Translocation and Leukotriene Synthetic Capacity of Nuclear 5-Lipoxygenase in Rat Basophilic Leukemia Cells and Alveolar Macrophages

摘要: Abstract Leukotriene (LT) synthesis involves the translocation of enzymatically active 5-lipoxygenase (5-LO) from a soluble site to bound site, where it interacts with 5-lipoxygenase-activating protein (FLAP). In human polymorphonuclear leukocytes (PMNs), 5-LO moves cytosol nuclear envelope (NE) interact FLAP. However, has recently been found within nucleus, as well cytosol, rat basophilic leukemia (RBL) cells and alveolar macrophages (AMs). To assess whether can contribute LT in these cells, we investigated this enzyme pool 1) translocates upon cell activation, 2) co-localizes FLAP, 3) is active. By fractionation followed by immunoblotting, both cytosolic decreased dramatically RBL following activation calcium ionophore A23187. Concurrently, increased pelletable pool, FLAP was also detected. The loss 5-LO, concomitant increase exclusively at NE, co-localization were confirmed indirect immunofluorescent confocal microscopy. AMs, moved found; however, did not translocate. Application methods PMNs that co-localized cell-free assay, proteins but PMNs, able generate products arachidonate, inhibited direct inhibitor zileuton. Cytosolic all types showed activity. These results demonstrate three distinct patterns are specific for each type: only pools cells. virtue its enzymatic activity ability translocate, potential AMs. Finally, provide foundation considering individual functions discrete future studies.