Figure 5.

Plk does not regulate fragmentation of the Golgi complex via Myt1. (A) Mock and Plk-depleted mitotic cytosol were western blotted with an anti-Plk antibody. Western blotting with an anti-CDK1 antibody was used as a loading control. (B) Quantification of Plk levels in mitotic cytosol upon immunodepletion. (C) Left panel. After incubation with thymidine for 12 h, permeabilized and salt-washed cells were incubated with mock or Plk-depleted mitotic cytosol, and an ATP-regenerating system for 1 h at 32°C. The organization of the Golgi membranes was visualized by fluorescence microscopy. Scale bar is 10 μm. Right panel. Percentage of cells with fragmented Golgi upon incubation with mock or Plk-depleted mitotic cytosol. For each condition, 200 cells were counted on 2 different coverslips (mean±s.d., n=3, *P<0.05). (D) Left panel. HeLa cells stably expressing ManII-GFP were transfected with control or Myt1 specific siRNA oligo, and after incubation with thymidine for 12 h, permeabilized and salt-washed cells were incubated with mock or Plk-depleted mitotic cytosol and an ATP-regenerating system. The organization of the Golgi membranes was visualized by fluorescence microscopy. Scale bar is 10 μm. Right panel. Percentage of cells with fragmented Golgi in the experimental conditions describe above. For each condition, 200 cells were counted on 2 different coverslips (mean±s.d., n=3, *P<0.05).