Fig. 4.

Significant nuclear deformation in response to local protrusion proximal to the nuclear surface requires myosin II activity and an intact LINC complex. (A) The formation and retraction of a lateral protrusion near the nucleus in control, Y27-treated and KASH4-overexpressing cells. Noticeable nuclear deformation is observed in control cells but not in myosin-II-inhibited or LINC-complex-disrupted cells. Scale bars: 10 µm. (B) Outlines of the protrusion (top) and retraction (bottom) of the newly formed local protrusion and the associated nuclear shape at the different time points. (C) Quantification of nuclear deformation upon the formation of lateral protrusion as measured by the strain in the nuclear width at the maximum deformation point. Strains represent the change (final−initial) in the nuclear width at the maximum deformation point divided by its initial value. Error bars represent s.e.m. N≥17 for each condition (for ‘Normal’, 121 cells were observed, 102 cells had protrusions and 102 cells were analyzed for strain calculation). For Y27-treated cells, 178 cells were observed, 150 cells had protrusions and 150 cells were analyzed for strain calculation. For KASH4 expression, 25 cells were observed, 17 cells had protrusions and 17 cells were analyzed for strain calculations. Each cell was observed for more than 8 hours. ^#P<0.00001.