Pervasive regulation of Drosophila Notch target genes by GY-box-, Brd-box-, and K-box-class microRNAs
Pervasive regulation of Drosophila Notch target genes by GY-box-, Brd-box-, and K-box-class microRNAs
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DOI：
10.1101/gad.1291905
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发表时间：
2005-05-01
影响因子：
10.5
通讯作者：
Rubin, GM
中科院分区：
文献类型：
--
作者：
Lai, EC;Tam, B;Rubin, GM
尽管已知数百种不同的动物microRNA（miRNAs），但目前仅了解少数的特定生物学功能。在这里，我们证明了三种不同的果蝇miRNAs家族直接调节两大家族的Notch靶基因，包括碱性螺旋-环-螺旋（bHLH）阻遏物和Bearded家族基因。这些miRNA通过GY-box（GUCUUCC）、Brd-box（AGCUUUA）和K-box（cUGUGAUa）基序调节Notch靶基因活性。这些是靶T-非翻译区（3 '-UTR）中的保守位点，其与miRNA的5'-末端或“种子”区互补。总的来说，这些基序代表了Notch靶基因中的> 40个miRNA结合位点，并且我们表明所有三类基序对于miRNA介导的体内调控是必要和足够的。重要的是，许多经验证的miRNA结合位点与“盒子：种子”区域之外的miRNA的配对有限。与此相一致，我们发现种子相关的miRNAs，否则是非常不同的，可以调节相同的靶序列。最后，我们表明，异位表达的几个Notch调控的miRNA诱导突变的表型，是Notch途径功能丧失的特点，包括损失的翅膀边缘，增厚的翅膀静脉，增加刚毛密度，和丛生的刚毛。总的来说，这些数据建立了对miRNA靶点识别的见解，并证明Notch信号通路是果蝇中miRNA介导的调控的主要靶点。
Although hundreds of distinct animal microRNAs (miRNAs) are known, the specific biological functions of only a handful are understood at present. Here, we demonstrate that three different families of Drosophila miRNAs directly regulate two large families of Notch target genes, including basic helix-loop-helix (bHLH) repressor and Bearded family genes. These miRNAs regulate Notch target gene activity via GY-box (GUCUUCC), Brd-box (AGCUUUA), and K-box (cUGUGAUa) motifs. These are conserved sites in target T-untranslated regions (3'-UTRs) that are complementary to the 5'-ends of miRNAs, or "seed" regions. Collectively, these motifs represent > 40 miRNA-binding sites in Notch target genes, and we show all three classes of motif to be necessary and sufficient for miRNA-mediated regulation in vivo. Importantly, many of the validated miRNA-binding sites have limited pairing to miRNAs outside of the "box:seed" region. Consistent with this, we find that seed-related miRNAs that are otherwise quite divergent can regulate the same target sequences. Finally, we demonstrate that ectopic expression of several Notch-regulating miRNAs induces mutant phenotypes that are characteristic of Notch pathway loss of function, including loss of wing margin, thickened wing veins, increased bristle density, and tufted bristles. Collectively, these data establish insights into miRNA target recognition and demonstrate that the Notch signaling pathway is a major target of miRNA-mediated regulation in Drosophila.