B-cell-specific DNA binding by an E47 homodimer.
AUTOR(ES)
Shen, C P
RESUMO
B cells express a unique E-box-binding activity that contains basic helix-loop-helix (bHLH) proteins encoded by the E2A gene. E2A proteins play a central role in immunoglobulin gene transcription and are also required for the generation of the B-lymphocyte lineage. In muscle, E2A proteins bind DNA as heterodimers with muscle-specific bHLH partners, such as MyoD and myogenin, and these heterodimers are thought to be both necessary and sufficient for muscle determination in cultured cells. Our results indicate that in B cells, the bHLH partners for E2A proteins are not B-cell-restricted proteins, but are the E2A proteins themselves. UV cross-linking, gel purification, and the analysis of "forced heterodimers" indicate that BCF1 is primarily a homodimer of the E2A protein E47. Since E47 is widely expressed, our results argue for a difference in the inherent DNA-binding properties of the E47 protein in B cells and may help explain the restricted B-lineage defect observed in E2A-deficient mice.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=230691Documentos Relacionados
- Phosphorylation of E47 as a potential determinant of B-cell-specific activity.
- Anatomy of a new B-cell-specific enhancer.
- E2A and E2-2 are subunits of B-cell-specific E2-box DNA-binding proteins.
- Transcription of HLA class II genes in the absence of B-cell-specific octamer-binding factor.
- Multiple motifs regulate the B-cell-specific promoter of the B29 gene.