pARIS-mCherry-httQ23 but not pARIS-mCherry-httQ100 restores Golgi reassembly after endogenous huntingtin depletion. A) Gene replacement experiments and Golgi reformation assays were performed adding back pARIS-mCherry-httQ23/Q100 in cells depleted from endogenous htt following the protocol indicated in the scheme. (B) Representative images of cells expressing pARIS-mCherry-httQ23 (upper pannel) or pARIS-mCherry-httQ100 (lower panel) at t = 0 and t = 120 after NZ washout. While cells expressing pARIS-mCherry-httQ23 completely reassemble the GA into tight stacks, cells expressing pARIS-mCherry-httQ100 display scattered Golgi fragments that are unable to reassemble in the perinuclear region. (C) Quantification of the GA reassembly is presented as an analysis of mean Golgi particle volume (μm3) before and after NZ washout for different treatments. Results were obtained from 3 independent experiments in which 280 cells were analyzed. One way ANOVA followed by Fisher's Post-hoc test: ***p < 0.0001; NS non significant. All comparisons are t = 0 vs t = 120; scRNA: 0.283 ± 0.044 vs 4.126 ± 0.771; siRNA-htt 0.073 ± 0.008 vs 0.158 ± 0.06; siRNA-htt + pARIS-mCherry-httQ23: 0.222 ± 0.035 vs 3.763 ± 0.712; siRNA-htt + pARIS-mCherry-httQ100: 0.062 ± 0.006 vs 0.171 ± 0.013.