Exp Mol Med.  2005 Oct;37(5):418-426.

Involvement of protein kinase C pathway in UVC-stimulated phospholipase D2 activity in Vero 76 cells

• Kim S
• Choi MS
• Choi MU

Abstract

Phospholipase D (PLD) activity is known to be related to oxidant-induced cellular signaling and membrane disturbance. Previously, an induction of PLD activity in various cell lines by X-ray irradiation was observed. In this study, we examined the effect of UVC radiation on the PLD activity in Vero 76 cells. At a dose of 10 kJ/m2 of UVC irradiation, the PLD activity was stimulated approximately 10-fold over the basal activity. This UVC-induced PLD activity was found to be dependent on the presence of extracellular calcium and was inhibited by catalase as well as amifostine-an intracellular thiol antioxidant. Pretreatments with Ro32-0432-a selective inhibitor of protein kinase C (PKC)-and downregulation of PKC by preincubation of phorbol 12-myristate 13-acetate significantly inhibited the UVC-induced PLD activity. UVC-stimulated PLD activity was observed only in murine PLD2 (mPLD2)-transfected Vero 76 cells and not in human PLD1 (hPLD1)-transfected cells. Transient incorporation of PKC with mPLD2 and the phosphorylation of mPLD2 by a and b forms of PKC by UVC irradiation were observed. These results suggest that the UVC-stimulated PLD activity in Vero 76 cells is mediated through transient phosphorylation of PLD2 by the translocation of PKC to PLD2.

Keyword

phospholipase D; protein kinase C; reactive oxygen species; ultraviolet rays

MeSH Terms

Animals
Antioxidants/metabolism
Calcium/metabolism
Cercopithecus aethiops
Chelating Agents/pharmacology
Enzyme Activation/radiation effects
Mice
Phospholipase D/genetics/*metabolism
Protein Isoforms/genetics/metabolism
Protein Kinase C/*metabolism
Protein Kinase Inhibitors/pharmacology
Reactive Oxygen Species
Research Support, Non-U.S. Gov't
Signal Transduction/*radiation effects
*Ultraviolet Rays
Vero Cells