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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ovariectomy or ovariohysterectomy on day 18 of pregnancy augmented mammary beta-casein content 28 h later. Progesterone injected immediately and 12 h after ovariectomy showed a clear inhibitory effect on casein synthesis. Estrogen induced a significant increase in mammary beta-casein content when injected 12 h after surgery. Treatment with CB-154 to prevent prolactin release did not affect the increase of casein induced by ovariectomy. When CB-154 was injected to ovariohysterectomized pregnant rats, significant reduction of casein synthesis was obtained. According to these findings, rat placental lactogen in the absence of prolactin and progesterone induces beta-casein synthesis. Therefore prolactin, ovarian and placental hormones interplay at the end of pregnancy for full expression of the mammary gland genome.
Mol Cell Endocrinol 1985 Feb
PMID:Hormonal regulation of casein synthesis at the end of pregnancy. 397 61

Progesterone-induced reinitiation of meiosis in Xenopus laevis oocytes involves a decrease in cAMP level. In these cells, adenylate cyclase is compartmentalized, with 25-30% in the plasma membrane fraction P-10000 (sedimenting at 10000 X g) and greater than 50% in the cytosol. Soluble adenylate cyclase appears not to be regulated via a GTP-binding regulatory protein (G/F) and is insensitive to progesterone. In contrast, membrane-bound adenylate cyclase seems to be linked to G/F, since it is stimulated by sodium fluoride, guanyl-5'-imidodiphosphate (Gpp(NH)p) and by cholera toxin; it is also inhibited by progesterone. The steroid inhibition is displayed towards basal and stimulated activities. The extent of progesterone inhibition of basal activity is dependent on Mg2+ and Mn2+ concentrations. The hormonal effect is independent of GTP concentration and is observed even in the presence of the non-hydrolysable analogue of GTP, Gpp(NH)p. The progesterone effect is not mediated by adenosine. Exposure of the P-10000 fraction to 5'-deoxy-5'-S-isobutylthioadenosine (a methyltransferase inhibitor) increases adenylate cyclase activity.
Mol Cell Endocrinol 1982 Oct
PMID:Adenylate cyclase in Xenopus laevis oocytes: characterization of the progesterone-sensitive, membrane-bound form. 629 Feb 96

Microinjection of cAMP-dependent protein kinase inhibitor (1.8 microM) increases the cAMP level of Xenopus oocyte. Its effect was observed in full-grown (stage VI) as well as in vitellogenic (stage IV) oocytes. In contrast the inhibitor I1 of protein phosphatase-1 blocks cAMP accumulation. Progesterone (1 microM) decreases the cAMP level in control and in PKI-treated oocytes of both stages. These results show that cAMP concentration is regulated by a cAMP-dependent phosphorylation indicating the presence of a feedback mechanism. The feedback control is disrupted when oocyte is induced to mature by progesterone.
Mol Cell Endocrinol 1983 Jul
PMID:cAMP-dependent protein kinase regulates in ovo cAMP level of the Xenopus oocyte: evidence for an intracellular feedback mechanism. 630 83

The mechanism by which progesterone modifies uterine smooth muscle cell contraction is still unknown. We investigated the biochemical basis of progesterone effects on myometrium of estradiol-primed rabbits. Progesterone did not affect adenylate cyclase basal activity and displayed no interaction with stimulators of myometrium adenylate cyclase (NaF, guanylyl nucleotides, beta-adrenoreceptor agonists, prostaglandins, forskolin) or with adenosine. On the other hand, adenosine inhibited myometrial adenylate cyclase, which correlates with its contracting properties in vivo; this inhibition is mediated through interaction at 'P sites'. We conclude that whilst adenosine inhibits myometrial adenylate cyclase by acting at 'P sites', progesterone does not interact directly with adenylate cyclase to regulate myometrial contractility.
Mol Cell Endocrinol 1984 May
PMID:The hormonal control of adenylate cyclase in rabbit myometrium: in vitro inhibition by adenosine and lack of effect of progesterone. 661 May 81

The objective of this study was to determine whether progesterone-induced estrogen receptor regulatory factor (ReRF) is a component of hamster uterine nuclei or a cytoplasmic contaminant of the nuclear fraction. Crude uterine nuclei were prepared in low salt buffer and were purified by either the hexylene glycol method or an isotonic sucrose-Triton X-100 procedure. ReRF activity was measured as a net percentage increase in estrogen receptor inactivation after incubation of a 0.5 M KCl nuclear extract at 36 degrees C for 30 min. Progesterone treatment (5 mg/kg, s.c. in oil, 2 h) increased net receptor inactivation to the same extent (9-12% net increase) in extract made from each nuclear preparation. Extensive washing of nuclei caused a progressive decline in recovery of ReRF activity, in parallel with the behavior of KCl-extractable nuclear protein and estrogen receptor. These results demonstrate that ReRF is a loosely bound component of the uterine nucleus.
Mol Cell Endocrinol 1983 Oct
PMID:Localization of estrogen receptor regulatory factor in the uterine nucleus. 664 77

Multiple molecular forms of plasminogen activator were detected in normal human mammary epithelial cells in culture. Cells derived from (normal) breast mammoplasty specimens and grown on the surface of collagen gels exhibited three major classes of plasminogen activator isozymes (Mr = 100,000 [100K], 75,000 [75K], and 55,000 [55K]). The activity of the 100K and 75K isozymes was greatly reduced when the cells were grown on conventional tissue-culture-grade plastic surfaces. MCF-7, a human mammary carcinoma cell line, exhibited predominantly or exclusively the 55K isozyme, irrespective of the cell growth substratum. The activity of the 55K isozyme was more than twofold higher for MCF-7 cells grown on collagen gels than for cells grown on plastic. Progesterone, diethylstilbestrol, and estrogen stimulated the activity of the 55K isozyme of MCF-7 cells, but only when the cells were grown on a plastic surface. The plasminogen activator activities of the normal human mammary epithelial cells were not stimulated by these hormones, irrespective of the growth substratum. These results show that the expression of plasminogen activator isozymes by human mammary epithelial cells is subject to modulation by the extracellular matrix. Normal and malignant cells may differ in their responsiveness to these effects.
Mol Cell Biol 1983 Jun
PMID:Effect of the extracellular matrix on plasminogen activator isozyme activities of human mammary epithelial cells in culture. 668 79

Granulosa and theca cells obtained from patients were isolated and cultivated in a chemically defined medium containing gonadotropins and/or testosterone. Progesterone secretion by granulosa cells was consistently stimulated (2-40-fold) in all 5 patients by the addition of follicle-stimulating hormone (FSH, 0.25 micrograms/ml). In the presence of testosterone (0.5 micro M) alone, progesterone production was stimulated (2-8-fold) in 4 out of the 5 patients and cells of one patient showed a greater response to testosterone than to FSH alone. In 2 of the 5 patients, it was also noted that FSH and testosterone acted in a synergistic manner to stimulate the production of progesterone by granulosa cells. On the other hand, human chorionic gonadotropin (hCG, 1.0 IU/ml) alone failed to exert any significant effect. None of the treatments examined altered the production of progesterone by theca cells. These results suggest a role for FSH and testosterone in regulating progesterone biosynthesis by granulosa cells of the human ovary during follicular development.
Mol Cell Endocrinol 1981 Jul
PMID:The role of gonadotropins and testosterone in progesterone production by human ovarian granulosa cells. 679 Mar 15

MCF-7 cells contain progesterone, estradiol and glucocorticoid receptors. Following addition of these hormones to the growth medium of the cells, hormone-receptor complexes were found to sediment with chromatin fragments produced by trace digestion with micrococcal nuclease. The binding in all cases could be competed by excess unlabeled hormone. In each case the fragments with which the hormone-receptor complexes were associated tended to be smaller than the bulk chromatin fragments, indicating a greater sensitivity of those chromatin regions to the nuclease. The mononucleosomes released by more extensive digestion with micrococcal nuclease contained different amounts of each of the three hormone-receptor complexes. Progesterone could usually be detected on mononucleosomes only after very brief sedimentation analyses, whereas glucocorticoid- and estradiol-labeled mononucleosomes were stable during long centrifugations. Comparison of glucocorticoid- and estradiol-labeled mononucleosomes indicated that their sedimentation rates differed from one another and from bulk nucleosomes. Estradiol nucleosomes from MCF-7 cells and rat uterus (Senior and Frankel, 1978) sediment significantly faster than bulk nucleosomes, while glucocorticoid nucleosomes from MCF-7 cells and rat hepatoma cells sediment with, or even fractionally slower than, bulk nucleosomes.
Mol Cell Endocrinol 1983 Jun
PMID:Progesterone, glucocorticoid and estradiol receptors in MCF-7 cells bind to chromatin. 686 95

Progesterone binds to specific high-affinity and limited-capacity binding sites of chick-oviduct microsomes of estrogen-primed chicks. The dissociation constant is 2 x 10(-9) M (range 1.6--3.0) and the number of binding sites 500 femtomoles/mg microsomal protein (range 464--551). Treatment of the estrogen-primed chicks by progesterone had no apparent effect on the progesterone-binding capacity or affinity. Competition studies showed that testosterone, R-5020, Org-2058, D-norgestrel, 5 alpha-dihydrotestosterone and R-2323 were effective competitors of progesterone, in that order, whereas cortisol, estradiol and estrone exhibited only minimal displacement. No displacement of microsome-bound [3H]progesterone was found with fenoterol or prostaglandin F2 alpha. No high-affinity progesterone-binding sites were found in the microsomal fractions of liver, muscle, intestine or brain. On the basis of steroid-binding affinity and steroid-specificity determinations, the microsomal progesterone-binding components seem to be different from the progesterone receptor previously described in chick oviduct cytosol.
Mol Cell Endocrinol 1980 Aug
PMID:Progesterone-binding properties of the microsomal fraction from chick oviduct. 690 88

Epithelial cell-rich fractions of rat mammary gland were prepared using percoll gradients after collagenase dispersion. Their insulin-binding characteristics were similar to those of crude acini but superior to unfractionated isolated cells. Optimal binding was obtained after 60 min at 20 degrees C or 16 h at 4 degree C at pH 7.8 Binding at 37 degrees C was lower due probably to an enhanced rate of insulin degradation. 48 h after ovariectomy of 18-day pregnant rats insulin binding to acini doubled due to an increase in the number of insulin receptors. Progesterone but not bromocriptine (which prevented the rise in serum prolactin which occurred after ovariectomy) prevented this increase in insulin binding. These results illustrate that the change in serum progesterone rather than prolactin increases insulin binding to the mammary cell at parturition whilst insulin binding decreases in adipose tissue at the same time (Flint et al., Mol. Cell Endocrinol, 20, 101-111, 1981) enabling coordinated changes in the metabolism of these 2 tissues to take place during the perinatal period.
Mol Cell Endocrinol 1982 May
PMID:Insulin binding to rat mammary gland at various stages of cell isolation and purification. 704 14


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