Fig. 1. yArf1 regulates mitochondria fusion and fission.
a, Schematic of the thermo-sensitive mutant Arf1-11 in yeast (Yahara et al.29). Amino acid coordinates are indicated in bold below the protein and corresponding mutated amino acids in red. b, Growth test of yARF1 and yarf1-11 strains on rich medium (YPD) and incubated at 23 °C, 30 °C and 37 °C. c, Cell viability assay of yARF1 and yarf1-11 strains performed after shifting cells to 37 °C. ODs were measured at regular timepoints. Mean and standard deviation are shown; n = 3 biological replicates. d, yARF1 and yarf1-11 strains phenotypes followed by microscopy after 0, 30, 60 and 120 min incubation time at 37 °C. Scale bar, 5 µm. e–h, Single timepoint images of movies done with strains expressing yArf1–GFP (e,g) or yArf1-11–GFP (f,h) together with the mitochondrial protein Tom70 fused to mCherry at 23 °C (e,f) or shifted to 37 °C (g,h). White arrows indicate sites of fission and yellow arrows fusion. Asterisk indicates a fusion event independent of Arf1 in h. Scale bar, 5 µm. Scale bar inlays, 2.5 µm. i,j, Measurements of mitochondrial fusion and fission events per cell (i) and the frequency of events where yArf1 is involved (j). Mean and standard deviation are shown; yARF1 23 °C = 271 cells, yARF1 37 °C = 231 cells, yarf1-11 23 °C = 379 cells and yarf1-11 37 °C = 186 cells from n = 3 biological replicates. Source numerical data are available in source data. See also Extended Data Fig. 1.