The skin-type antifreeze protein gene intron of the winter flounder is a ubiquitous enhancer lacking a functional C/EBPalpha binding motif.
The winter flounder antifreeze protein (AFP) intron contains a liver-specific enhancer (Element B) which was shown earlier to bind CCAAT/enhancer binding protein (C/EBP)alpha. In contrast, as demonstrated in the present studies, the intron of the skin-type AFP gene acted as a ubiquitous enhancer and contained a TA insertion at similar region to Element B (Element S) which destroyed its interaction with C/EBPalpha. Furthermore, a TA insertion of Element B by site-directed mutagenesis decreased its liver enhancer activity. The presence or absence of C/EBPalpha binding motifs in Element B and Element S, respectively, may provide a mechanism for their differential expression.
Miao
M
M
Biochemistry Division, Research Institute, Hospital for Sick Children, University of Toronto, Ont., Canada.
Chan
S L
SL
Hew
C L
CL
Gong
Z
Z
D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005399:Fishes / Q000235:genetics*; D005615:Freezing; D005786:Gene Expression Regulation; D007438:Introns; D009687:Nuclear Proteins / Q000502:physiology*; D011506:Proteins / Q000502:physiology*; D012879:Skin Physiological Phenomena
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011506:Proteins