Figure 6.

Zyxin unbinding kinetics in response to strain evaluated by FRAP. (A) Average values of the unbinding constant of zyxin as a function of the exposure time to Y-27632 (error bars indicate s.e.m.; N = 7, N = 3 and N = 4 recovery curves, for 0, 3 and 14 min after treatment; Mann-Whitney test, *p-value = 0.012 compare to t = 0 min). (B) Recovery curves for zyxin in control (black) and Y-27632-treated cells for 3 min (red) and 14 min (blue), together with the curves fit to the data using the FRAP model for focal adhesions described in Materials and Methods. (C) Average values of the unbinding constant of zyxin as a function of normal strain. As a rigid substrate control, FRAP experiments were performed in cells grown on coverglass. N = 6 recovery curves were analyzed from different focal adhesions of 5 and 6 cells at 13% and 30% strain, respectively. N = 12 curves from 8 cells cultured on coverglass; error bars indicate s.e.m.; Mann-Whitney test, *p-value = 0.026, **p-value = 0.00075, both compared to 13% strain. (D) Representative recovery curves for zyxin in cells under 13% normal strain (blue), 30% normal strain (red) and grown onto a rigid substrate (black), together with the curves fit to the data using the FRAP model for focal adhesions described in Materials and Methods.