A MGF/STAT5 binding site is necessary in the distal enhancer for high prolactin induction of transfected rabbit alpha s1-casein-CAT gene transcription.
The rabbit alphas1-casein gene contains a distal prolactin-dependent enhancer 3442-3285 bp 5' to the site of initiation of transcription. We have reported previously that four DNA/protein-binding sites (F1-F4) are located within this distal enhancer. We now show that one of this binding site (the F4 site) binds in vitro a MGF/STAT5-like factor. The functional importance of the F4 site was estimated by cotransfection of CHO cells with a chimeric gene containing or not the F4 sequence linked to the (-391/+1774)CAT gene and a plasmid encoding the rabbit mammary prolactin receptor. The F4 site is necessary for maximal response, of the enhancer to prolactin. However, this site has to be associated to the Fl-F3 fragment. It can be replaced by a genuine MGF/STAT5-binding site. A mutational analysis indicates that F4 and F1 sites are simultaneously involved to confer a high prolactin sensitivity.
Jolivet
G
G
Unité de Différenciation Cellulaire, Laboratoire de Biologie Cellulaire et Moléculaire, Institut National de la Recherche Agronomique, Jouy-en-Josas, France.
L'Hotte
C
C
Pierre
S
S
Tourkine
N
N
Houdebine
L M
LM
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016466:CHO Cells; D002364:Caseins / Q000235:genetics*; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D006224:Cricetinae; D004274:DNA, Recombinant / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008894:Milk Proteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000235:genetics; D011388:Prolactin / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011817:Rabbits; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D002364:Caseins; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D008894:Milk Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D011388:Prolactin; D015500:Chloramphenicol O-Acetyltransferase