Divalent Metal Transporter 1 is a Hypoxia-Inducible Gene
Divalent Metal Transporter 1 is a Hypoxia-Inducible Gene
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二价金属转运蛋白1是缺氧诱导基因
DOI：
10.1002/jcp.22485
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发表时间：
2011-06-01
影响因子：
5.6
通讯作者：
Ke, Ya
中科院分区：
文献类型：
--
作者：
Qian, Zhong-Ming;Wu, Xiao Mei;Ke, Ya
我们最近的研究表明，低氧诱导因子-1(HIF-1)α和二价金属转运蛋白1(DMT1)在化学或物理缺氧处理的HepG2细胞中的表达具有高度的相关性。因此，我们推测DMT1可能是HIF-1的靶基因之一。在这里，我们鉴定了DMT1外显子1B启动子区域，并确定了一个与HIF-1结合的功能性缺氧反应元件(HRE，5‘-TCAGTACCTAACGTGGCGCCACGGC-3’)。我们证明，在转染的HepG2细胞中，荧光素酶报告基因的低氧依赖激活是由含有假定的HRE序列的人DMT1外显子1B启动子片段介导的。我们还发现HIF-1结合位点(HBS)位于DMT1外显子1B启动子上，其核心序列HRE(5‘-ACGTG-3’)相对于人DMT1外显子1B基因的转录起始点在-327到-323之间。该序列的突变阻止了荧光素酶活性的刺激。凝胶迁移率改变分析表明，在DMT1基因启动子中发现的HRE序列与HIF-1结合。此外，我们提供的证据表明，低氧可以显著增加铁的摄取，而RNA干扰沉默总DMT1下调了DMT1的表达和HepG2细胞的铁摄取。我们的结论是DMT1是一个低氧诱导基因。J.细胞。物理。226：1596-1603,2011。(C)2010年Wiley-Liss公司
Our recent study revealed a high correlation between the expression of hypoxia-inducible factor-1 (HIF-1) alpha and divalent metal transporter 1 (DMT1) in HepG2 cells treated with chemical or physical hypoxia. We therefore speculated that DMT1 might be one of the target genes of HIF-1. Here, we characterized the DMT1 exon 1B promoter region and identified a functional hypoxia response element (HRE, 5'-TCAGTACCTAACGTGGCGCCACGGC-3') harboring a binding site for HIF-1. We demonstrated that hypoxia-dependent activation of a luciferase reporter gene in transfected HepG2 cells is mediated by a fragment of human DMT1 exon 1B promoter containing the putative HRE sequence. We also showed that the HIF-1 binding site (HBS) is in DMT1 exon 1B promoter with the core sequence of HRE (5'-ACGTG-3') at -327 to -323 relative to the transcription start site of the human DMT1 exon 1B gene. The mutation of this sequence prevented stimulation of luciferase activity. Electrophoretic mobility shift assays revealed that the HRE sequence found in the DMT1 gene promoter was bound by HIF-1. In addition, we provide evidence that hypoxia could significantly increase ferrous uptake, while the silencing of total DMT1 by RNA interference down-regulates DMT1 expression and ferrous uptake in HepG2 cells. We conclude that DMT1 is a hypoxia-inducible gene. J. Cell. Physiol. 226: 1596-1603, 2011. (C) 2010 Wiley-Liss, Inc.