Figure 2.

Cd²⁺ activates MET gene expression in rich medium. (A) Rapid induction of MET genes by Cd²⁺. MET gene expression in wild-type cells was assessed at the indicated times after the addition of 0.5 mM Cd²⁺ in the absence or presence of 0.5 mM EGTA. (B) Cd²⁺-mediated activation of MET genes depends on Met4. MET gene expression was assessed in wild-type and met4Δ (CC849-8A) cells at the indicated times after the addition of 0.5 mM Cd²⁺. (C) Met4 and TFIIB recruitment to MET gene promoters in response to Cd²⁺. ChIP experiments were carried out as in Figure 1 on wild-type cultures before and 40 min after the addition of 0.5 mM Cd²⁺. (D) Cd²⁺ specifically induces MET gene expression. MET gene expression was assessed in wild-type cells before and 40 min after addition of the indicated heavy metals by Northern analysis (left) and quantitative real-time RT–PCR (right). Heavy metals were added at the following concentrations: Cu²⁺ 1 mM, Zn²⁺ 1 mM, Co²⁺ 2 mM, Hg²⁺ 0.3 μM, Mn²⁺ 0.5 mM and Ag²⁺ 30 μM.