Figure 6.

The Golgi apparatus is involved in Trk transactivation. A, PC12 cells were pretreated for 30 min with 5 μg/ml brefeldin A or vehicle and then treated with CGS 21680 or NGF as indicated. In all cases of brefeldin A treatment, cells were exposed to the drug for a total duration of 3.5 hr. Trk immunoprecipitates were then analyzed by blotting with phosphotyrosine or pan-Trk antibodies. Phosphorylation of Akt was examined by blotting cell lysates with either phospho-Akt or anti-Akt antibodies for activated and total Akt levels. B, PC12 cells pretreated with brefeldin A or vehicle were treated with 10 nm CGS 21680 for 3 hr or 100 ng/ml NGF for 5 min and then stained for pTrkA (green) or total Trk (red) and imaged by standard immunofluorescent microscopy. Cell nuclei were visualized with DAPI.