Pregnane-X Receptor (PXR)

Pregnane-X Receptors (PXRs) are found in the liver and gut. They help protect the body from harmful substances by increasing the production of Drug transporters and enzymes that break down drugs, specifically those in the cytochrome P450 family. These receptors are usually active on their own, but certain foreign substances can make them even more active. PXR is activated by many different pregnenolone derivatives, which are natural precursors for all steroid hormones. One example is 5beta-pregnane-3,20-dione. PXRs have a large space for binding and can attach to a wide variety of substances, including antibiotics, antipsychotics, and bile acids.
Kliewer et al. 1998 Cell 92: 73-82
Moore et al. 2000 J Biol Chem 275: 15122-15127

Pregnane-X Receptor (PXR) is responsible for endogenous and xenobiotic drug detoxification and elimination
Wang et al. 2012a Expert Opin. Drug Metab. Toxicol. 8: 803-817

Dimer: NR1/2/RXR