Early B-Cell Factor, E2A, and Pax-5 Cooperate To Activate the Early B Cell-Specific mb-1 Promoter
AUTOR(ES)
Sigvardsson, Mikael
FONTE
American Society for Microbiology
RESUMO
Previous studies have suggested that the early-B-cell-specific mb-1(Igα) promoter is regulated by EBF and Pax-5. Here, we used in vivo footprinting assays to detect occupation of binding sites in endogenous mb-1 promoters at various stages of B-cell differentiation. In addition to EBF and Pax-5 binding sites, we detected occupancy of a consensus binding site for E2A proteins (E box) in pre-B cells. EBF and E box sites are crucial for promoter function in transfected pre-B cells, and EBF and E2A proteins synergistically activated the promoter in transfected HeLa cells. Other data suggest that EBF and E box sites are less important for promoter function at later stages of differentiation, whereas binding sites for Pax-5 (and its Ets ternary complex partners) are required for promoter function in all mb-1-expressing cells. Using DNA microarrays, we found that expression of endogenous mb-1 transcripts correlates most closely with EBF expression and negatively with Id1, an inhibitor of E2A protein function, further linking regulation of the mb-1 gene with EBF and E2A. Together, our studies demonstrate the complexity of factors regulating tissue-specific transcription and support the concept that EBF, E2A, and Pax-5 cooperate to activate target genes in early B-cell development.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139876Documentos Relacionados
- Activation of the Early B-Cell-Specific mb-1 (Ig-α) Gene by Pax-5 Is Dependent on an Unmethylated Ets Binding Site
- The Epstein-Barr Virus Promoter Initiating B-Cell Transformation Is Activated by RFX Proteins and the B-Cell-Specific Activator Protein BSAP/Pax5
- A novel lineage-specific nuclear factor regulates mb-1 gene transcription at the early stages of B cell differentiation.
- Overlapping Expression of Early B-Cell Factor and Basic Helix-Loop-Helix Proteins as a Mechanism To Dictate B-Lineage-Specific Activity of the λ5 Promoter
- Characterization and purification of Adh distal promoter factor 2, Adf-2, a cell-specific and promoter-specific repressor in Drosophila.