Functional and structural comparison of PXR and CAR

Biochim Biophys Acta. 2003 Feb 17;1619(3):235-8. doi: 10.1016/s0304-4165(02)00481-6.


The nuclear receptors pregnane X receptor (PXR, NR1I2) and constitutive active receptor (CAR, NR1I3) have both been proposed to function as xenosensors, but the details of their respective physiological roles are still being elucidated. We have contrasted these two receptors in a variety of experiments including gene expression assays, cell-based ligand profiling assays, and crystallographic/structural modeling analyses. These data highlight key differences between PXR and CAR.

Publication types

  • Comparative Study
  • Review

MeSH terms

  • Animals
  • Constitutive Androstane Receptor
  • Gene Expression
  • Humans
  • Ligands
  • Models, Molecular
  • Pregnane X Receptor
  • Receptors, Cytoplasmic and Nuclear / chemistry*
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Receptors, Steroid / chemistry*
  • Receptors, Steroid / metabolism*
  • Transcription Factors / chemistry*
  • Transcription Factors / metabolism*


  • Constitutive Androstane Receptor
  • Ligands
  • NR1I2 protein, human
  • NR1I3 protein, human
  • Pregnane X Receptor
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Steroid
  • Transcription Factors