Figure 5

Heat shock induced YB-1 aggregates represent bona fide SGs. (a) Confocal immunofluorescence analysis of YB-1 (red) and G3BP1 (magenta) in PAC2 cells at 26 °C (control) or after heat shock at 45 °C for 45 minutes. Cellular colocalization is present in perinuclear aggregates indicated by white arrows; (b) confocal immunofluorescence of YB-1 in PAC2 cells treated with cycloheximide (20 µg/ml) at 26 °C (upper part of the panel) or after heat shock at 45 °C for 45 minutes (lower part of the panel). Controls are represented in the left part of the panel. White arrows indicate YB-1 positive aggregates (lower panel, left). Yellow arrows indicate the bulk of the protein not forming aggregates (lower panel, right); (c) quantification of YB-1 positive SG aggregate dimensions in PAC2 cells documented in the cycloheximide treatment analysis presented in panel b. Statistical analysis was performed using 1-way ANOVA followed by Tukey’s multiple comparisons test. Levels of significance are indicated (*p = 0.05) (see also Table S1).