Concentration dependence of transcriptional transactivation in inducible E1A-containing human cells.
Concentration dependence of transcriptional transactivation in inducible E1A-containing human cells.
复制标题
含有 E1A 的诱导型人类细胞中转录反式激活的浓度依赖性。
DOI：
10.1128/mcb.8.11.4799-4807.1988
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发表时间：
1988
影响因子：
5.3
通讯作者：
Berk,AJ
中科院分区：
文献类型：
--
作者：
Brunet,LJ;Berk,AJ
腺病毒E1A蛋白对于从每个其它腺病毒早期启动子转录的正常时间激活是必需的。在没有病毒感染的情况下，E1A的高水平表达将有利于E1A介导的反式激活的生化研究。为此，我们将小鼠乳腺肿瘤病毒启动子控制下的腺病毒2型E1A基因导入HeLa细胞。未诱导的细胞表达很少或没有可检测的E1A mRNA。在诱导后，mRNA水平累积至293细胞中观察到的水平的约50%。E1A在这些细胞中的表达水平可以通过改变诱导糖皮质激素的浓度来控制。在这些不同E1A浓度的条件下，观察到H5dl312的E2、E3和E4启动子的激活在相同的E1A浓度下开始，并且随着E1A浓度的增加，来自每个启动子的转录增加。这些结果表明，E1A介导的反式激活与E1A蛋白的浓度成正比。E4启动子的E1A依赖性转录刺激在体外转录系统中再现，表明仅E1A蛋白的表达足以增加核提取物的转录活性。
The adenovirus E1A proteins are essential for the normal temporal activation of transcription from every other adenoviral early promoter. High-level E1A expression in the absence of viral infection would facilitate biochemical studies of E1A-mediated transactivation. Toward this end, we introduced the adenovirus type 2 E1A gene under the control of the murine mammary tumor virus promoter into HeLa cells. Uninduced cells expressed little or no detectable E1A mRNA. Upon induction, mRNA levels accumulated to about 50% of the level observed in 293 cells. The level of E1A expression in these cells could be controlled by varying the concentration of the inducing glucocorticoid. Under these conditions of varying E1A concentrations, it was observed that activation of the E2, E3, and E4 promoters of H5dl312 initiated at the same E1A concentration and that transcription from each promoter increased as the E1A concentration increased. These results indicate that E1A-mediated transactivation is proportional to the concentration of E1A protein. E1A-dependent transcriptional stimulation of the E4 promoter was reproduced in an in vitro transcription system, demonstrating that expression of only the E1A proteins was sufficient to increase the transcriptional activity of nuclear extracts.