ZNF667/Mipu1 is a novel anti-apoptotic factor that directly regulates the expression of the rat Bax gene in H9c2 cells

PLoS One. 2014 Nov 14;9(11):e111653. doi: 10.1371/journal.pone.0111653. eCollection 2014.

Abstract

ZNF667/Mipu1, a C2H2-type zinc finger transcription factor, was suggested to play an important role in oxidative stress. However, none of the target genes or potential roles of ZNF667 in cardiomyocytes have been elucidated. Here, we investigated the functional role of ZNF667 in H9c2 cell lines focusing on its molecular mechanism by which it protects the cells from apoptosis. We found that ZNF667 inhibited the expression and the promoter activity of the rat proapoptotic gene Bax gene, and at the same time prevented apoptosis of H9c2 cells, induced by H2O2 and Dox. Western immunoblotting analysis revealed that ZNF667 also inhibited Bax protein expression, accompanied by attenuation of the mitochondrial translocation of Bax protein, induced by H2O2. EMSA and target detection assay showed that the purified ZNF667 fusion proteins could interact with the Bax promoter sequence in vitro, and this interaction was dependent upon the ZNF667 DNA binding sequences or its core sequence in the promoter. Furthermore, ChIP assay demonstrated that a stimulus H2O2 could enhance the ability of ZNF667 protein binding to the promoter. Finally, a reporter gene assay showed that ZNF667 could repress the activity of the Bax gene promoter, and the repression was dependent upon its binding to the specific DNA sequence in the promoter. Our work demonstrates that ZNF667 that confers cytoprotection is a novel regulator of the rat Bax gene, mediating the inhibition of the Bax mRNA and protein expression in H9c2 cardiomyocytes in response to H2O2 treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis* / drug effects
  • Apoptosis* / genetics
  • Caspase 3 / metabolism
  • Cell Line
  • Doxorubicin / pharmacology
  • Enzyme Activation / drug effects
  • Gene Expression Regulation* / drug effects
  • Hydrogen Peroxide / pharmacology
  • Luciferases, Firefly / metabolism
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Nuclear Proteins / metabolism*
  • Promoter Regions, Genetic / genetics
  • Protein Binding / drug effects
  • Protein Transport / drug effects
  • Rats
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / metabolism*
  • bcl-2-Associated X Protein / genetics*
  • bcl-2-Associated X Protein / metabolism

Substances

  • Mipu1 protein, rat
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • bcl-2-Associated X Protein
  • Doxorubicin
  • Hydrogen Peroxide
  • Luciferases, Firefly
  • Caspase 3

Grants and funding

This work was supported by the Major National Basic Research Program of China (2007CB512007 for X.X.) and the National Natural Science Foundation of China (30971205 for L.J.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.