Chicken ovalbumin upstream-promoter transcription factor (COUP-TF) could act as a transcriptional activator or repressor of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene.
The chicken ovalbumin upstream-promoter transcription factor (COUP-TF) has a dual effect on the regulation of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene. COUP-TF could act as a transcriptional activator or repressor of this gene through different DNA sequences. COUP-TF induces expression of a reporter gene linked to the mitochondrial HMG-CoA synthase gene promoter in human hepatoma HepG2 cells, but represses it in a Leydig tumour cell line (R2C); in both these cell lines the expression of the mitochondrial HMG-CoA synthase gene mimics that of liver and testis. The activation is promoted by a fragment of the gene from coordinates -62 to +28, which contains a GC box and a TATA box, and where no COUP-TF binding site was observed by in vitro DNA binding studies. On the other hand, the COUP-TF inhibitory effect is mainly due to repression of peroxisome-proliferator-activated receptor-dependent activation of the gene, interacting with the region from -104 to -92. To our knowledge this work represents the second example of a target gene for COUP-TF I that could be either activated or repressed by the action of this receptor through different DNA sequences of the same gene.
Rodríguez
J C
JC
Unitat de Bioquímica, Facultat de Farmàcia, Barcelona, Spain.
Ortiz
J A
JA
Hegardt
F G
FG
Haro
D
D
D000818:Animals; D051838:COUP Transcription Factor I; D006528:Carcinoma, Hepatocellular; D002645:Chickens; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004794:Enzyme Repression / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D007984:Leydig Cell Tumor; D008830:Microbodies / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D010047:Ovalbumin / Q000235:genetics; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014407:Tumor Cells, Cultured
D051838:COUP Transcription Factor I; D004268:DNA-Binding Proteins; C497589:NR2F1 protein, human; C497591:Nr2f1 protein, rat; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; D014157:Transcription Factors; D010047:Ovalbumin; D004247:DNA; D006904:Hydroxymethylglutaryl-CoA Synthase