Figure 9.

Interaction between FAK and tension-signaling components determines FA size and localization. (A and B) WT and KO MKs were plated on FN for 12 h before a 12-h treatment with the ROCK inhibitor Y27632 or the MLCK inhibitor ML7. Mean of three independent experiments ± SD. Immunofluorescence microscopy (A) and quantitative analyses (B) show that ROCK or MLCK inhibition relaxes the constricted actin cytoskeleton, suppresses robust FAs marked by VIN, and promotes cell spreading in KO MKs. Black asterisks indicate significant differences between WT and KO (P ≤ 0.05), and green asterisks indicate significant difference of treated cells from untreated cells (P ≤ 0.05). (C) Box-and-whisker plots showing the relative integrated fluorescence intensity of VIN-stained FAs in the presence of 5 μM Y27632, 5 μM nocodazole, 5 μM ML7, or 2 μM blebbistatin. Box-and-whisker plots indicate the mean (squares), 25th percentile (bottom line), median (middle line), 75th percentile (top line), 5th and 95th percentile (whiskers), and minimum and maximum measurements (x). n ≥ 10 for each condition. Green asterisks indicate significant differences (P ≤ 0.05) of treated cells from untreated cells, and black asterisks indicate significant differences (P ≤ 0.05) between treatments by analysis of variance and Tukey post hoc test.