Figure 4
From: Calponin-3 is critical for coordinated contractility of actin stress fibers
Loss of Calponin-3 impairs stress fiber contractility. (A) Control, Cnn3 knockdown, and Cnn3 knockout U2OS cells transfected with GFP-actin were imaged for 30 min, and frames were captured every 30 s. Representative time-lapse frames for each condition are presented. Examples of stress fiber breakage events in Cnn3 knockdown and knockout cells are marked by yellow asterisks (‘*’). Scale bars, 10 μm. Please, see supplemental videos 1–3 for better visualization of abnormal stress fiber dynamics and breakage events. (B) Time-lapse frames from the region indicated by an orange box in panel ‘A’ representing a detailed view of stress fiber breakage event. Green arrowheads show the ends of this individual actomyosin bundle, yellow star the breakage point, and red arrowhead one end of the retracting fiber after the breakage. (C) Numbers of breakage events in each cell type was quantified in 8 cells per each condition. Statistical significance was assessed with Mann-Whitney test; p < 0.001 (***).
