Aromatase is an enzyme of the cytochrome P450 superfamily (EC 1.14.14.1), whose function is to aromatize androgens (that is, to selectively increase their aromaticity), producing estrogens. The Human Genome Organisation (HUGO is an organization involved in the Human Genome Project, a project about mapping the human genome The Mouse Genome Informatics (MGI website is run by The Jackson Laboratory. HomoloGene, a tool of the National Center for Biotechnology Information (NCBI is a system for automated detection of homologs (similarity attributable to descent The Entrez Global Query Cross-Database Search System is a powerful Federated search engine or Web portal that allows users to search many discrete Health sciences Ensembl is a joint scientific project between the European Bioinformatics Institute and the Wellcome Trust Sanger Institute, which was launched in 1999 in response to the imminent UniProt is the uni versal prot ein resource a central repository of Protein data created by combining Swiss-Prot, TrEMBL PubMed is a free search engine for accessing the MEDLINE database of citations and abstracts of biomedical research articles Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Cytochrome P450 (abbreviated CYP, P450, infrequently CYP450) is a very large and diverse superfamily of Hemoproteins found in all Domains This article is about the Enzyme Commission codes For the European Commission system for coding chemicals see EC-No. Androgen is the generic term for any natural or synthetic compound usually a Steroid Hormone, that stimulates or controls the development and maintenance of masculine Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, As such, it is an important factor in sexual development. Sexual development is the process by which an immature and sterile organism develops the capacity to reproduce

This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and catalyzes the last steps of estrogen biosynthesis, three successive hydroxylations of the A ring of androgens. Mutations in this gene can result in either increased or decreased aromatase activity; the associated phenotypes suggest that estrogen functions both as a sex steroid hormone and in growth or differentiation. The gene expresses two transcript variants. ^[1]

Aromatase converts testosterone to estradiol

Aromatase converts androstenedione to estrone

Genomics

In humans, the gene CYP19, located on chromosome 15q21. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries Estradiol (17β-estradiol (also oestradiol) is a Sex hormone. Androstenedione (also known as 4-androstenedione) is a 19- Carbon Steroid Hormone produced in the Adrenal glands and the Gonads Estrone (also oestrone) is an Estrogenic Hormone secreted by the Ovary. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance A chromosome is an organized structure of DNA and Protein that is found in cells. 1, encodes the aromatase enzyme. CYP19 is present in an early-diverging chordate, the cephalochordate amphioxus (the Florida lancelet, Branchiostoma floridae), but not in the earlier diverging tunicate Ciona intestinalis. Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive Chordates. The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive Chordates. The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive Chordates. The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive Chordates. Tunicate, also known as urochordata, tunicata (and by the common names of urochordates, sea squirts, and sea pork) is the Ciona intestinalis or vase tunicate is a Urochordata (sea squirt whose Genome has been sequenced and which has become over the past decade Thus the aromatase gene evolved early in chordate evolution and does not appear to be present in non-chordate invertebrates (e. An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate g. insects, molluscs, echinoderms, sponges, corals). Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 Echinoderms (Phylum Echinodermata) are a phylum of marine Animals (including Sea stars) The sponges or poriferans (from Latin porus "pore" and ferre "to bear" are Animals Corals are Marine organisms from the class Anthozoa and exist as small Sea anemone –like Polyps typically in colonies of many However, estrogens may be synthesized in some of these organisms, via unknown pathways. Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle,

Cellular and tissue location

The enzyme is located in the endoplasmic reticulum of the cell and its activity is regulated by tissue specific promoters that are in turn controlled by hormones, cytokines, and other factors. The endoplasmic reticulum (Greek endo = "within" (prefix plásma = "formed entity" Latin reticulum = "little net" or ER, is an Organelle In Biology, a promoter is a region of DNA that facilitates the transcription of a particular Gene. Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body Cytokines are a category of signalling Proteins and Glycoproteins that like Hormones and Neurotransmitters, are used extensively in cellular The principal action of the enzyme transforms androstenedione to estrone and testosterone to estradiol. Androstenedione (also known as 4-androstenedione) is a 19- Carbon Steroid Hormone produced in the Adrenal glands and the Gonads Estrone (also oestrone) is an Estrogenic Hormone secreted by the Ovary. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries Estradiol (17β-estradiol (also oestradiol) is a Sex hormone. The aromatase enzyme can be found in many tissues including gonads, brain, adipose tissue, placenta, blood vessels, skin, bone, endometrium as well as in tissue of endometriosis, uterine fibroids, breast cancer, and endometrial cancer. The gonad is the organ that makes Gametes The gonads in males are the Testes and the gonads in Females are the Ovaries. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain "Adipose" redirects here For the Doctor Who monster see " Partners in Crime " The placenta is an Ephemeral organ present in placental Vertebrates, such as Eutherial Mammals and Sharks during Gestation The blood vessels are part of the Circulatory system and function to transport Blood throughout the body The skin is the outer covering of living tissue of an animal (or plant Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce The endometrium is the inner membrane of the Mammalian Uterus. Endometriosis (from endo, "inside" and metra, " Womb " is a common medical condition characterized by growth beyond or outside the uterus Uterine fibroids (singular Uterine Fibroma) ( leiomyomata, singular leiomyoma) are Benign Tumors which grow from the muscle layers of Breast cancer is a Cancer that starts in the cells of the Breast in women and men Endometrial cancer refers to several types of malignancy which arise from the Endometrium, or lining of the Uterus.

Activity

steroidogenesis, showing both actions of aromatase at bottom center. Steroid metabolism is the complete set of Chemical reactions in organisms that produce modify and consume Steroids These Metabolic pathways include

Factors known to increase aromatase activity include age, obesity, insulin, gonadotropins, and alcohol. Senescence refers to the biological processes of a living Organism approaching an advanced age (i Obesity is a condition in which excess Body fat has accumulated to such an extent that health may be negatively affected Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Gonadotropins are Protein Hormones secreted by Gonadotrope cells of the Pituitary gland of Vertebrates Gonadotropin is sometimes In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Aromatase activity is decreased by prolactin, AMH, and smoking. Prolactin ( PRL) or Luteotropic hormone ( LTH) is a Peptide hormone primarily associated with Lactation. Anti-Müllerian hormone (AMH is a Dimeric Glycoprotein that inhibits the development of the Müllerian ducts in a male Embryo. Tobacco Smoking is the inhalation of smoke from burned dried or cured leaves of the Tobacco plant most often in the form of a Cigarette. Aromatase activity appears to be enhanced in certain estrogen-dependent local tissue next to breast tissue, endometrial cancer, endometriosis, and uterine fibroids.

Disorders

Aromatase excess syndrome

A number of investigators have reported on a rather rare syndrome of excess aromatase activity. In boys it can lead to gynecomastia and in girls to precocious puberty and gigantomastia. Gynecomastia, or gynaecomastia, ˌgaɪnəkoʊˈmæstiə is the development of abnormally large Mammary glands in Males resulting in breast enlargement which Precocious puberty (La pubertas praecox) is an unusually early onset of Puberty, the process of sexual maturation triggered by the brain or exogenous chemicals which Gigantomastia is extreme growth of the Breasts (ie 10 pounds per breast and more In both sexes, early epiphyseal closure leads to shortness. Epiphysis is the name for a rounded end of a long Bone. The epiphysis is filled with red Bone marrow, which produces Erythrocytes, or red blood cells

Aromatase deficiency syndrome

This syndrome is due to a mutation of gene CYP19 and inherited in an autosomal recessive way. Accumulations of androgens during pregnancy may lead to virilization of a female at birth (males are not affected). In biology and medicine virilization refers to the biological development of Sex differences, changes which make a Male body different from a Female body Females will have primary amenorrhea. Amenorrhoea ( BE) amenorrhea ( AmE) or amenorrhœa, is the absence of a Menstrual period in a woman of reproductive age Individuals of both sexes will be tall as lack of estrogen does not bring the epiphyseal lines to closure.

Aromatase inhibitors

The inhibition of the enzyme leads to profound hypoestrogenism (low estrogen levels). Hypoestrogenism refers to a lower than normal level of Estrogen. Thus aromatase inhibitors have become useful in the management of patients with breast cancer whose lesion was found to be estrogen receptor positive. Aromatase inhibitors ( AI) are a class of drugs used in the treatment of Breast cancer and Ovarian cancer in postmenopausal women that Breast cancer is a Cancer that starts in the cells of the Breast in women and men The estrogen receptor (ER is a member of the nuclear hormone family of Intracellular receptors which is activated by the Hormone 17β-estradiol

References

Further reading

External links

• "U.S. study of gay sheep may shed light on sexuality", via WikiNews, 15 August 2005. Wikinews is a free-content News source Wiki and a project of the Wikimedia Foundation.