A possible role of lysophospholipids produced by calcium-independent phospholipase A2 in membrane-raft budding and fission

AbstractPhospholipase A2 (PLA2) not only plays a role in the membrane vesiculation system but also mediates membrane-raft budding and fission in artificial giant liposomes. This study aimed to demonstrate the same effects in living cells. Differentiated Caco-2 cells were cultured on filter membranes. MDCK cells were challenged with Influenza virus. The MDCK cultures were harvested for virus titration with a plaque assay. Alkaline phosphatase (ALP), a membrane-raft associated glycosylphosphatidylinositol (GPI)-anchored protein, was 70% released by adding 0.2 mmol/l lysophosphatidylcholine, which was abolished by treatment with a membrane-raft disrupter, methyl-β-cyclodextrin. Activation of calcium-independent PLA2 (iPLA2) by brefeldin A increased the apical release of ALP by approximately 1.5-fold (p<0.01), which was blocked by PLA2 inhibitor bromoenol lactone (BEL). BEL also reduced Influenza virus production into the media (