Figure S1. Profilin accumulates in centrosomes during mitosis.

Immunofluorescence staining of profilin and γ-tubulin in B16 cells followed by intensity measurements of centrosomal fluorescence reveals increased labeling of Pfn in mitotic cells. (A) Cells captured during interphase (top) and during metaphase (bottom). Wide-field microscopy after simultaneous staining for Pfn, γ-tubulin (γ-Tb) and DNA (DAPI). The centrosomal region is shown at higher magnification at the bottom left corner (inset); the arrow points to the centrosome. (B) Bar graph illustrating fluorescence intensity of Pfn labeling in a standardized circular area (1.2 μm²) around the centrosomes in interphase (n = 31) and metaphase cells (n = 44) as determined by wide-field microscopy. Mean ± SEM, **P < 0.01. (C) High-resolution confocal microscopy (AiryScan) of a metaphase cell after simultaneous staining for Pfn, α-tubulin (α-Tb), and DNA (DAPI). Scale bars 10 μm.