FIGURE 2.

G3BP1 is methylated by PRMT1 and PRMT5 in vitro. Recombinant MBP-G3BP1 was incubated with a panel of purified GFP-tagged PRMTs in in vitro methylation reactions as described under “Experimental Procedures.” b and c, recombinant proteins bearing deletions of the indicated domains were incubated with GFP-PRMT1 or GFP-PRMT5, respectively. Loading controls of PRMTs are shown as Western blots against GFP (a, lower panel) or for G3BP constructs via ponceau staining (b, c, lower panel). U2OS cells were arsenite-treated and processed for IFA. Cells were stained for endogenous PRMT1 (d) or PRMT5 (e) in green, and counterstained with Tia1 in red. Yellow squares indicate regions depicted in vignettes. Original magnification: 63×.