Double knockdown of Surf4/ERGIC-53 or single knockdown of p25 leads to Golgi dispersal. (A) HeLa cells were transfected with control siRNA, Surf4/ERGIC-53 siRNA or p25 siRNA. The Golgi was visualized by immunofluorescence microscopy using anti-giantin. (B) Quantitative analysis of the Golgi phenotype in Surf4/ERGIC-53 and p25 knockdowns. More than 100 cells of three independent experiments were counted for each condition, and the percentage of cells with fragmented Golgi plotted. Results are means ± SD. Bar, 10 μm. (C) Cells treated with control, Surf4/ERGIC-53, or p25 siRNA were processed for electron microscopy and sections of 10,000× and 20,000× magnifications are shown. Arrows, Golgi ribbon. Asterisks, dispersed Golgi stacks. Bars, 0.5 μm.