Retinoic acid receptor (RAR) / Retinoid X receptor (RXR) signaling pathway (RAR/RXR pathway)

The Retinoic acid pathway refers to the metabolic and signaling system centered around retinoic acid, a metabolite of vitamin A that acts primarily through nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs). These receptors function as ligand-inducible transcription factors, forming heterodimers that bind to retinoic acid response elements (RAREs) in DNA and regulate the expression of genes critical for cell differentiation, proliferation, apoptosis, development (embryogenesis and organogenesis), immune function, and vision. Retinoic acid signaling is tightly regulated by enzymes controlling its synthesis and degradation, as well as by intracellular binding proteins (e.g., CRBP, CRABP). Dysregulation of this pathway is implicated in several diseases, including multiple cancers (notably acute promyelocytic leukemia), congenital malformations, and vision dysfunction. Retinoic acid and synthetic retinoids are approved or investigational drugs for treating cancers and dermatological disorders, but their use is limited by notable toxicities and resistance mechanisms. For pharmaceutical or translational use, the actionable molecular targets within the "retinoic acid pathway" are the retinoic acid receptors (RARα, RARβ, RARγ) and retinoid X receptors (RXRα, RXRβ, RXRγ), rather than the pathway as a whole. If a specific receptor or enzyme within this pathway is of interest, that should be specified for structured data extraction.

Other names

Retinoid pathwayRA signaling pathwayretinoic acid signalingretinoid signaling

Ligand binding to RARs/RXRs induces conformational changes, modulating gene transcription of target genes controlling differentiation, proliferation, and apoptosis. RAR/RXR agonists drive differentiation and cell cycle arrest, particularly in certain cancers such as acute promyelocytic leukemia (APL).