Inducible protein expression in Drosophila Schneider 2 cells using the lac operator–repressor system
Schneider line 2 cells, derived from Drosophila melanogaster, can be used as a highly versatile gene expression system. Two powerful promoters derived from the actin5C (Ac5) and metallothionein (Mtn) genes are available. The Mtn promoter can be used for the inducible expression of heterologous proteins unsuitable for constitutive expression. However, to circumvent using CuSO4 or CdCl2 as inducers of the Mtn promoter, we created a modified Ac5 promoter, Ac5LacO, in which two short lac operator sequences are embedded. Expression from the Ac5LacO promoter was regulated with co-expression of the lac repressor and IPTG. More than 25-fold induction of firefly luciferase expression was achieved in transient transfection experiments. Furthermore, we demonstrated that the lac operator–repressor regulatory system functioned in chromosomally integrated cell lines.
KeywordsDrosophila S2 cells lac operator–repressor Inducible expression IPTG
This work was supported by the Targeted Proteins Research Program (TPRP), the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.