FIGURE 6:

Cortactin is required for Dock4-mediated spine formation. (A) Cell lysates from HEK293T cells cotransfected with control or cortactin shRNAs and Myc-tagged cortactin were analyzed by immunoblotting with antibodies against Myc and α-tubulin. (B) Knockdown of endogenous cortactin in hippocampal neurons. Primary cultured rat hippocampal neurons were cotransfected with EGFP and the indicated shRNA expression vector at 11 DIV. At 4 d after transfection, neurons were fixed and stained with antibody against cortactin (magenta). Arrowheads indicate the transfected cells. Scale bar, 20 μm. (C–F) Cultured hippocampal neurons were cotransfected with EYFP and the indicated plasmids at 11 DIV and then fixed at 15 DIV. Morphology of dendrite segments is shown by EYFP fluorescence. Scale bar, 5 μm. (G) Under the same conditions as those in C–F, the dendritic protrusions per 10 μm of dendrite were counted. The data are mean ± SE of 45 cells in three independent experiments. ***p < 0.001 (vs. shControl), ^###p < 0.001 (vs. shCTTN + ELMO2 + Dock4).