P53 PROTEIN IN SYMPATHETIC NEURONS - CYTOPLASMIC LOCALIZATION AND NO APPARENT FUNCTION IN APOPTOSIS

The p53 tumour suppressor gene plays a major role in controlling cell cycle and apoptosis in many different cell types. Here we have examine d the status and the potential apoptosis inducing activity of p53 in s ympathetic neurons. The p53 protein is expressed in rat sympathetic ne urons cultured in the presence of NGF, The protein is not upregulated when these neurons are induced to die upon NGF deprivation. Over-expre ssion of wild-type human p53 in neurons cultured in the presence of NG F does not trigger apoptosis nor does it accelerate apoptosis when the neurons are deprived of NGF. Finally endogenous p53 expression is not necessary for neuronal cell death triggered by NGF deprivation since neurons prepared from p53 knockout mice undergo normal cell death upon NGF deprivation, Our results suggest that p53 may have an unknown fun ction in post-mitotic neurons which is distinct from its well describe d roles in apoptosis or cell cycle control. (C) 1996 Wiley-Liss, Inc.