Fig. 5. Indirect immunofluorescence analysis of HA-tagged lamin A (LaA, A-E) and lamin C (LaC, G-K) alleles expressed in Lmna^(–/–) fibroblasts. In each case the cells were labeled with the 12CA5 anti-HA antibody. Of the lamin A alleles only LaA N195K (C) fails to localize to the nuclear envelope. By contrast, none of the lamin C alleles, including wild-type lamin C (G) associate with the nuclear envelope. In about 35% of transfected cells spherical intranuclear LaC L85R aggregates could be observed (H, arrowheads). Appropriate localization of wild-type HA-lamin C (L) to the nuclear periphery (arrows) could be restored by cotransfection with wild-type lamin A (F). In this case, the nontagged lamin A was detected with the rabbit anti-lamin A-specific antibody (F).