Introduction of a proximal Stat5 site in the murine alpha-lactalbumin promoter induces prolactin dependency in vitro and improves expression frequency in vivo.
In order to establish a possible correlation between in vitro prolactin induction and the transcriptional activity of mammary gene promoters in transgenic mice, a functional Stat5-binding site was created by means of site-directed mutagenesis at position -70 on a 560 bp murine alpha-lactalbumin promotor linked to a CAT reporter gene. Surprisingly, the wild-type promoter was constitutively active in vitro and could not be induced by prolactin. Introducing the proximal Stat5 site abolished this constitutive activity and resulted in prolactin dependence in both CHO-K1- and HC11-transfected cells. In transgenic mice, both the frequency of lines expressing the transgene and the prevalence of mid to late pregnancy expression were increased.
Laboratoire de Génétique Biochimique et de Cytogénétique, INRA, Jouy-en-Josas, France.
S
S
Soulier
L
L
Lepourry
M G
MG
Stinnakre
B
B
Langley
P J
PJ
L'Huillier
J
J
Paly
J
J
Djiane
J C
JC
Mercier
J L
JL
Vilotte
D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D007768:Lactalbumin / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D008894:Milk Proteins; D009928:Organ Specificity; D011247:Pregnancy; D011388:Prolactin / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D008894:Milk Proteins; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D011388:Prolactin; D007768:Lactalbumin