A report on Estrogen receptor

A dimer of the ligand-binding region of ERβ (PDB rendering based on ).
The domain structures of ERα and ERβ, including some of the known phosphorylation sites involved in ligand-independent regulation.
A dimer of the ligand-binding region of ERα (PDB rendering based on ).
Nolvadex (tamoxifen) 20 mg
Arimidex (anastrozole) 1 mg

Estrogen receptors (ERs) are a group of proteins found inside cells.

- Estrogen receptor
A dimer of the ligand-binding region of ERβ (PDB rendering based on ).

42 related topics with Alpha

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An illustration of breast cancer

Breast cancer

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Cancer that develops from breast tissue.

Cancer that develops from breast tissue.

An illustration of breast cancer
Breast cancer showing an inverted nipple, lump, and skin dimpling
Early signs of possible breast cancer
Tumor in the breast visualized by Breast-Computertomography (Breast-CT)
All types of alcoholic beverages, including beer, wine, or liquor, cause breast cancer.
Ducts and lobules, the main locations of breast cancers
Overview of signal transduction pathways involved in programmed cell death. Mutations leading to loss of this ability can lead to cancer formation.
Histopathologic types of breast cancer, with relative incidences and prognoses
A mobile breast cancer screening unit in New Zealand
Chest after right breast mastectomy
Internal radiotherapy for breast cancer
Breasts after double mastectomy followed by nipple-sparing reconstruction with implants
An extreme example of an advanced recurrent breast cancer with an ulcerating axillary mass
Breast cancer surgery in 18th century
Radical mastectomy, Halsted's surgical papers
The pink ribbon is a symbol to show support for breast cancer awareness.
MRI showing breast cancer
Excised human breast tissue, showing an irregular, dense, white stellate area of cancer 2cm in diameter, within yellow fatty tissue
High-grade invasive ductal carcinoma, with minimal tubule formation, marked pleomorphism, and prominent mitoses, 40x field
Micrograph showing a lymph node invaded by ductal breast carcinoma, with an extension of the tumor beyond the lymph node
Neuropilin-2 expression in normal breast and breast carcinoma tissue
F-18 FDG PET/CT: A breast cancer metastasis to the right scapula
Needle breast biopsy
Elastography shows stiff cancer tissue on ultrasound imaging.
Ultrasound image shows irregularly shaped mass of breast cancer.
Infiltrating (invasive) breast carcinoma
Mammograms showing a normal breast (left) and a breast with cancer (right)
Stage T1 breast cancer
Stage T2 breast cancer
Stage T3 breast cancer
Metastatic or stage 4 breast cancer
Stage 1A breast cancer
Stage 1B breast cancer
Stage 2A breast cancer
Stage 2A breast cancer
Stage 2B breast cancer
Stage 2B breast cancer
Stage 2B breast cancer
Stage 3A breast cancer
Stage 3A breast cancer
Stage 3A breast cancer
Stage 3B breast cancer
Stage 3B breast cancer
Stage 4 breast cancer

Additionally, G-protein coupled estrogen receptors have been associated with various cancers of the female reproductive system including breast cancer.

Diethylstilbestrol

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Nonsteroidal estrogen medication, which is presently rarely used.

Nonsteroidal estrogen medication, which is presently rarely used.

Testosterone levels with no treatment and with various estrogens in men with prostate cancer. Determinations were made with an early radioimmunoassay (RIA). Source was Shearer et al. (1973).
Testosterone levels with placebo and 0.2 to 5 mg/day diethylstilbestrol (DES) for 6 months in men with prostate cancer. Determinations were made with a radioimmunoassay (RIA). Source was Kent et al. (1973).
Chemical structures of estradiol and DES. Note the preservation of the two hydroxyl groups in DES and the similar distance between them relative to estradiol, which is notable when it is considered that DES was discovered serendipitously.

DES is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol.

Human steroidogenesis, showing estriol at bottom right. In essence, it follows the pathway from dehydroepiandrosterone or DHEA (at left), but with a modified DHEA with an additional OH-group.

Estriol

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Steroid, a weak estrogen, and a minor female sex hormone.

Steroid, a weak estrogen, and a minor female sex hormone.

Human steroidogenesis, showing estriol at bottom right. In essence, it follows the pathway from dehydroepiandrosterone or DHEA (at left), but with a modified DHEA with an additional OH-group.

Estriol is an estrogen, specifically an agonist of the estrogen receptors ERα and ERβ.

Crystallographic structure of a heterodimer of the nuclear receptors PPAR-γ (green) and RXR-α (cyan) bound to double stranded DNA (magenta) and two molecules of the NCOA2 coactivator (red). The PPAR-γ antagonist GW9662 and RXR-α agonist retinoic acid are depicted as space-filling models (carbon = white, oxygen = red, nitrogen = blue, chlorine = green).

Nuclear receptor

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In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, cholesterol, and vitamins.

In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, cholesterol, and vitamins.

Crystallographic structure of a heterodimer of the nuclear receptors PPAR-γ (green) and RXR-α (cyan) bound to double stranded DNA (magenta) and two molecules of the NCOA2 coactivator (red). The PPAR-γ antagonist GW9662 and RXR-α agonist retinoic acid are depicted as space-filling models (carbon = white, oxygen = red, nitrogen = blue, chlorine = green).
Structures of selected endogenous nuclear receptor ligands and the name of the receptor that each binds to.
Mechanism of class I nuclear receptor action. A class I nuclear receptor (NR), in the absence of ligand, is located in the cytosol. Hormone binding to the NR triggers dissociation of heat shock proteins (HSP), dimerization, and translocation to the nucleus, where the NR binds to a specific sequence of DNA known as a hormone response element (HRE). The nuclear receptor DNA complex in turn recruits other proteins that are responsible for transcription of downstream DNA into mRNA, which is eventually translated into protein, which results in a change in cell function.
Mechanism of class II nuclear receptor action. A class II nuclear receptor (NR), regardless of ligand-binding status, is located in the nucleus bound to DNA. For the purpose of illustration, the nuclear receptor shown here is the thyroid hormone receptor (TR) heterodimerized to the RXR. In the absence of ligand, the TR is bound to corepressor protein. Ligand binding to TR causes a dissociation of corepressor and recruitment of coactivator protein, which, in turn, recruits additional proteins such as RNA polymerase that are responsible for transcription of downstream DNA into RNA and eventually protein.
Structural basis for the mechanism of nuclear receptor agonist and antagonist action. The structures shown here are of the ligand binding domain (LBD) of the estrogen receptor (green cartoon diagram) complexed with either the agonist diethylstilbestrol (top, ) or antagonist 4-hydroxytamoxifen (bottom, ). The ligands are depicted as space filling spheres (white = carbon, red = oxygen). When an agonist is bound to a nuclear receptor, the C-terminal alpha helix of the LDB (H12; light blue) is positioned such that a coactivator protein (red) can bind to the surface of the LBD. Shown here is just a small part of the coactivator protein, the so-called NR box containing the LXXLL amino acid sequence motif. Antagonists occupy the same ligand binding cavity of the nuclear receptor. However antagonist ligands in addition have a sidechain extension which sterically displaces H12 to occupy roughly the same position in space as coactivators bind. Hence coactivator binding to the LBD is blocked.
Phylogenetic tree of human nuclear receptors

Type I nuclear receptors include members of subfamily 3, such as the androgen receptor, estrogen receptors, glucocorticoid receptor, and progesterone receptor.

Testosterone levels with no treatment and with various estrogens in men with prostate cancer. Determinations were made with an early radioimmunoassay (RIA). Source was Shearer et al. (1973).

Ethinylestradiol

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Estrogen medication which is used widely in birth control pills in combination with progestins.

Estrogen medication which is used widely in birth control pills in combination with progestins.

Testosterone levels with no treatment and with various estrogens in men with prostate cancer. Determinations were made with an early radioimmunoassay (RIA). Source was Shearer et al. (1973).
Changes in levels of estrogen-sensitive proteins after treatment with oral estradiol or oral ethinylestradiol in postmenopausal women. FSH is a pituitary protein and represents general/systemic estrogenic effect, while SHBG and PZP are hepatic proteins and represent liver estrogenic effect.
SHBG levels in men with 1) intramuscular injection of 320 mg polyestradiol phosphate once every 4 weeks alone; 2) the combination of intramuscular injection of 80 mg polyestradiol phosphate once every 4 weeks plus 150 µg/day oral ethinylestradiol; 3) orchiectomy only.
EE levels while fasting or with a high-fat meal following ingestion of tablets containing a single oral dose of 20 µg EE and 2 mg norethisterone acetate in women.

EE is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol.

Illustration of an activator

Transcription factor

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Protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence.

Protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence.

Illustration of an activator
Schematic diagram of the amino acid sequence (amino terminus to the left and carboxylic acid terminus to the right) of a prototypical transcription factor that contains (1) a DNA-binding domain (DBD), (2) signal-sensing domain (SSD), and Activation domain (AD). The order of placement and the number of domains may differ in various types of transcription factors. In addition, the transactivation and signal-sensing functions are frequently contained within the same domain.
Domain architecture example: Lactose Repressor (LacI). The N-terminal DNA binding domain (labeled) of the lac repressor binds its target DNA sequence (gold) in the major groove using a helix-turn-helix motif. Effector molecule binding (green) occurs in the regulatory domain (labeled). This triggers an allosteric response mediated by the linker region (labeled).

Estrogen signaling is an example of a fairly short signaling cascade that involves the estrogen receptor transcription factor: Estrogen is secreted by tissues such as the ovaries and placenta, crosses the cell membrane of the recipient cell, and is bound by the estrogen receptor in the cell's cytoplasm.

Genistein

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Naturally occurring compound that structurally belongs to a class of compounds known as isoflavones.

Naturally occurring compound that structurally belongs to a class of compounds known as isoflavones.

Besides functioning as an antioxidant and anthelmintic, many isoflavones have been shown to interact with animal and human estrogen receptors, causing effects in the body similar to those caused by the hormone estrogen.

Clomifene

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Medication used to treat infertility in women who do not ovulate, including those with polycystic ovary syndrome.

Medication used to treat infertility in women who do not ovulate, including those with polycystic ovary syndrome.

It is a mixed agonist and antagonist of the estrogen receptor (ER).

Ethamoxytriphetol

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Synthetic nonsteroidal antiestrogen that was studied clinically in the late 1950s and early 1960s but was never marketed.

Synthetic nonsteroidal antiestrogen that was studied clinically in the late 1950s and early 1960s but was never marketed.

However, some estrogenic effects in the uterus have been observed, so it is not a pure antiestrogen (that is, a silent antagonist of the estrogen receptor (ER)) but is, instead, technically a selective estrogen receptor modulator (SERM).

Steroid hormone receptor

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Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells.

Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells.

Group A: Estrogen receptor (Sex hormones: Estrogen)