Fig. 6.

Requirement of FAK signaling for nocodazole-induced traction stress increase in myosin-II-inhibited cells. (A–D) Cells were pretreated sequentially with PF 573228 and blebbistatin to inhibit both FAK and myosin II (A,C), then with nocodazole (B,D). The addition of nocodazole caused neither morphological responses, as shown by phase contrast images (A,B), nor an increase in traction stress (C,D). (E) Quantification of average stress. Similar results were obtained using FAK knockout cells However, knockout cells re-expressing FAK showed a significant increase in traction stress after the addition of nocodazole. *P<0.05. Error bars indicate s.e.m. Scale bar: 25 μm. n=12, 13, 37, 39, 13 and 22 cells for PF 573228, PF 573228 and nocodazole, FAK^−/−, FAK^−/− and nocodazole, FAK rescue, and FAK rescue and nocodazole, respectively. The timeline indicates the temporal sequence of drug manipulation.