FIGURE 2:

Loss of AP-4 affects neuronal lysosomal composition. (A and B) Immunoblotting reveals decreased levels of Cleaved/Pro-Cathepsin L protein in AP-4 i³Neurons compared with Control i³Neurons (21 DIV; α-Tubulin used as loading Control; mean ± SEM from three independent experiments; *P < 0.05; **P < 0.01). (C) Control and AP-4 G4i i³Neurons (14 DIV) stained for Cathepsin L (green) and neurofilament (blue) showing a reduced number of Cathepsin L-enriched lysosomes in cell bodies of AP-4 i³Neurons. Bar, 10 μm. (D) Quantification of Cathepsin L-positive vesicles in AP-4 i³Neurons compared with Control i³Neurons (14 DIV; mean ± SEM from three independent experiments; 25–30 neurons per genotype; *P < 0.05). (E) Control and AP-4 G4i i³Neurons (14 DIV) stained for PPT-1 (green) and Tau (red). Bar, 10 μm. (F) Quantification of PPT-1 positive vesicles in AP-4 i³Neurons compared with Control i³Neurons (14 DIV; mean ± SEM from three independent experiments; >30 neurons per genotype; **P < 0.01).