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Query: UNIPROT:P06889 (Mol)
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The ability of various steroids to induce maturation of Pleurodeles waltlii oocytes after incubation has been studied. Progesterone is metabolized during the course of maturation. All metabolites isolated are less efficient than progesterone for inducing germinal vesicle breakdown. Progesterone binding to the 'melanosome' fraction has been studied (KD = 4.5 X 10(-8) M at 4 degrees C). 20BETA-Hydroxy-pregn-4-en-3-one, the main progesterone metabolite isolated from the oocyte, also binds to the melanosome fraction, but with a lower affinity (KD = 1.6 X 10(-7) M at 4 degrees C). At high concentration 20beta-hydroxy-pregn-4-en-3-one induces maturation, but at low concentration it is a competitive inhibitor of progesterone. Progesterone metabolism in Pleurodeles oocytes can be interpreted as an inactivation process, and also as a mechanism for inhibitime progesterone action.
Mol Cell Endocrinol 1975 Sep
PMID:Mechanism of action of progesterone on amphibian oocytes. A possible biological role for progesterone metabolism. 17 Nov 85

Granulosa cells from preovulatory follicles (PO) or from the enlarged preantral follicles of hypophysectomized immature diethylstilbestrol-treated (Hx-DES) rats were cultured with various combinations of FSH, androst-4-ene-3,17-dione (Ad), estradiol-17beta and dibutyryl cyclic AMP (dbcAMP). Progestin levels (progesterone and 20alpha-dihydroprogesterone) in the medium after 2 days of culture were assayed by radioimmunoassay. The control levels of the two progestins were lower for Hx-DES than for PO cells. Rat FSH (NIAMD-1-3;0.1 mug/ml) caused a 2-fold rise in progestin accumulation in both PO and Hx-DES cultures, dbcAMP (1 mM) increased progestin accumulation in PO cultures 4-5-fold, and to an even greater extent (10-20 fold) in Hx-DES cultures. Androstenedione (1.0 mug/ml) augmented progestin accumulation (1.5-3-fold), and synergized the steroidogenic action of FSH: in cells from Hx-DES rats, combined treatment with FSH and Ad caused a 5-10-fold increase over the values obtained with FSH alone. Testosterone and 5alpha-dihydrotestosterone, but not estradiol-17beta or estrone, mimicked these effects of Ad, Ad did not synergize the action of dbcAMP on progestin levels in Hx-DES cultures. It is proposed that androgen may play a role in the development of the FSH-responsive mechanism in preantral granulosa cells.
Mol Cell Endocrinol
PMID:A synergistic effect of androgen on the stimulation of progesterone secretion by FSH in cultured rat granulosa cells. 18 82

Progesterone causes in goblet cells of oviducts of estrogen hormone-stimulated immature quails selectively gene activation without affecting DNA synthesis. This biological model has been used to study the influence of poly ADP-ribosylation during the processes of DNA transcription. Administration of progesterone in vivo causes an increase of the activity of RNA polymerase I and II in isolated nuclei. This increase is accompanied by a marked decrease of the specific activity of poly (ADP-Rib) polymerase. After in vitro ADP-ribosylation of nuclear proteins the template capacity of chromatin for ""exogenous'' RNA synthesis (with E. coli DNA-dependent RNA polymerases) as well as for ""endogenous'' RNA synthesis with DNA dependent RNA polymerases II is not affected, whereas the data presented seem to indicate that the capacity for RNA synthesis mediated by ""endogenous'' DNA-dependent RNA polymerase I might be inhibited after ADP-ribosylation. Evidence is presented to show that a considerable amount of poly (ADP-Rib), synthesized by poly (ADP-Rib) polymerase in isolated nuclei, is linked with RNA polymerase I. The rate of synthesis of poly (ADP-Rib) is dependent on the incubation temperature (optimum at 25 degrees C) and it can be inhibited by the specific inhibitors of poly (ADP-Rib) polymerase nicotineamide, thymidine and formycin B. Poly (ADP-Rib) is probably associated with RNA polymerase I through a covalent linkage. ADP-ribosylated RNA polymerase I has been purified 550 fold with respect to the nuclear extract corresponding to a 4,000 fold purification from the whole cell homogenate. The ratio between poly (ADP-Rib), formed during preincubation of nuclei with NAD, and RNA polymerase I remains almost constant during the purification procedures. The extent of ADP-ribosylation of RNA polymerase I decreases during gene expression. Thus we conclude that poly ADP-ribosylation of this enzyme is one of the regulatory mechanisms by which specificity of DNA transcription is achieved.
Mol Cell Biochem 1976 Sep 30
PMID:Poly ADP-ribosylation of DNA-dependent RNA polymerase I from quail oviduct. Dependence on progesterone stimulation. 18 9

Newly synthesized non-histone proteins (NHP) labelled with [35S] methionine were isolated from uterine epithelium and stroma after different hormone treatments and examined by isoelectric focusing in polyacrylamide gels. Progesterone increased the proportion of basic NHP in the epithelium. This effect was detectable within 4 h and was maintained unchanged after oestrogen stimulation, which increased the synthesis of all classes of NHP. The proportion of basic NHP was higher in the untreated stroma than in the epithelium. Progesterone pretreatment did not increase the proportion of basic NHP in the stroma but prevented the increase in the more acidic NHP which followed treatment with oestrogen alone. The tendency to synthesize a higher proportion of basic NHP did not in any way correlate with the tissue's proliferative status.
Mol Cell Endocrinol 1977 Jan
PMID:The effects of sex-steroids on the synthesis of uterine non-histone proteins. 83 65

Metabolic transformations of progesterone in cultures of granulosa cells from immature hypophysectomized rats treated with diethylstilbestrol were studied in relation to the synergistic action of exogenous androgen and FSH on progestin (progesterone and 20alpha-dihydroprogesterone) accumulation. Androstenedione (Ad; 10 ng/ml) enhanced the sensitivity of rat granulosa cells to this steroidogenic action of FSH, lowering the threshold of the response from greater than 4 ng/ml (FSH alone) to 0.8 ng/ml in the presence of Ad. A synergistic effect with FSH was also shown by various 5alpha-androstane derivatives. They were, however, less effective than the parent delta4-3 keto androstenes. Progesterone underwent extensive 5alpha-reduction during culture, leading to accumulation of endogenous 5alpha-pregnane compounds, and to transformation of labelled progesterone into 5 alpha-reduced radiometabolites. These compounds corresponded in gas-liquid and thin-layer chromatographic behaviour to 3alpha-hydroxy-5alpha-pregnan-20-one, 20alpha-hydroxy-5alpha-pregnan-3-one and 5alpha-pregnane-3alpha,20alpha-diol. The rate of 5alpha-reduction of progestins was not affected by the presence of exogenous Ad (1 microgram/ml), ruling out the possibility that the effect of androgen on progestin accumulation depends on competitive inhibition of 5alpha-reductase. An involvement of androgen of thecal origin in the enhancement of the sensitivity of the FSH-responsive mechanism in granulosa cells is suggested.
Mol Cell Endocrinol 1977 Sep
PMID:Studies on the synergistic effect of androgen on the stimulation of progestin secretion by FSH in cultured rat granulosa cells: progesterone metabolism and the effect of androgens. 92 13

1. The effect of progesterone on renal haemodynamics and intrarenal sodium handing was evaluated in thirteen normal men on a constant diet. Clearances were measured during maximal water diuresis and again 4-7 days later, this time 3 h after progesterone was given intramuscularly. Seven additional studies were performed 3 days after progesterone administration. Another four tests were performed on volunteers who had manifested renal 'escape' from the sodium-retaining effect of deoxycorticosterone acetate. 2. In acute progesterone studies glomerular filtration rate was unchanged, whereas effective renal plasma flow increased, so that filtration fraction decreased significantly. A similar in crease in urinary sodium occurred whether subjects received a low or high sodium diet. Indices which related to the distal delivery of filtrate (fractional urine flow and the sum of fractional free water and sodium clearances) increased significantly in both groups. The progesterone-induced increase in sodium excretion was not related to changes in plasma renin activity, renin substrate or urinary aldosterone. After 3 days of progesterone, the increase of sodium excretion was less than in the acute studies and urinary aldosterone increased tow- to four-fold. Progesterone failed to produce an acute increse in urinary sodium in subjects hyperexpanded by administration of exogenous mineralocorticoids. 3. Results suggest that the acute natriuretic action of progesterone is in part independent of aldosterone inhibition and that progesterone may inhibit sodium reabsorption at proximal as well as distal sites in the nephron.
Clin Sci Mol Med 1975 Aug
PMID:Effect of progesterone on renal sodium handling in man: relation to aldosterone excretion and plasma renin activity. 114 5

Total polysomal RNA or poly(A)-containing RNA isolated from membrane-bound polysomes of normal lactating rabbits directed the synthesis of casein in a reticulocyte lysate. Casein was identified by immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis of the immunoprecipitate. The poly(A)-containing RNA was heterogeneous with one major peak corresponding to a 12-S sedimentation coefficient as determined by polyacrylamide gel electrophoresis. Using the same procedure, mRNAs isolated from the non-secreting tissue of pseudopregnant rabbits were found not to contain the 12-S peak and were unable to direct the synthesis of casein in vitro. Prolactin injected into pseudopregnant rabbits induced the synthesis of proteins immunoprecipitable by anti-casein anti-serum and induced the simultaneous appearance of the 12-S mRNA. Progesterone injected with prolactin prevented the induction of casein synthesis and the appearance of mRNA for casein. A close relationship was established between the ability of the tissue to synthesize immunoprecipitable casein and the corresponding mRNA content of polysomes.
Mol Cell Endocrinol 1975 Jul
PMID:Regulation of casein synthesis in the rabbit mammary gland. Titration of mRNA activity for casein under prolactin and progesterone treatments. 114 19

We have examined the effects of Xenopus pp60c-src with constitutive kinase activity on the morphology and maturation of Xenopus laevis oocytes. When RNA encoding this deregulated variant was injected into stage VI oocytes, we observed a gross alteration in the cortex of the oocyte. This alteration involved aggregation of pigment and invagination of the cortex in a large area proximal to the site of injection. This phenomenon was not seen in oocytes injected with RNA encoding wild-type pp60c-src. We have correlated this phenomenon with the tyrosine phosphorylation of 84- and 100-kDa proteins. These phosphorylated proteins colocalized with the alteration in the oocyte cortex when assayed by both biochemical and immunocytochemical methods. Neither the pigment aggregation nor phosphorylation of the 84- and 100-kDa proteins was observed in oocytes expressing a nonmyristoylated version of the deregulated pp60c-src. Expression of deregulated Xenopus fyn, a src-family member, resulted in a phenotype similar to that seen with deregulated src. However, in the fyn-injected oocytes, many more proteins were phosphorylated on tyrosine than in the src-injected oocytes. Progesterone stimulation of oocytes expressing deregulated pp60c-src resulted in an increase in the number of tyrosine-phosphorylated proteins. This change may represent the response of pp60src to the resumption of the cell cycle in maturing oocytes. These data suggest that the oocyte may be a particularly useful system for investigating the role of pp60c-src in the regulation of cytoskeletal structure and in the regulation of events associated with the cell cycle.
Mol Cell Biol 1992 Dec
PMID:Biochemical and cytological changes associated with expression of deregulated pp60src in Xenopus oocytes. 128 Mar 23

The effect of progesterone was studied on the sulfate entry in glandular epithelial cells of guinea-pig endometrium subcultured in bicameral chambers on matrix-coated filters in a chemically defined medium. At post-confluency (8 days of subculture), cells were treated with 10 nM estradiol alone or in association with various concentrations of progesterone. Optimal progesterone action was at a 16 h incubation time and a 10 nM hormonal concentration. Progesterone increased in a dose-dependent fashion the sulfate uptake specifically in glandular epithelial cells, preferentially from the basal surface. Progesterone effect on the sulfate uptake occurred only in estradiol-primed epithelial cells and was inhibited by the antiprogestin steroid RU-486. The progesterone-dependent increase in sulfate uptake was inhibited by the inhibitor of anion exchange, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). At physiological sulfate concentrations, progesterone essentially induces a high-affinity DIDS-sensitive transport system.
Mol Cell Endocrinol 1992 Dec
PMID:Progesterone stimulates sulfate uptake in subcultured endometrial epithelial cells. 130 1

Human progesterone receptors (PR) in T47D breast cancer cells are synthesized as two different sized proteins, PR-A [94 kilodaltons (kDa)] and PR-B (120 kDa). Progestin addition to cells (in vivo) causes a 2-fold increase in total phosphorylation of PR and an increase in the apparent mol wt of both PR-A and PR-B on sodium dodecyl sulfate (SDS)-gels. Time-course experiments showed that increased PR phosphorylation that results from hormone addition is a multistep process and involves a rapid increase into total 32P labeling that takes place before the more slowly occurring phosphorylation(s) responsible for the change in electrophoretic mobility of PR on SDS-gels. As an approach to test whether phosphorylation is involved in regulating PR activity, we have examined the effects of cellular modulators of protein phosphorylation on PR-mediated target gene transcription in vivo using a T47D cloned cell line containing a stably transfected mouse mammary tumor virus-chloramphenicol acetyltransferase construct. Treatment with 8-bromo-cAMP (activator of cAMP-dependent protein kinases) or okadaic acid (protein phosphatase-1 and -2A inhibitor) did not stimulate target gene expression in the absence of progestin. When added together with progestin, either compound augmented PR-mediated target gene transcription by 3- to 4-fold. The cyclic nucleotide-dependent protein kinase inhibitor H8 completely blocked target gene responsiveness to hormone. Neither 8-bromo-cAMP, okadaic acid, nor H8 altered the hormone- or DNA-binding activities of PR, as measured in vitro or affected cellular concentrations of PR. These agents, therefore, appeared to selectively modulate PR transcriptional activity. Moreover, none of these compounds altered expression from a control reporter gene, pSV2CAT, indicating that these agents affect PR-mediated processes directly and are not acting through a general effect on transcription. Effects on PR phosphorylation were assessed by measuring 32P labeling of PR in vivo. None of these treatments had a substantial effect on the extent of total 32P labeling of immune isolated PR or on the phosphorylation(s) responsible for PR up-shifts on SDS-gels. This suggests that these agents modulate PR transcriptional activity either through phosphorylation of another protein intimately involved in PR-mediated transcription or through modification of a key site(s) not measurable as a change in total PR phosphorylation or electrophoretic mobility on SDS gels.
Mol Endocrinol 1992 Apr
PMID:Effects of hormone and cellular modulators of protein phosphorylation on transcriptional activity, DNA binding, and phosphorylation of human progesterone receptors. 131 49


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