Fig. 1: The disaggregase Hsp104 is targeted to the nucleus when cells age.

a Micrographs of cells harboring endogenously GFP-tagged Hsp104, Hsp90 (yeast Hsp82) and Hsp70 (yeast Ssa4), respectively, visualized at 8 h and 72 h. The signal intensity of GFP-tagged Hsp104 and Ssa4 at 8 h was increased to ensure visibility (*). Scale bar: 2 µm. b Micrographs of cells described in (a) grown for 24 h on glucose or glycerol. Scale bar: 2 µm. c Micrographs of cells endogenously expressing Hsp104^GFP and Nup133^mCherry to visualize the nucleus after culturing for 48 h on glucose. Scale bar: 2 µm. d Micrographs of cells endogenously expressing Hsp104^GFP, visualized at indicated time points. Schematic drawings illustrate major phenotypes. N = Nucleus. The signal intensity of Hsp104^GFP at 8 h was increased to ensure visibility. Scale bar: 2 µm. e Quantification of nuclear accumulation of Hsp104^GFP in cells described in (d). Dot plots with mean (square) and median (line). Each dot represents one biological replicate (8 h: 444 cells; 24 h: 347 cells: 48 h: 380 cells; 72 h: 341 cells). Schematic drawings illustrate major phenotypes. N = Nucleus. f Quantification of the mean GFP intensity ratio between nucleus and cytoplasm of cells described in (d). Violin plots with mean (square) and median (line). Each dot represents one cell (8 h: 267 cells; 24 h: 275 cells; 48 h: 252 cells; 72 h: 203 cells). Measurements were taken from micrographs of 3 biological replicates. g Hsp104 immunogold-labeling of untagged cells at indicated time points. Representative transmission electron micrographs and quantification of labeling density are depicted. The nucleus (turquoise), cytoplasm (red) and mitochondria (Mito., gray) are highlighted and immunogold signal is depicted as red diamonds. Mitochondria served as negative control. Box plots with mean (square) and median (line) and whiskers with minima and maxima within 1.5 interquartile range are shown. 100 cells were analyzed per time point. Scale bar: 500 µm. n.s.: not significant (p ≥ 0.05); **p < 0.01; ***p < 0.001. Source data are provided as a Source Data file. See Supplementary Table 3 for details on statistical analyses.