title: Mammalian PSP24s (alpha and beta isoforms) are not responsive to lysophosphatidic acid in mammalian expression systems.
abstract: Xenopus PSP24 (xPSP24) is a G-protein-coupled receptor which was originally identified as a functional lysophosphatidic acid (LPA) receptor. We obtained two different types (alpha and beta) of mammalian homologues of xPSP24 and found that these receptors are highly expressed in the brain (Kawasawa et al., Biochem. Biophys. Res. Commun. 276, 952-956, 2000). These receptor did not respond to LPA by GTPgammaS binding assays, while Edg2 or Edg4 showed responses to LPA under the same assay conditions. Furthermore, a sensitive reporter gene assay using PC12 cells with serum response element promoter failed to detect any response of mammalian PSP24s to various concentrations of LPA. Thus, unlike xPSP24, we conclude that PSP24s are not functional LPA receptors in mammalian systems.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawasawa
authors.forename: K
authors.initials: K
authors.lastname: Kume
authors.forename: T
authors.initials: T
authors.lastname: Izumi
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D019143:Evolution, Molecular; D005455:Fluorescent Antibody Technique; D017930:Genes, Reporter / Q000235:genetics; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism / Q000494:pharmacology; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology*; D051379:Mice; D016716:PC12 Cells; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D020218:Response Elements / Q000235:genetics; D029867:Xenopus Proteins
chemical_list: D008246:Lysophospholipids; C415862:PSP24 receptor, Xenopus; D020033:Protein Isoforms; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D029867:Xenopus Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D020962:Heterotrimeric GTP-Binding Proteins