Epithelial Systems Biology Laboratory, NHLBI, National Institutes of Health, Bethesda, MD 20892-1603, USA.
National Cancer Center, Goyang Gyeonggi-do, Korea.
Sci Rep. 2016 Oct 11;6:34863. doi: 10.1038/srep34863.
Vasopressin-mediated regulation of renal water excretion is defective in a variety of water balance disorders in humans. It occurs in part through long-term mechanisms that regulate the abundance of the aquaporin-2 water channel in renal collecting duct cells. Here, we use deep DNA sequencing in mouse collecting duct cells to ask whether vasopressin signaling selectively increases Aqp2 gene transcription or whether it triggers a broadly targeted transcriptional network. ChIP-Seq quantification of binding sites for RNA polymerase II was combined with RNA-Seq quantification of transcript abundances to identify genes whose transcription is regulated by vasopressin. (View curated dataset at https://helixweb.nih.gov/ESBL/Database/Vasopressin/). The analysis revealed only 35 vasopressin-regulated genes (of 3659) including Aqp2. Increases in RNA polymerase II binding and mRNA abundances for Aqp2 far outstripped corresponding measurements for all other genes, consistent with the conclusion that vasopressin-mediated transcriptional regulation is highly selective for Aqp2. Despite the overall selectivity of the net transcriptional response, vasopressin treatment was associated with increased RNA polymerase II binding to the promoter proximal region of a majority of expressed genes, suggesting a nearly global positive regulation of transcriptional initiation with transcriptional pausing. Thus, the overall net selectivity appears to be a result of selective control of transcriptional elongation.
血管加压素介导的肾脏水排泄调节在人类各种水平衡紊乱中存在缺陷。这部分是通过长期机制调节肾脏集合管细胞中水通道蛋白-2（AQP2）的丰度来实现的。在这里，我们使用小鼠集合管细胞中的深度 DNA 测序来询问血管加压素信号是否选择性地增加 AQP2 基因转录，还是触发广泛靶向的转录网络。聚合酶 II 结合位点的 ChIP-Seq 定量与转录物丰度的 RNA-Seq 定量相结合，以鉴定受血管加压素调节的基因。（在 https://helixweb.nih.gov/ESBL/Database/Vasopressin/ 查看精选数据集）。分析显示，只有 35 个血管加压素调节基因（3659 个）包括 AQP2。AQP2 的 RNA 聚合酶 II 结合和 mRNA 丰度增加远远超过了所有其他基因的相应测量值，这与血管加压素介导的转录调节对 AQP2 具有高度选择性的结论一致。尽管净转录反应总体上具有选择性，但血管加压素处理与大多数表达基因的启动子近端区域 RNA 聚合酶 II 结合增加有关，这表明转录起始的几乎全局正调节伴随着转录暂停。因此，总体净选择性似乎是转录延伸选择性控制的结果。
