Cells expressing scinderin showed high levels of antigen CD41a (fibrinogen receptor) as a result of activation of the MEK-ERK1 pathway.
(A) Fluorescence microscope images of cells stained with a CD41a antibody. (B) Image analysis of the fluorescence intensity (A.U., arbitrary units) of the cells described in panel A. Bars represent mean ± SEM of 6 preparations (10-20 cells each) of pcDNA3-transfected cells and 19 preparations (5-10 cells each) from 6 different clones of pcDNA3-Sc–transfected cells. Fluorescence intensity was expressed per cell (*P < .01) and per μm2 of cell surface (**P < .05). (C) pcDNA3-Sc–transfected cells treated with 75 μM PD98059 for 4 days showed a decrease in the expression of CD41a (**P < .05) and (D) in cell volume (*P < .01). (E) The number of pcDNA3-Sc–transfected cells displaying surface blebs was also decreased by PD98059 treatment (**P < .05). (F) Western blots with an ERK1 antibody show the expression of the protein in untreated pcDNA3 and pcDNA3-Sc–transfected cells (C) and in the cells after treatment with 75 μM PD98059 (PD) for 4 and 8 days. Tubulin was used as gel-loading control. Bars represent the average from 6 different experiments (*P < .01; **P < .001).
