The hypoxia-inducible factor-1 DNA recognition site is cAMP-responsive.

Abstract

The hypoxia-inducible factor-1 (HIF-1) was first described as a DNA binding activity that specifically recognizes an 8 bp hypoxia response element (HRE) known to be essential for oxygen-regulated erythropoietin gene expression. In electrophoretic mobility shift assays (EMSAs) HIF-1 DNA binding activity is only detectable in nuclear extracts of cells cultivated in a low oxygen atmosphere. In addition to HIF-1, a constitutive DNA binding activity also specifically binds the HIF-1 probe. Based on EMSAs using competitor oligonucleotides, specific antibodies and recombinant proteins, we previously reported that the constitutive HRE binding factor is composed of ATF-1 and CREB-1. Here we show that this site is functionally responsive to the cAMP agonist 8Br-cAMP in a dose-dependent manner under hypoxic but not under normoxic conditions. These results were confirmed by using the protein kinase A (PKA) activator Sp-cAMPS and the PKA inhibitor Rp-cAMPS: while Sp-cAMPS was synergistic with hypoxia on the HIF-1 DNA recognition site, the Rp-cAMPS isomer showed no effect. Our findings suggest that the PKA-signaling pathway is enhancing oxygen-dependent gene expression via the HRE.

• Authors: I Kvietikova, R H Wenger, H H Marti, M Gassmann
• Journal: Kidney international (Kidney Int) Vol. 51 Issue 2 Pg. 564-6 (Feb 1997) ISSN: 0085-2538 [Print] United States
• PMID: 9027740 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA-Binding Proteins
• Enzyme Inhibitors
• HIF1A protein, human
• Hypoxia-Inducible Factor 1
• Hypoxia-Inducible Factor 1, alpha Subunit
• Nuclear Proteins
• Transcription Factors
• Erythropoietin
• 8-Bromo Cyclic Adenosine Monophosphate
• DNA
• Cyclic AMP
• Luciferases
• Cyclic AMP-Dependent Protein Kinases

Topics

• 8-Bromo Cyclic Adenosine Monophosphate (pharmacology)
• Binding Sites
• Cell Hypoxia (genetics, physiology)
• Cyclic AMP (metabolism)
• Cyclic AMP-Dependent Protein Kinases (antagonists & inhibitors, metabolism)
• DNA (genetics, metabolism)
• DNA-Binding Proteins (metabolism)
• Enzyme Activation (drug effects)
• Enzyme Inhibitors (pharmacology)
• Erythropoietin (genetics)
• Gene Expression Regulation
• Genes, Reporter
• HeLa Cells
• Humans
• Hypoxia-Inducible Factor 1
• Hypoxia-Inducible Factor 1, alpha Subunit
• Luciferases (genetics)
• Nuclear Proteins (metabolism)
• Transcription Factors
• Transfection