1378401

pubmed:Citation

1

Our previous studies have suggested that phosphatidylcholine-specific phospholipase D (PtdCho-PLD) plays a role in IgE-dependent diacylglycerol production, protein kinase C activation and mediator release in the RBL 2H3 mast cell line. We have extended these studies to examine the mechanisms by which PtdCho-PLD may be regulated in these cells. RBL 2H3 cellular lipids were labeled with [14C]arachidonic acid or [3H]myristic acid, then PtdCho-PLD activity was monitored by the formation of radiolabeled phosphatidylethanol when ethanol was included in the incubation medium. Trinitrophenol-ovalbumin conjugate (10 ng/ml), when added to cells previously sensitized with anti-(trinitrophenelated mouse IgE) (0.5 microgram/ml), ionomycin (1 microM) and thapsigargin (0.1 microM), stimulated PtdCho-PLD activation and mediator release in cells incubated in buffer containing 1.8 mM calcium, but not in cells incubated in calcium-free, buffer. Phorbol 12-myristate 13-acetate (0.1 microM) activated PtdCho-PLD in both buffers, but on its own did not trigger mediator release. When intracellular calcium was chelated with 5,5'-dimethyl-1,2-bis(2- aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, trinitrophenol-ovalbumin conjugate failed to activate PtdCho-PLD and histamine release. Similarly, down-regulation of protein kinase C activity by long-term exposure to the phorbol ester (0.1 microM) and preincubation of the cells with protein kinase inhibitors resulted in the loss of the trinitrophenol-ovalbumin response on PtdCho-PLD activity and histamine release. Taken together, the above results suggest that IgE-dependent PtdCho-PLD activation is dependent on both activation of protein kinase C and a rise in the intracellular free calcium concentration.

http://linkedlifedata.com/resource/pubmed/journal/0107600

http://linkedlifedata.com/resource/pubmed/chemical/Alkaloids, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Immunoglobulin E, http://linkedlifedata.com/resource/pubmed/chemical/Indoles, http://linkedlifedata.com/resource/pubmed/chemical/Ionomycin, http://linkedlifedata.com/resource/pubmed/chemical/Maleimides, http://linkedlifedata.com/resource/pubmed/chemical/Phospholipase D, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C, http://linkedlifedata.com/resource/pubmed/chemical/Ro 31-7549, http://linkedlifedata.com/resource/pubmed/chemical/Ro 31-8220, http://linkedlifedata.com/resource/pubmed/chemical/Staurosporine, http://linkedlifedata.com/resource/pubmed/chemical/Terpenes, http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate, http://linkedlifedata.com/resource/pubmed/chemical/Thapsigargin

Jul

pubmed-author:GilfillanA MAM, pubmed-author:LieII

1

NLM

163-8

pubmed-meshheading:1378401-Alkaloids, pubmed-meshheading:1378401-Animals, pubmed-meshheading:1378401-Calcium, pubmed-meshheading:1378401-Cell Line, pubmed-meshheading:1378401-Enzyme Activation, pubmed-meshheading:1378401-Histamine Release, pubmed-meshheading:1378401-Immunoglobulin E, pubmed-meshheading:1378401-Indoles, pubmed-meshheading:1378401-Ionomycin, pubmed-meshheading:1378401-Kinetics, pubmed-meshheading:1378401-Maleimides, pubmed-meshheading:1378401-Mast Cells, pubmed-meshheading:1378401-Phospholipase D, pubmed-meshheading:1378401-Protein Kinase C, pubmed-meshheading:1378401-Rats, pubmed-meshheading:1378401-Staurosporine, pubmed-meshheading:1378401-Terpenes, pubmed-meshheading:1378401-Tetradecanoylphorbol Acetate, pubmed-meshheading:1378401-Thapsigargin

The role of calcium and protein kinase C in the IgE-dependent activation of phosphatidylcholine-specific phospholipase D in a rat mast (RBL 2H3) cell line.

Journal Article