HCV-induced autophagosomes are generated via homotypic fusion of phagophores that mediate HCV RNA replication
Fig 2
Knockdown of STX7 inhibits homotypic fusion.
(A) Colocalization of ATG5 and STX7. Cells were transfected with mEmerald-ATG5 (green) for 2 days, followed by nutrient starvation for one hour or HCV infection for one day, and then stained with anti-STX7 antibody (red) for fluorescence microscopy. DAPI (blue) was used to stain nuclei. (B) Western-blot analysis of STX7 and ATG5 in replicon cells transfected with the control siRNA (siNC) or siSTX7 for two days. (C) In vitro fusion assay of phagophores isolated from replicon cells with or without STX knockdown. HCV replicon cells were transfected with the expression plasmid for mEmerald-ATG5 or mCherry-ATG5 for one day and then further transfected with siNC or siSTX7 for two days. Cells were then lysed for the in vitro membrane fusion assay. (D) Quantification of the homotypic fusion efficiency of phagophores shown in (C). *, p < 0.005.