Novel promoter/transactivator configurations for macrolide- and streptogramin-responsive transgene expression in mammalian cells

Background The recently developed heterologous macrolide‐ (E.REX system) and streptogramin‐ (PIP system) responsive gene regulation systems show significant differences in their regulation performance in diverse cell lines. Methods In order to provide optimal regulation modalities for a wide variety of mammalian cell lines, we have performed a detailed analysis of E.REX and PIP systems modified in (i) the transactivation domains of the antibiotic‐dependent transactivators, (ii) the type of minimal promoter used, and (iii) the spacing between the operator module and the minimal promoter. Results These novel E.REX and PIP regulation components showed not only dramatically improved regulation performance in some cell types, but also enabled their use in cell lines which had previously been inaccessible to regulated transgene expression. Conclusions Due to their modular set‐up the novel E.REX and PIP regulation systems presented here are most versatile and ready for future upgrades using different cell‐specific key regulation components. Copyright © 2002 John Wiley & Sons, Ltd.