FIG. 8.

MAP kinase activation and neurite outgrowth in cells overexpressing wild-type or catalytically inactive Shp2. (A) PC12 cells were stably transfected with an expression vector that directs the synthesis of wild-type (W.T) or Cys/Ser inactive mutant (C/S) Shp2. The cells were starved overnight, stimulated with aFGF (100 ng/ml for 5 min), and extracted with lysis buffer. Lysates from stimulated or unstimulated cells were immunoprecipitated with anti-Shp2 antibodies and immunoblotted (IB) with the indicated antibodies. (B) PC12 cells expressing vector alone (•) or wild-type (▪) or Cys/Ser inactive mutant (□) Shp2 were stimulated with aFGF (100 ng/ml) for different time periods. The upper and lower panels show the early and late time points of MAP kinase (MAPK) activation, respectively. Quantitation of MAP kinase activation was determined as described in Materials and Methods. (C) PC12 cells expressing the pLXSN vector alone (control) and cells overexpressing wild-type or Cys/Ser inactive mutant Shp2 were grown in the absence or presence of aFGF (100 ng/ml) and heparin (5 μg/ml). Neurite outgrowth was quantitated following induction for 72 h. Quantification of neurite outgrowth was calculated as described in Materials and Methods.