Fig. 1. A screen for TBC domain proteins that alter Golgi structure. (A-C) HeLa and hTERT-RPE1 cells were transfected with the GFP-tagged wild-type and catalytically inactive point mutant TBC-domain proteins listed in the figure. After 24 hours they were fixed, and then stained with antibodies to GM130 or TGN46. (A) The number of cells displaying a fragmented Golgi was then counted (n>100 per condition), expressed as a percentage, and then plotted as a bar graph; grey bars, wild-type (WT) GAPs; open bars, inactive mutants. (B) Cells triply stained for the expressed wild-type (WT) TBC1D20 and RN-tre, TGN46 and GM130 are shown. (C) Cells triply stained for the expressed catalytically inactive mutant (RA) TBC1D20 R105A and RN-tre 150A, TGN46, and GM130 are shown. Bars, 10 µm, in all panels.