The first intron of the 4F2 heavy-chain gene contains a transcriptional enhancer element that binds multiple nuclear proteins.
We utilized the human 4F2 heavy-chain (4F2HC) gene as a model system to study the regulation of inducible gene expression during normal human T-cell activation. Previous studies have demonstrated that 4F2HC gene expression is induced during normal T-cell activation and that the activity of the gene is regulated, at least in part, by the interaction of a constitutively active 5'-flanking housekeeping promoter and a phorbol ester-responsive transcriptional attenuator element located in the exon 1-intron 1 region of the gene. We now report that 4F2HC intron 1 contains a transcriptional enhancer element which is active on a number of heterologous promoters in a variety of murine and human cells. This enhancer element has been mapped to a 187-base-pair RsaI-AluI fragment from 4F2HC intron 1. DNase I footprinting and gel mobility shift analyses demonstrated that this fragment contains two nuclear protein-binding sites (NF-4FA and NF-4FB) which flank a consensus binding site for the inducible AP-1 transcription factor. Deletion analysis showed that the NF-4FA, NF-4FB, and AP-1 sequences are each necessary for full enhancer activity. Murine 4F2HC intron 1 displayed enhancer activity similar to that of its human counterpart. Comparison of the sequences of human and murine 4F2HC intron 1s demonstrated that the NF-4FA, NF-4FB, and AP-1 sequence motifs have been highly conserved during mammalian evolution.
Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor 48109.
B A
BA
Karpinski
L H
LH
Yang
P
P
Cacheris
G D
GD
Morle
J M
JM
Leiden
D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D005075:Biological Evolution; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004742:Enhancer Elements, Genetic; D005091:Exons; D027261:Fusion Regulatory Protein-1; D006801:Humans; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000235:genetics; D010957:Plasmids; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping
D000954:Antigens, Surface; D004268:DNA-Binding Proteins; D027261:Fusion Regulatory Protein-1; D009687:Nuclear Proteins; D009841:Oligonucleotides; D004247:DNA; D003850:Deoxyribonuclease I