Figure 7. Inhibition of fission impairs the NGF-induced translation of axonally targeted cortactin mRNA.
(A) Example of FRAP experiments showing pre-photobleaching, just post-photobleaching and 60 min post-photobleaching images. The NGF treated axon recovers fluorescence more extensively than the mDivi-1 pretreated axon. (B) Graph showing the quantification of the relative FRAP (% recovery from time 0 value to pre-photobleaching value) in NGF+DMSO and NGF+mDivi-1 treatment groups (n = axons). Differences between NGF+DMSO and NGF+mDivi-1 groups are detected starting at 35 min using Bonferroni posthoc time-matched multiple comparison tests. The NGF+CHX (35 μM cycloheximide 30 min pretreatment before NGF treatment as in Spillane et al., 2012) shows the extent of recovery due to translation independent diffusion or transport of the myrGFP reporter from the axon proximal to the region of bleaching. The recovery in the NGF+CHX and NGF+mDivi-1 groups was not different at any time point using Bonferroni posthoc time-matched multiple comparison tests. (C) Examples of the staining levels of cortactin in axons. A 30 min treatment with NGF increases cortactin levels and the increase is impaired by pretreatment with mDivi-1. Pretreatment with CHX blocks the increase in axonal cortactin levels induced by NGF (Spillane et al., 2012). (D) Quantification of the levels of cortactin in distal axons (total integrated staining intensity). Each datum represents one axon. Dunn’s posthoc multiple comparison tests. Median is denoted by arrowheads to the right of data points.
Figure 7—figure supplement 1. Effects of Mek-Erk inhibition on cortactin translation and inhibition of translation of NGF-induced fission.
