Succinylation regulates boar sperm linear motility via reprogramming glucose metabolism

Succinylation is a recently identified post-translational modification (PTM) that modulates enzyme activity and metabolism. However, how it regulates metabolic reprogramming in sperm remains unclear. In this study, we show that succinylation of pyruvate kinase M2 (PKM2) promotes oxidative phosphorylation (OXPHOS) and linear motility in boar sperm. Under low glucose (LG) extender, sperm linear motility was significantly enhanced, mitochondrial activity increased, glycolysis was inhibited, and the pentose phosphate pathway (PPP) was promoted. PKM2 interacted with voltage-dependent anion channel 3 (VDAC3), increasing mitochondrial permeability. Supplementing high glucose (HG) extender with succinic acid (SA) enhanced these effects. In contrast, the addition of resveratrol (RES) to LG extender, significantly reduced progressive motility (PM), decreased mitochondrial activity, and promoted the glycolysis pathway. Additionally, LG extender facilitated PKM2 succinylation and mitochondrial translocation. These findings demonstrate that PKM2 succinylation reprograms glucose metabolism from glycolysis to PPP, enhancing ATP production and supporting sustained linear motility, providing insights into optimizing sperm preservation.