IAC REPRESSOR CAN REGULATE EXPRESSION FROM A HYBRID-SV40 EARLY PROMOTER CONTAINING A LAC OPERATOR IN ANIMAL-CELLS
IAC REPRESSOR CAN REGULATE EXPRESSION FROM A HYBRID-SV40 EARLY PROMOTER CONTAINING A LAC OPERATOR IN ANIMAL-CELLS
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DOI：
10.1016/0092-8674(87)90536-8
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发表时间：
1987-06-05
期刊：
影响因子：
64.5
通讯作者：
ROBERTS, TM
中科院分区：
文献类型：
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作者：
BROWN, M;FIGGE, J;ROBERTS, TM
急诊大肠杆菌的lac操纵子和阻遏子适应于在哺乳动物细胞中的功能。检测了含有SV 40早期区（pSVIacO）或氯霉素乙酰转移酶基因（pSVlacOCAT）的质粒的功能，所述质粒与带有lac操纵子的杂合SV 40早期启动子连接。缺乏操纵子的相同质粒（pX-8和pX-8 CAT）为对照。在体外，从pSVlacO，但不是从pX-8，早期转录抑制乳糖阻遏物，抑制被克服了IPTG。抑制大T合成CAT活性发生在体内，只有当各自的操作员含有质粒与编码乳糖阻遏物的质粒共转染，或当受体细胞稳定合成乳糖阻遏物。IPTG在这两种情况下基本上缓解了阻遏。CAT酶的抑制被CAT mRNA丰度的降低所抵消。因此，乳糖操纵子的调节元件在哺乳动物细胞中发挥生理功能。
The E. coli lac operator and repressor were adapted for function in mammalian cells. Plasmids containing an SV40 early region (pSVIacO) or a chloramphenicol acetyl transferase gene (pSVlacOCAT) linked to a hybrid SV40 early promoter bearing a lac operator were tested for function. Identical plasmids lacking an operator (pX-8 and pX-8CAT) were controls. In vitro, early transcription from pSVlacO, but not from pX-8, was inhibited by lac repressor, and repression was overcome by IPTG. Repression of large T synthesis of CAT activity occurred in vivo only when the respective operator-containing plasmid was cotransfected with a plasmid encoding lac repressor, or when the recipient cells stably synthesized lac repressor. IPTG substantially relieved repression in both cases. CAT enzyme repression was paralleled by a decrease in CAT mRNA abundance. Thus regulatory elements of the lac operon function physiologically in mammalian cells.