Cooperative binding of c-Myb and Pax-5 activates the RAG-2 promoter in immature B cells.
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.
Kishi
Hiroyuki
H
Department of Immunology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Sugitani, Toyama, Japan.
Jin
Zhe-Xiong
ZX
Wei
Xing-Cheng
XC
Nagata
Takuya
T
Matsuda
Tadashi
T
Saito
Shigeru
S
Muraguchi
Atsushi
A
D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000378:metabolism; D001665:Binding Sites; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D018390:Gene Targeting; D005799:Genes, Dominant; D020570:Genes, myb; D006801:Humans; D007668:Kidney; D046911:Macromolecular Substances; D051379:Mice; D009687:Nuclear Proteins; D051757:PAX5 Transcription Factor; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D020598:Proto-Oncogene Proteins c-myb / Q000737:chemistry / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000502:physiology; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human; C497282:Pax5 protein, mouse; D020598:Proto-Oncogene Proteins c-myb; C499311:RAG2 protein, human; C499308:Rag2 protein, mouse; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C064655:V(D)J recombination activating protein 2; D004247:DNA