Tight control of gene expression in mammalian cells by tetracycline-responsive promoters
Key findings
Established the foundational Tet-Off inducible expression system in mammalian cells. The tet repressor from E. coli Tn10 was fused to the VP16 transactivation domain to create the tetracycline-controlled transactivator (tTA). tTA drives transcription from a minimal CMV promoter combined with tet operator (tetO) sequences. In tTA-expressing HeLa cells, the luciferase reporter was induced >10,000-fold above background. Critically, adding tetracycline (or doxycycline) suppresses tTA binding and shuts off expression within hours, giving tight, reversible transcriptional control. This tTA/TRE (tetracycline response element) architecture became the canonical Tet-Off vector design used across virtually all inducible transgene systems.