Complex organization of CTF/NF-I, C/EBP, and HNF3 binding sites within the promoter of the liver-specific vitellogenin gene.
Vitellogenin genes are expressed specifically in the liver of female oviparous vertebrates under the strict control of estrogen. To explain this tissue-specific expression, we performed a detailed analysis of the Xenopus laevis vitellogenin gene B1 promoter by DNase I footprinting and gel mobility-shift assays. We characterized five binding sites for the ubiquitous factor CTF/NF-I. Two of these sites are close to the TATA-box, whereas the others are located on both sides of the estrogen responsive unit formed by two imperfect estrogen response elements. Moreover two liver-enriched factors, C/EBP and HNF3, were found to interact with multiple closely spaced proximal promoter elements in the first 100 base pairs upstream of the TATA-box. To confirm the physiological significance of this in vitro analysis, in vivo DNase I footprinting experiments were carried out using the ligation-mediated polymerase chain reaction technique. The various cis-elements characterized in vitro as binding sites for known transcription factors and more particularly for liver-enriched transcription factors are efficiently recognized in vivo as well, suggesting that they play an important role in the control of the liver-specific vitellogenin gene B1 expression.
Cardinaux
J R
JR
Institut de Biologie Animale, Université de Lausanne, Switzerland.
Chapel
S
S
Wahli
W
W
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D051541:Hepatocyte Nuclear Factor 3-alpha; D008099:Liver / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009687:Nuclear Proteins / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014819:Vitellogenins / Q000235:genetics*; D014982:Xenopus laevis
D022762:CCAAT-Enhancer-Binding Proteins; C077305:CTF-1 transcription factor; D004268:DNA-Binding Proteins; D051541:Hepatocyte Nuclear Factor 3-alpha; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D014157:Transcription Factors; D014819:Vitellogenins