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) are nuclear receptors which form heterodimers with many different nuclear receptors, allowing them to bind to specific sequences in the promoters of target genes and regulate their transcription. For example, RXRA combines with the retinoic acid receptors RARA and RARB, allowing them to mediate the biological effects of retinoids, and in particular enabling retinoic acid-mediated gene activation. 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. After ligand binding, the corepressors dissociate from the receptors and associate with the coactivators leading to transcriptional activation.
Aside from RARs, RXRA is also known to bind to PPARA, and 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:
Nuclear Receptor Heterodimeric Partners
RAR-α RAR-β TR-α TR-β FXR LXR-α LXR-β PPAR-α PPAR-γ NR4A1 PXR (may also form heterotetramer) VDR (optional) SHP (inhibitory)
Other Transcription Factors
CLOCK MyoD NFKBIB NPAS2 POU2F1 TBP
Transcription Coactivators
BCL3 BRD8 ITGB3BP NCOA2 NCOA3 NCOA6 PPARGC1A TADA3L
Others Proteins
IGFBP3 NRIP1 RNF8 TRIM24
See also Retinoid X receptor
References
Further reading
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