Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The peptide hormone oxytocin is highly expressed in the hypothalamus within only a small number of magnocellular neurons. However, it is also expressed in a much larger number of cells in the bovine corpus luteum at high levels in an estrous cycle-dependent manner. By using nuclear extracts from this tissue for in vitro binding studies, two protein complexes have been shown to bind to a common site in the bovine oxytocin promoter. One of these proteins has been identified as the bovine homologue of the chicken ovalbumin upstream promoter transcription factor (COUP-TF). The second protein is here characterized as the bovine homologue of a tissue-specific transcription factor, steroidogenic factor 1 (SF-1). The relative expression of these two factors during luteal development correlates with the level of luteal oxytocin gene expression, with SF-1 being the factor binding to the promoter of the oxytocin gene when this promoter is activated. Cotransfection experiments using the murine testicular cell line TM4 show that SF-1 can stimulate the expression of a transfected oxytocin gene, suggesting that SF-1 may be involved in upregulation of the oxytocin gene in vivo, possibly by transducing a stimulatory signal to the RNA polymerase.
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PMID:Two orphan receptors binding to a common site are involved in the regulation of the oxytocin gene in the bovine ovary. 810 28

In vivo there appears to be a marked association between oestrogen levels and the expression of the oxytocin (OT) gene in most tissues. Transfection and DNA-protein binding experiments using high levels of either oestrogen receptor (ER)alpha or ERbeta imply a direct interaction of these transcription factors with the multiple hormone response element (HRE) at approximately -160 from the transcription start site of the OT gene in most species. In an extensive set of experiments, we show, using both transfection and protein-DNA binding, that low to moderate amounts of either oestrogen receptor, while being able to interact directly with a classic oestrogen response element (ERE) fail to interact with the human OT -160 HRE. Instead, this element, similar to its bovine counterpart, has a high affinity for the orphan receptors steroidogenic factor 1 and chicken ovalbumin upstream promoter transcription factor. Second, the human and bovine OT promoter can be made artificially responsive towards oestrogen in a cotransfection system over-expressing ERalpha or ERbeta, but not in cells expressing natural levels of these steroid receptors. Interestingly, nuclear extracts from both ERalpha-positive MCF7 cells and ERalpha-negative MDA-MB231 cells both contain a transcription factor which binds specifically to both the hOT-HRE element and to a classic ERE, and which has orphan receptor-like binding properties rather than those of an oestrogen receptor. Together, these and other results suggest that oestrogen action in vivo on the OT gene in all species is more likely to involve a DNA-independent mechanism than classic direct interactions with dimeric oestrogen receptors.
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PMID:The affinity and activity of the multiple hormone response element in the proximal promoter of the human oxytocin gene. 1204 22