Figure 5

Kalirin inhibits transferrin uptake by PC12 cells. A. PC12 cells were transiently transfected with vectors encoding GFP (green arrows), GFP-IgFn (yellow arrows) or Kalirin12-GFP (red arrows). After 48 h, cells were fed with serum-free medium containing 50 μg/ml AlexaFluor546 transferrin; 10 min later, cells were rinsed in serum-free medium, fixed and analyzed. All images were taken using the same exposure time; scale bar, 10 μm. B. Endocytosis of transferrin was scored as normal if fluorescent puncta were readily detected in the interior of the cell and reduced if they were absent entirely or not centrally collected. Results are percentage of total number of transfected cells per group. Data are from three separate experiments. Total N for each group: non-transfected, 34; GFP, 24; GFP-IgFn, 25; Kalirin12-GFP, 20. Using chi square analysis, p < 0.001 for group distribution, GFP vs. GFP-IgFn, GFP vs Kalirin12-GFP and GFP-IgFn vs Kalirin12-GFP.