Figure 5.

Autophagy enables cells to scavenge zinc by degrading abundant proteins. A–C, cells in 0.5-ml aliquots of SD (−zinc) were collected at the indicated time points. Note that as equivalent volumes of cell culture were sampled for this experiment, protein loading increases with each time point as cell density increases with growth. Therefore, equivalent band intensities of Adh1 actually represent the degradation of this protein over time. A, amount of Adh1-GFP or Adh4-GFP in wild-type or atg2Δ cells under zinc starvation. 0.5-ml aliquots were collected at the indicated time points from cell cultures. Lysates were prepared and analyzed by Western blotting. B, amount of Fba1-GFP or Pgk1-GFP in wild-type or atg2Δ cells under zinc starvation. Western blotting was performed as in A. C, amount of Rpl37A-GFP, Rpl37B-GFP, or Pho8 in wild-type or atg2Δ cells under zinc starvation. Western blotting was performed as in A.