Fig. 6.

Suggested cross-talk between the UPR, heme and iron homeostatic machinery. (A) GFP–Aft1 re-localizes to the nucleus during unfolded protein stress, as induced by either 2 mM DTT, 5 μg/ml tunicamycin or 24 h growth in inositol depletion medium. The nuclear accumulation is inhibited by lowering ergosterol biosynthesis by using ergosterol biosynthesis inhibitors (Fluconazole 20 μg/ml or Terbinafine 10 μg/ml). NT, not treated. Scale bar: 5 μm. (B) A schematic for a hypothetical feedback loop suggested for the heme and iron cross-talk with ergosterol biosynthesis and the UPR.