Figure 8.
APP intracellular domain BBXXB motif is required for interaction with GαS and mAICD-induced neurite outgrowth. a, The amino acid sequences of mAICD constructs are shown. The “BBXXB” motif RHLSK was mutated to AALSA to generate mAICD-mutAAA. b, Coimmunoprecipitation analysis of mAICD and mAICD-mutAAA with GαS in transfected N2a cells. Note that the BBXXB motif is essential for mAICD interaction with GαS. c, e, Representative images of N2a cells (c) and 8 DIV cortical neurons (e) coexpressing YFP and mAICD or mAICD-mutAAA. d, f, Analysis of the morphological changes in cells (or neurons) transfected with mAICD or mAICD-mutAAA were quantified from 3-D deconvolved image stacks that are plotted relative to cells (or neurons) transfected with mCtl. Statistical analysis was performed using ANOVA Kruskal–Wallis test followed by Dunn's post hoc multiple-comparison analysis. **p < 0.001, compared with mCtl-expressing N2a cells or cortical neurons. The total number of quantified cells is shown in parentheses. Error bars indicate SEM.