title: Lipoxygenase activity in altered gravity.
abstract: Lipoxygenases are a family of enzymes which dioxygenate unsaturated fatty acids, thus initiating lipoperoxidation of membranes or the synthesis of signalling molecules, or inducing structural and metabolic changes in the cell. This activity is the basis for the critical role of lipoxygenases in a number of pathophysiological conditions, both in animals and plants. We review the effects of microgravity on the catalytic efficiency of purified soybean (Glycine max) lipoxygenase-1, as well as the modulation of the activity and expression of 5-lipoxygenase in human erythroleukemia K562 cells subjected to altered gravity. We also outline the molecular properties of the lipoxygenase family and discuss its possible involvement in space-related processes, such as apoptosis (programmed cell death) and immuno-depression. Finally, we discuss the modulation of cyclooxygenase activity and expression in K562 cells exposed to altered gravity, because cyclooxygenase catalyzes the oxidation of arachidonate through a pathway different from that catalyzed by lipoxygenase activity.
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences and Biomedical Space Center, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Maccarrone
authors.forename: Natalia
authors.initials: N
authors.lastname: Battista
authors.forename: Monica
authors.initials: M
authors.lastname: Bari
authors.forename: Alessandro
authors.initials: A
authors.lastname: Finazzi-Agrò
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D016922:Cellular Senescence / Q000502:physiology; D018470:Gravity, Altered; D006801:Humans; D008084:Lipoxygenase / Q000378:metabolism*; D008214:Lymphocytes / Q000502:physiology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011973:Receptors, LDL / Q000378:metabolism; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D013025:Glycine max / Q000737:chemistry; D014407:Tumor Cells, Cultured / Q000201:enzymology
chemical_list: C495137:OLR1 protein, human; D011973:Receptors, LDL; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D008084:Lipoxygenase; D001094:Arachidonate 5-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases