Figure 6
G i α proteins associate with RTKs and their adaptor proteins in breast cancer cells, and are important for interactions of Gab1 with Shp2 or Grb2 in MEFs in response to EGF or bFGF. (A) MB231 cells were treated with bFGF (25 ng/ml) for 0, 2 or 5 min. Whole cell lysates were prepared. The associations of Gi3α with p-FGFR, Gab1 and FRS2 were determined by IB using anti-p-FGFR(Y766), anti-Gab1, anti-FRS2 and anti-Gi3α antibodies, respectively. (B-D) MB231 cells were treated with EGF (100 ng/ml) for 0, 2, 5, 10 or 20 min. The associations of Gi3α with p-EGFR, EGFR (B), Gab1 and Shp2 (C & D) were determined by IB using anti-p-EGFR (Y1173), anti-EGFR, anti-Gab1, anti-Shp2 and anti-Gi3α antibodies, respectively. (E & F) WT and Gi1/3 DKO MEFs were treated with EGF or bFGF for 0, 2 or 5 min. The association of Shp2 with Gab1 in response to EGF (E), and the associations of Grb2 with Gab1 and FRS2 in response to bFGF (F) were determined by IB. Experiments were repeated two to four times. Similar results were obtained.