Retinoic acid receptor (RAR) (RAR)

Retinoic acid receptors (RARs) are nuclear receptors that function as ligand-activated transcription factors, mediating most genomic actions of vitamin A (retinoids)[1][5]. There are three main RAR isoforms (RAR-alpha, RAR-beta, RAR-gamma), which form heterodimers with retinoid X receptors (RXRs) and regulate gene expression via binding to retinoic acid response elements (RAREs)[1][4]. RXRs are also nuclear receptors, activated specifically by 9-cis-retinoic acid[2][4], and dimerize with RAR and other nuclear receptors. STRA6, sometimes called the plasma membrane "vitamin A receptor," is a membrane protein that mediates cellular uptake of retinol from circulating retinol-binding protein, and also acts as a cytokine receptor[9]. Together, these receptors play essential roles in cellular differentiation, development, antioxidant defense, and immune function. Dysregulation or deficiency impacts embryogenesis, immune health, vision, and cancer risk. Drugs targeting these receptors are crucial in dermatology, oncology, and developmental disorders, but carry risks such as teratogenicity and toxicity, requiring careful patient selection and monitoring[7].

Other names

Retinoic acid receptorRARRetinoid X receptor (RXR, as obligate heterodimerization partner)STRA6 (membrane vitamin A/retinol receptor)Nuclear retinoid receptor

Ligand-activated transcriptional modulation (RAR and RXR bind DNA at retinoic acid response elements, recruit coactivators/corepressors, and regulate gene expression) For STRA6: facilitation of retinol uptake from retinol-binding protein and initiation of JAK/STAT signaling