Figure 2.

SNX18 is a positive regulator of autophagy. (A) HEK GFP-LC3 cells transfected with control (siCtrl) or two different SNX18 siRNA oligos (siSNX18-3 and siSNX18-5) were starved or not starved for 2 h in the presence or absence of BafA1. GFP-LC3 lipidation and SNX18 protein knockdown were monitored by immunoblotting. The graph shows the average GFP-LC3-II relative to actin normalized to siCtrl-1 fed ± SEM (error bars), n = 4. (B) The degradation of long-lived proteins in HeLa cells transfected with control or SNX18 siRNA was quantified after 4 h of starvation in the absence or presence of 3-MA and normalized to the degradation in fed cells (mean ± SEM [error bars], n = 3). (C) HEK GFP-LC3 cells were transfected with control or SNX18 siRNA and then with a myc control or siRNA-resistant myc-SNX18 plasmid. The number of GFP-LC3 spots per cell was quantified (graph shows mean ± SEM [error bars], n = 3). (D) HEK GFP-LC3 cells were transfected with myc-SNX18 or a myc control plasmid and treated as in A. The graph shows the average LC3-II levels relative to actin normalized to myc-transfected fed cells, ±SEM (error bars). n = 3. (E) HEK GFP-LC3 cells were transfected with control or Atg7 siRNA and then with myc-SNX18 or a myc control plasmid, followed by quantification of the number of GFP-LC3 spots per cell (graphs show mean ± SEM [error bars], n = 3). Representative images are shown. Bars, 5 µm. (F) The degradation of long-lived protein in HeLa cells transfected with myc-SNX18 or a myc control plasmid was quantified as in B (graph shows mean ± SEM [error bars], n = 4). *, P < 0.05; **, P < 0.01. See also Figs. S1 and S2.