DIFFERENT EXPRESSION OF ADENYLYL-CYCLASE ISOFORMS AFTER RETINOIC ACIDINDUCTION OF P19 TERATOCARCINOMA CELLS

We have investigated the adenylyl cyclase (AC) activity and gene expre ssion in retinoic acid (RA)-primed murine P19 teratocarcinoma cells, w hich recapitulate in vitro the first stages of neuroectodermal formati on. Here we show that the P19 stem cells possess a basal Ca2+/CaM-stim ulated AC activity, which increases about 10-fold after RA induction. The rise of AC activity is associated with a stage-specific up-regulat ion of AC2, AC5 and AC8 mRNAs and a down-regulation of AC3 mRNA. P19 c ells provide a powerful model to investigate the role and specific reg ulation of AC isoforms during neuronal differentiation. (C) 1997 Feder ation of European Biochemical Societies.