Fig. 5. Activation of p90Rsk2 in mouse spermatocytes is mediated by the MAPK pathway. (A) Extracts from control or OA-treated cells preincubated in the absence or presence of 10 µM U0126 to inhibit signaling through the MAPK pathway were immunoprecipitated using the anti-p90Rsk2 antibody. Kinase activity present in the immunoprecipitates was assayed as described in the legend to Fig. 3. Data represent the mean±s.d. of triplicate determinations from three separate experiments. (B) Western blot analysis of p90Rsk2 in representative samples of the immunoprecipitates. The upward shift in electrophoretic mobility in SDS-PAGE of the sample obtained from cells treated with OA indicate that p90Rsk2 was hyperphosphorylated and activated during G2/M progression of mouse spermatocytes.
