Pertussis toxin sensitive G-protein coupling of HDL receptor to phospholipase C in human platelets.
Initially we established that, in human platelets, low concentrations of HDL3 stimulate phosphatidylcholine (PC) hydrolysis and a transient increase in 1,2-diacylglycerol (DAG). In (3H) PC prelabelled platelets, phosphocholine is released into the medium during HDL3 induced PC turnover with a 1.5 to 2 fold increment, indicating that HDL3 stimulated DAG generation in platelets is likely due to phospholipase C (PLC). GTP or GTP-gamma-S augments, and pertussis toxin inhibits HDL3 stimulated DAG production. Treatment of platelet membranes with HDL3 or with proteoliposome containing apo A-I or A-II substantially prevents 41 kDa protein ADP-ribosylation that was induced by pertussis toxin, with apo A-II having an inhibitory potency greater than apo A-I. These data provide strong evidence that the pertussis sensible G protein (Go or Gi) is directly involved in coupling PLC to HDL3 receptor in platelets.
Nazih
H
H
Serlia: Institut Pasteur, Lille, France.
Devred
D
D
Martin-Nizard
F
F
Clavey
V
V
Fruchart
J C
JC
Delbart
C
C
D016632:Apolipoprotein A-I / Q000494:pharmacology; D016633:Apolipoprotein A-II / Q000494:pharmacology; D001792:Blood Platelets / Q000378:metabolism*; D002352:Carrier Proteins; D004075:Diglycerides / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000502:physiology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006801:Humans; D008075:Lipoproteins, HDL; D037342:Pertussis Toxin; D010713:Phosphatidylcholines / Q000378:metabolism*; D016601:RNA-Binding Proteins; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018110:Receptors, Lipoprotein; D010738:Type C Phospholipases / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D002352:Carrier Proteins; D004075:Diglycerides; D008075:Lipoproteins, HDL; D010713:Phosphatidylcholines; D016601:RNA-Binding Proteins; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein; D010566:Virulence Factors, Bordetella; C031616:high density lipoprotein receptors; C075197:high density lipoprotein binding protein; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins