Retinoid X receptor - AbsoluteAstronomy.com

The retinoid X receptor (RXR) is a type of nuclear receptor

Nuclear receptor

In the field of molecular biology, nuclear receptors are a class of proteins found within cells that are responsible for sensing steroid and thyroid hormones and certain other molecules...

that is activated by 9-cis retinoic acid. There are three retinoic X receptors (RXR): RXR-alpha
Retinoid X receptor alpha
Retinoid X receptor alpha , also known as NR2B1 is a nuclear receptor that in humans is encoded by the RXRA gene.- Function :...

, RXR-beta
Retinoid X receptor beta
Retinoid X receptor beta , also known as NR2B2 is a nuclear receptor that in humans is encoded by the RXRB gene....

, and RXR-gamma
Retinoid X receptor gamma
Retinoic acid receptor gamma , also known as NR2B3 is a nuclear receptor that in humans is encoded by the RXRG gene....

, encoded by the , , genes, respectively.

RXR heterodimerizes with subfamily 1 nuclear receptors including CAR

Constitutive androstane receptor

The constitutive androstane receptor also known as nuclear receptor subfamily 1, group I, member 3 is a protein that in humans is encoded by the NR1I3 gene...

, FXR

Farnesoid X receptor

The bile acid receptor , also known as farnesoid X receptor or NR1H4 is a nuclear receptor that is encoded by the NR1H4 gene in humans.- Function :...

, LXR

Liver X receptor

The liver X receptor is a member of the nuclear receptor family of transcription factors and is closely related to nuclear receptors such as the PPARs, FXR and RXR. Liver X receptors are important regulators of cholesterol, fatty acid, and glucose homeostasis...

, PPAR

Peroxisome proliferator-activated receptor

In the field of molecular biology, the peroxisome proliferator-activated receptors are a group of nuclear receptor proteins that function as transcription factors regulating the expression of genes...

, PXR

Pregnane X receptor

In the field of molecular biology, the pregnane X receptor , also known as the steroid and xenobiotic sensing nuclear receptor or nuclear receptor subfamily 1, group I, member 2 is a protein that in humans is encoded by the NR1I2 gene.PXR is a nuclear receptor whose primary function is to sense...

, RAR

Retinoic acid receptor

The retinoic acid receptor is a type of nuclear receptor that is activated by both all-trans retinoic acid and 9-cis retinoic acid. There are three retinoic acid receptors , RAR-alpha, RAR-beta, and RAR-gamma, encoded by the , , genes, respectively...

, TR

Thyroid hormone receptor

The thyroid hormone receptor is a type of nuclear receptor that is activated by binding thyroid hormone.-Function:Amongst the most important functions of thyroid hormone receptors are regulation of metabolism and heart rate...

, and VDR.

As with other type II nuclear receptors, the RXR heterodimer in the absence of ligand is bound to hormone response elements complexed with corepressor

Corepressor (genetics)

In molecular genetics, a corepressor is a substance that inhibits the expression of genes. A corepressor downregulates the expression of genes not through direct interaction with a gene promoter , but rather indirectly through interaction with repressor proteins that in turn bind to the...

protein. Binding of agonist ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

s to RXR results in dissociation of corepressor and recruitment of coactivator

Coactivator (genetics)

A coactivator is a protein that increases gene expression by binding to an activator which contains a DNA binding domain. The coactivator is unable to bind DNA by itself....

protein, which, in turn, promotes transcription of the downstream target gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

into mRNA and eventually protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

See also