Involvement of estrogen receptors α and β in the regulation of cervical permeability

2000 ◽  
Vol 278 (4) ◽  
pp. C689-C696 ◽  
Author(s):  
George I. Gorodeski ◽  
Dipika Pal
Keyword(s):  
Estrogen Receptor ◽  
Binding Sites ◽  
Estrogen Receptor Α ◽  
Binding Activity ◽  
Scatchard Analysis ◽  
Single Class ◽  
Estrogen Receptor Modulators ◽  
Transcription Inhibitor ◽  
Estrogen Binding ◽  
In Cells

Estrogen increases the permeability of cultured human cervical epithelia (Gorodeski, GI. Am J Physiol Cell Physiol 275: C888–C899, 1998), and the effect is blocked by the estrogen receptor modulators ICI-182780 and tamoxifen. The objective of the study was to determine involvement of estrogen receptor(s) in mediating the effects on permeability. In cultured human cervical epithelial cells estradiol binds to high-affinity, low-capacity sites, in a specific and saturable manner. Scatchard analysis revealed a single class of binding sites with a dissociation constant of 1.3 nM and binding activity of ∼0.5 pmol/mg DNA. Estradiol increased the density of estrogen-binding sites in a time- and dose-related manner (half time ≈ 4 h, and EC50≈ 1 nM). RT-PCR assays revealed the expression of mRNA for the estrogen receptor α (αER) and estrogen receptor β (βER). Removal of estrogen from the culture medium decreased and treatment with estrogen increased the expression of αER and βER mRNA. In cells not treated with estrogen, ICI-182780 and tamoxifen increased βER mRNA. In cells treated with estrogen, neither ICI-182780 nor tamoxifen had modulated significantly the increase in αER or βER mRNA. The transcription inhibitor actinomycin D blocked the estrogen-induced increase in permeability, and it abrogated the estradiol-induced increase in estrogen binding sites. These results suggest that the estrogen-dependent increase in cervical permeability is mediated by an αER-dependent increase in transcription.

Estrogen Receptor-Independent Catechol Estrogen Binding Activity:  Protein Binding Studies in Wild-Type, Estrogen Receptor-α KO, and Aromatase KO Mice Tissues†

Biochemistry ◽  
2004 ◽  
Vol 43 (21) ◽  
pp. 6698-6708 ◽  
Author(s):  
Brian J. Philips ◽  
Pete J. Ansell ◽  
Leslie G. Newton ◽  
Nobuhiro Harada ◽  
Shin-Ichiro Honda ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Protein Binding ◽  
Estrogen Receptor Α ◽  
Binding Activity ◽  
Wild Type ◽  
Binding Studies ◽  
Catechol Estrogen ◽  
Estrogen Binding

scholarly journals The Phosphorylated Estrogen Receptor α (ER) Cistrome Identifies a Subset of Active Enhancers Enriched for Direct ER-DNA Binding and the Transcription Factor GRHL2

2018 ◽  
Vol 39 (3) ◽  
Author(s):  
Kyle T. Helzer ◽  
Mary Szatkowski Ozers ◽  
Mark B. Meyer ◽  
Nancy A. Benkusky ◽  
Natalia Solodin ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Transcription Factor ◽  
Dna Binding ◽  
Protein Interactions ◽  
Posttranslational Modifications ◽  
Binding Sites ◽  
Protein Function ◽  
Estrogen Receptor Α ◽  
Binding Activity

ABSTRACT Posttranslational modifications are key regulators of protein function, providing cues that can alter protein interactions and cellular location. Phosphorylation of estrogen receptor α (ER) at serine 118 (pS118-ER) occurs in response to multiple stimuli and is involved in modulating ER-dependent gene transcription. While the cistrome of ER is well established, surprisingly little is understood about how phosphorylation impacts ER-DNA binding activity. To define the pS118-ER cistrome, chromatin immunoprecipitation sequencing was performed on pS118-ER and ER in MCF-7 cells treated with estrogen. pS118-ER occupied a subset of ER binding sites which were associated with an active enhancer mark, acetylated H3K27. Unlike ER, pS118-ER sites were enriched in GRHL2 DNA binding motifs, and estrogen treatment increased GRHL2 recruitment to sites occupied by pS118-ER. Additionally, pS118-ER occupancy sites showed greater enrichment of full-length estrogen response elements relative to ER sites. In an in vitro DNA binding array of genomic binding sites, pS118-ER was more commonly associated with direct DNA binding events than indirect binding events. These results indicate that phosphorylation of ER at serine 118 promotes direct DNA binding at active enhancers and is a distinguishing mark for associated transcription factor complexes on chromatin.

Characterization of Thromboxane A2/Prostaglandin H2 Receptors in Porcine Coronary Artery -The Inhibitory Effect of a Novel Dibenzoxepin Derivative, KW-3635

1992 ◽  
Vol 67 (05) ◽  
pp. 582-584 ◽  
Author(s):  
Ichiro Miki ◽  
Akio Ishii
Keyword(s):  
Coronary Artery ◽  
Binding Sites ◽  
Thromboxane A2 ◽  
Inhibitory Effect ◽  
Scatchard Analysis ◽  
Single Class ◽  
Porcine Coronary Artery ◽  
Equilibrium Binding ◽  
H2 Receptors

SummaryWe characterized the thromboxane A2/prostaglandin H2 receptors in porcine coronary artery. The binding of [3H]SQ 29,548, a thromboxane A2 antagonist, to coronary arterial membranes was saturable and displaceable. Scatchard analysis of equilibrium binding showed a single class of high affinity binding sites with a dissociation constant of 18.5 ±1.0 nM and the maximum binding of 80.7 ± 5.2 fmol/mg protein. [3H]SQ 29,548 binding was concentration-dependently inhibited by thromboxane A2 antagonists such as SQ 29,548, BM13505 and BM13177 or the thromboxane A2 agonists such as U46619 and U44069. KW-3635, a novel dibenzoxepin derivative, concentration-dependently inhibited the [3H]SQ 29,548 binding to thromboxane A2/prosta-glandin H2 receptors in coronary artery with an inhibition constant of 6.0 ± 0.69 nM (mean ± S.E.M.).

scholarly journals AKT Alters Genome-Wide Estrogen Receptor α Binding and Impacts Estrogen Signaling in Breast Cancer

2008 ◽  
Vol 28 (24) ◽  
pp. 7487-7503 ◽  
Author(s):  
Poornima Bhat-Nakshatri ◽  
Guohua Wang ◽  
Hitesh Appaiah ◽  
Nikhil Luktuke ◽  
Jason S. Carroll ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Cell Types ◽  
Estrogen Receptor Α ◽  
Estrogen Signaling ◽  
Primary Tumors ◽  
Genome Wide ◽  
Extracellular Signal

ABSTRACT Estrogen regulates several biological processes through estrogen receptor α (ERα) and ERβ. ERα-estrogen signaling is additionally controlled by extracellular signal activated kinases such as AKT. In this study, we analyzed the effect of AKT on genome-wide ERα binding in MCF-7 breast cancer cells. Parental and AKT-overexpressing cells displayed 4,349 and 4,359 ERα binding sites, respectively, with ∼60% overlap. In both cell types, ∼40% of estrogen-regulated genes associate with ERα binding sites; a similar percentage of estrogen-regulated genes are differentially expressed in two cell types. Based on pathway analysis, these differentially estrogen-regulated genes are linked to transforming growth factor β (TGF-β), NF-κB, and E2F pathways. Consistent with this, the two cell types responded differently to TGF-β treatment: parental cells, but not AKT-overexpressing cells, required estrogen to overcome growth inhibition. Combining the ERα DNA-binding pattern with gene expression data from primary tumors revealed specific effects of AKT on ERα binding and estrogen-regulated expression of genes that define prognostic subgroups and tamoxifen sensitivity of ERα-positive breast cancer. These results suggest a unique role of AKT in modulating estrogen signaling in ERα-positive breast cancers and highlights how extracellular signal activated kinases can change the landscape of transcription factor binding to the genome.

scholarly journals Identification and analysis of human erythropoietin receptors on a factor-dependent cell line, TF-1

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 375-380 ◽  
Author(s):  
T Kitamura ◽  
A Tojo ◽  
T Kuwaki ◽  
S Chiba ◽  
K Miyazono ◽  
...  
Keyword(s):  
Cell Line ◽  
Binding Sites ◽  
Bone Marrow Cells ◽  
Scatchard Analysis ◽  
Hematopoietic Growth Factors ◽  
Single Class ◽  
Gm Csf ◽  
Molecular Weights ◽  
Human Erythropoietin ◽  
Macrophage Colony

Abstract We have recently established a novel cell line, TF-1, from bone marrow cells of a patient with erythroleukemia, that showed an absolute growth dependency on each of three hematopoietic growth factors: erythropoietin (EPO) granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin 3 (IL-3). EPO stimulated the proliferation of TF-1 cells even at the physiologic concentration (0.03 U/mL). We performed binding experiments on TF-1 cells using radioiodinated EPO. The binding of radioiodinated EPO to TF-1 was specific, time- and temperature-dependent, and saturable. Scatchard analysis of the saturation binding data suggested the existence of a single class of binding sites (kd = 0.40 nmol/L; number of binding sites = 1,630 per cell). TF-1 cells were usually maintained in RPMI 1640 containing 10% fetal bovine serum and 5 ng/mL GM-CSF. The kd and the number of the EPO receptors were not changed by incubating the cells with IL-3, although culturing the cells in the presence of EPO resulted in down-modulation of EPO receptors. The chemical cross-linking study demonstrated that two molecules with apparent molecular weights of 105 kilodalton (Kd) and 90 Kd were the binding components of EPO. Present data suggest that human EPO receptors are very similar to the previously reported murine EPO receptors.

CORTICOSTERONE BINDING BY MOUSE SERA DURING FOETAL AND POST-NATAL DEVELOPMENT

1977 ◽  
Vol 84 (1) ◽  
pp. 177-190 ◽  
Author(s):  
Lia Savu ◽  
Emmanuel Nunez ◽  
Max-Fernand Jayle
Keyword(s):  
Amniotic Fluid ◽  
Binding Sites ◽  
Binding Proteins ◽  
Serum Proteins ◽  
Equilibrium Dialysis ◽  
Normal Adult ◽  
Scatchard Analysis ◽  
Mammalian Development ◽  
Single Class ◽  
Mean Values

ABSTRACT The binding properties of corticosterone binding globulin (CBG) of mouse sera have been studied by equilibrium dialysis and electrophoretic techniques, at different stages of foetal and post-natal development. Scatchard analysis has demonstrated in all cases a single class of high affinity saturable binding sites for corticosterone. Remarkable increases of the binding capacities were observed in the foetal and pregnant sera, as compared to normal adult and immature levels. The mean values of n1M1 × g−1 of serum proteins (concentration of binding sites, n1 × moles of binding proteins M1) were 21 10−8 in 14–19 day pregnant females, 17 10−8 in the amniotic fluid, 4.2 10−8 in 14–19 day embryos, and only 0.8 10−8 in the normal adult female. Neonatal mice, aged 0–6 days exhibited no CBG activities. The association constants showed values of 2.5–4.1 108 m−1 when measured with foetal sera, and of 1.2–2.1 108 m−1 with pregnant or control adult sera and with the amniotic fluid, at 25°C. Comparative electrophoretic, thermal denaturation and competition studies with foetal and pregnant plasma CBG's are also reported. The results are discussed in relation to the origin of CBG in the foetal serum, and also with respect to similar studies in the rat, guinea pig and man. The possible biological implications of serum steroid binding proteins in mammalian development are briefly outlined.

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