Fig. 5.

The effects of the HGPS mutation on different stages of the cell cycle. Mitotic HeLa cells expressing GFP-LAΔ50 were fixed and stained for immunofluorescence with anti-LA (red). The GFP N-terminal tag appeared green. (a) A cell in the metaphase–anaphase transition showing that LA was diffusely organized throughout the cytoplasm because of its normal disassembly during mitosis, whereas GFP-LAΔ50 was seen mainly in large cytoplasmic aggregates. (b and c) The same types of aggregates remained in cells in telophase/early cytokinesis (b) and after daughter cell nuclei had reformed in early G₁ (c). (d–f) HGADFN003 cells processed for immunofluorescence with an Ab directed against proliferating cell nuclear antigen. Passage 6 cells with the typical pattern were seen in early (d) or mid-late (e) S phase, whereas f depicts the only pattern detected in a passage 26 cell containing a lobulated nucleus. This latter staining appeared similar to an early S-phase pattern. (Scale bars = 5 μm.)