FIGURE 3.
Expression of other P-body proteins does not induce significant eIF2α phosphorylation. A, A549 cells were transfected with plasmids expressing 1 μg/1.5 × 105 cells of V5-Caf1 (top left panel), V5-Ccr4 (top right panel), V5-Pan2 (bottom left panel), and V5-Pan3 (bottom right panel). Cells were incubated with antibodies against V5 (green) and phospho-eIF2α (red). The highlighted area of the larger merged color image is separated into its constituent colors in the bottom panels. B, quantification of eIF2α phosphorylation in response to expression of several P-body contained proteins as described under “Experimental Procedures.” **, p < 0.0001. Error bars indicate mean ± S.E. C, deconvolution microscopic analysis of cytoplasmic distribution of endogenous Dcp1a determined by plotting intensity profiles along the white line (inset shown in grayscale) transecting several P-bodies. D, cytoplasmic distribution of GFP-Dcp1and endogenous Rck/p54 was determined as in C. A.U., arbitrary units.