Figure 3.

α-Actinin-4 knockout is rescued by either expression of α-actinin-4–GFP or α-actinin-1–GFP. The numbers of stress fibers in rescue cells are negatively correlated to the amount of expression and the affinity of actinin for actin. A, micrographs α-actinin-4 knockout cells rescued with either actinin-4, actinin-1, or mutant K255E–actinin-4 tagged with GFP and stained for actin. A.U., arbitrary units. Scale bars are 20 μm. B, graphs showing the mean fluorescent intensity of actin along stress fibers as a function of different α-actinin's expression in the knockout cell line ±95% confidence interval. C, graph showing the number of stress fibers as a function of the mean GFP fluorescence in that cell in WT and K255E rescued cells.