Figure 3.

S53P blocks activation of PHO5 and ADH2 reporter plasmids. The PHO5_UAS-PHO5_TATA-lacZ and ADH2_UAS-CYC1_TATA-lacZ reporter plasmids were introduced into the isogenic strains YMH130 (SUA7⁺) and YMH300 (sua7–36) and assayed for β-galactosidase activities under repressing and inducing conditions. (A) PHO5. Repressing (lanes 1 and 3) and inducing (lanes 2 and 4) conditions are described in the legend to Fig. 2. Absolute activities are 68, 1,920, 59 and 160 units of β-galactosidase in columns 1–4, respectively. (B) ADH2. Repressing conditions are 2% glucose (lanes 1 and 3); inducing conditions are 2% ethanol + 2% glycerol (lanes 2 and 4). Absolute activities are 5.2, 2,042, 2.3 and 225 units β-galactosidase in columns 1–4, respectively. All assays were done in duplicate, using three independent transformants. Error bars denote SD and in all cases are less than 25%.