Regulation of 5-Lipoxygenase Activity in Rat Basophilic Leukemia Cells

Mg2+ Activates 5-Lipoxygenase in Vitro: Dependency on Concentrations of Phosphatidylcholine and Arachidonic Acid

“…First, calcium ionophore A23187 was shown to stimulate 5LO activity in human PMNL (). Subsequently, the relevance of elevated intracellular calcium levels (evoked by ionophores and other stimuli) for activation of 5LO has been studied in more detail ( − ). Also, in cell-free systems and after purification, calcium stimulates 5LO activity ( , ) although it should be observed that 5LO has some activity in vitro also without addition of calcium ( − ).…”

Fatty acid modulation of tumor cell-platelet-vessel wall interaction

“…It has been shown that Ca 2÷ activates 5-LOX in vitro [110]. Translocation of 5-LOX from cytosol to membrane has also been observed upon activation by ionophore A23187 [110]. The nature of the membrane translocation and its physiological relevance are not yet understood.…”

“…EGF has been demonstrated to stimulate LOX activity and therefore the production of HETE [108] and HODE [119]. It has been shown that Ca 2÷ activates 5-LOX in vitro [110]. Translocation of 5-LOX from cytosol to membrane has also been observed upon activation by ionophore A23187 [110].…”

“…Here, we will not discuss the enzyme activity regulated by factors such as ions, inhibitors, suicide substrates, etc. These aspects have been reviewed previously [1,5,101,102]. Instead, we focus on more recent work and put emphasis on their genetic regulation and regulation by growth factors and cytokines.…”

“…Multiple GC boxes were found in the 5' region, raising the possibility of 5-LOX as a housekeeping gene. However, this is not very likely since LOX activity is highly inducible [110,111] and its expression demonstrates a tissue specificity [99]. Recent discovery of a 5-1i-poxygenase-activating protein (FLAP), which is required for leukotriene synthesis by 5-LOX [112,113], suggests an alternative mechanism of regulation of 5-LOX.…”