Department of Obstetrics and Gynecology, University of Leipzig, Leipzig, Germany.
Nucleic Acids Res. 2011 Jan;39(2):440-53. doi: 10.1093/nar/gkq796. Epub 2010 Sep 10.
The tumor suppressor p53 is a central regulator of cell-cycle arrest and apoptosis by acting as a transcription factor to regulate numerous genes. We identified all human p53-regulated mRNAs by microarray analyses and searched for protein-coding genes which contain intronic miRNAs. Among others, this analysis yielded the panthothenate kinase 1 (PANK1) gene and its intronic miRNA-107. We showed that miRNA-107 and PANK1 are coregulated by p53 in different cell systems. The PANK1 protein, which catalyzes the rate-limiting step of coenzyme A biosynthesis, is also upregulated by p53. We observed that p53 directly activates PANK1 and miRNA-107 transcription through a binding site in the PANK1 promoter. Furthermore, p53 is recruited to the PANK1 promoter after DNA damage. In order to get more insight into miRNA-107 function we investigated its potential target genes. Cell-cycle regulators are significantly enriched among predicted miRNA-107 targets. We found miRNA-107-dependent regulation of two important regulators of G(1)/S progression, CDK6 and the RB-related 2 gene RBL2 (p130). CDK6 and p130 proteins are downregulated upon miRNA-107 expression. Our results uncover a novel miRNA-dependent signaling pathway which leads to downregulation of cell cycle proteins in the absence of transcriptional repression.
肿瘤抑制因子 p53 通过作为转录因子来调节众多基因,从而成为细胞周期停滞和细胞凋亡的中央调节剂。我们通过微阵列分析鉴定了所有人类 p53 调节的 mRNA,并搜索了含有内含子 miRNA 的编码蛋白基因。在其他分析中,这产生了泛酰巯基乙胺激酶 1(PANK1)基因及其内含子 miRNA-107。我们表明,miRNA-107 和 PANK1 在不同的细胞系统中被 p53 共同调节。PANK1 蛋白是辅酶 A 生物合成的限速步骤的催化剂,也被 p53 上调。我们观察到 p53 通过 PANK1 启动子中的结合位点直接激活 PANK1 和 miRNA-107 的转录。此外,p53 在 DNA 损伤后被募集到 PANK1 启动子上。为了更深入地了解 miRNA-107 的功能,我们研究了其潜在的靶基因。细胞周期调节剂在预测的 miRNA-107 靶基因中显著富集。我们发现 miRNA-107 对 G1/S 进程的两个重要调节剂 CDKs 和 RB 相关基因 2 (p130)有依赖性调节。CDK6 和 p130 蛋白在 miRNA-107 表达时下调。我们的结果揭示了一种新的 miRNA 依赖的信号通路,该通路导致细胞周期蛋白在没有转录抑制的情况下下调。