PNAS:翻译阻遏引起基因沉默

生物谷

                             生物谷报道：翻译阻遏引起基因沉默


        应激性小RNAs型链球菌Hfq折叠，通过碱基配对从而down-regulate 靶mRNAs的表达。这种小RNAs型的核糖核蛋白复合体包括Hfq 和RNase E两部分。sRNP(regulatory outcomes of the RNase E/Hfq/small RNA-containing ribonucleoprotein complex )调节靶mRNA的快速降解和翻译阻遏。带着 sRNP介导的mRNA不稳定对全靶基因沉默影响的探寻我们使用了无mRNA降解的菌株进行实验，研究证明sRNP缺损时只偶然发生翻译抑制。所以我们得出结论：通过sRNP调节的翻译阻遏影响基因沉默。sRNP介导的mRNA降解的生理作用可能是去除了mRNAs翻译不活跃的细胞，从而导致基因沉默。

原始出处：Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan Teppei Morita, Yukari Mochizuki, and Hiroji Aiba* .Translational repression is sufficient for gene silencing by bacterial small noncoding RNAs in the absence of mRNA destruction .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.

友情连接:Translational repression is sufficient for gene silencing by bacterial small noncoding RNAs in the absence of mRNA destruction