Figure 3.

Opposite effects of pin1Δ and CTD-S7A mutations on phosphate regulon expression. (A) S. pombe strains bearing the indicated pin1 and rpb1-CTD alleles were grown to A₆₀₀ of 0.5 to 0.8 in liquid culture in YES medium at 30°C. Cells were then harvested, washed with water, and assayed for Pho1 acid phosphatase activity by conversion of p-nitrophenylphosphate to p-nitrophenol. Activity is expressed as the ratio of A₄₁₀ (p-nitrophenol production) to A₆₀₀ (input cells). Each datum in the bar graph is the average of assays using cells from at least three independent cultures ± SEM. (B) Total RNA from fission yeast cells with the indicated genotypes was analyzed by reverse transcription primer extension using a mixture of radiolabeled primers complementary to the pho84, act1, and pho1 mRNAs (top panel) or the tgp1 mRNA (bottom panel). The reaction products were resolved by denaturing PAGE and visualized by autoradiography. The positions and sizes (nt) of DNA markers are indicated on the right.