Nuclear retinoic acid receptor and retinoid X receptor (RAR and RXR)

Nuclear retinoic acid receptors (RAR) and retinoid X receptors (RXR) are two closely related families of ligand-activated nuclear receptors functioning as transcription factors[1][2][3][4][5][7][8]. Both families consist of three subtypes (α, β, γ) and act primarily as heterodimers (RAR:RXR) that bind DNA at specific response elements and regulate gene transcription in response to their respective ligands, mainly all-trans and 9-cis retinoic acids[1][3][4][5][7][8]. These receptors play central roles in embryonic development, cell differentiation, metabolism, immune regulation, and homeostasis, and are implicated in a variety of diseases including cancer, neurodegeneration, and inflammation[2][6]. RXRs also act as obligate heterodimer partners for several other nuclear receptors (e.g., PPAR, LXR, FXR), expanding their influence across multiple physiological processes[1][2][5][7]. Pharmacological modulation of RAR or RXR with agonists or antagonists alters gene expression profiles and underpins the therapeutic action or toxicity of retinoid-based drugs[1][2][4][5].

Other names

RARRXRRetinoic acid receptorRetinoid X receptor

Agonists bind to the receptor, inducing conformational changes that promote dissociation of corepressors, recruitment of coactivators, and initiation of gene transcription[1][4][5][7][8]. Heterodimer formation with other nuclear receptors (e.g., PPAR, LXR, RAR) modulates various signaling pathways and regulates expression of target genes[1][2][3][5][7].