5-Oxo-eicosatetraenoic acid-induced chemotaxis: identification of a responsible receptor hGPCR48 and negative regulation by G protein G(12/13).
While screening genes encoding G protein-coupled receptors (GPCRs) in the human genome, we and other groups have identified a GPCR named hGPCR48 as a high affinity receptor for 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), which is arachidonic acid metabolite and an endogenous chemoattractant for granulocytes. Using Chinese hamster ovary (CHO) cells stably expressing hGPCR48, we show here that activation of the receptor causes the chemotaxis of the cells toward 5-oxo-ETE. We also show that the chemotaxis of human granulocytes toward 5-oxo-ETE is inhibited by pretreatment with anti-hGPCR48 antibodies, indicating that hGPCR48 is an endogenous receptor responsible for chemotaxis of granulocytes toward 5-oxo-ETE. In addition, we show that the chemotaxis of CHO cells expressing hGPCR48 is suppressed by pretreatment with pertussis toxin, and enhanced by overexpression of the carboxy terminal peptides of Galpha (12/13) subunits or a regulator of the G protein signaling domain of p115RhoGEF, both of which are known to suppress G(12/13)-dependent signaling pathways. These results indicate that hGPCR48 couples with G(i/o) and G(12/13) proteins, which then initiate or attenuate the chemotaxis of the cells toward 5-oxo-ETE, respectively.
Department of Nano-Material Systems, Gunma University Graduate School of Engineering, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515.
Daigo
D
Koike
Hideru
H
Obinata
Atsushi
A
Yamamoto
Shigeki
S
Takeda
Hironobu
H
Komori
Futoshi
F
Nara
Takashi
T
Izumi
Tatsuya
T
Haga
D000818:Animals; D001095:Arachidonic Acids / Q000502:physiology*; D016466:CHO Cells; D002478:Cells, Cultured; D002633:Chemotaxis / Q000502:physiology*; D006224:Cricetinae; D003412:Cricetulus; D015536:Down-Regulation / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D006801:Humans; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors / Q000502:physiology*
D001095:Arachidonic Acids; D043562:Receptors, G-Protein-Coupled; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D019204:GTP-Binding Proteins