B, C Representative kymographs (B) and quantitative analysis (C) showing the relative motility of axonal LEs during 5-min time-lapse imaging from cortical neurons at DIV14. Neurons were co-transfected with GFP-Rab7 and a pcDNA vector alone as a control or expressing WT or mutant snapin as indicated. Vertical lines correspond to stationary organelles; oblique traces reflect retrograde (leftward) or anterograde (rightward) transport. Motile or stationary organelles were normalized to the total number of organelles per axon segment selected for recording and averaged from the total number of axons indicated in parentheses. Retrograde transport of Rab7-labeled LEs was robustly inhibited by expressing snapin-L99K and reduced by expressing snapin-S50D. Data are means ± s.e.m., Kruskal–Wallis test with Dunn’s
post hoc test.
P-values: *0.01–0.05; **0.001 to 0.01; **** < 0.0001. (See also
Supplementary Fig S1.)