Promiscuous enzyme SQOR in cellular metabolism and ferroptosis regulation.

Ferroptosis, an iron-dependent form of programmed cell death, is primarily driven by the accumulation of lipid peroxides through radical generation, notably via the Fenton reaction. Emerging evidence highlights the intricate link between ferroptosis and cellular metabolism, with metabolic enzymes playing pivotal roles in its regulation. Sulfide quinone oxidoreductase (SQOR), traditionally recognized for its role in hydrogen sulfide (H2S) detoxification and electron transport chain (ETC) activation, has recently been identified as a promiscuous enzyme with a novel function in ferroptosis regulation. This review explores SQOR's canonical function in H2S metabolism and its emerging role in ferroptosis resistance through the production of ubiquinol and hydropersulfides, radical-trapping antioxidants. Additionally, we provide insights into potential future research directions, emphasizing SQOR's therapeutic relevance in ferroptosis-associated diseases. [BMB Reports 2025; 58(6): 233-237].