RXRA
Description
The RXRA (retinoid X receptor alpha) is a protein-coding gene located on chromosome 9.
Retinoid X receptor alpha (RXR-alpha), also known as NR2B1 (nuclear receptor subfamily 2, group B, member 1) is a nuclear receptor that in humans is encoded by the RXRA gene.
== Function == Retinoid X receptors (RXRs) and retinoic acid receptors (RARs), are nuclear receptors that mediate the biological effects of retinoids by their involvement in retinoic acid-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 superfamily of transcription factors. 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 system genes.
== Interactive pathway map ==
== Interactions == Retinoid X receptor alpha has been shown to interact with:
== See also == Retinoid X receptor
== References ==
== Further reading ==
== External links == FactorBook RXRA This article incorporates text from the United States National Library of Medicine, which is in the public domain.
RXRA is a nuclear receptor that binds to retinoic acid and acts as a transcription factor. It forms homodimers or heterodimers with other retinoic acid receptors (RARs) and binds to specific DNA sequences in response to retinoic acid ligands (all-trans or 9-cis retinoic acid), regulating gene expression in various biological processes. RXRA/RAR heterodimers bind to retinoic acid response elements (RAREs) composed of tandem 5'-AGGTCA-3' sites known as DR1-DR5. RXR's high affinity ligand is 9-cis retinoic acid. In the absence of ligand, RXRA-RAR heterodimers associate with corepressors, leading to transcriptional repression. Upon ligand binding, corepressors dissociate, and coactivators are recruited, resulting in transcriptional activation. RXRA serves as a common heterodimeric partner for other nuclear receptors, including RARA, RARB, and PPARA. The RXRA/RARB heterodimer can act as a transcriptional repressor or activator depending on the DNA context. The RXRA/PPARA heterodimer is essential for PPARA transcriptional activity on fatty acid oxidation genes. RXRA, along with RARA, positively regulates microRNA-10a expression, inhibiting GATA6/VCAM1 signaling in vascular endothelial cells. RXRA enhances RARA binding to RAREs and may facilitate the nuclear import of heterodimerization partners. RXRA promotes myelin debris phagocytosis and remyelination in macrophages, attenuates the innate immune response to viral infections, and regulates calcium signaling by repressing ITPR2 gene expression.
RXRA is also known as NR2B1, RXR-alpha, RXRalpha.
