MicroRNA（普遍存在的,、調(diào)控基因表達的短非編碼RNA）已知影響信使RNA (mRNA)和蛋白的水平,。但因為蛋白生成依賴于mRNA的存在,，所以確定由微RNA調(diào)控的mRNA解理與翻譯抑制的相對貢獻一直有困難,。
現(xiàn)在,，David Bartel及其同事理清了兩個機制之間的關(guān)系,，并且發(fā)現(xiàn),，與人們所預(yù)料的相反的是，微RNA主要通過使目標(biāo)mRNA失去穩(wěn)定性來發(fā)揮作用,，而不是通過抑制它們的翻譯來發(fā)揮作用,。這些結(jié)果表明，需要對很多以前的結(jié)論進行一次重新評估,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09267
Mammalian microRNAs predominantly act to decrease target mRNA levels
Huili Guo,Nicholas T. Ingolia,Jonathan S. Weissman& David P. Bartel
MicroRNAs (miRNAs) are endogenous ~22-nucleotide RNAs that mediate important gene-regulatory events by pairing to the mRNAs of protein-coding genes to direct their repression. Repression of these regulatory targets leads to decreased translational efficiency and/or decreased mRNA levels, but the relative contributions of these two outcomes have been largely unknown, particularly for endogenous targets expressed at low-to-moderate levels. Here, we use ribosome profiling to measure the overall effects on protein production and compare these to simultaneously measured effects on mRNA levels. For both ectopic and endogenous miRNA regulatory interactions, lowered mRNA levels account for most (≥84%) of the decreased protein production. These results show that changes in mRNA levels closely reflect the impact of miRNAs on gene expression and indicate that destabilization of target mRNAs is the predominant reason for reduced protein output.
