Retinoic acid receptor

The retinoic acid receptor (RAR) is a type of nuclear receptor that is activated by both all-trans retinoic acid and 9-cis retinoic acid. There are three retinoic acid receptors (RAR), RAR-alpha, RAR-beta, and RAR-gamma, encoded by the, , genes, respectively. Each receptor isoform has several splice variants: two- for alpha, four- for beta, and two- for gamma.

As with other type II nuclear receptors, RAR heterodimerizes with RXR and in the absence of ligand, the RAR/RXR dimer binds to hormone response elements complexed with corepressor protein. Binding of agonist ligands to RAR results in dissociation of corepressor and recruitment of coactivator protein that, in turn, promotes transcription of the downstream target gene into mRNA and eventually protein.