Hydrogen Sulfide Coordinates Glucose Metabolism Switch through Destabilizing Tetrameric Pyruvate Kinase M2

Cancer cells reprogram their glucose metabolic pathway from oxidative phosphorylation toward aerobic glycolysis. Pyruvate kinase M2 (PKM2), which converts phosphoenolpyruvate (PEP) to pyruvate, is considered the rate-limiting enzyme involved in cancer glucose metabolism. By reducing PKM2 enzyme activity, cancer cells attain a greater fraction of glycolytic metabolites for macromolecule synthesis needed for rapid proliferation. Here we demonstrate that hydrogen sulfide (H 2 S) destabilizes PKM2 tetramer into dimer/monomer, leading to reduced PKM2 enzyme activity and an increase in the activation of nuclear transcriptional genes mediated by dimeric PKM2. Proteomic profiling of endogenous PKM2 reveals the occurrence of sulfhydration at cysteines, notably at cysteine 326. Blocking PKM2 sulfhydration at cysteine 326 through amino acid mutation stabilizes PKM2 tetramer and crystal structure further indicating that the tetramer organization of PKM2 C326S is different from the currently known T or R states, revealing PKM2 C326S as a newly identified form. The presence of a PKM2 C326S mutant in cancer cells effectively rewires glucose metabolism to mitochondrial respiration, resulting in the significant inhibition of tumor growth. Collectively, PKM2 sulfhydration by H 2 S serves as a glucose metabolic rewiring mechanism in promoting tumorigenesis, and inhibition of PKM2 sulfhydration may be applied as a new therapeutic approach targeting cancer metabolism. One-Sentence Summary H 2 S rewires glucose metabolism by destabilizing PKM2 tetramerization majorly through sulfhydration at cysteine 326 Highlights H 2 S enhances PKM2 dissociation from tetramer to dimer to facilitate dimeric PKM2 nuclear translocation. H 2 S modifies PKM2 sulfhydration, notably at cysteine 326. The crystal structure reveals PKM2 C326S as a unique tetramer conformation. Blockage of PKM2 sulfhydration at C326 rewires cancer glucose metabolism and significantly inhibits tumor growth.