Interference with the perinuclear actin rim by perinuclear-localized Gelsolin (GSN) (a) Fluorescence microscope micrographs of confluent B16–F10 cells either non-transfected or expressing GFP-KASH2ext, GSN-GFP-KASH2ext, or GFP-KASH2 induced to migrate in the wound healing assay for 3 h stained for filamentous actin (Phalloidin) and DNA (Hoechst). Lamin B1 was immunostained. The edge of the scratch is in the top region of each micrograph. The nuclei in the orange rectangles are magnified on the left side. Scale bar: 20 μm. (b) Quantification of the effect of GFP-KASH2ext, GSN-GFP-KASH2ext, and GFP-KASH2 on perinuclear actin filaments. In each experiment, 20–30 cells of each transfection were measured for the Phalloidin signal at the nuclear periphery. The average mean intensity was calculated and normalized to non-transfected cells. The average mean intensity in three independent experiments ± s.e. is presented. Statistical significance was evaluated by the Student’s t-test, * p < 0.05. (c) Quantification of the effect of GFP-KASH2ext, GSN-GFP-KASH2ext, and GFP-KASH2 on the total amount of actin filaments. In each experiment, 20–30 cells of each transfection were measured for the mean Phalloidin signal in the whole cell. The average mean intensity was calculated and normalized to non- transfected cells. The average mean intensity in three independent experiments ± s.e. is presented. Differences between samples were not significant statistically by the Student’s t-test (d) Laser scanning microscope micrographs of non-transfected and transfected B16–F10 cells as in a.