Figure 3: YAP1 drives flow-induced cellular motility.

(a) YAP1 and TAZ localize to the nucleus in response to WSS (6 h). Nuclei were detected by Draq5. Scale bar is equivalent to 25 μm (n=3 independent experiments). Three or more images were taken in each experiment and representative images are shown. (b) The frequency of YAP1/TAZ nuclear localization significantly increases with fluid flow (n=3 independent experiments; two-tailed t-test, **P<0.0001). (c) Consistent with translocation to the nucleus, WSS stimulated dephosphorylation of serine-127 YAP1 and slightly elevated TAZ expression. (d) Still photos from time-lapse DsRed movie file for the 8xGTIIC-DsRed-Monomer TEAD reporter positive cells with static or WSS. Scale bar, 50 μm. (e) Efficiency of YAP1 and TAZ knockdown was measured by western blot analysis of PC3 cells transfected with control siRNA or siRNAs against YAP1 or TAZ. (f) Time-lapse imaging was used to measure motility during 6 h of WSS or static culture. (g) Quantification of migration speed of individual cells shows that knockdown of YAP1, but not TAZ, impairs motility stimulated by WSS (n=3 independent experiment, Kruskal–Wallis one-way ANOVA, **P<0.001). (h) Motility plots from time-lapse images when YAP1/TAZ downstream target, AMOTL2 or CTGF, was absent. (i) AMOTL2 and CTGF knockdown did not affect enhanced migration speed induced by WSS. Error bars represent±s.e.m.