The retinoid X receptor (RXR)[1] is a type of nuclear receptor that is activated by 9-cis retinoic acid, which is discussed controversially to be of endogenous relevance,[2][3] and 9-cis-13,14-dihydro-retinoic acid, which is likely to be the major endogenous mammalian RXR-selective agonist.[4] There are three retinoic X receptors (RXR): RXR-alpha, RXR-beta, and RXR-gamma, encoded by the RXRA, RXRB, RXRG genes, respectively.

RXR heterodimerizes with subfamily 1 nuclear receptors including CAR, FXR, LXR, PPAR,[5] PXR, RAR, TR, and VDR.

As with other type II nuclear receptors, the RXR heterodimer in the absence of ligand is bound to hormone response elements complexed with corepressor protein. Binding of agonist ligands to RXR results in dissociation of corepressor and recruitment of coactivator protein, which, in turn, promotes transcription of the downstream target gene into mRNA and eventually protein.

See also


  1. ^ Germain P, Chambon P, Eichele G, Evans RM, Lazar MA, Leid M, De Lera AR, Lotan R, Mangelsdorf DJ, Gronemeyer H (2006). "International Union of Pharmacology. LXIII. Retinoid X receptors". Pharmacol Rev. 58 (4): 760–72. doi:10.1124/pr.58.4.7. PMID 17132853. 
  2. ^ de Lera AR, Krezel W, Rühl R (2016). "An Endogenous Mammalian Retinoid X Receptor Ligand, At Last!". ChemMedChem. 11: 1–12. doi:10.1002/cmdc.201600105. PMID 27151148. 
  3. ^ Allenby G, Bocquel MT, Saunders M, Kazmer S, Speck J, Rosenberger M, Lovey A, Kastner P, Grippo JF, Chambon P, Levin AA (1993). "Retinoic acid receptors and retinoid X receptors: interactions with endogenous retinoic acids". Proc Natl Acad Sci USA. 90 (1): 30–4. doi:10.1073/pnas.90.1.30. PMC 45593Freely accessible. PMID 8380496. 
  4. ^ Rühl R, Krzyżosiak A, Niewiadomska-Cimicka A, Rochel N, Szeles L, Vaz B, Wietrzych-Schindler M, Álvarez S, Szklenar M, Nagy L, de Lera AR, Krężel W (2015). "9-cis-13,14-Dihydroretinoic Acid Is an Endogenous Retinoid Acting as RXR Ligand in Mice". PLOS Genetics. 11 (6): e1005213. doi:10.1371/journal.pgen.1005213. PMC 4451509Freely accessible. PMID 26030625. 
  5. ^ Plutzky J (April 2011). "The PPAR-RXR transcriptional complex in the vasculature: energy in the balance". Circ. Res. 108 (8): 1002–16. doi:10.1161/CIRCRESAHA.110.226860. PMID 21493923. 

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