Serine and ethanolamine incorporation into different plasmalogen pools: Subcellular analyses of phosphoglyceride synthesis in cultured glioma cells |
| |
Authors: | Zhaolin Xu David M. Byers Frederick B. St. C. Palmer Harold W. Cook |
| |
Affiliation: | (1) Atlantic Research Centre and Departments of Pediatrics and Biochemistry, Dalhousie University, Rm. C-204, CRC, 5849 University Avenue, B3H 4H7 Halifax, Nova Scotia, Canada |
| |
Abstract: | In cultured glioma cells, plasma membrane (PM) is enriched in phosphatidylserine (PtdSer) and plasmalogens (1-O-alk-1 -enyl-2-acyl-sn-glycero-3-phosphoethanolamine). Serine can be a precursor of headgroups of both ptdSer and ethanolamine phosphoglycerides (PE) including plasmalogens and non-plasmalogen PE (NP-PE). Synthesis of phospholipids was investigated at the subcellular level using established fractionation procedures and incorporation of [3H(G)]L-serine and [1,2-14C]ethanolamine. Specific radioactivity of PtdSer from [3H]serine was 2-fold greater in PM than in microsomes, reaching maximum by 2–4 h. Labeled plasmalogen from [3H]serine appeared in PM by 4 h and increased to 48 h, whereas almost no plasmalogen accumulated in microsomes within 12 h. In contrast, labeled plasmalogen from [1,2-14C]ethanolamine appeared in both PM and microsomes at early incubation times and became enriched in PM beyond 12 h. Thus, in glioma cells: (1) greater and faster accumulation of labeled PtdSer in PM may reflect direct synthesis from serine within PM; (2) PM is a major source of PtdSer for decarboxylation and PE synthesis; (3) NP-PE in both PM and microsome provides headgroup for synthesis of plasmalogen; and, (4) plasmalogen synthesis may involve different intracellular pools depending on headgroup origin.Abbreviations NP-PE nonplasmenylethanolamine phosphoglycerides including both diacyl and alkylacyl species - PE total ethanolamine phosphoglycerides: plasmalogen-plasmenylethanolamine or alkenylacyl ethanolamine phosphoglyceride (1-O-alk-1 -enyl-2-acyl-sn-glycero-3-phosphoethanolamine) - PL phospholipid - PM plasma membrane - PtdCho phosphatidylcholine - PtdSer phosphatidylserine |
| |
Keywords: | Phosphatidylserine ethanolamine phosphoglycerides plasmalogens phospholipid metabolism subcellular fractions glioma cells |
本文献已被 SpringerLink 等数据库收录! |
|