Figure 7.

Gle1A self-association is perturbed in vitro by modification of Ser⁸⁸–Thr¹⁰² and is required for proper SG response. A–C, phosphorylation of Gle1A perturbs Gle1A association. Representative EM images for bacterially expressed and purified recombinant Gle1A^1–360 (A), gle1A^{1–360 6A} (B), and gle1A^{1–360 6D} (C) proteins are shown. Insets depict disk outline (dashed lines) with major and minor axes indicated (solid lines). Scale bar, 50 nm. D, circularity was quantified from at least 171 disks per protein and analyzed by unpaired t test. Major axis/minor axis represents the ratio of longest to shortest diameter of the elliptical as shown by insets in A–C. A ratio of 1 indicates a circle. Error bars represent S.D. E and F, GFP-gle1A-Fin_major exhibits reduced capacity for rescuing SG defects. E, CTRL or GLE1 siRNA–treated cells were transfected with GFP, GFP-GLE1A, or GFP-gle1A-Fin_major plasmids, heat-shocked for 60 min at 45 °C, and processed for immunofluorescence using anti-G3BP antibodies. Scale bar, 10 μm. F, quantification from three independent experiments, performed in duplicate, is shown for the number of SGs in CTRL or GLE1 siRNA–treated cells expressing the indicated plasmids. Data were quantified for at least 65 cells per condition and analyzed using a two-tailed, unpaired t test. Error bars represent S.E.