De novo CDP‐choline‐dependent glycerophosphorylcholine synthesis and its involvement as an intermediate in phosphatidylcholine synthesis

[摘要]

The activity of CDP-choline-dependent glycerophosphorylcholine synthetase (CDP-choline:sn-3-glycerophosphate cholinetransferase), a newly discovered enzyme involved in the recently proposed pathways of acyl-specific phosphatidylcholine synthesis, is reported in rat liver. Endogenous CDP-choline, synthesized via the CMP-driven back reaction of phosphorylcholine transferase, is also shown to be a choline donor for this glycerophosphorylcholine synthetase. The function of glycerophosphorylcholine as an intermediate in phosphatidylcholine synthesis is demonstrated by specific isotope trapping whereby unlabelled glycerophosphorylcholine inhibited label incorporation from sn-[¹⁴C]glycerol-3-phosphate into phosphatidylcholine in mouse gastrocnemius, a tissue that is essentially devoid of the cytidine pathway for phosphatidylcholine synthesis and uses a non-allelic glycerophosphorylcholine synthetase (exogenous PC:sn-3-glycerophosphate cholinetransferase) in the synthesis of glycerophosphorylcholine.

[学科分类] 生物化学/生物物理

[关键词] Glycerophosphorylcholine;Phosphatidylcholine;CDP-choline;Phosphatidylethanolamine;(Muscle);PC;phosphatidylcholine;PE;phosphatidylethanolamine;PG;phosphatidylglycerol;PI;phosphatidylinositol;PS;phosphatidylserine;G3P;sn-glycerol-3-phosphate;GPC;sn-glycerol-3-phosphorylcholine;C22:6n—3;all-cis-4;7;10;13;16;19-docosahexaenoate