Retinoic acid receptor (RAR)

Retinoic acid receptors (RARs) are a family of ligand-activated transcription factors belonging to the nuclear receptor superfamily. They exist as three distinct subtypes—RAR-alpha, RAR-beta, and RAR-gamma—and function primarily as heterodimers with retinoid X receptors (RXRs) to regulate the expression of genes involved in cell growth, differentiation, and embryonic development [1, 3, 10]. Upon binding to their natural ligands, such as all-trans retinoic acid, the RAR-RXR complex undergoes a conformational change that facilitates the recruitment of coactivator proteins and the initiation of transcription at specific DNA sequences known as retinoic acid response elements (RAREs) [3, 20]. Dysregulation of RAR signaling is a hallmark of several diseases, most notably acute promyelocytic leukemia (APL), where a chromosomal translocation creates the oncogenic PML-RARA fusion protein [13, 20]. Therapeutic targeting of RARs with synthetic retinoids has proven highly effective in treating APL and various dermatological conditions like acne and psoriasis, although these treatments are often limited by significant safety concerns, including severe teratogenicity and mucocutaneous toxicity [5, 15, 16].

Other names

Retinoic acid receptor (RAR)-Retinoid X receptor (RXR) complexRAR-RXR heterodimerRetinoic acid receptor alpha (RARα)Retinoic acid receptor beta (RARβ)Retinoic acid receptor gamma (RARγ)NR1B1NR1B2NR1B3

Agonism; the drug binds to the retinoic acid receptor (RAR) subunit within the RAR-RXR heterodimer, inducing a conformational change that triggers the release of corepressors (such as NCoR) and the recruitment of coactivators (such as histone acetyltransferases), thereby initiating the transcription of target genes containing retinoic acid response elements (RAREs).