CBP/p300 Functions as a Possible Transcriptional Coactivator of Ah Receptor Nuclear Translocator (Arnt)

J Biochem. 1997 Oct;122(4):703-10. doi: 10.1093/oxfordjournals.jbchem.a021812.


A heterodimer of AhR (aryl hydrocarbon receptor) and Arnt (AhR nuclear translocator) conveys a transactivation signal of aromatic hydrocarbons such as 2,3,7,8-tetrachlorodibenzo-p-dioxin and 3-methylcholanthrene to the genes for a group of drug-metabolizing enzymes. This inducible expression of the genes is inhibited by adenovirus E1A, suggesting that CBP/p300 is somehow involved in the transactivation of the genes by the AhR and Arnt heterodimer. Yeast and mammalian two hybrid systems revealed that CBP/p300 interacted with the transactivation domain of Arnt, but not with that of AhR, via the CREB-binding domain. The pull down assay using GST-Arnt hybrid protein confirmed the interaction between Arnt and CBP/p300. Considering these results and that Arnt or Arnt2 functions as a common partner in the formation of transcriptional regulators with other bHLH/PAS proteins such as AhR, HLF, and HIF-1alpha, the possibility arises that CBP/p300 is extensively involved as a coactivator in the transactivation process by bHLH/PAS (a conserved sequence motif among Per, Arnt, and Sim) heterodimer transcription factors through interaction with Arnt or Arnt2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism*
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Histone Acetyltransferases
  • Plasmids
  • Receptors, Aryl Hydrocarbon / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Trans-Activators / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • p300-CBP Transcription Factors


  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Receptors, Aryl Hydrocarbon
  • Trans-Activators
  • Transcription Factors
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Acetyltransferases
  • Histone Acetyltransferases
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor