Epstein-Barr virus nuclear antigen 3A protein regulates CDKN2B transcription via interaction with MIZ-1

Nucleic Acids Res. 2014 Sep;42(15):9700-16. doi: 10.1093/nar/gku697. Epub 2014 Aug 4.

Abstract

The Epstein-Barr virus (EBV) nuclear antigen 3 family of protein is critical for the EBV-induced primary B-cell growth transformation process. Using a yeast two-hybrid screen we identified 22 novel cellular partners of the EBNA3s. Most importantly, among the newly identified partners, five are known to play direct and important roles in transcriptional regulation. Of these, the Myc-interacting zinc finger protein-1 (MIZ-1) is a transcription factor initially characterized as a binding partner of MYC. MIZ-1 activates the transcription of a number of target genes including the cell cycle inhibitor CDKN2B. Focusing on the EBNA3A/MIZ-1 interaction we demonstrate that binding occurs in EBV-infected cells expressing both proteins at endogenous physiological levels and that in the presence of EBNA3A, a significant fraction of MIZ-1 translocates from the cytoplasm to the nucleus. Moreover, we show that a trimeric complex composed of a MIZ-1 recognition DNA element, MIZ-1 and EBNA3A can be formed, and that interaction of MIZ-1 with nucleophosmin (NPM), one of its coactivator, is prevented by EBNA3A. Finally, we show that, in the presence of EBNA3A, expression of the MIZ-1 target gene, CDKN2B, is downregulated and repressive H3K27 marks are established on its promoter region suggesting that EBNA3A directly counteracts the growth inhibitory action of MIZ-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / metabolism
  • Cell Nucleus / metabolism
  • Cyclin-Dependent Kinase Inhibitor p15 / biosynthesis
  • Cyclin-Dependent Kinase Inhibitor p15 / genetics*
  • DNA-Binding Proteins / metabolism
  • Down-Regulation
  • Epstein-Barr Virus Nuclear Antigens / chemistry
  • Epstein-Barr Virus Nuclear Antigens / metabolism*
  • Gene Expression Regulation*
  • HEK293 Cells
  • HeLa Cells
  • Histones / metabolism
  • Humans
  • Kruppel-Like Transcription Factors / chemistry
  • Kruppel-Like Transcription Factors / metabolism*
  • Nuclear Proteins / metabolism
  • Nucleophosmin
  • Promoter Regions, Genetic
  • Protein Interaction Domains and Motifs
  • Proto-Oncogene Proteins c-myc / metabolism
  • Repressor Proteins / chemistry
  • Repressor Proteins / metabolism*
  • Transcription, Genetic*

Substances

  • Cyclin-Dependent Kinase Inhibitor p15
  • DNA-Binding Proteins
  • EBNA-3A antigen
  • EBNA-3B antigen
  • Epstein-Barr Virus Nuclear Antigens
  • Histones
  • Kruppel-Like Transcription Factors
  • NPM1 protein, human
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-myc
  • Repressor Proteins
  • ZBTB17 protein, human
  • Nucleophosmin
  • Alcohol Oxidoreductases
  • C-terminal binding protein