The glycolytic enzymes glyceraldehyde‐3‐phosphate dehydrogenase and hexokinase interact with cell cycle proteins in maize

• Published in: FEBS letters 2023-08, Vol.597 (16), p.2072-2085
• Main Authors: Vargas‐Cortez, Teresa, Guerrero‐Molina, Estefany Damaris, Axosco‐Marin, Javier, Vázquez‐Ramos, Jorge Manuel, Lara‐Núñez, Aurora
• Format: Article
• Language: English
• Subjects: cyclins; cyclin‐dependent kinases; glyceraldehyde‐3‐phosphate dehydrogenase; glycolysis; hexokinase; maize
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1002/1873-3468.14704

Cyclin/cyclin‐dependent kinase (CDK) heterodimers have multiple phosphorylation targets and may alter the activity of these targets. Proteins from different metabolic processes are among the phosphorylation targets, that is, enzymes of central carbon metabolism. This work explores the interaction of Cyc/CDK complex members with the glycolytic enzymes hexokinase 7 (HXK7) and glyceraldehyde‐3‐phosphate dehydrogenase (GAP). Both enzymes interacted steadily with CycD2;2, CycB2;1 and CDKA;1 but not with CDKB1;1. However, Cyc/CDKB1;1 complexes phosphorylated both enzymes, decreasing their activities. Treatment with a CDK‐specific inhibitor (RO‐3306) or with lambda phosphatase after kinase assay restored total HXK7 activity, but not GAP activity. In enzymatic assays, increasing concentrations of CDKB1;1, but not of CycD2;2, CycB2;1 or CycD2;2/CDKB1;1 complex, decreased GAP activity. Cell cycle regulators may modulate carbon channeling in glycolysis by two different mechanisms: Cyc/CDK‐mediated phosphorylation of targets (e.g., HXK7; canonical mechanism) or by direct and transient interaction of the metabolic enzyme (e.g., GAP) with CDKB1;1 without a Cyc partner (alternative mechanism). Cell cycle regulators from maize may alter the pace of carbon channeling in glycolysis by two different mechanisms: (a) Cyclin/cyclin‐dependent kinase (CDK) complexes interact with and phosphorylate hexokinase 7; (b) the presence of CDKB, without a cyclin partner, alters the activity of glyceraldehyde‐3‐phosphate dehydrogenase. In both cases, the cell cycle regulators exert an inhibitory effect on the glycolytic enzymes.