Fig. 7. Transfection of AKAP149-derived RVXF peptides in G1 phase elicits lamin phosphorylation and disassembly. (A) RAXF or RVXF peptides were transfected for 1.5 hours using DOTAP in early G1-phase HeLa cells starting at 0.5 hour after release from mitotic arrest. Nuclei and NEs were purified and proteins immunoblotted using indicated antibodies. – indicates untreated cells; DOTAP indicates cells exposed to DOTAP alone. (B) Nuclei isolated from RVXF- or RAXF-transfected G1 cells were analyzed by immunofluorescence using anti-B-type lamin and anti-lamin A/C antibodies. Bar, 10 µm. (C) G1-phase cells were transfected with peptides as in A, while under metabolic ³²P labeling. Nuclei were isolated, A- and B-type lamins were immunoprecipitated (IP) and analyzed by autoradiography (³²P) and immunoblotting (Blot) using anti-lamin A/C and anti-B-type lamin antibodies. A, B and C point to lamin A, B-type lamins and lamin C, respectively.