Mechanism of regulation of the hypoxia-inducible factor-1 alpha by the von Hippel-Lindau tumor suppressor protein

EMBO J. 2000 Aug 15;19(16):4298-309. doi: 10.1093/emboj/19.16.4298.

Abstract

In normoxic cells the hypoxia-inducible factor-1 alpha (HIF-1 alpha) is rapidly degraded by the ubiquitin-proteasome pathway, and activation of HIF-1 alpha to a functional form requires protein stabilization. Here we show that the product of the von Hippel-Lindau (VHL) tumor suppressor gene mediated ubiquitylation and proteasomal degradation of HIF-1 alpha under normoxic conditions via interaction with the core of the oxygen-dependent degradation domain of HIF-1 alpha. The region of VHL mediating interaction with HIF-1 alpha overlapped with a putative macromolecular binding site observed within the crystal structure of VHL. This motif of VHL also represents a mutational hotspot in tumors, and one of these mutations impaired interaction with HIF-1 alpha and subsequent degradation. Interestingly, the VHL binding site within HIF-1 alpha overlapped with one of the minimal transactivation domains. Protection of HIF-1 alpha against degradation by VHL was a multistep mechanism, including hypoxia-induced nuclear translocation of HIF-1 alpha and an intranuclear hypoxia-dependent signal. VHL was not released from HIF-1 alpha during this process. Finally, stabilization of HIF-1 alpha protein levels per se did not totally bypass the need of the hypoxic signal for generating the transactivation response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • COS Cells
  • Cell Line
  • Crystallography, X-Ray
  • Cysteine Endopeptidases / metabolism
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / metabolism
  • Green Fluorescent Proteins
  • Humans
  • Hypoxia*
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Immunoblotting
  • Ligases*
  • Luminescent Proteins / metabolism
  • Models, Biological
  • Molecular Sequence Data
  • Multienzyme Complexes / metabolism
  • Mutation
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Oxygen / metabolism
  • Plasmids / metabolism
  • Precipitin Tests
  • Proteasome Endopeptidase Complex
  • Protein Structure, Tertiary
  • Proteins / chemistry
  • Proteins / genetics
  • Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Signal Transduction
  • Transcription Factors / metabolism
  • Transcriptional Activation
  • Transfection
  • Tumor Suppressor Proteins*
  • Ubiquitin-Protein Ligases*
  • Ubiquitins / metabolism
  • 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
  • Luminescent Proteins
  • Multienzyme Complexes
  • Nuclear Proteins
  • Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Ubiquitins
  • Green Fluorescent Proteins
  • Ubiquitin-Protein Ligases
  • Von Hippel-Lindau Tumor Suppressor Protein
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex
  • Ligases
  • VHL protein, human
  • Oxygen