Fig. 4.

Myosin II is rapidly recruited to the cell cortex in response to load. (A) Load causes myosin II to be recruited to the cell cortex. Blebs are indicated by an asterisk (*). (Scale bar: 10 µm.) (B) Quantification of cortical enrichment of myosin II under load. Data are represented as mean ± SD for n ≥ 20 cells for each case; one-way ANOVA, *P < 0.0005. (C) Time course showing that myosin II is rapidly recruited to the cell cortex under load. Data are given as mean ± SEM; n = 10 cells; one-way ANOVA, P < 0.005. Cortical enrichment is calculated by measuring the ratio of fluorescence intensity of membrane and cytoplasm around the cell. Ax2 cells expressing myosin II–GFP (GFP–MhcA) and chemotaxing to cyclic AMP under 0.5% agarose gels were used throughout. In time courses, load is applied at t = 0.