Phospholipase D Activity in PC12 Cells

Autor: Jin Hyouk Park, Krishna M. Ella, Anthony F. McNair, Kathryn E. Meier, April E. Wisehart-Johnson, Chen Qi
Rok vydání: 1997
Předmět:
Zdroj: Journal of Biological Chemistry. 272:12909-12912
ISSN: 0021-9258
Popis: PC12 neuronal cells express a membrane phospholipase D (PLD) activity that is detected at similar levels in undifferentiated or differentiated cells. The regulation of this activity by agonists was explored. Membrane phospholipase D activity was increased by treatment of cells with the phorbol ester phorbol 12-myristate 13-acetate (PMA) or with nerve growth factor. The ability of PMA to activate PLD was confirmed in intact PC12 cells. Basal activity of PLD in membranes was reduced in RG20, a PC12 cell line overexpressing the human α2A-adrenergic receptor. PMA did not increase PLD activity in RG20 cells, as assessed both in membrane preparations and in intact cells. Cyclic AMP levels did not regulate phospholipase D activity in either cell type. However, incubation of RG20 cells with the α2-adrenergic antagonist rauwolscine or with pertussis toxin increased membrane PLD activity and restored activation of PLD by PMA. These data suggest that the effects of the overexpressed α2A-adrenergic receptor on PLD activity are mediated by precoupling of the receptor to the heterotrimeric GTP-binding protein, Gi, but are independent of adenylate cyclase regulation. The results of this study suggest that membrane phospholipase D activity can be negatively regulated via Gi in PC12 cells.
Databáze: OpenAIRE