Sphingosine 1-phosphate and dioleoylphosphatidic acid are low affinity agonists for the orphan receptor GPR63.
Five high affinity G-protein-coupled receptors for sphingosine 1-phosphate (S1P) have been characterised so far (S1P(1,2,3,4,5) formerly referred to as edg1,5,3,6,8). In this study, we show that S1P, dihydro-sphingosine 1-phosphate (dihydro-S1P) and dioleoylphosphatidic acid (doPA) are agonists for the orphan receptor GPR63. All three phospholipids mobilise intracellular calcium in CHO cells transiently transfected with GPR63. Calcium signals required cotransfection of a chimeric Galpha(q/i) protein in a fluorometric imaging plate reader (FLIPR) assay but did not require overexpressed G proteins in an aequorin assay, using a green fluorescent protein (GFP)-aequorin fusion protein as a bioluminescent Ca(2+) reporter. GPR63 expression in CHO cells confers proliferative responses to S1P in a pertussis toxin (PTX)-insensitive manner. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) indicated highest expression in brain, especially in the thalamus and the nucleus caudatus. In peripheral tissues, highest expression was observed in thymus, stomach and small intestine; lower abundance of transcripts was detected in kidney, spleen, pancreas and heart. The discovery that S1P, dihydro-S1P and dioleoylphosphatidic acid activate GPR63 will facilitate the identification of agonists and antagonists, and help to unravel the biological function of this receptor.
Niedernberg
Anke
A
Disease Group Cardiovascular, Aventis Pharma Germany, Rooms 354, 358 and 360, 3rd Floor, Bldg H825, 65926 Frunkfurt, Germany.
Tunaru
Sorin
S
Blaukat
Andree
A
Ardati
Ali
A
Kostenis
Evi
E
D000331:Aequorin; D000818:Animals; D016466:CHO Cells; D020013:Calcium Signaling / Q000502:physiology; D006224:Cricetinae; D019204:GTP-Binding Proteins / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008246:Lysophospholipids; D010712:Phosphatidic Acids / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D014018:Tissue Distribution; D014162:Transfection
D008246:Lysophospholipids; D010712:Phosphatidic Acids; D011956:Receptors, Cell Surface; C037657:dioleoylphosphatidic acid; C060504:dihydrosphingosine 1-phosphate; C060506:sphingosine 1-phosphate; D000331:Aequorin; D019204:GTP-Binding Proteins; D013110:Sphingosine