Bi Y M, Rothstein S J, Wildeman A G
Department of Molecular Biology and Genetics, University of Guelph, Ontario, Canada N1G 2W1.
Gene. 2001 Nov 28;279(2):175-9. doi: 10.1016/s0378-1119(01)00742-9.
The tetracycline (Tet) transactivator system is a powerful promoter system to control gene expression. However, expression of a cytotoxic gene in this system has been limited due to the lethal effect caused by low levels of basal expression of the toxic gene. In this report, we describe a novel strategy to express a toxic gene using the Tet system. The barstar gene is placed downstream of a minimal promoter and the barnase gene downstream of the tetracycline responsive element minimal promoter. When barnase is expressed at a basal level, its toxicity in human cell culture is offset by the similar basal level expression of barstar. However, when the barnase expression is induced with the transactivator protein, its overproduction leads to cell death. Therefore, this strategy allows cytotoxicity to be effectively regulated by tetracycline.
四环素（Tet）反式激活系统是一种用于控制基因表达的强大启动子系统。然而，由于毒性基因的低水平基础表达所导致的致死效应，该系统中细胞毒性基因的表达受到了限制。在本报告中，我们描述了一种使用Tet系统表达毒性基因的新策略。将barstar基因置于最小启动子的下游，而将barnase基因置于四环素反应元件最小启动子的下游。当barnase以基础水平表达时，其在人细胞培养中的毒性会被barstar相似的基础水平表达所抵消。然而，当用反式激活蛋白诱导barnase表达时，其过量产生会导致细胞死亡。因此，该策略能够通过四环素有效地调节细胞毒性。
