FXR/NR1H4 Proteins and Enzymes

FXR and LXR fall into a category of proteins termed orphan receptors; because of their lack of a defined function, and in the case of LXR, the lack of a defined ligand. FXR has been shown to bind a class of lipid molecules called farnesoids. LXR/RXR heterodimers have highest affinity for DR-4 DNA elements while FXR/RXR heterodimers bind IR-1 elements. Both LXR/RXR and FXR/RXR heterodimers retain their responsiveness to 9-cis retinoic acid. The steroid receptor superfamily acts through direct ...