The adult enhancer factor-1, a Drosophila melanogaster transcriptional repressor, modulates the promoter activity of the rat class-I alcohol dehydrogenase-encoding gene.
Expression of the Drosophila melanogaster alcohol dehydrogenase-encoding gene (ADH) in the adult fat body is controlled by the ADH adult enhancer site (AAE). The D. melanogaster transcription repressor, adult enhancer factor-1 (AEF-1), binds to AAE at a site which overlaps with a sequence recognized by the mammalian transcription factor, CCAAT/enhancer-binding protein alpha [C/EBP alpha; Falb and Maniatis, Genes Dev. 6 (1992a) 454-465]. C/EBP alpha also activates the promoter of the rat class-I ADH gene in a sequence-specific manner [Potter et al., Arch. Biochem. Biophys. 285 (1991a) 246-251]. In this study, we explored the possibility that D. melanogaster AEF-1 influences transcription of the rat class-I ADH. By DNase I footprint analysis, bacterially produced AEF-1 protects a region of DNA between nucleotides (nt) -22 and -36 of the rat class-I ADH promoter (pADH), just 5' to the binding site of C/EBP alpha, a result confirmed by the electrophoretic mobility shift assay (EMSA). Co-transfection of a rat pADH-CAT reporter construct with expression vectors containing C/EBP alpha, AEF-1, or both, indicates that AEF-1 inhibits induction of the rat pADH by C/EBP alpha. Moreover, rat liver nuclear extracts appear to contain AEF-1-like-binding activities to AAE by EMSA. These experiments suggest an evolutionarily conserved mechanism by which AEF-1 modulates expression of the D. melanogaster and rat ADH genes.
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
J J
JJ
Potter
E
E
Mezey
V W
VW
Yang
D000426:Alcohol Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D012097:Repressor Proteins / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection
C073554:Aef1 protein, Drosophila; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D007527:Isoenzymes; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA; D000426:Alcohol Dehydrogenase; D003850:Deoxyribonuclease I