Fig. 5. Lamins, emerin and LAP2ß are more readily extracted from cells of the FPLD patients than from control cells. (A) Fibroblasts from control individuals and FPLD patients were lysed in SDS, and whole-cell extracts corresponding to 1.2, 2.5, 3.7 and 5x10⁵ cells were analyzed by immunoblotting using anti-lamins (LA/C and LB), anti-emerin and anti-LAP2ß antibodies. Note the increase in intensity of the different signals that parallels the increase in cell number, with a saturation of the signals at 5x10⁵ cells. Note also the similar intensity of signals for each protein in both panels. (B) Control (C) and fibroblasts from FPLD patients were sequentially extracted under increasingly stringent conditions (see Materials and Methods). Soluble fractions (S1, S2 and S3), insoluble material (Ins.) and proteins from whole-cell extracts (Total) were analyzed in parallel by immunoblotting. Samples loaded in each lane correspond to an identical cell number. Note that lamins, emerin and LAP2ß are extracted at a lower stringency in cells from the patients than in control cells. Similar data were obtained with cells from patient JM (LaA/C R482Q) or from patients KN and LM (R482W). A representative blot is shown.