YIpDCE1 - an integrating plasmid for dual constitutive expression in yeast.

YIpDCE1 (Dual Constitutive Expression), a novel Saccharomyces cerevisiae integrating plasmid, constitutively expresses two genes under the control of separate phosphoglycerol kinase promoters. YIpDCE1 contains the complete ADE2 gene which can be used as a marker for selecting integrants at mutant ade2 loci commonly present in laboratory yeast strains. The YIpDCE1 plasmid can be inserted into the ade2-101 locus of the HF7c strain used in two hybrid screens. Thus it could be useful for analysis of two hybrid interactions that occur in the context of additional protein components (e.g. modifying enzymes such as kinases or phosphatases, or multimeric complexes consisting of three or four distinct protein components). YIpDCE1 has been used to create strains simultaneously overexpressing the permease (FTR1) and oxidase (FET3) components of the yeast high-affinity iron uptake system. This confers constitutive high-affinity iron uptake on the transformed strains, bypassing the normal regulatory mechanisms.