Epigenetic deregulation of the LMP1/LMP2 locus of Epstein-Barr virus by mutation of a single CTCF-cohesin binding site

J Virol. 2014 Feb;88(3):1703-13. doi: 10.1128/JVI.02209-13. Epub 2013 Nov 20.

Abstract

The chromatin regulatory factors CTCF and cohesin have been implicated in the coordinated control of multiple gene loci in Epstein-Barr virus (EBV) latency. We have found that CTCF and cohesin are highly enriched at the convergent and partially overlapping transcripts for the LMP1 and LMP2A genes, but it is not yet known how CTCF and cohesin may coordinately regulate these transcripts. We now show that genetic disruption of this CTCF binding site (EBVΔCTCF166) leads to a deregulation of LMP1, LMP2A, and LMP2B transcription in EBV-immortalized B lymphocytes. EBVΔCTCF166 virus-immortalized primary B lymphocytes showed a decrease in LMP1 and LMP2A mRNA and a corresponding increase in LMP2B mRNA. The reduction of LMP1 and LMP2A correlated with a loss of euchromatic histone modification H3K9ac and a corresponding increase in heterochromatic histone modification H3K9me3 at the LMP2A promoter region in EBVΔCTCF166. Chromosome conformation capture (3C) revealed that DNA loop formation with the origin of plasmid replication (OriP) enhancer was eliminated in EBVΔCTCF166. We also observed that the EBV episome copy number was elevated in EBVΔCTCF166 and that this was not due to increased lytic cycle activity. These findings suggest that a single CTCF binding site controls LMP2A and LMP1 promoter selection, chromatin boundary function, DNA loop formation, and episome copy number control during EBV latency.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Binding Sites
  • CCCTC-Binding Factor
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Epigenesis, Genetic*
  • Epstein-Barr Virus Infections / genetics
  • Epstein-Barr Virus Infections / metabolism*
  • Epstein-Barr Virus Infections / virology
  • Gene Expression Regulation, Viral
  • Herpesvirus 4, Human / chemistry
  • Herpesvirus 4, Human / genetics*
  • Herpesvirus 4, Human / physiology
  • Histones / genetics
  • Histones / metabolism
  • Humans
  • Mutation*
  • Promoter Regions, Genetic
  • Protein Binding
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Viral Matrix Proteins / chemistry
  • Viral Matrix Proteins / genetics*
  • Viral Matrix Proteins / metabolism
  • Virus Latency

Substances

  • CCCTC-Binding Factor
  • CTCF protein, human
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • EBV-associated membrane antigen, Epstein-Barr virus
  • Histones
  • Repressor Proteins
  • Viral Matrix Proteins
  • cohesins