Fig. 4

APP localizes exogenous GB1a protein to axons in cultured hippocampal neurons. a Representative images of hippocampal neurons co-expressing Myc-GB1a and GFP in APP^−/− and control littermate (WT) mice. Neurons were transfected at DIV5, fixed at DIV10, permeabilized and then stained with anti-Myc antibodies. Note that APP^−/− neurons exhibit significantly reduced axonal Myc-GB1a expression. Dendrites were distinguished from axons using morphological criteria⁶⁶. Scale bar 10 μm. b Higher magnification images of distal axons and dendrites from APP^−/− and WT neurons expressing exogenous Myc-GB1a, GFP and mCherry. Scale bar 10 μm. c Images of distal axons and dendrites from APP^−/− neurons expressing exogenous Myc-GB1a, GFP and APPmCherry or APLP-2mCherry. Note that APPmCherry but not APLP-2mCherry rescues axonal localization of Myc-GB1a. Scale bar 10 μm. d Exogenous Myc-GB1a levels in axons and dendrites of transfected APP^−/− or WT neurons. Normalized fluorescence refers to the Myc-GB1a immunofluorescence intensity normalized to the GFP fluorescence intensity. ****P < 0.0001, unpaired Student’s t-test. e Axon:dendrite (A:D) ratio of Myc-GB1a in APP^−/− and WT neurons transfected with Myc-GB1a in the presence of mCherry, APPmCherry or APLP-2mCherry (DIV10). The n number of neurons analyzed is indicated. ***P < 0.001, ****P < 0.0001, one-way ANOVA. Data are presented as mean ± s.e.m. Source data are provided as a Source Data file