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Estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy. Estrogens are synthesized in all vertebrates and some insects. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males than in females, estrogens nevertheless have important physiological roles in males. Like all steroid hormones, estrogens readily diffuse across the cell membrane. Once inside the cell, they bind to and activate estrogen receptors (ERs) which in turn modulate the expression of many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feminizing Hormone Therapy
Feminizing hormone therapy, also known as transfeminine hormone therapy, is a form of Transgender_health_care#Gender-affirming_care , gender-affirming care and a gender-affirming hormone therapy , gender-affirming hormone therapy to change the secondary sex characteristics of transgender people from masculine to feminine. It is a common type of transgender hormone therapy (another being masculinizing hormone therapy) and is used to treat transgender women and non-binary gender, non-binary transfeminine individuals. Some, in particular intersex people, but also some non-transgender people, take this form of therapy according to their personal needs and preferences. The purpose of the therapy is to cause the development of the secondary sex characteristics of the desired sex, such as breasts and a feminine pattern of body hair, hair, fat distribution, fat, and skeletal muscle, muscle distribution. It cannot undo many of the changes produced by naturally occurring puberty, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERα
Estrogen receptor alpha (ERα), also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of two main types of estrogen receptor, a nuclear receptor (mainly found as a chromatin-binding protein) that is activated by the sex hormone estrogen. In humans, ERα is encoded by the gene ''ESR1'' (EStrogen Receptor 1). Structure The estrogen receptor (ER) is a ligand-activated transcription factor composed of several domains important for hormone binding, DNA binding, and activation of transcription. Alternative splicing results in several ESR1 mRNA transcripts, which differ primarily in their 5-prime untranslated regions. The translated receptors show less variability. Ligands Agonists Non-selective * Endogenous estrogens (e.g., estradiol, estrone, estriol, estetrol) * Natural estrogens (e.g., conjugated equine estrogens) * Synthetic estrogens (e.g., ethinylestradiol, diethylstilbestrol) Selective Agonists of ERα selective over ERβ in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen Receptor
Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen receptors, namely ERα and ERβ, which belong to the nuclear receptor family. The second class consists of membrane estrogen receptors (mERs), such as GPER (GPR30), ER-X, and Gq-mER, Gq-mER, which are primarily G protein-coupled receptors. This article focuses on the nuclear estrogen receptors (ERα and ERβ). Upon activation by estrogen, intracellular ERs undergo protein targeting, translocation to the nucleus where they bind to specific DNA sequences. As DNA-binding transcription factors, they regulate the activity of various genes. However, ERs also exhibit functions that are independent of their DNA-binding capacity. These non-genomic actions contribute to the diverse effects of estrogen signaling in cells. Estrogen receptors (ERs) b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol
Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many other tissues including bone, fat, skin, liver, and the brain. Though estradiol levels in males are much lower than in females, estradiol has important roles in males as well. Apart from humans and other mammals, estradiol is also found in most vertebrates and crustaceans, insects, fish, and other animal species. Estradiol is produced within the follicles of the ovaries and in oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERβ
Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by the ''ESR2'' gene. Function ERβ is a member of the family of estrogen receptors and the superfamily of nuclear receptor transcription factors. The gene product contains an N-terminus, N-terminal DNA binding domain and C-terminus, C-terminal ligand binding domain and is localized to the nucleus, cytoplasm, and mitochondria. Upon binding to 17-β-estradiol, estriol or related ligands, the encoded protein forms homo-dimers or hetero-dimers with estrogen receptor alpha, estrogen receptor α that interact with specific DNA sequences to activate transcription. Some isoforms dominantly inhibit the activity of other estrogen receptor family members. Several alternatively spliced transcript variants of this gene have been described, but the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrone
Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized from cholesterol and secreted mainly from the gonads, though they can also be formed from adrenal androgens in adipose tissue. Relative to estradiol, both estrone and estriol have far weaker activity as estrogens. Estrone can be converted into estradiol, and serves mainly as a precursor or metabolic intermediate of estradiol. It is both a precursor and metabolite of estradiol. In addition to its role as a natural hormone, estrone has been used as a medication, for instance in menopausal hormone therapy; for information on estrone as a medication, see the estrone (medication) article. Biological activity Estrone is an estrogen, specifically an agonist of the estrogen receptors ERα and ERβ. It is a far less potent estrogen than is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPER
G protein-coupled estrogen receptor 1 (GPER), also known as G protein-coupled receptor 30 (GPR30), is a protein that in humans is encoded by the ''GPER'' gene. GPER binds to and is activated by the female sex hormone estradiol and is responsible for some of the rapid effects that estradiol has on cells. Discovery The classical estrogen receptors first characterized in 1958 are water-soluble proteins located in the interior of cells that are activated by estrogenenic hormones such as estradiol and several of its metabolites such as estrone or estriol. These proteins belong to the nuclear hormone receptor class of transcription factors that regulate gene transcription. Since it takes time for genes to be transcribed into RNA and translated into protein, the effects of estrogens binding to these classical estrogen receptors is delayed. However, estrogens are also known to have effects that are too fast to be caused by regulation of gene transcription. In 2005, it was discove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estetrol
Estetrol (E4), or oestetrol, is one of the four natural estrogenic steroid hormones found in humans, along with estrone (E1), estradiol (E2), and estriol (E3). Estetrol is a major estrogen in the body. In contrast to estrone and estradiol, estetrol is a native estrogen of fetal life. Estetrol is produced exclusively by the fetal liver and is found in detectable levels only during pregnancy, with relatively high levels in the fetus and lower levels in the maternal circulation. In addition to its physiological role as a native hormone, estetrol can be used as a medication, see estetrol (medication). Estetrol, in combination with drospirenone, has recently been approved as a new estrogenic component of a combined oral contraceptive (COC) and estetrol alone is in clinical development for the treatment of menopausal symptoms as well as breast and prostate cancer. Biological function So far, the physiological function of estetrol remains unknown. The potential role of estetrol as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Estrogen Receptor
Membrane estrogen receptors (mERs) are a group of receptor (biochemistry), receptors which bind estrogen. Unlike nuclear estrogen receptors, which mediate their effects via slower Genome, genomic mechanisms, mERs are cell surface receptors that rapidly alter cell signaling via modulation of intracellular Signal transduction, signaling cascades. Nuclear estrogen receptors such as ERα and ERβ become mERs through palmitoylation, a post-translational modification that enhances ER association with Caveolin 1, caveolin-1 to enable trafficking of ERs to the membrane or membrane caveolae. Other putative mERs include GPER (GPR30), GPRC6A, ER-X, ERx and Gq-mER, Gq-mER. Structure-function relationship In mice and humans, ERβ localization in the plasma membrane occurs after palmitoylation on cysteine 418. Dimerization of mERs appears necessary for their function in rapid cell signaling. Signaling mechanisms G-protein coupled receptors Various electrophysiological studies support E2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
