Translational repression is sufficient for gene silencing by bacterial small noncoding RNAs in the absence of mRNA destruction
Translational repression is sufficient for gene silencing by bacterial small noncoding RNAs in the absence of mRNA destruction
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DOI：
10.1073/pnas.0509638103
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发表时间：
2006-03-28
影响因子：
11.1
通讯作者：
Aiba, H
中科院分区：
文献类型：
--
作者：
Morita, T;Mochizuki, Y;Aiba, H
应激诱导的大肠杆菌Hfq结合小RNA SgrS和RyhB通过碱基配对下调靶mRNA的表达。这些小RNA与Hfq和RNase E形成核糖核蛋白复合物。RNase E/Hfq/含小RNA的核糖核蛋白复合物（sRNP）的调节结果是靶mRNA的快速降解和翻译抑制。在这里，我们问在多大程度上sRNP介导的mRNA不稳定有助于通过使用菌株的mRNA的快速降解不再发生的靶基因的整体沉默。我们证明，翻译抑制发生在sRNP介导的mRNA不稳定的情况下。我们的结论是，翻译抑制是足够的基因沉默sRNP。由sRNP介导的mRNA降解的一个可能的生理作用是清除细胞中的无活性mRNA，使基因沉默不可逆。
Stress-induced Hfq-binding small RNAs of Escherichia coli, SgrS and RyhB, down-regulate the expression of target mRNAs through base-pairing. These small RNAs form ribonucleoprotein complexes with Hfq and RNase E. The regulatory outcomes of the RNase E/Hfq/small RNA-containing ribonucleoprotein complex (sRNP) are rapid degradation of target mRNAs and translational inhibition. Here, we ask to what extent the sRNP-mediated mRNA destabilization contributes to the overall silencing of target genes by using strains in which the rapid degradation of mRNA no longer occurs. We demonstrate that translational repression occurs in the absence of sRNP-mediated mRNA destabilization. We conclude that translational repression is sufficient for gene silencing by sRNP. One possible physiological role of mRNA degradation mediated by sRNP is to rid the cell of translationally inactive mRNAs, making gene silencing irreversible.