Phospholipase D is associated in a phorbol ester-dependent manner with protein kinase C-alpha and with a 220-kDa protein which is phosphorylated on serine and threonine.
Many studies have shown that phospholipase D (PLD) is activated by protein kinase C (PKC) in vivo and in vitro. In this study, a PLD isoform (rPLD1) was shown to bind to PKC-alpha in Rat1 fibroblasts treated with phorbol ester. The PKC-alpha binding domain of rPLD1 was localized to its N-terminus. The phospholipase was shown to become associated also with a 220-kDa protein (p220) in the fibroblasts and in Sf9 cells infected with recombinant baculovirus coding rPLD1. This interaction was increased by phorbol myristate acetate (PMA) treatment. p220 was phosphorylated on serine/threonine in PMA-stimulated Rat1 cells, and rPLD1 expressed in Sf9 cells was also serine/threonine phosphorylated in response to PMA treatment. These data suggest the PMA induces the formation of a RPLD1/PKC alpha/P220 complex in cells, some components of which undergo serine/threonine phosphorylation.
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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D000818:Animals; D002460:Cell Line; D005347:Fibroblasts; D005982:Glutathione Transferase / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D010739:Phospholipase D / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010768:Phosphoserine / Q000032:analysis*; D010769:Phosphothreonine / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D018411:Spodoptera; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014162:Transfection
D007527:Isoenzymes; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D010769:Phosphothreonine; D010768:Phosphoserine; D005982:Glutathione Transferase; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate