Figure 6: Knockdown of syntabulin in neurons affects PICK1 axonal targeting.

(A) Test of syntabulin shRNA knockdown efficiency in HEK293T cells, which were transfected with myc-Syntabulin and the lentiviral constructs of syntabulin shRNAs. (B) Staining of endogenous syntabulin in neurons after shRNA viral infection for 5 days. The result shows that syntabulin expression was knocked down highly efficiently by shRNA #1. Arrowheads indicate a neuron in which syntabulin was successfully knocked down. Scale bar = 20 μm. (C) YFP-PICK1 distribution in neurons after syntabulin knockdown. Arrowheads indicate the axons which are MAP2 signal-free. Scale bar = 20 μm. (D) Quantification of PICK1 axonal targeting after syntabulin knockdown. The A/D ratios were normalized against control. The result shows a slight but significant impairment in the axonal targeting of PICK1 after syntabulin knockdown compared to control. **P = 0.008, nonparametric Kruskal-Wallis Test, n = 6 independent experiments; error bars represent the SEM. (E) Quantification result of axonal clustering of PICK1 after syntabulin knockdown. Result showed no significant change on PICK1 clustering after syntabulin knockdown. one-way ANOVA and Sidak test, n = 3 independent experiments. Error bars represent the SEM.