Fig. 2.
In vitro p38 activity is induced by Epo and IL-3 stimulation. FD-EPO cells (A) and FDC-P2 cells (B and C) were stimulated with Epo (A) and IL-3 (B), respectively, for the indicated time up to 60 minutes or stimulated with (+) or without (−) NaCl (C) for 30 minutes. The immunoprecipitates with anti-p38–specific antibody were incubated with [γ-32P]ATP and GST-ATF-2 as a substrate. Arrows indicate the phosphorylated GST-ATF-2 (molecular weight, 40 kD).