Fig. 2. PKD-K618N is localized to specific domains of the TGN. HeLa cells stably transfected with GST–FLAG-tagged PKD-K618N (GF17 cells) were fixed at steady state and prepared for immunogold labeling with anti-GST antibody to visualize PKD-K618N (10 nm particles, arrows), and the Golgi markers GM130 (for cis/medial compartment), galactosyl transferase (for trans-Golgi compartment and TGN) and TGN46 (for the TGN) (5 nm particles). (A and B) GST–FLAG-tagged PKD-K618N is located to the tubular-vesicular profiles attached to the trans side of the Golgi stack and rarely to its lateral side (B). (C and D) GST–FLAG-tagged PKD-K618N does not co-localize withGM-130. Gold labeling for GST–FLAG-tagged PKD-K618N (arrows) is located on the opposite side of the Golgi stack compared with GM130 (small 5 nm gold particles). (E) GST–FLAG-tagged PKD-K618N (arrows) is partially co-localized with the galactosyl transferase (small 5 nm gold particles). (F) GST–FLAG-tagged PKD-K618N (arrows) co-localizes with TGN46 (5 nm gold particles) on the trans side of the Golgi stack. Bar: (A, E, F), 70 nm; (B), 250 nm; (C), 150 nm; (D), 300 nm.