Time-resolved in situ assembly of the leukotriene-synthetic 5-lipoxygenase/5-lipoxygenase-activating protein complex in blood leukocytes.

摘要: 5-Lipoxygenase (5-LO) catalyzes the initial steps in biosynthesis of proinflammatory leukotrienes. Upon cell activation, 5-LO translocates to nuclear membrane where arachidonic acid is transferred by 5-LO-activating protein (FLAP) for metabolism. Although previous data indicate association with FLAP, situ assembly native 5-LO/FLAP complexes remains elusive. Here, we show time-resolved colocalization immunofluorescence microscopy and interaction proximity ligation assay at Ca(2+)-ionophore A23187-activated human monocytes neutrophils relation activity. translocation product formation completed within 1.5-3 min, delayed proceeds up 30 min. Though contain comparable amounts protein, produce 3-5 times higher levels products due prolonged activity, accompanied translocation. Arachidonic seemingly acts as adaptor assembly, whereas FLAP inhibitors (MK886, 100 nM; BAY X 1005, 3 µM) disrupt complex. We conclude that may regulate activity 2 ways: first inducing an flexible efficient synthesis, followed a tight complex terminates