Regulated mammalian expression system is based on a novel on/off switch that relies on the rapid and sensitive modulation by coumarin-related compounds of a chimeric transactivator protein.

• Low basel levels
• Robust and rapid induction
• Down regulation of gene expression in mammalian cells
• Novobiocin switches off the expression

The system features low basal levels, robust and rapid induction, and down regulation of gene expression in mammalian cells. Nanomolar concentrations of the antibiotic coumermycin promote homodimerisation of a chimeric transactivator that then binds to lambda operator sequences for a protein of interest. Protein expression levels can be regulated by adjusting the coumermycin concentration. The expression can be promptly switched off by adding novobiocin, which acts as an antagonist by dissociating the dimerized transactivator protein.

The protein coding region of interest is cloned into either the pF12A RM Flexi® vector or pF12K RM Flexi vector. These vectors incorporate regulatory promoter sequences upstream of the protein-region and are compatible with the Flexi Vector System. The pReg neo Vector is designed to express a chimeric transactivator protein that interacts with the regulatory promoter region in the pF12A and pF12K RM Flexi Vectors in response to coumermycin and novobiocin. Components should be stored at –20 °C.