Peroxidation of polyunsaturated fatty acids by lipoxygenases drives ferroptosis

Significance Ferroptosis is a regulated form of cell death induced by loss of glutathione peroxidase 4 (GPX4) phospholipid peroxidase activity and lethal accumulation of reactive oxygen species. Small-molecule inhibitors of GPX4 induce ferroptosis; however, the interaction between these inhibitors and GPX4 has remained elusive, as has the identity of the reactive oxygen species that drive execution of ferroptosis. We identified here a ligand-binding site on GPX4 and determined the specific lipids oxidized during ferroptosis. We further identified two key drivers of lipid peroxidation during ferroptosis: lipoxygenases and phosphorylase kinase G2. These findings reveal a previously enigmatic mechanism of ferroptotic lipid peroxide generation and suggest new strategies for pharmacological control of ferroptosis and diseases associated with this mode of cell death.