(A-C) After the N2S cells were transfected with Flag-CCZ1/Flag-MON1A or Flag vehicle, the levels of FL-APP, APP-CTFs and Flag-CCZ1, Flag-MON1A were examined by immunoblotting. Data are quantified as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, vs. the relative control. (D-E) Intracellular and extracellular Aβ1-40 and Aβ1-42 levels in N2S cells over-expressing CCZ1-MON1A were determined by ELISA analysis. Data are quantified as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 vs. the relative control. (F-H) N2S cells were transfected with Mon1a shRNA or nontargeting shRNA. The levels of FL-APP, APP-CTFs were detected by immunoblotting. Data are quantified as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 vs. the relative control. (I-J) ELISA analysis of intracellular and extracellular Aβ levels in control and Mon1a KD cells. Data are quantified as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 vs. the relative control. (K-L) N2S cells over-expressing CCZ1-MON1A were transiently transfected with GFP-Lc3 and stained with APP antibody. The colocalization of GFP-LC3 and APP/APP-CTFs was visualized under confocal microscope. Quantification data are presented as the mean ± SEM, n = 20-25 cells from 3 independent experiments. Scale bar, 7.5 μm. (M-N) N2S cells over-expressing CCZ1-MON1A were transiently transfected with mcherry-LAMP1 and the GFP-APP, and the colocalization of mcherry-LAMP1 and GFP-APP under basal or CQ treated conditions were visualized under confocal microscope. Quantification data were presented as the mean ± SEM, n = 20-25 cells from 3 independent experiments. Scale bar, 7.5 μm.