Figure 5. Effect of the PTP1B inhibitor, CinnGEL 2Me, on the time-course of EGFR Tyr992 phosphorylation

Serum-starved, subconfluent rat corneal endothelial cells were pre-incubated for 1 h in Medium 199, gentamicin, and DMSO(-) or supplemented with 1 mM CinnGel 2Me(+). EGF (25 ng/ml) was then added and samples were taken for western blot analysis at various times following EGF addition. Representative western blot in (A) shows phosphorylated Tyr992 at 175 kDa. Densitometric analysis was conducted using β-actin for normalization. The graph in (B) shows average levels of phosphorylated Tyr992. Results are the average of duplicate gels from four separate experiments. Bars represent SEM.