Transcriptional activation by a matrix associating region-binding protein. contextual requirements for the function of bright
| Autor: | M H, Kaplan, R T, Zong, R F, Herrscher, R H, Scheuermann, P W, Tucker |
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| Rok vydání: | 2001 |
| Předmět: |
Cell Nucleus
Chloramphenicol O-Acetyltransferase Transcriptional Activation B-Lymphocytes Binding Sites Transcription Genetic Restriction Mapping RNA-Binding Proteins Oncogenes Transfection Recombinant Proteins Cell Line Ribonucleoprotein U1 Small Nuclear DNA-Binding Proteins Trans-Activators Deoxyribonuclease I Drosophila Proteins Humans Immunoglobulin Heavy Chains Transcription Factors |
| Zdroj: | The Journal of biological chemistry. 276(24) |
| ISSN: | 0021-9258 |
| Popis: | Bright (B cell regulator of IgH transcription) is a B cell-specific, matrix associating region-binding protein that transactivates gene expression from the IgH intronic enhancer (E mu). We show here that Bright has multiple contextual requirements to function as a transcriptional activator. Bright cannot transactivate via out of context, concatenated binding sites. Transactivation is maximal on integrated substrates. Two of the three previously identified binding sites in E mu are required for full Bright transactivation. The Bright DNA binding domain defined a new family, which includes SWI1, a component of the SWI.SNF complex shown to have high mobility group-like DNA binding characteristics. Similar to one group of high mobility group box proteins, Bright distorts E mu binding site-containing DNA on binding, supporting the concept that it mediates E mu remodeling. Transfection studies further implicate Bright in facilitating spatially separated promoter-enhancer interactions in both transient and stable assays. Finally, we show that overexpression of Bright leads to enhanced DNase I sensitivity of the endogenous E mu matrix associating regions. These data further suggest that Bright may contribute to increased gene expression by remodeling the immunoglobulin locus during B cell development. |
| Databáze: | OpenAIRE |
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