Exo70 is enriched at the centrosome of B cells. (A) Confocal images of centrin-GFP–expressing cells (shown in red) activated with BCR ligand–positive or –negative beads for the indicated times. Exo70 (green) and LAMP-1 (cyan). Scale bar: 3 µm. (B) Exo70 and centrosome polarity indexes were calculated from the images in A. ****, P < 0.0001; two-way ANOVA with Sidak’s multiple comparison test; n ≥ 39 cells from three independent experiments. (C) Correlation analysis between Exo70 and centrosome polarity indexes from B cells resting (red) and activated for 120 min (blue). (Spearman correlation coefficient). (D) Left: Scheme depicting the method used to quantify centrosome-associated Exo70. Right: Quantification of centrosome-associated Exo70 during B cell activation. ****, P < 0.0001; two-way ANOVA with Sidak’s multiple comparison test; n ≥ 64 cells from three independent experiments. (E) Pearson’s coefficient between Exo70 and centrin-GFP at different times. *, P = 0.0112; ***, P = 0.0009; two-way ANOVA with Sidak’s multiple comparison test; n ≥ 52 cells from two independent experiments. Error bars are mean ± SEM.