Figure 5. FIGURE 5: Re-addition of zinc to zinc-deprived cells triggers Zrt1-dependent activation of the PKA target trehalase.

(A) Activation of trehalase in the wild-type strain after addition of different concentrations of ZnCl₂ to cells deprived for zinc for two days in the presence of the EDTA chelator. 100 nM (open circles), 500 nM (closed squares), 1 μM (open squares), 10 μM (closed triangles), 100 μM (open triangles), 1 mM (closed diamonds) ZnCl₂ and starvation medium as negative control (closed circles).

(B) Activation of trehalase in wild-type (closed symbols) and zrt1Δ (open symbols) strains after addition of different concentrations of ZnCl₂ to cells deprived for zinc for two days in the presence of the EDTA chelator. 1 μM (circles), 100 μM (squares) and 1 mM (triangles). (A,B) All experiments were performed 3-5 times, representative results are shown.

(C) Phosphorylation of trehalase on the amino acid residues S21 and S83 as detected with phosphospecific antibodies in response to addition of 100 μM ZnCl₂ to cells of the wild type strain deprived for zinc for two days in the presence of the EDTA chelator. The trehalase-HA construct was expressed from the pYX212-NTH1-HA (LEU2) plasmid in the BY4742-strain.

(D) Uptake of different concentrations of Zn⁶⁵Cl₂ in the wild type (black bars) and zrt1Δ strains (white bars), n = 2. The inset shows the uptake at the lower concentrations in enlarged format.