Evidence for stimulation of glycerophospholipid synthesis in cultured human cells infected with measles virus.

Change of lipid metabolism in FL cells derived from human amniotic membrane during fusion from within induced by measles virus was studied. The following results were obtained. (1) Incorporation of [32P]orthophosphate and [methyl]-14C]choline into the lipid fraction of infected cells was higher than that of control cells. In this case, no detectable alteration of labeled phospholipid composition was observed. (2) Radioactivity of the lipids in subcellular fractions of infected-cells labeled with [1-14C]oleic acid for a short term also increased. (3) It was confirmed that specific enzyme activities in phosphatidylcholine synthesis, i.e. ATP:choline phosphotransferase [EC 2.7.1.32], CTP:phosphocholine cytidyltransferase [EC 2.7.7.15], and CDPcholine: 1,2-diacylglycerol cholinephosphotransferase [EC 2.7.8.2] in each subcellular fraction of the infected-cells were higher than those of control cells. (4) AcylCoA: 1-acyl-GPC acyltransferase activity in microsomal fraction of the infected-cells was enhanced. The above results indicate that there is stimulation of cellular phospholiid synthesis in de novo pathway and acylation of lysophospholipids in the infected-cells. A marked increase in radioactivity-incorporation (10.3 fold) of [1-14C]oleic acid into triacylglycerol in the cytosol of the infected cells was also observed.