Effect of protein kinase and phosphatase inhibitors on expression of hypoxia-inducible factor 1.
Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric bHLH-PAS protein essential for erythropoietin gene transcription in hypoxic cells. Here we show that both 2-aminopurine and sodium fluoride, inhibitors of serine/threonine kinases and phosphatases, respectively, interfered with the hypoxic induction of HIF-1 DNA-binding activity and expression of HIF-1 alpha and HIF-1 beta(ARNT) subunits. Genistein, an inhibitor of tyrosine kinases, completely blocked the synthesis of both HIF-1 subunits as well as HIF-1 DNA-binding activity. Sodium orthovanadate, an inhibitor of tyrosine phosphatases increased the basal level of HIF-1 proteins and HIF-1 activity. These data suggest that protein phosphorylation events play an important role in the hypoxia signal-transduction pathway that leads to synthesis of HIF-1 alpha and HIF-1 beta proteins and the induction of HIF-1 DNA-binding activity.
D015075:2-Aminopurine / Q000494:pharmacology*; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D015151:Immunoblotting; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D047428:Protein Kinase Inhibitors; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*; D012969:Sodium Fluoride / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis*; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; D014157:Transcription Factors; D015075:2-Aminopurine; D012969:Sodium Fluoride; D017027:Protein Tyrosine Phosphatases