Ca2+ effect on ATP-independent lysophospholipid transacylases is indissociable from Ca2+ effect on phospholipase A2 activity in rat platelet sonicates.
CoA-dependent transacylation and phospholipid hydrolysis were studied in parallel experiments using rat platelet sonicates. The decrease observed in palmitoyllyso-sn-glycero-3-phosphocholine (palmitoyllyso-GPC) transcylation as a function of Ca2+ concentration was found to be correlated with appearance of endogenous lysoderivatives. We also demonstrated that endogenously produced acyllyso-sn-glycero-3-phosphoethanolamine (acyllyso-GPE) induced CoA-dependent arachidonate transfer from diacyl-GPC. These results further argue for a two-step arachidonate release from diacyl-GPC when platelets are stimulated with thrombin.
Breton
M
M
URA CNRS 217, Laboratoire de Biochimie, CHU Saint-Antoine, Paris, France.
Masrar
H
H
Bereziat
G
G
Colard
O
O
D000217:Acyltransferases / Q000097:blood*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001792:Blood Platelets / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology*; D008245:Lysophospholipase / Q000097:blood*; D009097:Multienzyme Complexes / Q000097:blood*; D010740:Phospholipases / Q000097:blood*; D010741:Phospholipases A / Q000097:blood*; D054467:Phospholipases A2; D051381:Rats
D009097:Multienzyme Complexes; D000255:Adenosine Triphosphate; D000217:Acyltransferases; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D008245:Lysophospholipase; C021782:lysophospholipase-transacylase; D002118:Calcium