Extracellular
ATP has been known to have many functions as a fast transmitter, and a co-transmitter, and to have morphogenic and mitogenic activity in neuronal cells. Although it was reported that
ATP activates
phospholipase D (
PLD), the role of
PLD versus the
ATP function was unclear in neuronal cells. In this study, we investigated the role of
PLD on the
ATP-induced extracellular signal regulated
protein kinase (ERK) activation and mitogenic effect in rat
pheochromocytoma PC12 cells. In these cells
ATP caused PLD2 activation and ERK phosphorylation, which was dramatically reduced by wild-type PLD2-overexpression but not by
lipase-inactive-mutant PLD2-overexpression. The accumulation of
phosphatidic acid (PA) by preincubating PC12 cells with
propranolol (an inhibitor of PA
phosphohydrolase) also decreased the ERK phosphorylation. Inhibition of
phosphatases by
okadaic acid or
pervanadate completely blocked PLD2-dependent ERK dephosphorylation. In addition,
ATP-stimulated
thymidine incorporation was reduced by the overexpression of wild-type PLD2, but not by the overexpression of
lipase-inactive-mutant PLD2.
Okadaic acid pretreatment overcame the decrease of
ATP-induced
thymidine incorporation by PLD2 overexpression. Taken together, we suggest that PLD2 activity might play a negative role in
ATP-induced ERK phosphorylation and mitogenic signal possibly through
phosphatases.