Figure 1

Accumulation of SFKs and tyrosine-phosphorylated proteins in the centrosome during G₂ and M phases. (a) HeLa S3/Fyn or HeLa S3/TR/c-Src cells treated with or without Dox for inducible expression were triply stained for Fyn or c-Src (green), γ-tubulin (red), and DNA (blue). Cells entering the late G₂ and M phases were assessed by chromosome condensation. Scale bars, 10 μm. (b) HeLa S3/TR, HeLa S3/TR/c-Src, or HeLa S3/Fyn cells were treated with or without Dox for inducible expression. A Western blot analysis was conducted using the indicated antibodies. (c) Centrosomal endogenous c-Src cells were triply stained for c-Src (green), γ-tubulin (red), and DNA (blue) in Caco-2 cells. Scale bar, 20 μm. (d) Parental HeLa S3 cells were treated with 20 µM PP2 or 0.1% dimethyl sulfoxide (DMSO, solvent control) for 6 h. Double staining for pTyr (green) and DNA (red) was performed and the fluorescence intensity of pTyr in the centrosome of each cell was quantitated from three independent experiments (n = 121 cells for DMSO, n = 118 cells for PP2 treatment). Bars represent the means ± S.D. of a representative experiment. p values were calculated by the Student’s t-test. Scale bar, 10 μm. (e) Parental HeLa S3 cells were triply stained for pTyr (green), γ-tubulin (red), and DNA (blue). Scale bar, 10 μm. (a,c–e) White, white with red, and yellow arrows indicate the centrosome position, centrosomal Fyn or c-Src accumulation, and endogenous tyrosine-phosphorylated proteins or endogenous c-Src in the centrosome, respectively.