title: Hypoxia-inducible factor 1: regulation by hypoxic and non-hypoxic activators.
abstract: Oxygen availability is crucial for cellular metabolism. Hypoxia-inducible factor 1 (HIF-1) is the major oxygen homeostasis regulator. Under normoxic conditions, HIF-1 is rapidly degraded by the proteasome. However, under hypoxic conditions, HIF-1 is stabilized and permits the activation of genes essential to cellular adaptation to low oxygen conditions. These genes include the vascular endothelial growth factor (VEGF), erythropoietin and glucose transporter-1. There is increasing evidence showing that HIF-1 is also implicated in biological functions requiring its activation under normoxic conditions. Amongst others, growth factors and vascular hormones are implicated in this normoxic activation. In this review, we will focus on differences between hypoxic and non-hypoxic induction and activation of HIF-1. We will also discuss the biological functions of HIF-1 associated with these two induction pathways. The clear understanding of both HIF-1 activation mechanisms could have a major impact in cancer and vascular disease.
authors.affiliation: Centre de recherche de L'Hôtel-Dieu de Québec, Department of Medicine, Université Laval, 10 Rue McMahon, Qué., Canada G1R 2J6.
authors.forename: Marc-André C
authors.initials: MA
authors.lastname: Déry
authors.forename: Maude D
authors.initials: MD
authors.lastname: Michaud
authors.forename: Darren E
authors.initials: DE
authors.lastname: Richard
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004921:Erythropoietin / Q000235:genetics; D005786:Gene Expression Regulation; D051272:Glucose Transporter Type 1; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000502:physiology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D042442:Vascular Endothelial Growth Factors / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D051272:Glucose Transporter Type 1; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009004:Monosaccharide Transport Proteins; D009687:Nuclear Proteins; C495677:SLC2A1 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D042442:Vascular Endothelial Growth Factors; D004921:Erythropoietin; D046988:Proteasome Endopeptidase Complex; D010100:Oxygen