Assessment of agonism at G-protein coupled receptors by phosphatidic acid and lysophosphatidic acid in human embryonic kidney 293 cells.
Several different molecular species of phosphatidic acid (PA) bind to a G-protein coupled receptor (GPCR) to induce activation of the p42/p44 mitogen-activated protein kinase (p42/p44 MAPK) pathway in HEK 293 cells. PA is active at low nanomolar concentrations and the response is sensitive to pertussis toxin (which uncouples GPCRs from G(i/o)). The de-acylated product of PA, lysophosphatidic acid (LPA), which binds to members of the endothelial differentiation gene (EDG) family of receptors also stimulated p42/p44 MAPK in a pertussis toxin sensitive manner, but with an approximately 100 - 1000 fold lower potency compared with the different molecular species of PA. RT - PCR using gene-specific primers showed that HEK 293 cells express EDG2 and PSP24, the latter being a lipid binding GPCR out with the EDG cluster. We conclude that PA is a novel high potency GPCR agonist.
Alderton
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F
Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR, UK.
Sambi
B
B
Tate
R
R
Pyne
N J
NJ
Pyne
S
S
D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D008246:Lysophospholipids / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D010712:Phosphatidic Acids / Q000494:pharmacology*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D008246:Lysophospholipids; D010712:Phosphatidic Acids; D011956:Receptors, Cell Surface; D012313:RNA; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate