Figure 4.

DPS1 and DPS2 can mediate cell type-specific transcriptional activation and repression in vivo. The α2p/Mcm1p binding sites listed on the left (sequences shown in Table 1) were inserted into the assay vectors indicated at the top and tested for repression activity (A) or activation activity (B), as described in Materials and Methods. (A) β-Galactosidase levels were determined on three independent transformants of the indicated plasmid in strain EG123 (a strain) and strain 246.1.1 (α strain). Values are the average of the three determinations. Repression ratio is the activity obtained in the a strain containing the indicated plasmid divided by the activity obtained in the α strain containing the same plasmid. (B) β-Galactosidase levels were determined on three independent transformants of the indicated plasmid in strain EG123 (a strain). Activation ratio was calculated by dividing the β-galactosidase activity obtained with the plasmid containing the indicated site by that obtained with the plasmid lacking any site.