Figure 8. Dorsal stress fibers exhibit different lifespans depending on their interactions with the actomyosin network.

(A) Individual frames from a representative movie of GFP-actin expressing cell demonstrating the disassembly of non-contractile dorsal stress fibers located at the ‘unstable’ zone. Bar, 5 μm. (B) Frames from a movie of GFP-actin expressing cell displaying the disassembly of the non-contractile dorsal stress fiber region extending beyond the contractile transverse arc. Bar, 5 μm. (C) Quantification of the stability of dorsal stress fibers at different cell regions revealed that these actin bundles are more stable at the sides of the leading edge as compared to the central region of the leading edge. Amount of dorsal stress fibers (%), remaining after 30 min follow-up, is shown (mean +/- SD), n = 5 cells, 8–20 fibers per cell were analysed. (D) Representation of the ‘unstable’ and ‘stable’ dorsal stress fiber zones in U2OS cells.

DOI: http://dx.doi.org/10.7554/eLife.06126.021

Figure 8—figure supplement 1. Enlargement and lifespan of focal adhesions depends on their location in migrating cells.

(A) Dorsal stress fiber-attached focal adhesions on the sides of a migrating cell (orange arrowheads) become more prominent in size and participate in formation of contractile ventral stress fibers. In contrast, dorsal stress fibers and focal adhesions in the central region of the leading edge (red arrowheads), which do not participate in the formation of ventral stress fibers, diminish in size and eventually disappear. Image frames are from movies of U2OS cells expressing GFP-actin and CFP-zyxin. Bar, 10 um. (B) Quantification of the areas of individual focal adhesions (fold change in comparison to the initial area of the adhesion) located at the tips of dorsal stress fibers and maturing ventral stress fibers. Cells were imaged for one hour and the mean values (+/- SD) of focal adhesions from 7 cells are shown.

DOI: http://dx.doi.org/10.7554/eLife.06126.022