Figure 6.

SNAPIN is important for autophagosome acidification. HEK293 cell lines stably transduced with scrambled (SCR)- (panel A) or SNAPIN shRNA (panel B)-expressing lenti-viruses, were transfected with the ptf-LC3 plasmid, which expresses LC3 tagged with tandem fluorescent RFP and GFP. The red fluorescence is expressed regardless of the pH, while the green fluorescence is quenched at low pH. (C) The average numbers of GFP- and RFP-positive puncta from SCR or SNAPIN shRNA-expressing cells are shown as a bar graph (n = 20; **p < 0.01, compared with the same colored puncta in SCR shRNA HEK293 cells). (D) The ratio of green:red puncta in cells was calculated and presented (n = 20 cells; **p < 0.01), comparing SCR and SNAPIN shRNA-expressing HEK293 cells. (E) Immunoblot analysis of the 2 cell lines. Scale bar: 13.3 μm. Results (panels A-D) were obtained from 4 independent experiments.