Figure 6

Expression of the NEM-linked G268R and D286G-actin mutants. Expression of the EGFP-tagged G268R-actin in either undifferentiated myoblasts (A) or differentiated myotubes (B) lead to good integration of the actin mutant into endogenous actin structures. In contrast, the D286G-isoform stayed delocalized in the majority of transfected myoblasts (C). After differentiation, EGFP fluorescence revealed the formation of giant rods in the cytoplasm of D286G-transfected myotubes (D, E; long arrows) that did not co-stain with phalloidin or alpha-actinin (D', D", E', E"; long arrows). In some myotubes, mutant actin integrated into stress fibres, but their structures were abnormally wavy (E, E"; short arrows).