RXRA Human

Retinoid X Receptor Alpha (RXRα), also known as NR2B1 (nuclear receptor subfamily 2, group B, member 1), is a nuclear receptor encoded by the RXRA gene in humans . This receptor plays a crucial role in mediating the biological effects of retinoids by participating in retinoic acid-mediated gene activation .

RXRα is a member of the steroid and thyroid hormone receptor superfamily of transcription factors . It functions by forming homodimers or heterodimers with other nuclear receptors, such as retinoic acid receptors (RARs), and binding to specific sequences in the promoters of target genes to regulate their transcription . The protein encoded by the RXRA gene is involved in various biological processes, including fatty acid oxidation and the cytochrome P450 system .

In the absence of a ligand, RXR-RAR heterodimers associate with a multiprotein complex containing transcription corepressors that induce histone deacetylation, chromatin condensation, and transcriptional suppression . Upon ligand binding, the corepressors dissociate from the receptors, and coactivators are recruited, leading to transcriptional activation .

Recombinant human RXRα is a fragment protein expressed in Escherichia coli, with a purity greater than 95% . This recombinant protein is used in various research applications, including SDS-PAGE, to study the receptor’s function and interactions . The high-affinity ligand for RXRs is 9-cis retinoic acid, which binds to the receptor and regulates gene expression .

RXRα interacts with several proteins and nuclear receptors, including BCL3, BRD8, CLOCK, FXR, IGFBP3, ITGB3BP, LXR-β, MyoD, NCOA6, NFKBIB, NPAS2, NRIP1, NR4A1, NCOA2, NCOA3, POU2F1, PPARGC1A, PPAR-γ, RNF8, RAR-α, SHP, TADA3L, TBP, TRIM24, TR-β, and VDR . These interactions are essential for the receptor’s role in regulating gene expression and various biological processes.

Mutations or dysregulation of the RXRA gene have been associated with several diseases, including pancreatic adenocarcinoma and bladder urothelial carcinoma . Understanding the function and interactions of RXRα is crucial for developing targeted therapies for these conditions.