PRDX6 augments selenium utilization to limit iron toxicity and ferroptosis
H. Fujita, Yuki Tanaka, Seiryo Ogata, Noriyuki Suzuki, Sota Kuno, Uladzimir Barayeu, Takaaki Akaike, Yasumitsu Ogra, Kazuhiro Iwaï
Abstract
Abstract Ferroptosis is a form of regulated cell death induced by iron-dependent accumulation of lipid hydroperoxides. Selenoprotein glutathione peroxidase 4 (GPX4) suppresses ferroptosis by detoxifying lipid hydroperoxides via a catalytic selenocysteine (Sec) residue. Sec, the genetically encoded 21 st amino acid, is biosynthesized from a reactive selenium donor on its cognate tRNA [Ser]Sec . It is thought that intracellular selenium must be delivered ‘safely’ and ‘efficiently’ by a carrier protein owing to its high reactivity and very low concentrations. Here, we identified peroxiredoxin 6 (PRDX6) as a novel selenoprotein synthesis factor. Loss of PRDX6 decreases the expression of selenoproteins and induces ferroptosis via a reduction in GPX4. Mechanistically, PRDX6 increases the efficiency of intracellular selenium utilization by transferring selenium between proteins within the selenocysteyl-tRNA [Ser]Sec synthesis machinery, leading to efficient synthesis of selenocysteyl-tRNA [Ser]Sec . These findings highlight previously unidentified selenium metabolic systems and provide new insights into ferroptosis.