Author Contributions: Y.K. and Z.M.Q. designed the research, controlled and analyzed the data, and wrote the paper; M.F., X.M.W. F.D., L.Y. and W.H.Y. performed the research; and all authors checked the final version.
Original Research Article
Divalent metal transporter 1 is a hypoxia-inducible gene†
Article first published online: 17 MAR 2011
Copyright © 2010 Wiley-Liss, Inc.
Journal of Cellular Physiology
Volume 226, Issue 6, pages 1596–1603, June 2011
How to Cite
Qian, Z.-M., Mei Wu, X., Fan, M., Yang, L., Du, F., Yung, W.-H. and Ke, Y. (2011), Divalent metal transporter 1 is a hypoxia-inducible gene. J. Cell. Physiol., 226: 1596–1603. doi: 10.1002/jcp.22485
- Issue published online: 17 MAR 2011
- Article first published online: 17 MAR 2011
- Accepted manuscript online: 13 OCT 2010 12:00AM EST
- Manuscript Accepted: 5 OCT 2010
- Manuscript Received: 29 JUL 2010
- The Hong Kong Research Grants Council HKPU-562309 CUHK466907
- NSFC-RGC Joint Research CUHK433/08
- NSFC 30770806 30971197
- The Hong Kong Polytechnic University Research Grant G-YG11
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 exon1B 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 exon1B promoter containing the putative HRE sequence. We also showed that the HIF-1 binding site (HBS) is in DMT1 exon1B promoter with the core sequence of HRE (5′-ACGTG-3′) at −327 to −323 relative to the transcription start site of the human DMT1 exon1B 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. © 2010 Wiley-Liss, Inc.