title: Hypoxia-inducible factor 1alpha protein expression is controlled by oxygen-regulated ubiquitination that is disrupted by deletions and missense mutations.
abstract: Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that mediates cellular and systemic homeostatic responses to reduced O(2) availability in mammals, including angiogenesis, erythropoiesis, and glycolysis. HIF-1 activity is controlled by the O(2)-regulated expression of the HIF-1alpha subunit. Under nonhypoxic conditions, HIF-1alpha protein is subject to ubiquitination and proteasomal degradation. Here we report that missense mutations and/or deletions involving several different regions of HIF-1alpha result in constitutive expression and transcriptional activity in nonhypoxic cells. We demonstrate that hypoxia results in decreased ubiquitination of HIF-1alpha and that missense mutations increase HIF-1alpha expression under nonhypoxic conditions by blocking ubiquitination.
authors.affiliation: Institute of Genetic Medicine, Departments of Pediatrics and Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-3914, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Sutter
authors.forename: E
authors.initials: E
authors.lastname: Laughner
authors.forename: G L
authors.initials: GL
authors.lastname: Semenza
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D046911:Macromolecular Substances; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010100:Oxygen / Q000502:physiology*; D017354:Point Mutation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection; D014452:Ubiquitins / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D014452:Ubiquitins; D010100:Oxygen