Figure 9.

Activation of Pho8 by zinc. A and B, pho2Δ pho8Δ cells expressing pgk1-driven Pho8-HA ΔC (A) or pho8-driven Pho8-GFP (B) were grown overnight in ZL-EMM to an A₆₀₀ of ∼5. Cells were preincubated with 0, 0.1, or 1 mm cycloheximide for 2 h (A) or 30 min (B) before being exposed to 100 μm zinc (t = 0). Cells were then harvested for alkaline phosphatase (ALP) activity assays or immunoblot analysis at the indicated time points. Alkaline phosphatase activity and immunoblot analyses were performed as described in Fig. 3. C, the indicated strains expressing Pho8-HA ΔC were treated with cycloheximide for 2 h, shocked with 100 μm zinc, and assayed for alkaline phosphatase activity as described above.