Figure 7.

Functional coupling of membrane-tethered APP intracellular domain with Gα_S-protein. a, Immunofluorescence localization of mAICD and HA-tagged wild-type Gα_S (Gα_S-wt) or dominant-negative Gα_S mutant (Gα_S-C3S) in N2a cells. The boxed regions are shown as enlarged insets. Line scans (right panels) show overlapping peaks of mAICD (green) and Gα_S-wt (red) localization along a small stretch in the cell body. b, Coimmunoprecipitation analysis of mAICD interaction with Gα_S was evaluated in stable N2a cells expressing mAICD following transient transfection of Gα_S-wt. Non-denaturing lysates were immunoprecipitated with mAb HA or mAb 9E10 (negative control) and analyzed by immunoblotting with CT11 to detect mAICD. c, As positive control, interaction between dopamine D₁ receptor (D1-R) or β1 adrenergic receptor (β₁A-R) and Gα_S-wt was analyzed by coimmunoprecipitation. d, e, Quantification of neurite outgrowth in N2a cells (d) or cortical neurons (e) 24 h following cotransfection of EV, mCtl, or mAICD with Gα_S-Wt or Gα_S-C3S. Statistical significance was examined by ANOVA Kruskal–Wallis test followed by Dunn's post hoc multiple-comparison analysis. **p < 0.001, compared with EV/EV or EV/mCtl control cells. ^##p < 0.001, compared with EV within mAICD transfected group when cells are G-protein transfected. The total number of quantified cells is shown in parentheses. Error bars indicate SEM.