Biochem/physiol Actions
The nuclear pregnane X receptor (PXR; NR1I2) is an important component of the body′s adaptive defense mechanism against toxic substances including foreign chemicals (xenobiotics). PXR is activated by a large number of endogenous and exogenous chemicals including steroids, antibiotics, antimycotics, bile acids, and the herbal antidepressant St. John′s wort. PXR is known to regulate the expression of several additional genes encoding proteins involved in xenobiotic metabolism, including multidrug resistance protein 1 (MDR1) (8,9), multidrug resistance-associated protein 2 (MRP2) (10,11), and organic anion transporter polypeptide 2. Elucidation of the three-dimensional structure of the PXR ligand binding domain revealed that it has a large, spherical ligand binding cavity that allows it to interact with a wide range of hydrophobic chemicals. Thus, unlike other nuclear receptors that interact selectively with their physiological ligands, PXR serves as a generalized sensor of hydrophobic toxins. PXR binds as a heterodimer with the 9-cis retinoic acid receptor (NR2B) to DNA response elements in the regulatory regions of cytochrome P450 3A monooxygenase genes and a number of other genes involved in the metabolism and elimination of xenobiotics from the body.
Physical form
Clear and colorless frozen liquid solution
Preparation Note
Use a manual defrost freezer and avoid repeated freeze-thaw cycles. While working, please keep sample on ice.
| biological source | human |
| recombinant | expressed in E. coli |
| assay | ≥85% (SDS-PAGE) |
| form | frozen liquid |
| mol wt | ~35 kDa |
| packaging | pkg of 10 μg |
| storage condition | avoid repeated freeze/thaw cycles |
| concentration | 700 μg/mL |
| color | clear colorless |
| NCBI accession no. | NM_003889 |
| UniProt accession no. | O75469 |
| shipped in | dry ice |
| storage temp. | −70°C |
| Gene Information | human ... NR1I2(8856) |
