PRDX6 dictates ferroptosis sensitivity by directing cellular selenium utilization
Junya Ito, Toshitaka Nakamura, Takashi Toyama, Deng Chen, Carsten Berndt, Gereon Poschmann, André Mourão, Sebastian Doll, Mirai Suzuki, Weijia Zhang, Jiashuo Zheng, Dietrich Trümbach, Naoya Yamada, Koya Ono, Masana Yazaki, Yasutaka Kawai, Mieko Arisawa, Yusuke Ohsaki, Hitoshi Shirakawa, Adam Wahida, Bettina Proneth, Yoshiro Saito, Kiyotaka Nakagawa, Eikan Mishima, Marcus Conrad
Abstract
Selenium-dependent glutathione peroxidase 4 (GPX4) is the guardian of ferroptosis, preventing unrestrained (phospho)lipid peroxidation by reducing phospholipid hydroperoxides (PLOOH). However, the contribution of other phospholipid peroxidases in ferroptosis protection remains unclear. We show that cells lacking GPX4 still exhibit substantial PLOOH-reducing capacity, suggesting a contribution of alternative PLOOH peroxidases. By scrutinizing potential candidates, we found that although overexpression of peroxiredoxin 6 (PRDX6), a thiol-specific antioxidant enzyme with reported PLOOH-reducing activity, failed to prevent ferroptosis, its genetic loss sensitizes cancer cells to ferroptosis. Mechanistically, we uncover that PRDX6, beyond its known peroxidase activity, acts as a selenium-acceptor protein, facilitating intracellular selenium utilization and efficient selenium incorporation into selenoproteins, including GPX4. Its physiological significance was demonstrated by reduced GPX4 expression in Prdx6-deficient mouse brains and increased sensitivity to ferroptosis in PRDX6-deficient tumor xenografts in mice. Our study highlights PRDX6 as a critical player in directing cellular selenium utilization and dictating ferroptosis sensitivity.