Fig. 6. Fluorescence microscopy of cells stably expressing fluorescent CK chimeras depicting CKF network disruption upon treatment with OV. (A) Inverse contrast fluorescence micrographs taken from living AK13-1 cells at 0.2 minute intervals during OV treatment (10 mM) showing HK13-EGFP fluorescence. The image series starts 1 minute after addition of OV and displays the rapid disruption of the CKF network. Note that the breakdown of CKFs into small granules (arrows) is paralleled by dissociation of desmosome-anchored filaments (arrowheads). (B-D) Fluorescence microscopy of hepatocellular carcinoma-derived PLC cells PK18-5 stably expressing fluorescent fusion protein HK18-YFP. Cells were fixed with methanol/acetone prior to (B) or 15 minutes after addition of 50 mM OV (C). Note the loss of filaments and the formation of rods and granules in C. D shows inverse contrast images at high magnification that were taken from a live cell recording (Movie 1; recording intervals 1 second) demonstrating details of OV-induced CKF-disruption. Note the straightening of CKFs (arrows) prior to fragmentation into rods and granules. Bars, 10 µm in (A-C) and 1 µm in (D).