Figure 2.
Time course of COPI depletion shows that Golgi disperses before AVs are formed, but Golgi dispersal does not cause AV formation. (A) COPI subunits were depleted in 293/GFP-LC3 cells and analyzed 24, 36, and 48 h after addition of siRNA. Immunoblotting for β′- and α-COP confirms loss of COP subunits. (B) GFP-LC3-I and -II were monitored by immunoblots in parallel lysates using anti-GFP antibodies at the indicated times. (C) After 24 h siRNA treatment, depletion of β′-COP caused morphological changes and a reduction in perinuclear population of GM130. Box indicates enlarged area. (D) Rab1a/b was depleted using siRNAs for 48 h. Lysates were probed with anti-Rab1 to confirm depletion. (E) β′-COP or Rab1a/b were depleted as in D, and analyzed by indirect immunofluorescence using anti-GM130 and GFP fluorescence. In β′-COP panel, the asterisk indicates cells that did not show an accumulation of GFP-LC3–positive AVs.