Figure 2.

Orthovanadate-induced invadopodia ring expansion results from the coordinated processes of invadopodia assembly at the periphery and disassembly at the ring center. BHK-RSV cells plated for 24 h were transiently transfected with cDNA encoding cortactin-GFP. The expressed fusion protein was followed by time-lapse videomicroscopy for 130 min at room temperature, in the absence (control) or in the presence of 5 mM orthovanadate (+Na₃VO₄) by using a confocal microscope. Bar, 10 μm. Image deconvolution and zoom, using MetaMorph software revealed the individual invadopodia within the invadopodia rings. Merge of the images in false colors from 0 min (red), 80 min (blue), and 130 min (green) allowed following each invadopodia along the time course of the experiment. According to the color pattern, five regions could be defined from the center to the periphery of the ring that reflected both the spatiotemporal organization of invadopodia within the ring and the relative immobility of the individual invadopodia.