Lysophosphatidic acid induces a pertussis toxin-sensitive Ca(2+)-activated Cl- current in Xenopus laevis oocytes.
Lysophosphatidic acid (LPA) induces a Ca(2+)-activated Cl- current in defolliculated Xenopus laevis oocytes. The response appears mediated by a specific membrane receptor, because no current is induced when related compounds [phosphatidic acid (PA), lysophosphatidylcholine (LPC), and lysophosphatidylserine (LPS)] are applied extracellularly or when LPA is injected intracellularly. Incubation in pertussis toxin prevents the response. The response is mediated by a Ca(2+)-activated Cl- current because 1) it is abolished by intracellular ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA; 5 mM) but not affected by changes in extracellular Ca2+ concentration and 2) the reversal potential becomes more positive at lower Cl- concentrations. Suramin (2 mM) blocks the LPA-induced current, but PA, LPS, LPC, and the platelet-activating factor antagonist WEB-2086 do not. The response is dose dependent for LPA concentrations from 10(-8) to 10(-3) M. Incubation of oocytes in LPA does not induce germinal vesicle breakdown. These findings suggest that this novel oocyte response to LPA is mediated by a specific membrane receptor linked to a pertussis toxin-sensitive G protein.
Durieux
M E
ME
Department of Anesthesiology, University of Virginia Health Sciences Center, Charlottesville 22908.
Salafranca
M N
MN
Lynch
K R
KR
Moorman
J R
JR
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D016922:Cellular Senescence / Q000187:drug effects; D002712:Chlorides / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D008246:Lysophospholipids / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*; D014982:Xenopus laevis / Q000378:metabolism*
D002712:Chlorides; D008246:Lysophospholipids; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D002118:Calcium