Distinct factors regulate the murine RAG-2 promoter in B- and T-cell lines.
Mol Cell Biol
; 19(4): 2601-12, 1999 Apr.
Article
in En
| MEDLINE
| ID: mdl-10082526
ABSTRACT
The recombination activating genes RAG-1 and RAG-2 are expressed in a lymphoid-cell-specific and developmentally regulated fashion. To understand the transcriptional basis for this regulation, we have cloned and characterized the murine RAG-2 promoter. The promoter was lymphoid cell specific, showing activity in various B- and T-cell lines but little activity in nonlymphoid cells. To our surprise, however, the promoter was regulated differently in B and T cells. Using nuclear extracts from B-cell lines, we found that the B-cell-specific transcription factor BSAP (Pax-5) could bind to a conserved sequence critical for promoter activity. BSAP activated the promoter in transfected cells, and the BSAP site was occupied in a tissue-specific manner in vivo. An overlapping DNA sequence binding to a distinct factor was necessary for promoter activity in T cells. Full promoter activity in T cells was also dependent on a more distal DNA sequence whose disruption had no effect on B-cell activity. The unexpected finding that a B-cell-specific factor regulates the RAG-2 promoter may explain some of the recently observed differences in the regulation of RAG transcription between B and T cells.
Full text:
1
Database:
MEDLINE
Main subject:
Transcription Factors
/
B-Lymphocytes
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T-Lymphocytes
/
Promoter Regions, Genetic
/
DNA-Binding Proteins
Limits:
Animals
Language:
En
Year:
1999
Type:
Article