Molecular mechanisms of transcription activation by HLF and HIF1alpha in response to hypoxia: their stabilization and redox signal-induced interaction with CBP/p300
Open Access
- 1 April 1999
- journal article
- research article
- Published by Springer Science and Business Media LLC in The EMBO Journal
- Vol. 18 (7), 1905-1914
- https://doi.org/10.1093/emboj/18.7.1905
Abstract
Hypoxia‐inducible factor 1 α (HIF1α) and its related factor, HLF, activate expression of a group of genes such as erythropoietin in response to low oxygen. Transfection analysis using fusion genes of GAL4DBD with various fragments of the two factors delineated two transcription activation domains which are inducible in response to hypoxia and are localized in the C‐terminal half. Their sequences are conserved between HLF and HIF1α. One is designated NAD (N‐terminal activation domain), while the other is CAD (C‐terminal activation domain). Immunoblot analysis revealed that NADs, which were rarely detectable at normoxia, became stabilized and accumulated at hypoxia, whereas CADs were constitutively expressed. In the mammalian two‐hybrid system, CAD and NAD baits enhanced the luciferase expression from a reporter gene by co‐transfection with CREB‐binding protein (CBP) prey, whereas CAD, but not NAD, enhanced β‐galactosidase expression in yeast by CBP co‐expression, suggesting that NAD and CAD interact with CBP/p300 by a different mechanism. Co‐transfection experiments revealed that expression of Ref‐1 and thioredoxin further enhanced the luciferase activity expressed by CAD, but not by NAD. Amino acid replacement in the sequences of CADs revealed a specific cysteine to be essential for their hypoxia‐inducible interaction with CBP. Nuclear translocation of thioredoxin from cytoplasm was observed upon reducing O2 concentrations.Keywords
This publication has 51 references indexed in Scilit:
- Cellular and developmental control of O2 homeostasis by hypoxia-inducible factor 1αGenes & Development, 1998
- Transactivation and Inhibitory Domains of Hypoxia-inducible Factor 1α: MODULATION OF TRANSCRIPTIONAL ACTIVITY BY OXYGEN TENSIONPublished by Elsevier BV ,1997
- Activation of Hypoxia-inducible Factor-1; Definition of Regulatory Domains within the α SubunitPublished by Elsevier BV ,1997
- Activation of Hypoxia-inducible Transcription Factor Depends Primarily upon Redox-sensitive Stabilization of Its α SubunitPublished by Elsevier BV ,1996
- Induction of Phosphoglycerate Kinase 1 Gene Expression by HypoxiaPublished by Elsevier BV ,1996
- A CBP Integrator Complex Mediates Transcriptional Activation and AP-1 Inhibition by Nuclear ReceptorsCell, 1996
- cDNA Cloning of a Murine Homologue ofDrosophilaSingle-Minded, Its mRNA Expression in Mouse Development, and Chromosome LocalizationBiochemical and Biophysical Research Communications, 1996
- Effect of Altered Redox States on Expression and DNA-Binding Activity of Hypoxia-Inducible Factor 1Biochemical and Biophysical Research Communications, 1995
- The Aryl Hydrocarbon Receptor ComplexAnnual Review of Pharmacology and Toxicology, 1995
- Redox Regulation of Fos and Jun DNA-Binding Activity in VitroScience, 1990