Supplementary Figure 7: Reduced localization of syntaxin-1 at Munc13-1 knockdown synapses.
From: Synaptic weight set by Munc13-1 supramolecular assemblies
a, b Immunofluorescence images of bassoon (red) and syntaxin-1 (cyan) of control (a) and Munc13-1 knockdown neurons (b). Scale bar, 5 µm. Cells were fixed with 1% paraformaldehyde (PFA) on ice and permeabilized with saponin. Arrowheads indicate synaptic sites identified by bassoon immunofluorescence. Synaptic syntaxin-1 immunofluorescence was clearly observed in control neurons. Images are representative of 4 (a) and 2 (b) experiments repeated, respectively. c Quantification of syntaxin-1 immunofluorescence intensity at control and Munc13-1 knockdown neurons (n = 90 ROIs, respectively). “S” and “N” denote synaptic and non-synaptic, respectively. Data are represented as mean ± SEM. Two-tailed Wilcoxon rank sum test was used for statistical analysis. P = 2.6×10−7 (95% confidence interval 0.32 to 0.66, W = 5850) for controls; P = 0.13 (95% confidence interval −0.031 to 0.26, W = 4584) for Munc13-1 knockdown. **P < 0.001; n.s., not significant, P > 0.05.
