Up-Regulation of TRPM6 Transcriptional Activity by AP-1 in Renal Epithelial Cells
Up-Regulation of TRPM6 Transcriptional Activity by AP-1 in Renal Epithelial Cells
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DOI：
10.1002/jcp.21988
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发表时间：
2010-03-01
影响因子：
5.6
通讯作者：
Miwa, Masao
中科院分区：
文献类型：
--
作者：
Ikari, Akira;Sanada, Ayumi;Miwa, Masao
瞬时受体电位melastatin 6（TRPM 6）通道参与肾脏对镁的重吸收。我们最近发现TRPM 6的表达被EGF上调，但其调控机制尚不清楚。TRPM 6 mRNA在HEK 293细胞中内源性表达。TRPM 6 mRNA的表达由EGF增加，这是由U 0126，MEK抑制剂抑制。在TRPM 6 5 '侧翼区从-1，214至-718观察到人TRPM 6的启动子活性。这种启动子活性被EGF增强，被U 0126抑制。在-1，214/-718区域内鉴定了三个推定的AP-1结合位点。推测的AP-1结合位点（-741/-736）的突变完全抑制EGF诱导的启动子活性。EGF增加p-ERK 1/2，c-Fos，c-Jun和p-c-Jun水平，U 0126抑制。c-Fos或c-Jun siRNA的引入抑制EGF诱导的启动子活性。染色质免疫沉淀分析显示，c-Fos和c-Jun在1，214/ 718区域内与AP-1结合位点结合。这些结果表明，EGF通过激活ERK/AP-1依赖的途径上调TRPM 6 mRNA的表达。J.细胞。222：481-487，2010。(C)2009 Wiley-Liss，Inc.
Transient receptor potential melastatin 6 (TRPM6) channel is involved in the reabsorption of magnesium in the kidney. We recently found that TRPM6 expression is up-regulated by EGF, but the regulatory mechanism has not been clear. TRPM6 mRNA was endogenously expressed in HEK293 cells. TRPM6 mRNA expression was increased by EGF, which was inhibited by U0126, an MEK inhibitor. Promoter activity of human TRPM6 was observed in the TRPM6 5'-flanking region from -1,214 to -718. This promoter activity was enhanced by EGF and inhibited by U0126. Three putative AP-1 binding sites were identified within the region of -1,2 14/-718. The mutation of the putative AP-1 binding site (-741/-736) completely inhibited the EGF-induced promoter activity. EGF increased p-ERK 1/2, c-Fos, c-Jun, and p-c-Jun levels, which were inhibited by U0126. The introduction of c-Fos or c-Jun siRNA inhibited the EGF-induced promoter activity. A chromatin immunoprecipitation assay revealed that c-Fos and c-Jun bind to the AP-1 binding site within the region of 1,214/ 718. These results suggest that EGF up-regulates TRPM6 mRNA expression mediate via the activation of ERK/AP-1-dependent pathway. J. Cell. Physiol. 222: 481-487, 2010. (C) 2009 Wiley-Liss, Inc.