Sequence-specific methylation inhibits the activity of the Epstein-Barr virus LMP 1 and BCR2 enhancer-promoter regions

Virology. 1994 May 1;200(2):661-7. doi: 10.1006/viro.1994.1229.


We reported earlier that variable expression of the Epstein-Barr virus (EBV) encoded membrane protein LMP 1 in nasopharyngeal carcinoma and the host-cell-phenotype-dependent activity of the BCR2 promoter (one of the possible initiator sites for transcripts of Epstein-Barr nuclear antigens) in Burkitt's lymphoma (BL) lines can be related to the methylation status of the 5'-flanking regulatory regions of the BNLF 1 and BCR2 promoter, respectively. Here we report that clones of the BL line Mutu that differ in expression of LMP 1 also show a differential methylation pattern of the LMP 1 regulatory sequences: this region is hypomethylated in an LMP 1 expressing (group III) clone but methylated in a group I clone that does not express LMP 1. We introduced in vitro methylated reporter plasmids carrying BNLF 1 and BCR2 enhancer-promoter sequences into the BL line Raji and found that overall methylation of 5'-CG-3' sequences by the Spiroplasma methylase Sssl significantly reduced their activity compared to unmethylated or mock-methylated controls. Methylation of 5-CCGG-3' sequences by Hpall methyltransferase gave similar results. On the contrary, methylation of 5'GCGC-3' sequences by Hhall methyltransferase gave similar results. On the contrary, methylation of 5'-GCGC-3' sequences by Hpal methyltransferase resulted only in a moderate reduction of BNLF 1 enhancer-promoter activity. These data support the notion that methylation at discrete sites within control regions of latent, growth-transformation associated EBV genes may contribute to silencing their expression.

Publication types

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

MeSH terms

  • Burkitt Lymphoma / genetics*
  • DNA Modification Methylases / metabolism*
  • Enhancer Elements, Genetic / genetics
  • Herpesvirus 4, Human / genetics*
  • Humans
  • Methylation
  • Oncogene Proteins, Viral / genetics*
  • Promoter Regions, Genetic / genetics
  • Regulatory Sequences, Nucleic Acid / genetics*
  • Structure-Activity Relationship
  • Transfection
  • Tumor Cells, Cultured
  • Viral Matrix Proteins / genetics*
  • Viral Proteins / genetics*


  • EBV-associated membrane antigen, Epstein-Barr virus
  • Oncogene Proteins, Viral
  • Viral Matrix Proteins
  • Viral Proteins
  • DNA Modification Methylases