Glucocorticoid repression of human with-no-lysine (K) kinase-4 gene expression is mediated by the negative response elements in the promoter.
Glucocorticoid repression of human with-no-lysine (K) kinase-4 gene expression is mediated by the negative response elements in the promoter.
复制标题
DOI：
10.1677/jme-07-0049
复制
发表时间：
2008
影响因子：
3.5
通讯作者：
Chunyi Li;Yan Li;Yinghui Li;Hong Liu;Zhi-jun Sun;Jing-yu Lu;Yanyan Zhao
中科院分区：
文献类型：
--
作者：
Chunyi Li;Yan Li;Yinghui Li;Hong Liu;Zhi-jun Sun;Jing-yu Lu;Yanyan Zhao
含非赖氨酸激酶-4(WNK4)是一种丝氨酸/苏氨酸激酶，在调节液体和电解质的动态平衡中起着重要作用。糖皮质激素对WNK4基因表达的影响尚不清楚，糖皮质激素是关键的生理调节因子。在此，我们用地塞米松(Dex)处理人胚胎肾293(HEK293)细胞，通过Northern印迹和实时定量聚合酶链式反应发现人WNK4(HWNK4)的mRNA水平降低。用5‘末端快速扩增法定位hWNK4转录起始点后，通过聚合酶链式反应获得一系列5’端缺失的hWNK4启动子-荧光素酶。在COS-7和HEK293细胞中，Dex以糖皮质激素受体(GR)依赖的方式抑制hWNK4的转录活性。在hWNK4基因启动子的-285和-337位分别检测到两个负的糖皮质激素反应元件(NGRE)，并通过凝胶迁移率改变分析和染色质免疫沉淀证实Dex增强了与它们的GR结合活性。综上所述，这些数据表明hWNK4是一个新的糖皮质激素调节基因，其表达是通过GR与启动子区域的nGRE相互作用而被抑制的。
With-no-lysine (K) kinase-4 (WNK4) is a serine/threonine kinase that plays an essential role in the regulation of fluid and electrolyte homeostasis. The effects of glucocorticoids, key physiological regulators, on the WNK4 gene expression are still unknown. Here, we used dexamethasone (Dex) to treat the human embryo kidney 293 (HEK293) cells and found a decrease of human WNK4 (hWNK4) mRNA level by northern blot and real-time quantitative PCR. After an hWNK4 transcriptional initiation site was located by 5' rapid amplification of cDNA end assay, a series of 5'-deleted hWNK4 promoter-luciferase constructs were generated by PCR. Transfection of these constructs in COS-7 and HEK293 cells revealed that Dex inhibited the hWNK4 transcriptional activity in glucocorticoid receptor (GR)-dependent pattern. Two negative glucocorticoid response elements (nGREs) were identified at -285 and -337 of the hWNK4 gene promoter and the GR binding activity to them was increased by Dex as shown by electrophoretic mobility shift assay and chromatin immunoprecipitation. In summary, these data demonstrated that hWNK4 was a new glucocorticoid-regulated gene whose expression was inhibited through the interaction of GR with nGREs in the promoter region.