cKit and Shp2 inhibitors have no effect on BACE activity but enhance AβPP surface localization. A) BACE activity assay of cKit and Shp2 inhibitors. A BACE substrate analog peptide (0.1 μM) was used as inhibition control. B) The HEK293 cells stably expressing AβPP751 were treated with 1 μM of DMSO control, Y10 or PHPS1 for 2 h, and surface biotinylation assay was performed to analyze AβPP and a control membrane protein CD71 (transferrin receptor) surface localization. Biotinylated proteins were pulled-down by Neutravidin beads and detected by WB with anti-AβPP antibody (6E10), and anti-CD71 antibody. C) Statistical analysis of AβPP surface localization in (B). Results normalized to AβPP and CD71 inputs. p-Y, phosphotyrosine. Results are mean ± standard deviation, n=3. Asterisks (*) indicate statistical significance of p<0.05 by t-test.