Combinatorial regulation of the murine RAG-2 promoter by Sp1 and distinct lymphocyte-specific transcription factors.
The recombination activation genes, RAG-1 and RAG-2, encode the critical components of the recombinase complex responsible for the generation of functional antigen receptor genes. In order to gain an insight into the transcription factors and cis-acting elements that regulate the lymphocyte-specific expression of RAG-2, the promoter-region of this gene was isolated and characterized. This analysis demonstrated that a relatively small promoter fragment could confer lymphocyte-restricted expression to a reporter construct. Our work and that of others subsequently revealed that RAG-2 promoter expression is positively regulated by BSAP (PAX-5) and c-Myb transcription factors in B- and T-lineage cells, respectively. Although BSAP and c-Myb were deemed necessary for lymphocyte-specific expression, our analysis also uncovered a G-rich region at the 5'-end of the core promoter that was essential for full activity in lymphocyte cell lines. Site-directed mutagenesis revealed that a GA-box within the G-rich region was required for full promoter activity and subsequent DNA binding assays demonstrated that this element was specifically recognized by Sp1. Apart from showing that Sp1 interacts within the RAG-2 promoter, we also demonstrate that the Sp1-binding site is necessary for the high-level activation of this promoter.
Miranda
Gustavo A
GA
Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles 405 Hilgard Ave, Los Angeles, CA 90095-1606, USA.
Villalvazo
Maria
M
Galic
Zoran
Z
Alva
Jackelyn
J
Abrines
Roxanna
R
Yates
Yvette
Y
Evans
Cory J
CJ
Aguilera
Renato J
RJ
D000818:Animals; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D016297:Mutagenesis, Site-Directed; D051757:PAX5 Transcription Factor; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D051757:PAX5 Transcription Factor; C497282:Pax5 protein, mouse; C499308:Rag2 protein, mouse; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; C064655:V(D)J recombination activating protein 2; D051705:Sp3 Transcription Factor