4S polycyclic aromatic hydrocarbon receptor (glycine N-methyltransferase) and the aryl hydrocarbon receptor nuclear translocator (hypoxia inducible factor-1β) interaction in Chinese hamster ovary and rat hepatoma cells: 4S PAH-R/ARNT hetero-oligomers?

J Cell Biochem. 2011 Aug;112(8):2015-8. doi: 10.1002/jcb.23120.

Abstract

Rat CYP1A1 promoter-luciferase, transiently transfected wild-type and 4S PAH receptor (glycine N-methyl transferase, GNMT)-transformed Chinese hamster ovary (CHO) cells were exposed to benzo[a]pyrene and assayed for luciferase activity as an indicator of CYP1A1 promoter activity. CHO cells transformed with the rat 4S PAH receptor/GNMT expression vector had twice the induction level of luciferase activity with respect to wild-type CHO cells in concert with previously published reports that the 4S PAH receptor/GNMT mediates benzo[a]pyrene induction of CYP1A1 gene expression. Lysates of GNMT-transformed CHO cells and wild-type H4IIE rat hepatoma cells exposed to benzo[a]pyrene were immuno-precipitated with anti-GNMT antibodies, separated by SDS-polyacrylamide gel electrophoresis and transferred to PVDF membrane for Western blot analysis with anti-aryl hydrocarbon receptor nuclear translocator (ARNT, HIF-1β) antibodies. Results of this analysis indicated that the 4S PAH receptor/GNMT forms a hetero-oligomer (dimer?) with ARNT/HIF-1β which dissociates in the presence of B[a]P. These observations further indicate the role of GNMT (which has been shown to be multifunctional) and B[a]P in the induction of CYP1A1 and also a potential role of GNMT in the modulation of hypoxia inducible factor-1 function with respect to the HIF-1β subunit (ARNT).

MeSH terms

  • Animals
  • Aryl Hydrocarbon Receptor Nuclear Translocator / genetics
  • Aryl Hydrocarbon Receptor Nuclear Translocator / metabolism*
  • Benzo(a)pyrene / pharmacology
  • CHO Cells
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Cell Line, Tumor
  • Cricetinae
  • Cricetulus
  • Cytochrome P-450 CYP1A1 / genetics
  • Cytochrome P-450 CYP1A1 / metabolism*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / genetics
  • Glycine N-Methyltransferase / genetics
  • Glycine N-Methyltransferase / metabolism*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Protein Multimerization*
  • Protein Structure, Quaternary
  • Rats

Substances

  • Neoplasm Proteins
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Benzo(a)pyrene
  • Cytochrome P-450 CYP1A1
  • Glycine N-Methyltransferase
  • Gnmt protein, rat