Figure 2.

Phosphorylation of ERBB induced by EGF or HRG ligands in HeLa, A431, and MCF7 cells. (a) Western blotting of ERBB1-B4 after ligand stimulation (numbers at the top indicate minutes). pB1, pB2, pB3, and pB4 denote phosphorylated ERBB1, ERBB2, ERBB3, and ERBB4, respectively. (b) The time course of the ERBB phosphorylation obtained from Western blotting. Fold changes compare the phosphorylation level with just before the ligand stimulation (time 0). Closed circles and open triangles indicate EGF and HRG stimulation, respectively. (c) The fold change of ERBB phosphorylation at 5 min. Crosses and open circles respectively represent the experimental results and global model fitting.