A transcriptional regulatory element in the coding sequence of the human Bcl-2 gene

Immunology. 2005 Jan;114(1):25-36. doi: 10.1111/j.1365-2567.2004.02073.x.


We investigated the protein-binding sites in a DNAse I hypersensitive site associated with bcl-2 gene expression in human B cells. We mapped this hypersensitive site to the coding sequence of exon 2 of the bcl-2 gene in the bcl-2-expressing REH B-cell line. Electrophoretic mobility shift assays (EMSAs) with extracts from REH cells revealed three previously unrecognized B-Myb-binding sites in this sequence. The protein was identified as B-Myb by using a specific antibody and EMSAs. Accordingly, the levels of B-Myb and bcl-2 proteins, and of Myb EMSA activity, were correlated over a wide range of cell lines, representing different stages of B-cell development. Transfection of REH cells with antisense B-myb down-regulated EMSA activity and the level of bcl-2, and led to the apoptosis of REH cells. Transfection of the bcl-2-non-expressing RPMI 8226 cell line with a B-Myb expression vector induced B-Myb EMSA activity and the expression of bcl-2. Reporter assays indicated that the HSS8 sequence containing the three B-Myb sites may act as an enhancer when it is linked to the bcl-2 gene promoter. Interaction of B-Myb with HSS8 may enhance bcl-2 gene expression by co-operating with positive regulatory elements (e.g. previously identified B-Myb response elements) or silencing negative response elements in the bcl-2 gene promoter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Apoptosis / immunology
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • Base Sequence
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Deoxyribonuclease I / genetics
  • Electrophoretic Mobility Shift Assay
  • Enhancer Elements, Genetic / immunology*
  • Gene Expression Regulation
  • Genes, Regulator
  • Genes, bcl-2*
  • Humans
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides, Antisense
  • Palatine Tonsil / immunology
  • Protein Binding
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Proto-Oncogene Proteins c-myb / physiology
  • Transcription, Genetic*
  • Transfection
  • Tumor Cells, Cultured
  • Up-Regulation


  • Oligodeoxyribonucleotides, Antisense
  • Proto-Oncogene Proteins c-bcl-2
  • Proto-Oncogene Proteins c-myb
  • Deoxyribonuclease I