Figure 5: RanGTP is enriched in the tip of the neurite and the soma.

(A,B) Images of 3DIV hippocampal neurons immunofluorescence stained with antibody against Ran (A) and RanGTP (B), respectively. The inset in middle panel A shows the same image around the soma region with reduced image contrast. All images have the same scale and the scale bar represents 10 μm. (C) Ran (green) or RanGTP (red) intensity linescan along a 10 μm stretch from the neurite tip in 3DIV hippocampal neurons. RanGTP accumulated significantly more compared to Ran in the neurite tip. Mean ± SEM from 3 independent experiments, ***p < 0.001, two-way ANOVA followed by Bonferroni post-test. (D) To obtain the intensity change at the neurite tip, Ran or RanGTP intensity average within 1 μm from the neurite tip was divided by the intensity along the entire neurite. A ratio above 1.0 indicates an increase, while a ratio below 1.0 indicates a decrease of Ran at the neurite tip. The intensity ratios were classified into three groups. The group with ratio equal to or greater than 1.5 is shown in red, the group with ratio in between 1.5 and 1.0 is shown in orange, and the group with ratio in between 1.0 and 0 is shown in yellow. *p < 0.05, **p < 0.01, two-tailed Student’s t-test. Error bars represent SEM from three independent repeats. A total of 131 and 120 neurites were analyzed for Ran and RanGTP from three independent repeats, respectively.