Identification of a phosphothionate analogue of lysophosphatidic acid (LPA) as a selective agonist of the LPA3 receptor.
Lysophosphatidic acid (LPA) is a bioactive lysophospholipid mediator that acts through G protein-coupled receptors. Most cell lines in culture express one or more LPA receptors, making it difficult to assign a response to specific LPA receptors. Dissection of the signaling properties of LPA has been hampered by lack of LPA receptor subtype-specific agonists and antagonists. The present study characterizes an ester-linked thiophosphate derivative (1-oleoyl-2-O-methyl-rac-glycerophosphothionate, OMPT) of LPA. OMPT is a functional LPA analogue with potent mitogenic activity in fibroblasts. In contrast to LPA, OMPT does not couple to the pheromone response through the LPA(1) receptor in yeast cells. OMPT induces intracellular calcium increases efficiently in LPA(3) receptor-expressing Sf9 cells but poorly in LPA(2) receptor-expressing cells. Guanosine 5'-O-(3-[(35)S]thio)triphosphate binding assays in mammalian cells showed that LPA exhibits agonistic activity on all three LPA receptor subtypes, whereas OMPT has a potent agonistic effect only on the LPA(3) receptor. In transiently transfected HEK293 cells, OMPT stimulates mitogen-activated protein kinases through the LPA(3) but not the LPA(1) or LPA(2) receptors. Furthermore, OMPT-induced intracellular calcium mobilization in mammalian cells is efficiently inhibited by the LPA(1)/LPA(3) receptor-selective antagonist VPC12249. These results establish that OMPT is an LPA(3)-selective agonist. OMPT binding to the LPA(3) receptor in mammalian cells is sufficient to elicit multiple responses, including activation of G proteins, calcium mobilization, and activation of mitogen-activated protein kinases. Thus OMPT offers a powerful probe for the dissection of LPA signaling events in complex mammalian systems.
Hasegawa
Yutaka
Y
M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Erickson
James R
JR
Goddard
Graham J
GJ
Yu
Shuangxing
S
Liu
Shuying
S
Cheng
Kwai Wa
KW
Eder
Astrid
A
Bandoh
Koji
K
Aoki
Junken
J
Jarosz
Renata
R
Schrier
Andrew D
AD
Lynch
Kevin R
KR
Mills
Gordon B
GB
Fang
Xianjun
X
D016475:3T3 Cells; D000818:Animals; D002118:Calcium / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000166:cytology; D008246:Lysophospholipids / Q000737:chemistry / Q000494:pharmacology*; D008322:Mammals; D051379:Mice; D008809:Mice, Inbred C3H; D008934:Mitogens / Q000494:pharmacology; D063086:Organothiophosphates / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000819:agonists* / Q000037:antagonists & inhibitors; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D015398:Signal Transduction / Q000187:drug effects*; D018411:Spodoptera; D015003:Yeasts / Q000187:drug effects
C473891:1-oleoyl-2-O-methyl-rac-glycerophosphothionate; D008246:Lysophospholipids; D008934:Mitogens; D063086:Organothiophosphates; D010712:Phosphatidic Acids; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D002118:Calcium