Protein Methylation and Stress Granules: Posttranslational Remodeler or Innocent Bystander?
Figure 2
Inhibiting cellular methylation alters the composition of FMRP-containing stress granules. (a) HeLa cells were either treated for 24 hrs with 10 μM AdOx to reduce cellular methylation or left untreated. Subsequently, the cells were treated with 0.5 mM sodium arsenite for 20 minutes to induce the formation of stress granules and then immunostained with antibodies, which detect FMRP (red) and its paralog FXR1P (green). The cells were then imaged by confocal microscopy. The upper panels show a region within a cell exhibiting a robust amount of stress granules. FMRP and FXR1P colocalizing stress granules (lower panels) were computed using Image J by multiplying the red and green fluorescence intensities according to Kayali et al. [28]. The arrows mark stress granules in the AdOx-treated cell which are devoid of FXR1P. (b) The graph quantifies the extent of FMRP/FXR1P colocalization as a function of AdOx treatment for more than 800 stress granules for each treatment (P < .01, ANOVA). All of the results have been adapted from Dolzhankaya et al. [19, Figure 6 and Table 1].
