Figure 1
From: ALS-linked FUS exerts a gain of toxic function involving aberrant p38 MAPK activation
ALS-linked mutant FUS proteins impair anterograde and retrograde FAT. (A) ALS-linked mutations (G230C, R495X and R521G) investigated in this study are mapped onto the domain structure of GST-FUS. RRM = RNA recognition motif, RGG = arginine-glycine-glycine-rich, ZFD = zinc-finger domain and NLS = nuclear localization signal. (B–G) FUS proteins (2.5 μM) were perfused into isolated squid axoplasm and fast axonal transport (FAT) rates (μm/s) of membrane bounded-organelles measured as a function of time (minutes). For (B,C), slopes of the linear best fits for velocities obtained for each axoplasm (D–G) were averaged and plotted as bar graphs in Graphpad Prism with the standard error of the mean (SEM) for anterograde (blue bars; A) and retrograde (red bars; B) velocities. Those conditions with statistical significance (p < 0.05) relative to FUS WT are denoted by *, determined by one-way Anova and Tukey post-hoc test for multiple comparisons. (D–G) Motility plots comprised of the raw data for every axoplasm (‘n’ denotes the number of axoplasms analyzed for each condition) are shown, where linear best fits of the compiled data are shown for anterograde (blue arrowheads; linear fit shown as a solid blue line) and retrograde (red arrowheads; linear fit shown as a solid red line) directions. Protein obtained from at least two independent protein expression and purifications were included for each FUS variant.
