Phosphatidylcholine-specific phospholipase C-mediated induction of phospholipase D activity in Fas-expressing murine cells

We have previously reported that Fas cross-linking resulted in the activati on of phosphatidylcholine-specific phospholipase C (PC-PLC) and the subsequ ent activation of protein kinase C (PKC) and phospholipase D (PLD) in A20 c ells. In an attempt to correlate the existence of PC-PLC activity and activ ation of PLD by Fas activation among various Fas-expressing murine cell lin es, we have investigated the effect of anti-Fas monoclonal antibody on PC-P LC and PLD activities in A20, P388D1 and YAC-1 cell lines. Upon treatment o f anti-Fas monoclonal antibody to these three cell lines, the activation of PLD was only observed in A30 cells. When the effect of anti-Fas monoclonal antibody on PKC and PC-PLC activities in Fas-expressing clones were invest igated, the activation of PKC and PC-PLC was detected only in A20 clones. R esults presented here also show that exogenous addition of Bacillus cereus PC-PLC activates PC hydrolysis, PKC and PLD in all three murine cell lines. These findings suggest that the activation of PC-PLC is a necessary requir ement for the activation of PLD by Fas cross-linking and cell lines devoid of functional PC-PLC activity could exhibit enhanced PLD activity by exogen ous addition of PC-PLC. (C) 2000 Elsevier Science Inc. All rights reserved.