Binding of a 100-kDa ubiquitous factor to the human prolactin promoter is required for its basal and hormone-regulated activity.
cAMP strongly stimulates the activity of the human prolactin (hPRL) promoter. We have previously shown that two types of cis-element are required for this cAMP regulation; binding sites for the pituitary-specific factor Pit-1, and the sequence spanning nucleotides -115 to -85 (named sequence A). Sequence A contains the TGACG motif found in the consensus sequence of the cAMP-responsive element (CRE). In this study, we show that a mutation in the TGACG motif of sequence A strongly reduces not only the cAMP regulation but also the Ca2+ regulation and basal activity of the hPRL promoter. Furthermore, gel-shift assays indicate that the mutation prevents binding of a ubiquitous factor which is not the CRE-binding protein. Southwestern experiments suggest that this ubiquitous factor's molecular mass is approximately 100 kDa. We conclude that binding of a 100-kDa ubiquitous factor to sequence A is required for full basal and hormonal regulation of hPRL-promoter activity.
Peers
B
B
Laboratoire de Biologie Moléculaire et de Génie Génétique, Institut de Chimie, Université de Liège, Belgium.
Nalda
A M
AM
Monget
P
P
Voz
M L
ML
Belayew
A
A
Martial
J A
JA
D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009841:Oligonucleotides; D010957:Plasmids; D011388:Prolactin / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000378:metabolism*
D009841:Oligonucleotides; D015534:Trans-Activators; D011388:Prolactin; D000242:Cyclic AMP