The contribution of VHL substrate binding and HIF1-alpha to the phenotype of VHL loss in renal cell carcinoma.
Clear-cell renal carcinoma is associated with inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene. VHL is the substrate recognition subunit of an E3 ligase, known to target the alpha subunits of the HIF heterodimeric transcription factor for ubiquitin-mediated degradation under normoxic conditions. We demonstrate that competitive inhibition of the VHL substrate recognition site with a peptide derived from the oxygen degradation domain of HIF1alpha recapitulates the tumorigenic phenotype of VHL-deficient tumor cells. These studies prove that VHL substrate recognition is essential to the tumor suppressor function of VHL. We further demonstrate that normoxic stabilization of HIF1alpha alone, while capable of mimicking some aspects of VHL loss, is not sufficient to reproduce tumorigenesis, indicating that it is not the critical oncogenic substrate of VHL.
Maranchie
Jodi K
JK
Urologic Oncology Branch, National Institutes of Health, Bethesda, MD 20892, USA.
Vasselli
James R
JR
Riss
Joseph
J
Bonifacino
Juan S
JS
Linehan
W Marston
WM
Klausner
Richard D
RD
D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D016147:Genes, Tumor Suppressor; D051272:Glucose Transporter Type 1; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007124:Immunoenzyme Techniques; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008025:Ligases / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010641:Phenotype; D010957:Plasmids; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein
D051272:Glucose Transporter Type 1; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008164:Luminescent Proteins; D009004:Monosaccharide Transport Proteins; D011993:Recombinant Fusion Proteins; C495677:SLC2A1 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D049452:Green Fluorescent Proteins; D008156:Luciferases; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D008025:Ligases; C497446:VHL protein, human