α5(IV), but not α1(IV), deficiency results in impaired activation of ERK.

<p>(A) Western blot analyses of phosphorylation levels of ERK, Akt, FAK and Src and α1(IV), α2(IV) and α5(IV) expression in α5(IV)- or α1(IV)-knockdown A549 cells. (B) Western blot analyses of phosphorylation levels of ERK in α5(IV)-knockdown A549 cells expressing constitutively active MEK1. (C-E) Expression of constitutively active MEK1 in α5(IV)-knockdown A549 cells rescued the defects in cell proliferation (C), migration (D), and anchorage-independent cell growth (E). Data are presented as mean ± SD. **P < 0.01.