Tissue-specific regulatory elements in the human alcohol dehydrogenase 6 gene.
The human alcohol dehydrogenase gene ADH6 is expressed at the highest levels in fetal and adult liver. We have mapped cis-acting elements that affect its expression. The sequence from bp -34 to -62 (site C) that includes the TATA box was strongly bound by nuclear proteins from liver, hepatoma cells, and fibroblasts. A truncation that removed the upstream part of site C but left the TATA homology intact dramatically reduced transcription; altering 5 bp in this region had much less effect. Part of site C can be bound by C/EBPalpha, but cotransfection with C/EBPalpha or C/EBPbeta did not stimulate transcription. The proximal region did not display tissue specificity, so we cloned the upstream region to search for additional regulatory sequences. The region between -1.6 and -2.3 kb stimulated transcription in hepatoma cells and inhibited it in fibroblasts. We identified two sites in this region that affect transcription independently of their orientation. Site 1 was a negative regulatory element in fibroblasts but had no effect in hepatoma cells. Site 2 was a positive regulatory element in hepatoma cells but had no effect in fibroblasts. This combination of positive and negative regulatory elements can play a significant role in the tissue-specific expression of ADH6.
Zhi
X
X
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis 46202-5122, USA.
Chan
E M
EM
Edenberg
H J
HJ
D000426:Alcohol Dehydrogenase / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015698:Genomic Library; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014018:Tissue Distribution; D014158:Transcription, Genetic
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000426:Alcohol Dehydrogenase