Fig. 7: Brillouin Microscopy and FRAP data acquisitions on G3BP1-GFP condensates in presence or absence of doxycycline-induced aberrant FUSP525L.
Here, FUSP525L presence in G3BP1-GFP granules was confirmed via immunofluorescence (Supplementary Fig. 9; Supplementary Note 2). A First panel: FRAP data are shown as mean (solid curve) ± SD (shaded areas), obtained from n = 3 independent biological replicates (in every replicate, at least 10 cells were acquired). Second panel: immobile fractions of G3BP1-GFP condensates without doxycycline (blue and orange distributions, also shown in Fig. 5C, second panel) and with doxycycline (yellow and violet distributions). Here, ARS treatment increased immobile fractions in both DOX- (p = 5*10-12) and DOX+ (p = 1*10-5) samples; instead, DOX treatment (inducing FUSP525L expression) did not modify the mobility of either ARS- (p = 0.94) or ARS+ (p = 0.998, red bar and text) samples. Statistical analyses were performed with two-sided Kruskal-Wallis tests followed by multiple comparison post-hoc tests. Third panel: half-recovery times of G3BP1-GFP condensates in DOX- (these data are shown in Supplementary Fig. 8A, second panel) and DOX+ cells. Likewise immobile fractions, ARS treatment increased half-times in both DOX- (p = 2*10-16) and DOX+ (p = 1*10-20) samples, while DOX treatment did not modify times of either ARS- (p = 0.998) or ARS+ (p = 0.997, red bar and text) samples. Statistical analyses were performed with two-sided, one-way ANOVA followed by multiple comparison post-hoc tests. B Left: Brillouin shift maps of DOX + G3BP1-GFP cells untreated and treated with ARS, together with fluorescence maps of HOECHST (labeling nuclei) and GFP (labeling exclusively G3BP1). Black dotted shapes indicate granules in Brillouin maps. Scale bars = 5 µm. Right: Brillouin shifts of G3BP1-GFP condensates in absence (already shown in Fig. 5B, second panel) or in presence of FUSP525L, from n = 3 independent biological replicates (in every replicate, at least 5 cells were acquired). As in FRAP, ARS treatment increased Brillouin shifts of both DOX- (p = 0.027) and DOX+ (p = 0.017) samples. Unlike FRAP, however, DOX treatment increased Brillouin shifts of ARS+ condensates (p = 2*10-5, red bar and asterisks); ARS- samples showed no differences (p = 0.71). Statistical analyses were performed with two-sided, one-way ANOVA followed by multiple comparison post-hoc test. ns not significative; *: p < 0.05; ****: p < 0.0001. Source data are provided as Source Data file.
