Src Kinases Regulate De Novo Actin Polymerization during Exocytosis in Neuroendocrine Chromaffin Cells
Figure 7
Cytochalasin D inhibits the new formation of actin filaments and disturbs the subplasmalemmal actin network in ACCs.
(A–B) Cultured chromaffin cells were permeabilized in the presence of 0.3 µM AF488-G-actin, 10 µM free Ca2+ and 4 µM of CytoD or the vehicle DMSO. Note that CytoD treatment drastically inhibited the de novo actin polymerization. (C–F) Intact cells were incubated for 10 minutes with 4 µM CytoD, or the vehicle DMSO, at 37°C, then maintained resting conditions (C–D) or stimulated with 20 µM ionomycin (E–F), fixed, stained with phalloidin-rhodamine B and visualized by confocal microscopy. Note that Cyto D significantly reduced the cortical F-actin signal in both, resting and stimulated cells. A, C and E show representative confocal images for each condition. Scale bar = 10 µm. B, D and F correspond to quantification of the cortical actin fluorescence intensity, where data are means ± SEM from at least 15 cells per each condition. *p<0.05 compared to DMSO.