Fig. 4. PTEN overexpression has no effect on Erk1/2 phosphorylation or expression. In A, serum-deprived SHEP/PTP, SHEP/wtPTEN, SHEP/C124S, and SHEP/G129E cells are exposed to 10 nM IGF-I for 30 min, followed by Western analysis using a P-Erk1/2 antibody. In B, serum-deprived SHEP/PTP, SHEP/wtPTEN, SHEP/C124S, and SHEP/G129E cells are exposed to 10 nM IGF-I for 30 min, followed by Western analysis for Erk1/2.