Responses to androgens of rat ventral prostate nuclear androgen-binding sites sensitive and resistant to micrococcal nuclease

The Prostate ◽  
1982 ◽  
Vol 3 (5) ◽  
pp. 439-457 ◽  
Author(s):  
P. Davies ◽  
P. Thomas ◽  
M. G. Giles
Keyword(s):  
Binding Sites ◽  
Micrococcal Nuclease ◽  
Ventral Prostate ◽  
Rat Ventral Prostate ◽  
Androgen Binding

Extraction of androgen–receptor complexes from regions of rat ventral prostate nuclei sensitive or resistant to nucleases

1983 ◽  
Vol 99 (1) ◽  
pp. 51-61 ◽  
Author(s):  
P. Davies
Keyword(s):  
Androgen Receptor ◽  
Binding Sites ◽  
Micrococcal Nuclease ◽  
Ventral Prostate ◽  
Receptor Complex ◽  
Sedimentation Analysis ◽  
Receptor Complexes ◽  
Rat Ventral Prostate ◽  
Profile Characteristic ◽  
Androgen Binding

Rat ventral prostate nuclei contain androgen-binding sites which are susceptible or resistant to excision by endonucleolytic action. Those which were susceptible were associated both with oligonucleosomal and subnucleosomal particles. The sedimentation profile characteristic of a nuclear androgen-receptor complex could be obtained by exhaustive nucleolytic digestion or by treatment of fractions with KCl (0·6 mol/l). Androgen-binding sites resistant to DNAase I were also resistant to KCl, whereas those sites resistant to micrococcal nuclease were partially extractable with KCl. Nuclease-resistant sites could be extracted with heparin (10 mg/ml). Androgen–receptor complexes obtained from nuclease-sensitive or nuclease-resistant regions by extraction with KCl or heparin were indistinguishable by routine sedimentation analysis.

scholarly journals Binding of androgens to a nuclear-envelope fraction from the rat ventral prostate

1980 ◽  
Vol 186 (3) ◽  
pp. 641-647 ◽  
Author(s):  
Y A Lefebvre ◽  
Z Novosad
Keyword(s):  
Nuclear Envelope ◽  
Binding Sites ◽  
Specific Binding ◽  
Ventral Prostate ◽  
Scatchard Analysis ◽  
Rat Ventral Prostate ◽  
Membrane Isolation ◽  
Triton X ◽  
Androgen Binding ◽  
Plasma Membrane Isolation

A nuclear-envelope fraction was isolated from the rat ventral prostate which is virtually free of DNA and contains little RNA or plasma membrane. Isolation of this nuclear-envelope fraction after incubation of purified nuclei with radioactive dihydrotestosterone results in labelling of the membrane. More binding of dihydrotestosterone is observed after incubations at 22 degrees C for 17 h than at 4 degrees C for 17 h or at 22 degrees C for 60 min. Scatchard analysis revealed a class of binding sites with KD 8.4 nM. Dihydrotesterone and testosterone were almost equally effective as competitors of labelled dihydrotestosterone binding on the purified nuclear-envelope fraction, whereas diethylstilboestrol was less effective and dexamethasone did not compete well. When the outer membrane of the nuclei was removed with Triton X-100, a 24% decrease in specific binding of androgens was observed. Castration 24 h before preparation of nuclei resulted in loss of the androgen binding to the membrane.

Postnatal development of lectin binding sites in the rat ventral prostate

1989 ◽  
Vol 21 (11) ◽  
pp. 651-658 ◽  
Author(s):  
Ch. Hauke ◽  
R. Horn ◽  
W. Breuer ◽  
F. Sinowatz
Keyword(s):  
Postnatal Development ◽  
Binding Sites ◽  
Lectin Binding ◽  
Ventral Prostate ◽  
Rat Ventral Prostate ◽  
Lectin Binding Sites

SPECIFIC HIGH-AFFINITY OESTRADIOL BINDING IN RAT VENTRAL PROSTATE

1980 ◽  
Vol 87 (2) ◽  
pp. 285-292 ◽  
Author(s):  
M. GINSBURG ◽  
I. JUNG-TESTAS ◽  
E. E. BAULIEU
Keyword(s):  
Binding Sites ◽  
Ventral Prostate ◽  
Scatchard Analysis ◽  
Endocrine Control ◽  
High Affinity ◽  
Rat Ventral Prostate ◽  
Low Salt ◽  
Equilibrium Dissociation ◽  
Intact Rats ◽  
Binding Component

The presence of a specific saturable oestradiol-binding component was demonstrated in cytosol from rat ventral prostate. Centrifugation of cytosol, previously incubated with [3H]oestradiol at 0 °C, on low salt glycerol—Tris gradients revealed two oestradiol-binding systems with sedimentation coefficients of 8S and 4S. Excess unlabelled dihydrotestosterone (17β-hydroxy-5α-androstan-3-one) did not compete with the oestradiol binding, whereas excess unlabelled oestradiol or diethylstilboestrol abolished the 8S and 4S peaks. The oestradiol binding to these components could not be detected after proteolytic treatment. Scatchard analysis of saturable oestradiol binding in cytosol of prostates from intact rats and from rats 14 days after orchidectomy indicated that the equilibrium dissociation constant (KDeq) was about 10−10 mol/l at 0 °C, and the concentrations of high-affinity binding sites were approximately 10 fmol oestradiol bound/mg protein. Lower concentrations of oestradiol binding (approximately 2 fmol/mg protein) were found in cytosols from prostates obtained 2 and 4 days after castration. The transient decrease of oestradiol binding was not due to the presence in prostate cytosol of a factor that inactivated the oestradiol receptor. It is proposed that the oestradiol receptor in the cytosol from ventral prostate tissue of the rat is under endocrine control.

ANDROGEN RECEPTORS IN PROLACTIN PRODUCING PITUITARY TUMOURS IN RATS

1977 ◽  
Vol 86 (2) ◽  
pp. 288-298 ◽  
Author(s):  
Arne Attramadal ◽  
Oddvar Naess ◽  
Egil Haug ◽  
Vidar Hansson ◽  
Ken Purvis
Keyword(s):  
Androgen Receptor ◽  
Binding Sites ◽  
Androgen Receptors ◽  
Sedimentation Coefficient ◽  
Ventral Prostate ◽  
Scatchard Analysis ◽  
Receptor Complex ◽  
Pituitary Tumours ◽  
High Affinity ◽  
Androgen Binding

ABSTRACT The androgen receptor system in prolactin secreting oestrogen induced pituitary tumours has been studied. The tumour cytosol was found to contain specific androgen receptors binding [3H]5α-dihydrotestosterone (DHT) and [3H] testosterone (T) with high affinity and low capacity. Scatchard analysis of the saturation data for T revealed one class of high affinity binding sites. The equilibrium constant of dissociation (Kd) was ∼ 4 × 10−10 m and the number of binding sites was calculated to be 12.8 femtomoles/mg protein. The sedimentation coefficient of the androgen receptor complex in low salt sucrose gradients was ∼ 7 S, the electrophoretic mobility (RF) in 3.25 % polyacrylamide gels ∼ 0.5 and the isoelectric point 5.8. The protein nature of the receptor was indicated by the finding that protease, but not DNase and RNase, eliminated androgen binding. Furthermore, the receptor was thermolabile and functionally dependent on free SH-groups since androgen binding was eliminated by heating 45°C for 30 min) and treatment with p-chloromercuriphenyl sulphonate (1 mm). Steroid specificity was tested in vitro by examining the competing efficiency of different unlabelled steroids for the binding of [3H]T. The affinity of DHT for the receptor was approximately twice that of testosterone while the binding affinity of oestradiol-17β and progesterone was very low. Cortisol had no affinity for the androgen receptor. The dissociation of the androgen receptor complex was very slow at 0°C (t ½ > 48 h). Thus, the characteristics of the cytoplasmic androgen receptors of the prolactin producing pituitary tumours are very similar to those of the androgen receptors earlier demonstrated in the anterior pituitary, hypothalamus, ventral prostate, epididymis and testis. The presence of specific androgen receptors in prolactin producing pituitary tumours indicates that androgen is involved in the regulation of synthesis and release of prolactin.

Interaction of steroids with the nuclear envelope

1986 ◽  
Vol 64 (6) ◽  
pp. 594-600 ◽  
Author(s):  
Y. A. Lefebvre ◽  
J. T. Venkatraman ◽  
E. J. Golsteyn ◽  
G. M. Howell
Keyword(s):  
Nuclear Envelope ◽  
Binding Site ◽  
Rat Liver ◽  
Mammary Carcinoma ◽  
Binding Sites ◽  
Ventral Prostate ◽  
Mouse Mammary Carcinoma ◽  
Rat Ventral Prostate ◽  
Affinity Labelling ◽  
Steroid Binding

Three approaches have been taken to determine the molecular mechanism by which steroid hormones traverse the nuclear envelope on their way to the genome. The first approach involved characterization of steroid binding to nuclear envelope preparations. We have characterized androgen binding to nuclear envelopes isolated from the rat ventral prostate, the rat liver, and androgen-responsive and androgen-unresponsive cell lines of the Shionogi mouse mammary carcinoma and glucocorticoid binding to rat liver. Relatively high affinity binding sites for steroids have been identified on nuclear envelopes. Importantly, the number and specificity of the sites correlates with the responsiveness of the tissue to the steroid. In the second approach, we have undertaken to identify the steroid binding site directly. As the characteristics of the rat ventral prostate site resembled those of the nuclear androgen receptor, we have begun purifying that receptor and have found fast protein liquid chromatography to be very effective. By affinity labelling studies, the dexamethasone binding site on the rat liver nuclear envelope has been identified as a peptide of molecular weight of approximately 90 000. The third approach we have used is to identify androgen-dependent peptides in nuclear envelope preparations. In both the rat ventral prostate and an androgen-responsive cell line of the Shionogi mouse mammary carcinoma, we have identified abundant androgen-dependent peptides. The relationship of these peptides to the binding sites identified by the first two approaches and their role in steroid transport is being investigated.

DISTRIBUTION OF ACCEPTOR SITES FOR ANDROGEN-RECEPTOR COMPLEXES BETWEEN TRANSCRIPTIONALLY ACTIVE AND INACTIVE FRACTIONS OF RAT VENTRAL PROSTATE CHROMATIN

1980 ◽  
Vol 87 (2) ◽  
pp. 225-240 ◽  
Author(s):  
P. DAVIES ◽  
P. THOMAS ◽  
N. M. BORTHWICK ◽  
M. G. GILES
Keyword(s):  
Androgen Receptor ◽  
Rna Polymerase ◽  
Transcriptional Activity ◽  
Nuclear Dna ◽  
Intact Cell ◽  
Micrococcal Nuclease ◽  
Ventral Prostate ◽  
Receptor Complexes ◽  
Rat Ventral Prostate ◽  
Nascent Rna

Rat ventral prostate chromatin was separated into two main fractions by controlled digestion with micrococcal nuclease. The soluble fraction obtained after lysis of digested nuclei with EDTA (1 mmol/l), the S2 fraction, represented approximately 17% of the original nuclear DNA, and showed properties consistent with transcriptional activity, i.e. enrichment in nascent RNA, non-histone protein and endogenous RNA polymerase B activity as well as depletion in histones. The fraction sedimented after lysis of nuclei, fraction P, comprised approximately 60% of nuclear DNA, was depleted in nascent RNA, non-histone proteins and endogenous RNA polymerase B activity, but had a higher content of histones. In an attempt to relate the concentration of acceptor sites for androgen-receptor complexes with transcriptional activity, it was shown that the S2 fraction was enriched in these acceptor sites. However, if measurements were based on the intact cell the transcriptionally inactive portion contained 2·5–3 times as many 'acceptor' sites, although these sites had lower affinity for androgen-receptor complexes than had those in the transcriptionally active fraction.

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