Transcriptional regulation of the bovine oxytocin receptor gene.
The oxytocin receptor (OTR) is expressed in the cow uterus at high levels at estrus and at term of pregnancy. This expression appears to be controlled mostly at the transcriptional level and correlates with increasing estrogen concentration and progesterone withdrawal. Approximately 3200 base pairs of the upstream region of the bovine OTR gene were cloned and analyzed using a combination of bioinformatic, electrophoretic mobility shift (EMSA), and transfection analyses. Using nuclear proteins from high- and low-expressing tissues, EMSA indicated no significant quantitative or qualitative changes in specific DNA-protein binding, suggesting that transcription is probably controlled by signalling systems targeting constitutive factors. Using various cell types, including primary and immortalized ruminant endometrial epithelial cells, as hosts for transfection of promoter-reporter constructs showed that endogenous activity resided only in the longest, i.e., 3.2-kb, construct but not in those shorter than 1.0 kb. While estrogen appears to be important in vivo, no effect of estradiol was found on any construct directly; only when the longest 3.2-kb construct was used in combination with some cotransfected steroid receptor cofactors, e.g., SRC1e, was an estradiol-dependent effect observed. A putative interferon-responsive element (IRE) was found at approximately -2,400 from the transcription start site. This element was shown to bind mouse IRF1 and IRF2 as well as similar proteins from bovine endometrial and myometrial nuclear extracts. This element also responded to these factors when cotransfected into various cell types. The bovine equivalents to IRF1 and IRF2 were molecularly cloned from endometrial tissue and shown to be expressed in a temporal fashion, supporting the role of interferon-tau in maternal recognition of pregnancy. Of many factors tested or analyzed, these components of the IFN system are the only ones found to significantly influence the transcription of the bovine OTR gene.
Telgmann
Ralph
R
Institute for Hormone and Fertility Research University of Hamburg, 22529 Hamburg, Germany.
Bathgate
Ross A D
RA
Jaeger
Stefanie
S
Tillmann
Gina
G
Ivell
Richard
R
D000818:Animals; D015152:Blotting, Northern / Q000662:veterinary; D002417:Cattle / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology; D024202:Electrophoretic Mobility Shift Assay / Q000662:veterinary; D004717:Endometrium / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D007150:Immunohistochemistry / Q000662:veterinary; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D007370:Interferon Type I / Q000502:physiology; D010750:Phosphoproteins / Q000502:physiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011257:Pregnancy Proteins / Q000502:physiology; D011401:Promoter Regions, Genetic; D018045:Receptors, Oxytocin / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics; D012097:Repressor Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000502:physiology*; D014162:Transfection
D004268:DNA-Binding Proteins; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D007370:Interferon Type I; D010750:Phosphoproteins; D011257:Pregnancy Proteins; D018045:Receptors, Oxytocin; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C020947:interferon tau; D004247:DNA