Highly controlled heterologous gene expression through combined utilization of the tetracycline-repressible transactivator and the lac repressor.
To achieve strictly on-off switching of a desired cDNA expression in a broader range of mammalian cell types, we introduced the Escherichia coli lac operator sequences into the tetracycline-repressible promoter and created a chimeric promoter (designated here as the TcIP promoter) whose activity was reciprocally controlled by tetracycline and isopropyl thiogalactopyranoside (IPTG). cDNAs were connected downstream of the TcIP promoter and stably transfected into interleukin (IL-2 or IL-3)-dependent lymphoid cells that ectopically coexpress the tetracycline-repressible transactivator and the lac repressor. Whereas the parental tetracycline-repressible promoter exhibited constitutive activities when stably introduced into the lymphoid cells, cDNA expression from the TcIP promoter was strongly inhibited by tetracycline and was potently induced by IPTG in stable transfectants. Hence, the TcIP promoter made it possible to achieve highly controlled cDNA expression in cells wherein the parental promoter did not function in an inducible manner. Potential application of this promoter was provided by expressing cyclin-dependent kinase inhibitor, p27(Kip1). Induced expression of p27(Kip1) by the TcIP promoter in the lymphoid cells strongly reduced cellular responsiveness to IL-2 or IL-3, consistent with the idea that p27(Kip1) is a critical target that must be inactivated by the interleukin-triggered mitogenic signals.
Japanese Foundation for Cancer Research, Cancer Institute, 1-37-1 Kami-Ikebukuro, Tokyo, Toshima-ku, 170-8455, Japan.
Y
Y
Hoshikawa
K
K
Amimoto
R
R
Mizuguchi
M
M
Hatakeyama
D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002455:Cell Division; D002460:Cell Line; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018076:DNA, Complementary; D029968:Escherichia coli Proteins; D005786:Gene Expression Regulation / Q000235:genetics*; D007376:Interleukin-2 / Q000378:metabolism; D007377:Interleukin-3 / Q000378:metabolism; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D056968:Lac Repressors; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D013752:Tetracycline / Q000494:pharmacology*; D015534:Trans-Activators / Q000378:metabolism*; D014162:Transfection; D025521:Tumor Suppressor Proteins
D001426:Bacterial Proteins; C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D029968:Escherichia coli Proteins; D007376:Interleukin-2; D007377:Interleukin-3; D056968:Lac Repressors; D008869:Microtubule-Associated Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D007544:Isopropyl Thiogalactoside; D013752:Tetracycline