Cooperative binding of c-Myb and Pax-5 activates the RAG-2 promoter in immature B cells

Blood. 2002 Jan 15;99(2):576-83. doi: 10.1182/blood.v99.2.576.

Abstract

The recombination activating gene-1 (RAG-1) and RAG-2 are expressed specifically in immature lymphoid cells undergoing the recombination of antigen receptor genes. The regulation of murine RAG-2 promoter was studied and it was revealed that the -41/-17 RAG-2 promoter region, which is conserved between humans and mice, was indispensable for the RAG-2 promoter activity in B-cell lines. The region contained 2 cis elements that bound c-Myb and Pax-5. Mutation in the c-Myb-binding site in the promoter reduced the promoter activity in B-cell lines. Cooperative activation of the RAG-2 promoter was seen by a combination of c-Myb and Pax-5 in a human embryonic kidney cell line (293T), via their synergistic DNA-binding. Deletion experiments showed that the C-terminus of c-Myb was responsible for their interaction. Furthermore, the dominant-negative c-Myb mutant suppressed the activation of the RAG-2 promoter in a pre-B-cell line as well as in 293T cells. These results suggest that cooperative binding of c-Myb and Pax-5 to the RAG-2 promoter is one of the mechanisms to direct the restricted expression of the RAG-2 in immature B cells.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocyte Subsets / cytology*
  • B-Lymphocyte Subsets / metabolism
  • Binding Sites
  • Cell Line
  • DNA / metabolism
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / physiology*
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / physiology*
  • Gene Targeting
  • Genes, Dominant
  • Genes, myb
  • Humans
  • Kidney
  • Macromolecular Substances
  • Mice
  • Nuclear Proteins
  • PAX5 Transcription Factor
  • Promoter Regions, Genetic*
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins c-myb / chemistry
  • Proto-Oncogene Proteins c-myb / physiology*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / physiology
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Structure-Activity Relationship
  • Transcription Factors / chemistry
  • Transcription Factors / physiology*
  • Transcription, Genetic
  • Transfection

Substances

  • DNA-Binding Proteins
  • Macromolecular Substances
  • Nuclear Proteins
  • PAX5 Transcription Factor
  • PAX5 protein, human
  • Pax5 protein, mouse
  • Proto-Oncogene Proteins c-myb
  • RAG2 protein, human
  • Rag2 protein, mouse
  • Recombinant Fusion Proteins
  • Transcription Factors
  • V(D)J recombination activating protein 2
  • DNA