RRC ID 39126
Author Okamoto H, Takuwa N, Gonda K, Okazaki H, Chang K, Yatomi Y, Shigematsu H, Takuwa Y.
Title EDG1 is a functional sphingosine-1-phosphate receptor that is linked via a Gi/o to multiple signaling pathways, including phospholipase C activation, Ca2+ mobilization, Ras-mitogen-activated protein kinase activation, and adenylate cyclase inhibition.
Journal J Biol Chem
Abstract In Chinese hamster ovary (CHO) cells transiently transfected with an expression vector for EDG1, but not an empty vector, sphingosine-1-phosphate (SP) at a concentration as low as 10(-10) M caused an increase in the intracellular free Ca2+ concentration ([Ca2+]i) as a result of mobilization of Ca2+ from both intracellular and extracellular pools. In a CHO clone stably expressing EDG1 receptor (CHO-EDG1 cells), SP induced increases in the production of inositol phosphates and the [Ca2+]i and inhibited forskolin-induced increase in the cellular cAMP content, all in a manner sensitive to pertussis toxin. SP also activated mitogen-activated protein kinase in CHO-EDG1 cells in pertussis toxin-sensitive and Ras-dependent manners. To evaluate the spectrum of agonists for EDG1, we used human erythroleukemia (HEL) cells, which at naive state do not respond to SP or structurally related lipids with an increase in the [Ca2+]i. In HEL cells stably expressing EDG1 receptor (HEL-EDG1 cells), SP dose-dependently increased the [Ca2+]i with half-maximal and maximal concentration values of 10(-9) and 3 x 10(-7) M, respectively; sphingosylphosphorylcholine at exclusively high concentrations, but not sphingosine at all, also increased the [Ca2+]i. HEL-EDG1 cells bound 32P-labeled SP, which was displaced dose dependently by unlabeled SP. These results indicate that EDG1, a member of the EDG family G protein-coupled receptors, is a specific, high-affinity SP receptor.
Volume 273(42)
Pages 27104-10
Published 1998-10-16
DOI 10.1074/jbc.273.42.27104
PMID 9765227
MeSH Adenylate Cyclase Toxin Adenylyl Cyclase Inhibitors Animals CHO Cells Calcium / metabolism Calcium-Calmodulin-Dependent Protein Kinases / metabolism Colforsin / pharmacology Cricetinae Enzyme Activation GTP-Binding Protein alpha Subunits, Gi-Go / metabolism* Genistein / pharmacology Immediate-Early Proteins / metabolism* Lysophospholipids* Pertussis Toxin Receptors, Cell Surface / metabolism* Receptors, G-Protein-Coupled* Receptors, Lysophospholipid Signal Transduction Sphingosine / analogs & derivatives* Sphingosine / pharmacology Type C Phospholipases / antagonists & inhibitors Type C Phospholipases / metabolism Virulence Factors, Bordetella / pharmacology ras Proteins / metabolism
IF 4.106
Times Cited 224
Human and Animal Cells