Retinoic acid receptor beta (RAR-beta), also known as NR1B2 (nuclear receptor subfamily 1, group B, member 2) is a
nuclear receptor
In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These receptors work with other proteins to regulate the expression of speci ...
that in humans is encoded by the ''RARB''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
This gene encodes retinoic acid receptor beta, a member of the thyroid-steroid hormone receptor superfamily of nuclear transcriptional regulators. This receptor localizes to the cytoplasm and to subnuclear compartments. It binds retinoic acid, the biologically active form of
vitamin A
Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...
which mediates cellular signalling in embryonic morphogenesis, cell growth and differentiation. It is thought that this protein limits growth of many cell types by regulating gene expression. The gene was first identified in a hepatocellular carcinoma where it flanks a
hepatitis B
Hepatitis B is an infectious disease caused by the ''Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection.
Many people have no symptoms during an initial infection. Fo ...
virus integration site. A deregulation of this gene has also been detected in uterine
cervical carcinoma
Cervical cancer is a cancer arising from the cervix. It is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body. Early on, typically no symptoms are seen. Later symptoms may include abnormal ...
preneoplastic lesions.
The gene expresses at least two transcript variants; one additional transcript has been described, but its full length nature has not been determined.
Epigenetics
The Retinoic acid receptor beta aberrant promoter
DNA hypermethylation has been observed associated with cancer onset/progression. Indeed, this improper
epigenetic
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "o ...
phenomenon has been observed in women affected by
Vulvar Squamous cell carcinoma arose from
vulver lichen sclerosus.
Methylation of the Retinoic acid receptor beta promoter may be a marker of cancer risk in patients affected by this disease.
Interactions
Retinoic acid receptor beta has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
NR4A2.
See also
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Retinoic acid receptor
The retinoic acid receptor (RAR) is a type of nuclear receptor which can also act as a ligand-activated transcription factor that is activated by both all-trans retinoic acid and 9-cis retinoic acid the retinoid active derivatives of Vitamin A ...
References
Further reading
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Intracellular receptors
Transcription factors
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