Figure 7.

Na pump and VSV-G exit the TGN in separate PGTIs en route to the lateral membrane. SNAP cells were transfected with a plasmid encoding Ts 045 VSV-G–YFP and incubated for 24 h at 40°C to accumulate newly synthesized VSV-G in the ER. Next, samples were BG blocked at 40°C, washed, and incubated for a short 10-min recovery period to permit synthesis of new SNAP-tagged Na pump protein. (A and B) Samples were subjected to 19°C Golgi block and fixed immediately (19°C; A) or warmed to 31°C for 15 min (B). Samples were labeled with TMR-STAR (red) and imaged for YFP (green). The boxed areas are shown at higher magnification in the panels below. The green arrow highlights a PGTI containing only VSV-G, whereas the red arrow highlights a carrier containing only the Na pump. Bars, 5 µm.