The absence of polymerization-competent actin monomers leads to the delocalization of Lmod, but not Tmod. (A). Representative immunolocalization of Lmod (left panel) and Tmod (right panel) in cardiomyocytes after 15-min treatment with 20 μM LatB. Cells were costained with phalloidin to visualize F-actin and with an antibody against the Z-disk protein α-actinin. Bars, 10 μm. (B) Analysis of Tmod and Lmod localization 5/15/30 min after treatment with 20 μM LatB. Incubation of cardiomyocytes with LatB induces rapid dissociation of Lmod from sarcomeres, whereas the localization of Tmod was not affected. For each experiment, >200 cells were analyzed. Data represent averages from three independent experiments; error bars, ±SEM. (C) LatB treatment induces Lmod delocalization to the perinuclear region of cardiomyocytes, as well as to rods inside the nucleus (arrowheads). Bars, 10 μm.