HIF activation by pH-dependent nucleolar sequestration of VHL

Nat Cell Biol. 2004 Jul;6(7):642-7. doi: 10.1038/ncb1144. Epub 2004 Jun 6.

Abstract

Hypoxia and acidosis occur in a wide variety of physiological and pathological settings that include muscle stress, tumour development and ischaemic disorders. A central element in the adaptive response to cellular hypoxia is HIF (hypoxia-inducible factor), a transcription factor that activates an array of genes implicated in oxygen homeostasis, tumour vascularization and ischaemic preconditioning. HIF is activated by hypoxia, but undergoes degradation by the VHL (von Hippel-Lindau) tumour suppressor protein in the presence of oxygen. Here, we demonstrate that hypoxia induction or normoxic acidosis can neutralize the function of VHL by triggering its nucleolar sequestration, a regulatory mechanism of protein function that is observed rarely. VHL is confined to nucleoli until neutral pH conditions are reinstated. Nucleolar sequestration of VHL enables HIF to evade destruction in the presence of oxygen and activate its target genes. Our findings suggest that an increase in hydrogen ions elicits a transient and reversible loss of VHL function by promoting its nucleolar sequestration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acidosis / genetics
  • Acidosis / metabolism
  • Active Transport, Cell Nucleus / genetics
  • Animals
  • Cell Compartmentation / genetics
  • Cell Hypoxia / genetics
  • Cell Nucleolus / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation / genetics
  • Green Fluorescent Proteins
  • Humans
  • Hydrogen-Ion Concentration
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Luminescent Proteins
  • Mice
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Oxidation-Reduction
  • Oxygen / metabolism
  • PC12 Cells
  • Rats
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors*
  • Transcriptional Activation / genetics
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism*
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*
  • Up-Regulation / genetics
  • Von Hippel-Lindau Tumor Suppressor Protein

Substances

  • DNA-Binding Proteins
  • HIF1A protein, human
  • Hif1a protein, mouse
  • Hif1a protein, rat
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Luminescent Proteins
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Green Fluorescent Proteins
  • Ubiquitin-Protein Ligases
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, human
  • Oxygen