Mutagenesis scanning confirms the importance of TM5 and TM7 in Ypq1 degradation. (A) Heat map showing the degradation defect of strong blocking Ypq1 mutants (cutoff = 90%). (B) Number of residues within TM5, TM7, and TM3 that conferred a strong degradation block when mutated to Ala. (C) Subcellular localization of Ypq1-GFP mutants after 6 h Lys starvation. WT, L218A, and F287A are positive degradation controls. Scale bar, 2 µm. (D) Helical wheel projections of Ypq1 TM5, TM7, and TM3 showing residues that blocked degradation when mutated to Ala (red).