Fig. 5.
PABP1 and PABP4 are not determinants of poly(A) RNA localisation. (A) Knockdown of PABP1 and PABP4 protein in siRNA-treated HeLa cells was confirmed by western blotting. GAPDH was used as a loading control. (B) After transfection with a control siRNA (yellow bars) or PABP1 and PABP4-specific siRNAs (orange bars), HeLa cells were treated with 50 J/m2 UV followed by 15 hours incubation, and adherent cells assayed for annexin V–FITC and PI staining by flow cytometry. Percentage annexin V-negative and PI-negative cells are shown. Data represented as means ± s.e.m. of three independent experiments. (C) Control or PABP1 and PABP4 siRNA-transfected HeLa cells were treated with 50 J/m2 UV followed by 15 hours incubation or with 0.5 mM sodium arsenite for 1 hour. Poly(A) RNA was detected by FISH using a Cy3–oligo(dT)40 probe (red). DNA was stained by DAPI (blue). Scale bar: 20 μm. (D) siRNA-transfected HeLa cells were treated with 50 J/m2 UV followed by 3 hours incubation or with 0.5 mM sodium arsenite for 1 hour. The cells were then fixed and G3BP (red) detected by immunofluorescence. DNA was stained with DAPI (blue). Scale bar: 20 μm.