Figure 2.

ROCK1 phosphorylates APP695 at Ser655. (a) ROCK1 activity assay when recombinant ROCK1 protein was incubated with S6K, APP‐CTF, and vehicle. One‐way ANOVA followed by Student–Newman–Keuls test, F _3,28 = 6.28. (b) Representative S655 phospho‐peptide spectrum of APP⁶⁹⁵. APP‐CTF was incubated with recombinant ROCK1 and examined by LC‐MS/MS after 3 hr. (c) Co‐IP experiments in HEK 293T cells confirmed decreased interaction of ROCK1 with APP after S655A mutation in APP⁶⁹⁵ plasmid. (d) Quantification of interaction between ROCK1 and APP after APP695 and S655A plasmid transfection in HEK 293T cells. t ₄ = 6.67, two‐tailed Student's t test. (e) Immunofluorescence and quantification of phosphorylated APP at S655 (APP pS655) in the hippocampus of APP/PS1 and WT mice (n = 6, t ₁₀ = 8.72). Scale bar, 50 μm. (f) Immunofluorescence and quantification of phosphorylated APP at S655 (APP pS655) in the hippocampus of AD patients and normal control (n = 6, t ₁₀ = 5.8). Scale bar, 50 μm. Data were presented as Mean ± SEM. ***p < 0.001; *p < 0.05