Identification of activating transcription factor 4 (ATF4) as an Nrf2-interacting protein. Implication for heme oxygenase-1 gene regulation

J Biol Chem. 2001 Jun 15;276(24):20858-65. doi: 10.1074/jbc.M101198200. Epub 2001 Mar 26.

Abstract

Nrf2 regulates expression of genes encoding enzymes with antioxidant (e.g. heme oxygenase-1 (HO-1)) or xenobiotic detoxification (e.g. NAD(P)H:quinone oxidoreductase, glutathione S-transferase) functions via the stress- or antioxidant-response elements (StRE/ARE). Nrf2 heterodimerizes with small Maf proteins, but the role of such dimers in gene induction is controversial, and other partners may exist. By using the yeast two-hybrid assay, we identified activating transcription factor (ATF) 4 as a potential Nrf2-interacting protein. Association between Nrf2 and ATF4 in mammalian cells was confirmed by co-immunoprecipitation and mammalian two-hybrid assays. Furthermore, Nrf2.ATF4 dimers bound to an StRE sequence from the ho-1 gene. CdCl(2), a potent inducer of HO-1, increased expression of ATF4 in mouse hepatoma cells, and detectable induction of ATF4 protein preceded that of HO-1 (30 min versus 2 h). A dominant-negative mutant of ATF4 inhibited basal and CdCl(2)-stimulated expression of a StRE-dependent/luciferase fusion construct (pE1-luc) in hepatoma cells but only basal expression in mammary epithelial MCF-7 cells. A dominant mutant of Nrf2 was equally inhibitory in both cell types in the presence or absence of CdCl(2). These results indicate that ATF4 regulates basal and CdCl(2)-induced expression of the ho-1 gene in a cell-specific manner and possibly in a complex with Nrf2.

Publication types

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

MeSH terms

  • Activating Transcription Factor 3
  • Activating Transcription Factor 4
  • Amino Acid Sequence
  • Animals
  • Breast
  • Cadmium Chloride / pharmacology
  • Cell Line
  • Cloning, Molecular
  • Conserved Sequence
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Dimerization
  • Epithelial Cells
  • Female
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation, Enzymologic*
  • Genes, Reporter
  • Heme Oxygenase (Decyclizing) / genetics*
  • Heme Oxygenase-1
  • Humans
  • Leucine Zippers
  • Liver Neoplasms, Experimental
  • Membrane Proteins
  • Mice
  • Molecular Sequence Data
  • NF-E2-Related Factor 2
  • Rats
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Trans-Activators / chemistry
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Transcription Factors / chemistry
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism*
  • Transcriptional Activation
  • Transfection
  • Tumor Cells, Cultured

Substances

  • ATF4 protein, human
  • Activating Transcription Factor 3
  • Atf3 protein, rat
  • Atf4 protein, rat
  • DNA-Binding Proteins
  • Membrane Proteins
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Nfe2l2 protein, mouse
  • Nfe2l2 protein, rat
  • Recombinant Proteins
  • Trans-Activators
  • Transcription Factors
  • Activating Transcription Factor 4
  • HMOX1 protein, human
  • Heme Oxygenase (Decyclizing)
  • Heme Oxygenase-1
  • Hmox1 protein, mouse
  • Cadmium Chloride