Figure 4.

FAK^Y397 activation is involved in integrin α11 cytoplasmic tail-mediated cell proliferation and migration. (A) Effect of FAK and ERK inhibition in α11-mediated cell proliferation. _Huα11-WT and _Huα11-1171 cells were allowed to attach on collagen I or fibronectin in presence of either DMSO or U0126 (20 µM) or PF573228 (10 µM) in reduced serum conditions for 24 hours. Attached cells were fixed, stained with 0.1% crystal violet and absorbance was read at 595 nm. Results were expressed as mean ± standard deviation of at least three replicates pooled from three independent experiments. (B) Integrin α11 tail-mediated ERK activation is dependent on FAK^Y397 activation. Serum starved _Huα11-WT and _Huα11-1171 cells were treated with DMSO or U0126 or PF573228 and allowed to attach on collagen I for 30 minutes. After 30 minutes, cells were lysed, and the lysates were analyzed for total and phosphorylated levels of FAK^Y397 and ERK by Western blotting. Protein bands were quantified by densitometry analysis and data shown are pooled from at least three independent experiments (Full size immunoblots are shown in supplementary). Statistical significance was assessed by two tailed, unpaired t-tests and P-values are expressed as ***P < 0.001; **P < 0.01 and *P < 0.05.