Human apolipoprotein A-IV gene expression is modulated by members of the nuclear hormone receptor superfamily.
Human apolipoprotein A-IV (apo A-IV) is essentially synthesized in intestine and to a lower extent in liver. The presence of detectable amounts of apo A-IV messenger in HepG2 and Caco-2 cells enables us to study the transcription regulation of the gene in these cells. A main hypersensitive site to DNase I is detected in the DNA of HepG2 nuclei, in a region situated about 3400 base pairs upstream from the cap site. Transient expression experiments in HepG2, Caco-2 and HeLa cells indicate that HNF-4 activates the transcription of a reporter gene through the -3500/+67 sequence of the apo A-IV gene. This activation is repressed by another transcription factor, Ear3/COUP-TF. On the contrary, HNF-1, whose expression is controlled by HNF-4, is not involved in the regulation of the reporter gene transcription through the -6700/+67 genome sequence. These results indicate that the apo A-IV gene expression is modulated by orphan ligand members of the superfamily of nuclear hormone receptors.
Ochoa
A
A
Unité d'Expression des Gènes Eucaryotes, Institut Pasteur, Paris, France.
Bovard-Houppermans
S
S
Zakin
M M
MM
D001054:Apolipoproteins A / Q000096:biosynthesis / Q000235:genetics*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051838:COUP Transcription Factor I; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D006367:HeLa Cells; D051557:Hepatocyte Nuclear Factor 4; D006801:Humans; D009928:Organ Specificity / Q000235:genetics; D010750:Phosphoproteins; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D001054:Apolipoproteins A; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051838:COUP Transcription Factor I; D004268:DNA-Binding Proteins; D051557:Hepatocyte Nuclear Factor 4; C403128:MLX protein, human; C497589:NR2F1 protein, human; D010750:Phosphoproteins; D014157:Transcription Factors; C022205:apolipoprotein A-IV; D003850:Deoxyribonuclease I