Ras mediates the activation of phospholipase D by v-Src.
We demonstrated previously that v-Src activates a phospholipase D (PLD) activity (Song, J., Pfeffer, L.M., and Foster, D.A. (1991) Mol. Cell. Biol. 11, 4903-4908) and that this activation is dependent upon a G protein(s) (Jiang H., Alexandropoulos, K., Song, J., and Foster, D.A. (1994) Mol. Cell. Biol. 14, 3676-3682). An in vitro PLD assay was developed to study G protein involvement in v-Src-induced PLD activity. Maximal PLD activity in membranes isolated from v-Src-transformed cells was dependent upon both GTP and cytosol. In this report, we present three lines of evidence demonstrating that v-Src-induced PLD activity is mediated by Ras. First, a neutralizing Ras monoclonal antibody (Y13-259) inhibits PLD activity in membranes isolated from v-Src-transformed Balb/c 3T3 cells. Second, immobilized Ras protein depleted cytosol of the ability to stimulate PLD activity. This effect was dependent upon preloading immobilized Ras with GTP. Last, expression of a dominant negative Ras mutant in v-Src-transformed cells reduced PLD activity to the level observed in the nontransformed parental cells. These data establish a novel role for Ras in the regulation of PLD activity.
Jiang
H
H
Institute for Biomolecular Structure and Function, Hunter College, City University of New York, New York 10021.
Lu
Z
Z
Luo
J Q
JQ
Wolfman
A
A
Foster
D A
DA
D016475:3T3 Cells; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D004789:Enzyme Activation; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D016296:Mutagenesis; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D014162:Transfection; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
D009227:Myristic Acids; D019814:Myristic Acid; D016718:Arachidonic Acid; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D015688:Oncogene Protein pp60(v-src); D010739:Phospholipase D; D018631:ras Proteins