RRC ID 39835
Author Murakami M, Koduri RS, Enomoto A, Shimbara S, Seki M, Yoshihara K, Singer A, Valentin E, Ghomashchi F, Lambeau G, Gelb MH, Kudo I.
Title Distinct arachidonate-releasing functions of mammalian secreted phospholipase A2s in human embryonic kidney 293 and rat mastocytoma RBL-2H3 cells through heparan sulfate shuttling and external plasma membrane mechanisms.
Journal J Biol Chem
Abstract We analyzed the ability of a diverse set of mammalian secreted phospholipase A(2) (sPLA(2)) to release arachidonate for lipid mediator generation in two transfected cell lines. In human embryonic kidney 293 cells, the heparin-binding enzymes sPLA(2)-IIA, -IID, and -V promote stimulus-dependent arachidonic acid release and prostaglandin E(2) production in a manner dependent on the heparan sulfate proteoglycan glypican. In contrast, sPLA(2)-IB, -IIC, and -IIE, which bind weakly or not at all to heparanoids, fail to elicit arachidonate release, and addition of a heparin binding site to sPLA(2)-IIC allows it to release arachidonate. Heparin nonbinding sPLA(2)-X liberates arachidonic acid most likely from the phosphatidylcholine-rich outer plasma membrane in a glypican-independent manner. In rat mastocytoma RBL-2H3 cells that lack glypican, sPLA(2)-V and -X, which are unique among sPLA(2)s in being able to hydrolyze phosphatidylcholine-rich membranes, act most likely on the extracellular face of the plasma membrane to markedly augment IgE-dependent immediate production of leukotriene C(4) and platelet-activating factor. sPLA(2)-IB, -IIA, -IIC, -IID, and -IIE exert minimal effects in RBL-2H3 cells. These results are also supported by studies with sPLA(2) mutants and immunocytostaining and reveal that sPLA(2)-dependent lipid mediator generation occur by distinct (heparanoid-dependent and -independent) mechanisms in HEK293 and RBL-2H3 cells.
Volume 276(13)
Pages 10083-96
Published 2001-3-30
DOI 10.1074/jbc.M007877200
PII S0021-9258(19)34277-2
PMID 11106649
MeSH Amino Acid Sequence Animals Arachidonic Acid / metabolism* Cell Line Cell Membrane / metabolism* Dinoprostone / metabolism Electrophoresis, Polyacrylamide Gel Group II Phospholipases A2 Group V Phospholipases A2 Heparan Sulfate Proteoglycans / metabolism* Heparin / metabolism Humans Hydrogen-Ion Concentration Hydrolysis Immunohistochemistry Leukotriene C4 / metabolism Mast Cells / metabolism Mast-Cell Sarcoma / metabolism* Mice Microscopy, Confocal Models, Biological Molecular Sequence Data Mutagenesis, Site-Directed Phospholipases A / metabolism* Phosphorylation Platelet Activating Factor / metabolism Protein Binding RNA / metabolism Rats Recombinant Proteins / metabolism Sequence Homology, Amino Acid Time Factors Transfection Tumor Cells, Cultured
IF 4.238
Times Cited 143
WOS Category BIOCHEMISTRY & MOLECULAR BIOLOGY
Resource
Human and Animal Cells