Identification of the nuclear receptor CAR:HSP90 complex in mouse liver and recruitment of protein phosphatase 2A in response to phenobarbital

FEBS Lett. 2003 Jul 31;548(1-3):17-20. doi: 10.1016/s0014-5793(03)00720-8.


The nuclear receptor CAR, a phenobarbital (PB)-responsive transcription factor, translocates into the nucleus of hepatocytes after PB induction. In non-induced mice, CAR forms a physical complex with heat shock protein 90 (HSP90) in the cytoplasm. In response to PB induction, protein phosphatase 2A is recruited to the CAR:HSP90 complex. This recruitment may lead CAR to translocate into the nucleus, consistent with the inhibitions of nuclear CAR accumulation in PB-induced mouse primary hepatocytes by okadaic acid as well as by geldanamycin.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Active Transport, Cell Nucleus / physiology
  • Animals
  • Constitutive Androstane Receptor
  • Cytosol / chemistry
  • HSP90 Heat-Shock Proteins / metabolism*
  • Hepatocytes / chemistry
  • Hepatocytes / ultrastructure
  • Liver / chemistry*
  • Liver / cytology
  • Mice
  • Mice, Inbred Strains
  • Phenobarbital / pharmacology*
  • Phosphoprotein Phosphatases / metabolism*
  • Protein Phosphatase 2
  • Protein Transport / physiology
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Transcription Factors / metabolism*
  • Transcriptional Activation


  • Constitutive Androstane Receptor
  • HSP90 Heat-Shock Proteins
  • Receptors, Cytoplasmic and Nuclear
  • Transcription Factors
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 2
  • Phenobarbital