Marsolier M C, Chaussivert N, Lefebvre O, Conesa C, Werner M, Sentenac A
Service de Biochimie et de Génétique Moléculaire, Commissariat à l'Energie Atomique, Saclay, Gif-sur-Yvette, France.
Proc Natl Acad Sci U S A. 1994 Dec 6;91(25):11938-42. doi: 10.1073/pnas.91.25.11938.
A yeast chimeric RNA polymerase III transcription system was constructed to explore the ordered, multistep process of gene activation in vivo. A promoter-deficient U6 RNA gene harboring GAL4-binding sites could be reactivated by fusing the GAL4 DNA-binding domain to components of the general transcription factor TFIIIC (tau) or TFIIIB. Expression of chimeric tau 138 or tau 131 (but not tau 95) subunits activated transcription from GAL4-binding sites located at various positions, including upstream of or within the gene. The function(s) of the B block binding domain of TFIIIC was provided by the fused GAL4-(1-147) domain. The GAL4-(1-147)-TFIIIB70 fusion protein acted at a distance like an activator of transcription. In contrast, none of the 10 different GAL4-(1-147)-polymerase subunit fusions was able to induce transcription, suggesting that RNA polymerase recruitment is not sufficient to initiate transcription.
构建了一种酵母嵌合RNA聚合酶III转录系统，以探索体内基因激活的有序多步骤过程。携带GAL4结合位点的启动子缺陷型U6 RNA基因可通过将GAL4 DNA结合结构域与通用转录因子TFIIIC（tau）或TFIIIB的组分融合而重新激活。嵌合tau 138或tau 131（而非tau 95）亚基的表达激活了位于不同位置（包括基因上游或基因内）的GAL4结合位点的转录。TFIIIC的B块结合结构域的功能由融合的GAL4-(1-147)结构域提供。GAL4-(1-147)-TFIIIB70融合蛋白像转录激活剂一样在一定距离外起作用。相比之下，10种不同的GAL4-(1-147)-聚合酶亚基融合物均不能诱导转录，这表明RNA聚合酶的募集不足以启动转录。
