Werfel Stanislas, Leierseder Simon, Ruprecht Benjamin, Kuster Bernhard, Engelhardt Stefan
Institut für Pharmakologie und Toxikologie, Technische Universität München (TUM), 80802 Munich, Germany.
DZHK (German Center for Cardiovascular Research), Munich Heart Alliance, 80802 Munich, Germany.
Nucleic Acids Res. 2017 Sep 29;45(17):10218-10228. doi: 10.1093/nar/gkx640.
MicroRNAs (miRNAs) have been described to simultaneously inhibit hundreds of targets, albeit to a modest extent. It was recently proposed that there could exist more specific, exceptionally strong binding to a subgroup of targets. However, it is unknown, whether this is the case and how such targets can be identified. Using Argonaute2-ribonucleoprotein immunoprecipitation and in vivo competitive binding assays, we demonstrate for miRNAs-21, -199-3p and let-7 exceptional regulation of a subset of targets, which are characterized by preferential miRNA binding. We confirm this finding by analysis of independent quantitative proteome and transcriptome datasets obtained after miRNA silencing. Our data suggest that mammalian miRNA activity is guided by preferential binding of a small set of 3'-untranslated regions, thereby shaping a steep gradient of regulation between potential targets. Our approach can be applied for transcriptome-wide identification of such targets independently of the presence of seed complementary sequences or other predictors.
微小RNA（miRNA）已被描述为可同时抑制数百个靶标，尽管程度较为有限。最近有人提出，可能存在与一部分靶标更具特异性、异常强的结合。然而，情况是否如此以及如何识别这类靶标尚不清楚。通过AGO2核糖核蛋白免疫沉淀和体内竞争性结合试验，我们证明了miRNA-21、-199-3p和let-7对一部分靶标的特殊调控作用，这些靶标的特征是miRNA优先结合。我们通过分析miRNA沉默后获得的独立定量蛋白质组和转录组数据集证实了这一发现。我们的数据表明，哺乳动物miRNA的活性由一小部分3'非翻译区的优先结合所引导，从而在潜在靶标之间形成陡峭的调控梯度。我们的方法可用于全转录组范围识别这类靶标，而无需考虑种子互补序列或其他预测因子的存在。
