Down-regulation of phospholipase D during differentiation of mouse F9 teratocarcinoma cells

Phospholipase D has been recognized as playing an important role in signal transduction in many types of cells. We investigated the expression of phos pholipase D during the differentiation of F9 embryonal teratocarcinoma cell s. The ADP ribosylation factor-dependent phospholipase D activity, as measu red by an in vitro assay, and H2O2-induced phospholipase D activity and pho spholipase D protein content in whole cells mere decreased during the diffe rentiation of F9 cells induced by a combination of dibutyryl cyclic AMP and all-trans retinoic acid. In contrast, these changes were not observed when cells were induced by retinoic acid. These results suggest that down-regul ation of phospholipase D protein is associated with differentiation of F9 c ells to a parietal endoderm lineage. (C) 1999 Federation of European Bioche mical Societies.