TG1019/OXE, a Galpha(i/o)-protein-coupled receptor, mediates 5-oxo-eicosatetraenoic acid-induced chemotaxis

• Published in: Biochemical and biophysical research communications 2005-09, Vol.334 (4), p.987-995
• Main Authors: Hosoi, Takeshi, Sugikawa, Emiko, Chikada, Aiko, Koguchi, Yutaka, Ohnuki, Tetsuo
• Format: Article
• Language: English
• Subjects: Animals; Arachidonic Acids - administration & dosage; Chemotaxis - drug effects; Chemotaxis - physiology; CHO Cells; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Receptors, Eicosanoid - genetics; Receptors, Eicosanoid - metabolism; Receptors, G-Protein-Coupled - metabolism; Recombinant Proteins - metabolism
• ISSN: 0006-291X

We have previously identified a Galpha(i/o)-protein-coupled receptor (TG1019/OXE) using 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) as its ligand. We investigated signal transduction from TG1019 following stimulation with 5-oxo-ETE and role of TG1019 in 5-oxo-ETE-induced chemotaxis, using Chinese hamster ovary cells expressing TG1019 (CHO/TG1019 cells). 5-Oxo-ETE induced intracellular calcium mobilization and rapid activation of MEK/ERK and PI3K/Akt pathways in CHO/TG1019 cells. CHO/TG1019 cells stimulated with 5-oxo-ETE and other eicosanoids exhibited chemotaxis with efficacies related to agonistic activity of each eicosanoid for TG1019. Pretreatment of the cells with pertussis toxin, a phospholipase C (PLC) inhibitor (U73122) or a PI3K inhibitor (LY294002), markedly suppressed 5-oxo-ETE-induced chemotaxis, whereas pretreatment with a MEK inhibitor (PD98059) had no significant effect on the chemotaxis. Our results show that TG1019 mediates 5-oxo-ETE-induced chemotaxis and that signals from TG1019 are transduced via Galpha(i/o) protein to PLC/calcium mobilization, MEK/ERK, and PI3K/Akt, among which PLC and PI3K would play important roles in the chemotaxis.