Abstract
HIF is a transcriptional complex that plays a central role in mammalian oxygen homeostasis. Recent studies have defined posttranslational modification by prolyl hydroxylation as a key regulatory event that targets HIF-alpha subunits for proteasomal destruction via the von Hippel-Lindau ubiquitylation complex. Here, we define a conserved HIF-VHL-prolyl hydroxylase pathway in C. elegans, and use a genetic approach to identify EGL-9 as a dioxygenase that regulates HIF by prolyl hydroxylation. In mammalian cells, we show that the HIF-prolyl hydroxylases are represented by a series of isoforms bearing a conserved 2-histidine-1-carboxylate iron coordination motif at the catalytic site. Direct modulation of recombinant enzyme activity by graded hypoxia, iron chelation, and cobaltous ions mirrors the characteristics of HIF induction in vivo, fulfilling requirements for these enzymes being oxygen sensors that regulate HIF.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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2,2'-Dipyridyl / metabolism
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Amino Acid Sequence
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Animals
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Caenorhabditis elegans / physiology*
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Caenorhabditis elegans Proteins*
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Chromatography, High Pressure Liquid
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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Gene Expression Regulation / genetics
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HeLa Cells
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Helminth Proteins / chemistry
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Helminth Proteins / genetics
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Helminth Proteins / metabolism*
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Homeostasis
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Humans
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Hydroxylation
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Hypoxia-Inducible Factor 1
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Hypoxia-Inducible Factor 1, alpha Subunit
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Indicators and Reagents
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Ligases / metabolism
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Molecular Sequence Data
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Oxygen / metabolism
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Procollagen-Proline Dioxygenase / metabolism
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Protein Isoforms
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Protein Structure, Secondary
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Rats
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Recombinant Proteins / metabolism
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Sequence Alignment
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Transcription Factors / genetics
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Transcription Factors / metabolism
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Tumor Suppressor Proteins*
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Ubiquitin-Protein Ligases*
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Von Hippel-Lindau Tumor Suppressor Protein
Substances
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Caenorhabditis elegans Proteins
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DNA-Binding Proteins
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Egl-9 protein, C elegans
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HIF1A protein, human
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Helminth Proteins
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Hif1a protein, rat
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Hypoxia-Inducible Factor 1
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Hypoxia-Inducible Factor 1, alpha Subunit
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Indicators and Reagents
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Nuclear Proteins
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Protein Isoforms
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Recombinant Proteins
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Transcription Factors
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Tumor Suppressor Proteins
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2,2'-Dipyridyl
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Procollagen-Proline Dioxygenase
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Ubiquitin-Protein Ligases
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Von Hippel-Lindau Tumor Suppressor Protein
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Ligases
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VHL protein, human
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Oxygen