Activation of Transcription in Vitro by the BRCA1 Carboxyl-terminal Domain

摘要: The breast and ovarian specific tumor suppressor protein, BRCA1, has been shown to be a transcription factor because its carboxyl terminus, when fused the GAL4 DNA binding domain, activates gene expression in cells. In this study, purified GAL4-BRCA1 protein functions transcriptional activation assays using minimal vitro system. When compared with standard activator, GAL4-VP16, levels of produced by BRCA1 fusion were stronger presence certain coactivators. is maximal PC4 (positive component 4) coactivator but not HMG2 (high mobility group 2) template negatively supercoiled. By contrast, VP16 was highest as well templates had linear topology. Activation largely unaffected concentration TFIIH, whereas strongly affected TFIIH concentrations. differing cofactor requirements suggest that GAL4-VP16 regulate different steps pathways lead activation.