Fig. 4. SIRT1 deacetylates Beclin 1 and stimulates autophagic degradation of E-cadherin.

a The protein expression in Sk-Mel-28 cells stably expressing vector or Flag-SIRT1 were extracted and immunoprecipitated using an anti-acetylated lysine antibody. b The protein expression in A375-shSIRT1 and control cells were extracted and immunoprecipitated using an anti-acetylated lysine antibody. c Sk-Mel-28 cells stably expressing vector or Flag-SIRT1 were transfected with mCherry-EGFP-LC3 for 24 h. The cells were then imaged by confocal microscopy. Scale bars, 5 μm. d Quantitation of the red and yellow puncta in c. The bars represent mean ± SE of 50 cells; three independent experiments, **P < 0.01 (Student’s t test). e Sk-Mel-28 cells expressing either vector or Flag-SIRT1 were treated with or without CQ (100 mM) for 12 h, and protein expression was measured by western blotting. f Sk-Mel-28 cells expressing either vector or Flag-SIRT1 were transfected with HA-tagged Beclin 1 (WT, 2KR) for 24 h, and protein expression was then measured by western blotting. AceK, acetylated lysine