Novel elements in the uteroglobin promoter are a functional target for prolactin signaling.
To quantify uteroglobin (UG) gene expression, varying lengths of 5' flanking sequence were subcloned into a luciferase reporter plasmid and introduced into HRE-H9 uterine epithelial cells. In response to estrogen, prolactin (PRL) and progesterone, transcriptional activity was maximal for the full-length construct, pUG3.1-LUC. Transcriptional activity was reduced (P < 0.05) by the removal of the progesterone receptor binding site, tested with pUG2.3-LUC, and eliminated (P < 0.05) by the removal of the remaining 5' flanking sequences, tested with pUG0.1-LUC. When the effects of PRL +/- progesterone were evaluated, progesterone alone increased (P < 0.05) the transcriptional activity of pUG3.1-LUC, and the deletion mutant, pUG3.1deltaRUSH-LUC. Transcription of pUG3.1-LUC was further increased (P < 0.05) by PRL + progesterone. However, deletion of the proximal promoter region -170/-85, tested with pUG3.1deltaRUSH-LUC, eliminated (P > 0.05) the PRL effect. These data support the speculation that RUSH proteins which bind to this region of the promoter play an important regulatory role in PRL signal transduction.
Hewetson
A
A
Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
Chilton
B S
BS
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D002467:Cell Nucleus / Q000737:chemistry; D004847:Epithelial Cells / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011817:Rabbits; D011980:Receptors, Progesterone / Q000032:analysis; D011981:Receptors, Prolactin / Q000032:analysis; D011993:Recombinant Fusion Proteins; D017384:Sequence Deletion / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics*; D014598:Uteroglobin / Q000235:genetics*; D014599:Uterus / Q000166:cytology / Q000378:metabolism
D004967:Estrogens; D011980:Receptors, Progesterone; D011981:Receptors, Prolactin; D011993:Recombinant Fusion Proteins; D011374:Progesterone; D011388:Prolactin; D014598:Uteroglobin