Serine 707 of APPL1 is Critical for the Synaptic NMDA Receptor-Mediated Akt Phosphorylation Signaling Pathway

APPL1 is physically associated with PSD95 in the brain and cultured neurons. (A) Representative 3D-SIM images showing co-localization of APPL1 with PSD95 in cultured hippocampal neurons. Scale bar, 5 μm. (B) Statistics for APPL1 and PSD95 cluster density in dendrites. The mean density of APPL1 clusters was 1.3 ± 0.12 per μm (total 38 neurons, n = 3) and of PSD95 clusters was 1.4 ± 0.14 per μm (total 45 neurons, n = 3). (C) Statistics for APPL1 and PSD95 co-localization. The percentage of APPL1 co-localized with PSD95 was 38 ± 3.61% (total 40 neurons, n = 3), and the that of PSD95 co-localized with APPL1 was 18 ± 1.8% (total 40 neurons, n = 3). (D) APPL1 and PSD95 coexist in the same protein complex in brain tissue. Preparations from adult mouse hippocampus were immunoprecipitated (IP) and blotted with antibodies against PSD95 or APPL1. Three independent co-IP tests were performed for each group