Is 9-cis-retinoic acid the endogenous ligand for the retinoic acid-X receptor?

摘要: Specific 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 heterodimers, each combination with retinoic acid-X receptor (RXR). 9-Cis-retinoic acid binds RXR high affinity activates it. Though 9-cis-retinoic was initially found animal tissues, later work could not be detected. A search for a ligand tissues showed that unsaturated fatty acids, particularly linoleic, linolenic, docosahexaenoic bound ligands, although low affinity. critical experiment demonstrated that, at least developing mouse skin, is RXR.