Fig. 6. Effects of the specific MEK and p38^MAPK inhibitors, PD98059 and SB203580, on the levels of nuclear cPLA-. (A) Cells (1x10⁵) were seeded onto coverslips and grown overnight. Cells were then pre-treated with PD98059 or SB203580 (20 µM in HEPES/Tyrode's buffer) for 30 minutes at 37°C (control cells were incubated with buffer alone). cPLA- was detected by immunofluorescence microscopy. Bar, 10 µm. (B) The level of nuclear staining in sections taken through the control, PD98059- and SB203580-treated cells were quantified. The plot shows average intensity (in arbitrary units)±s.e.m. (n=90, data from three independent experiments). (C) Nuclei were isolated from control and PD98059-, SB203580- and staurosporine-treated cells. 20 µg of total homogenate (T) and nuclear (N) proteins were analysed by western blotting. (D) Quantification of the relative amounts of cPLA₂- present in the nuclear and total fractions (expressed as a percentage of the total±s.e.m., n=3)