Molecular mechanism of glycolytic flux control intrinsic to human phosphoglycerate kinase

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 118; no. 50; pp. 1 - 11
• Main Authors: Yagi, Hiromasa, Kasai, Takuma, Rioual, Elisa, Ikeya, Teppei, Kigawa, Takanori
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 14.12.2021
• Subjects: Adaptation; Adenine; Adenosine diphosphate; Adenosine Diphosphate - metabolism; Adenosine triphosphate; Adenosine Triphosphate - metabolism; ATP; Binding; Biological Sciences; Catalysis; Catalytic Domain; Chemical reactions; Cooperativity; Enzymes; Escherichia coli; Fluctuations; Gene Expression Regulation, Enzymologic - physiology; Gene regulation; Glyceric Acids - metabolism; Glycolysis; Glycolysis - physiology; Homeostasis; Humans; Intracellular; Kinases; Ligands; Models, Molecular; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nucleotides; Phosphoglycerate kinase; Phosphoglycerate Kinase - genetics; Phosphoglycerate Kinase - metabolism; Physiology; Protein Binding; Protein Conformation; Regulatory mechanisms (biology); Spectroscopy; Transcription; solution NMR; ligand-binding cooperativity; enzyme regulation; glycolysis; in-cell NMR
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2112986118

Glycolysis plays a fundamental role in energy production and metabolic homeostasis. The intracellular [adenosine triphosphate]/[adenosine diphosphate] ([ATP]/[ADP]) ratio controls glycolytic flux; however, the regulatory mechanism underlying reactions catalyzed by individual glycolytic enzymes enabling flux adaptation remains incompletely understood. Phosphoglycerate kinase (PGK) catalyzes the reversible phosphotransfer reaction, which directly produces ATP in a near-equilibrium step of glycolysis. Despite extensive studies on the transcriptional regulation of PGK expression, the mechanism in response to changes in the [ATP]/[ADP] ratio remains obscure. Here, we report a protein-level regulation of human PGK (hPGK) by utilizing the switching ligand-binding cooperativities between adenine nucleotides and 3-phosphoglycerate (3PG). This was revealed by nuclear magnetic resonance (NMR) spectroscopy at physiological salt concentrations. MgADP and 3PG bind to hPGK with negative cooperativity, whereas MgAMPPNP (a nonhydrolyzable ATP analog) and 3PG bind to hPGK with positive cooperativity. These opposite cooperativities enable a shift between different ligand-bound states depending on the intracellular [ATP]/[ADP] ratio. Based on these findings, we present an atomic-scale description of the reaction scheme for hPGK under physiological conditions. Our results indicate that hPGK intrinsically modulates its function via ligand-binding cooperativities that are finely tuned to respond to changes in the [ATP]/[ADP] ratio. The alteration of ligand-binding cooperativities could be one of the self-regulatory mechanisms for enzymes in bidirectional pathways, which enables rapid adaptation to changes in the intracellular environment.