A plasmid vector facilitating gene expression in both yeast and mammalian cells

A plasmid vector with combined features of yeast shuttle vector and mammalian expression vector was constructed to facilitate expression of cloned gene in both cell-types. All necessary elements required for plasmid maintenance and selection in E. coli, yeast and mammalian cells were size-economically arranged in this plasmid. The human cytomegalovirus (CMV) immediate early promoter and yeast GAL1 promoter were sequentially placed in front of the gene to be expressed. The synthetic splicing donor and acceptor sequences were inserted into the immediate upstream and downstream of the GAL1 promoter, allowing the CMV promoter to direct the expression of a given gene in mammalian cell environment by splicing out the interfering GAL1 promoter sequence. When the resulting vector containing LocZ as a test gene was introduced into yeast and mammalian cells, both cells efficiently produced β-galactosidase, demonstrating its dual host usage.