Fig. 4. GST-Grp1-PH [WT] and GST-Grp1-PH mutant [K273A] labeling in thawed cryosections of U87MG and Swiss 3T3 cells. U87MG cells (A) and Swiss 3T3 cells (B) were either treated with PDGF 50 ng/ml for 10 minutes or left unstimulated in the presence or absence of wortmannin, as indicated. The labeling densities for GST-Grp1-PH [WT] or the mutant PH domain [K273A] over the plasma membrane (PM), endoplasmic reticulum (ER) and nuclear area (nucleus) are shown. Labeling densities were calculated as golds per intersection (PM, ER) or golds per test point (nucleus), determined as described in the Materials and Methods. Data shown are expressed as fold-stimulation relative to unstimulated control cells. Results are the means of three experiments. Error bars represent s.e.m.