SAPK/JNK regulates cdc2/cyclin B kinase through phosphorylation and inhibition of cdc25c.

Cells undergo M phase arrest in response to stresses like UV irradiation or DNA damage. Stress-activated protein kinase (SAPK, also known as c-Jun N-terminal kinase, JNK) is activated by such stress stimuli. We addressed the potential effects of SAPK activation on cell cycle regulatory proteins.