Fig. 8. Myotubularin and plasma membrane remodeling. (A) HeLa cells transfected with either wild-type or D278A substrate-trap mutant were left untreated (-) or were treated with cytochalasin D at 400 µM for 2 hours (+). Co-localization with endogenous actin showed disruption of the actin filaments, while both myotubularin constructs still showed labeling of the plasma membrane. (B) D278A mutant (in green) transfected in HeLa cells showed no co-localization with focal adhesion labeled by an anti-vinculin antibody (in red). (C) Co-localization of different myotubularin constructs with Rac1-induced plasma membrane ruffles in COS cells co-transfected with constitutively activated Rac1 V12 (flag-tagged). Wild-type myotubularin and its N-terminal part localized to the ruffles while the del(233-237) construct did not.