Reassembly of the GA after NZ washout is perturbed at different stages in AK1- and AK1B-transfected cells. (A–C) RPE-1 cells expressing GT-mCherry (A) or coexpressing GT-mCherry and either GFP-AK1 (B) or GFP-AK1B (C) were treated with NZ for 3 h and incubated at 4°C for 1 h in the presence of the drug. After washout, cells were recorded by video microscopy. Time after NZ removal is shown. (A) Video frames illustrating two-step reassembly of the GA in control cells. Golgi elements partially fuse in the cell periphery before being translocated toward the CTR. (B) In AK1-transfected cells, Golgi elements fuse in the cell periphery at lower rates than in control cells and do not apparently move toward the cell center. (C) In AK1B-transfected cells, Golgi elements are radially translocated toward the CTR without peripheral fusion. (right) An identical experiment in fixed cells. CTR position is indicated (yellow arrows). γtub, γ-tubulin. Bars, 3 µm.