Retinoid X receptor alpha (RXR-alpha), also known as NR2B1 (nuclear receptor subfamily 2, group B, member 1) 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 s ...
that in humans is encoded by the ''RXRA'' gene.
Function
Retinoid X receptor
The retinoid X receptor (RXR) is a type of nuclear receptor that is activated by 9-cis retinoic acid, which is discussed controversially to be of endogenous relevance, and 9-''cis''-13,14-dihydroretinoic acid, which is likely to be the major en ...
s (RXRs) and
retinoic acid receptors (RARs), are nuclear receptors that mediate the biological effects of retinoids by their involvement in
retinoic acid
Retinoic acid (used simplified here for all-''trans''-retinoic acid) is a metabolite of vitamin A1 (all-''trans''- retinol) that mediates the functions of vitamin A1 required for growth and development. All-''trans''-retinoic acid is required in ...
-mediated gene activation. These receptors exert their action by binding, as homodimers or heterodimers, to specific sequences in the promoters of target genes and regulating their transcription. The protein encoded by this gene is a member of the steroid and
thyroid hormone receptor
The thyroid hormone receptor (TR) is a type of nuclear receptor that is activated by binding thyroid hormone. TRs act as transcription factors, ultimately affecting the regulation of gene transcription and translation. These receptors also hav ...
superfamily of
transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...
s.
In the absence of ligand, the RXR-RAR heterodimers associate with a multiprotein complex containing transcription corepressors that induce histone deacetylation, chromatin condensation and transcriptional suppression. On ligand binding, the corepressors dissociate from the receptors and associate with the coactivators leading to transcriptional activation. The RXRA/PPARA heterodimer is required for
PPARA transcriptional activity on fatty acid oxidation genes such as
ACOX1 and the
cytochrome P450
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compo ...
system genes.
Interactive pathway map
Interactions
Retinoid X receptor alpha has been shown to
interact with:
*
BCL3,
*
BRD8
Bromodomain-containing protein 8 is a protein that in humans is encoded by the ''BRD8'' gene.
The protein encoded by this gene interacts with thyroid hormone receptor in a ligand-dependent manner and enhances thyroid hormone-dependent activation ...
,
*
CLOCK
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and t ...
,
*
FXR[
* ]IGFBP3
Insulin-like growth factor-binding protein 3, also known as IGFBP-3, is a protein that in humans is encoded by the ''IGFBP3'' gene. IGFBP-3 is one of six insulin-like growth factor-binding protein, IGF binding proteins (IGFBP1, IGFBP-1 to IGFBP6, I ...
,[
* NRIP1,]NR4A1
The nuclear receptor 4A1 (NR4A1 for "nuclear receptor subfamily 4 group A member 1") also known as Nur77, TR3, and NGFI-B is a protein that in humans is encoded by the ''NR4A1'' gene.
Nuclear receptor 4A1 (NR4A1) is a member of the '' NR4A'' nucl ...
,PPAR-γ
In the field of molecular biology, the peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptor proteins that function as transcription factors regulating the expression of genes. PPARs play essential roles in the reg ...
,
See also
* Retinoid X receptor
The retinoid X receptor (RXR) is a type of nuclear receptor that is activated by 9-cis retinoic acid, which is discussed controversially to be of endogenous relevance, and 9-''cis''-13,14-dihydroretinoic acid, which is likely to be the major en ...
References
Further reading
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External links
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{{DEFAULTSORT:Retinoid X Receptor Alpha
Intracellular receptors
Transcription factors