Lack of correlation in JNK activation and p53-dependent Fas expression induced by apoptotic stimuli

Induction of Fas expression by DNA-damaging agents is dependent on the expr ession of functional p53, and has been suggested to play an important role in apoptosis induction, JNK (c-Jun N-terminal kinase), which is capable of phosphorylating p53, is also involved in apoptotic signaling induced by var ious apoptotic stimuli, Here, we report that although Fas induction is clos ely linked to the expression of wild type p53, it is not correlated with JN K activation induced by apoptotic stimuli. JNK activation does not necessar ily lead to Fas expression, even in cells containing wild type p53. In addi tion, Fas expression can be induced without significant JNK activation. Fur thermore, induction of Fas expression is not sufficient for apoptosis induc tion; however, it may sensitize cells to Fas-ligation induced apoptosis, (C ) 1999 Academic Press.