Absolute requirement of aryl hydrocarbon receptor nuclear translocator protein for gene activation by hypoxia

Arch Biochem Biophys. 1996 Oct 15;334(2):389-94. doi: 10.1006/abbi.1996.0469.


Hypoxia-inducible factor 1 (HIF-1) is a DNA-binding heterodimeric protein complex originally described in the transcriptional activation of the erythropoietin gene by hypoxia. This protein complex is composed of two subunits, HIF-1alpha and -1beta (aryl hydrocarbon receptor nuclear translocator, ARNT). In this study, we used ARNT-deficient cells, derived from the mouse hepatoma cell line Hepa1c1c7, to further characterize HIF-1 complex formation and its relationship with gene activation by hypoxia and desferrioxamine (Df). Gel shift assays revealed that ARNT is absolutely required for the formation of the HIF-1 DNA-binding complex. Results from RNase protection assays and Northern blots showed that the lack of functional HIF-1 complex completely abrogated the response to hypoxia of vascular endothelial growth factor (VEGF) and the glycolytic enzymes aldolase A (ALDA) and phosphoglycerate kinase 1 (PGK-1), genes known to be upregulated by low oxygen tension. Desferrioxamine induction of VEGF and PGK-1 genes was reduced in the ARNT-deficient cells, but at difference with hypoxia, it was not completely suppressed. These results suggest that Df is able to activate gene transcription through HIF-1-independent mechanisms. Exposure to hypoxia or Df did not induce any changes in HIF-1alpha and -1beta mRNA levels, suggesting that posttranscriptional mechanisms are involved in HIF-1 complex activation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / biosynthesis
  • Animals
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Blotting, Northern
  • Cell Hypoxia
  • Cell Line
  • Cell Nucleus / metabolism
  • DNA-Binding Proteins / metabolism*
  • Deferoxamine / pharmacology
  • Endothelial Growth Factors / biosynthesis
  • Fructose-Bisphosphate Aldolase / biosynthesis
  • Gene Expression Regulation, Neoplastic* / drug effects
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Liver Neoplasms, Experimental
  • Lymphokines / biosynthesis
  • Mice
  • Nuclear Proteins / metabolism*
  • Phosphoglycerate Kinase / biosynthesis
  • Receptors, Aryl Hydrocarbon / biosynthesis*
  • Transcription Factors / metabolism*
  • Transcriptional Activation
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors


  • Actins
  • Arnt protein, mouse
  • DNA-Binding Proteins
  • Endothelial Growth Factors
  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Lymphokines
  • Nuclear Proteins
  • Receptors, Aryl Hydrocarbon
  • Transcription Factors
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Phosphoglycerate Kinase
  • Fructose-Bisphosphate Aldolase
  • Deferoxamine