Matrix degradation under actin-rich membrane protrusions. MDA-MB-231 cells were transiently transfected with tagRFP-LifeAct, cultured on fluorescent matrix for 24 h, and subjected to time-lapse video microscopy. Images were acquired every 15 s for 5 min and are displayed at 3/10 of a second per frame. Bars, 10 µm.
