Is 9-Cis-Retinoic Acid the Endogenous Ligand for the Retinoic Acid-X Receptor?
2006; Oxford University Press; Volume: 64; Issue: 12 Linguagem: Inglês
10.1111/j.1753-4887.2006.tb00186.x
ISSN1753-4887
Autores Tópico(s)Antioxidant Activity and Oxidative Stress
Resumospecific proteins in the nucleus act as transcription factors upon activation through binding of small molecules (all-trans-retinoic acid, thyroid hormone, vitamin D, and others). The activated (liganded) receptors bind to specific DNA elements as heterodimers, each in combination with the retinoic acid-X receptor (RXR). 9-Cis-retinoic acid binds to RXR with high affinity and activates it. Though 9-cis-retinoic acid was initially found in animal tissues, in later work 9-cis-retinoic acid could not be detected. A search for a ligand for RXR in tissues showed that unsaturated fatty acids, particularly linoleic, linolenic, and docosahexaenoic acids, bound to and activated RXR as specific ligands, although with low affinity. A critical experiment demonstrated that, at least in developing mouse skin, 9-cis-retinoic acid is not the ligand for RXR
Referência(s)