Figure 6. Integrin a5 knock-down strongly reduces the activity of EGFR in A431 cells.
(A) The cells were transduced with α5 shRNA or treated with PD168393 as described above followed by western-blot analysis. The blots were probed with 1:1000 dilution of EGFR and pEGFR antibodies and 1:500 dilution of anti-β-actin mAb. (B) Integrin α5 interacts with EGFR. Co-immunoprecipitation of EGFR with integrin α5. A 1 mg aliquat of cell extracts obtained from intact A431 cells was immunoprecipitated with 5 μl of the human α5β1 mAb (MAB 1999, Chemicon). The precipitates were run on SDS-PAGE and western blotted with the polyclonal antibodies to α5 subunit and EGFR. As a control, cell lysate proteins (30 μg) were resolved and western blotted with the α5 and EGFR antibodies. Control immunoprecipitation with an α5β1 isotype specific IgG is shown.