在这里，我们表明Pum 2也直接结合到5'7 mG帽结构;这样做，它排除了eIF 4 E结合帽。使用缺失分析，我们已经映射的帽相互作用结构域的泵2的蛋白质的氨基末端，并确定了一个保守的色氨酸残基，介导这种特定的相互作用。基于报告基因mRNA的检测表明，Pum 2需要保守的色氨酸来抑制注射的非洲爪蟾卵母细胞的翻译。因此，除了其在调节poly（A）尾长和mRNA稳定性方面的作用外，我们的研究结果表明，脊椎动物Pumilio可以通过阻断帽上必需起始复合物的组装来抑制翻译。
Pumilio 2 (Pum2) interacts with the 39 UTR-containing pumilio binding element (PBE) of RINGO/SPY mRNA to repress translation in Xenopus oocytes. Here, we show that Pum2 also binds directly to the 5' 7mG cap structure; in so doing, it precludes eIF4E from binding the cap. Using deletion analysis, we have mapped the cap interaction domain of Pum2 to the amino terminus of the protein and identified a conserved tryptophan residue that mediates this specific interaction. Reporter mRNA-based assays demonstrate that Pum2 requires the conserved tryptophan to repress translation in injected Xenopus oocytes. Thus, in addition to its suggested role in regulating poly(A) tail length and mRNA stability, our results suggest that vertebrate Pumilio can repress translation by blocking the assembly of the essential initiation complex on the cap.