Osmotic shock induces activation of JNKs and p38 and induces apoptotic cell death in SKT6 cells. (A) Activation of JNK1, JNK2, and p38. SKT6 cells were cultured in the presence (+) or absence (−) of 0.1 mol/L NaCl for 1 hour, and in vitro kinase assays of JNK1, JNK2, and p38 were performed in the immunoprecipitates with each specific antibody and GST-c-Jun or GST-ATF-2 as a substrate. (B) DNA fragmentation of the cells treated (+) or untreated (−) with 0.1 mol/L NaCl for 24 hours. M indicates the size marker (HaeIII digests of ▹X174 DNA).