Fig. 7. Stretching of substrata induces zyxin accumulation at peripheral FAs in cells in which myosin II is inhibited. Cells grown on an FN-coated elastic substratum were treated with 100 µM blebbistatin for 30 minutes and then the substratum was uniaxially stretched (50% for 3 minutes) in the presence of blebbistatin. (A-D) Cells with (C,D) or without (A,B) stretching of the substratum were double stained for 5 integrin (A,C) and zyxin (B,D). (D) Arrows indicate accumulated zyxin at peripheral FAs. Double-headed arrow indicates the direction of the stretch axis. (C) Red arrows indicate the central 5-integrin clusters that are not associated with zyxin accumulation. (E-I) Stretched cells were double stained for F-actin (E,G, red in I) and zyxin (F,H, green in I). The boxed area in E is shown at higher magnification in G-I: zyxin was accumulated along F-actin bundles near their ends. (E) Zyxin was accumulated along F-actin bundles that were oriented parallel to the stretch axis (cell 1) but was not found along the bundles perpendicular to the axis (cell 2). Folds perpendicular to the stretch axis (arrowheads in E,F) were generated by relaxing the stretched substrata for observations. Scale bars: 20 µm (A-F); 10 µm (G-I). (J) The fluorescence intensity of zyxin near the end of an F-actin bundle was plotted against the angle of the bundle to the stretch axis. The fluorescence intensities within 6 µm along the F-actin bundle from its tip were measured and normalized with respect to the maximum value. A total of 104 F-actin bundles in 27 cells were plotted. The red line represents the linear fitting. CC, correlation coefficient.