Expression and characterization of a 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor highly expressed on human eosinophils and neutrophils.
Using a bioinformatics approach, we have isolated a novel G-protein-coupled receptor (GPCR), R527, and have demonstrated that this receptor shows no significant homology to previously deorphanized GPCRs. Quantitative reverse transcription-polymerase chain reaction analysis of the expression of GPCR R527 indicated a very high level of mRNA expression in eosinophils, with high expression also detected in neutrophils and lung macrophages. Stable cell lines were generated expressing this receptor together with the G-protein alpha-subunit G alpha(16). These cells were used to screen an agonist collection in a calcium mobilization assay and 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) was identified as a putative ligand. 5(S)-hydroxyperoxy-6E,8Z,11Z,14Z-eicosatetraenoic acid was also shown to activate the receptor, whereas the leukotrienes LTB(4), LTC(4), LTD(4), and LTE(4) failed to elicit a response. In cAMP assays, pertussis toxin reversed the inhibitory effects of 5-oxo-ETE on cAMP production, indicating that the receptor is G alpha(i)-coupled. The GPCR R527 shows pharmacological properties similar to those of the previously described 5-oxo-ETE receptor expressed on eosinophils, neutrophils, and monocytes. These cell types show chemotactic responses to 5-oxo-ETE, and this eicosanoid has been proposed to play a key role in the inflammatory response. The molecular identification of a receptor binding 5-oxo-ETE will expand our understanding of the physiological role of this mediator and may provide new therapeutic opportunities.
Jones
Carol E
CE
Novartis Horsham Research Centre, Horsham West Sussex, UK. carol.jones@pharma.novartis.com
Holden
Suzanne
S
Tenaillon
Laurent
L
Bhatia
Umesh
U
Seuwen
Klaus
K
Tranter
Pamela
P
Turner
Jonathan
J
Kettle
Rachel
R
Bouhelal
Rochdi
R
Charlton
Steven
S
Nirmala
N R
NR
Jarai
Gabor
G
Finan
Peter
P
D000595:Amino Acid Sequence; D001095:Arachidonic Acids / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000378:metabolism; D004804:Eosinophils / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled; D017386:Sequence Homology, Amino Acid
D001095:Arachidonic Acids; C472320:G-protein-coupled receptor R527, human; D008024:Ligands; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D000242:Cyclic AMP