Dynamic, site-specific interaction of hypoxia-inducible factor-1alpha with the von Hippel-Lindau tumor suppressor protein

Cancer Res. 2001 May 15;61(10):4136-42.

Abstract

Hypoxia-inducible factor (HIF)-1alpha is a transcription factor that plays a critical role in regulating genes involved in erythropoiesis and angiogenesis. Recent evidence indicates that the von Hippel-Lindau tumor suppressor protein (VHL) is part of a ubiquitin ligase complex that promotes the degradation of HIF-1alpha under normoxic conditions. Under hypoxic conditions, HIF-1alpha is markedly stabilized. A critical issue in understanding the hypoxic response is the identification of hypoxia-regulated steps. We show here that hypoxia and cobalt treatment modulate the capacity of a HIF-1alpha fragment comprising residues 531-652 to coimmunoprecipitate with VHL. Hypoxia and cobalt both significantly diminish the interaction, and furthermore, normoxia treatment after hypoxia rapidly normalizes it. This HIF-1alpha fragment confers hypoxia and cobalt inducibility on a heterologous protein. Significantly, contained within this fragment is a short 27-residue sequence that behaves identically in all respects noted above. Finally, evidence is provided to show that cobalt and hypoxia both induce a posttranslational modification (or loss of one) in HIF-1alpha that affects its binding to VHL. We propose that dynamic, site-specific interaction of HIF-1alpha with VHL provides one mechanism by which HIF-1alpha can be regulated.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • COS Cells
  • Cell Hypoxia / physiology
  • Cobalt / pharmacology
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / genetics
  • HeLa Cells
  • Humans
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Immunoblotting
  • Ligases*
  • Molecular Sequence Data
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Precipitin Tests
  • Proteins / genetics
  • Proteins / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Substrate Specificity
  • Transcription Factors / genetics
  • Transfection
  • Tumor Suppressor Proteins*
  • Ubiquitin-Protein Ligases*
  • Von Hippel-Lindau Tumor Suppressor Protein

Substances

  • DNA-Binding Proteins
  • Fungal Proteins
  • GAL4 protein, S cerevisiae
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Nuclear Proteins
  • Proteins
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Cobalt
  • Ubiquitin-Protein Ligases
  • Von Hippel-Lindau Tumor Suppressor Protein
  • Ligases
  • VHL protein, human