Increased transcript levels and kinetic function of pyruvate kinase during severe dehydration in aestivating African clawed frogs, Xenopus laevis.

In African clawed frogs, severe dehydration reduces the phosphorylation of liver pyruvate kinase by 25%, and artificially removing phosphate groups from this enzyme in healthy frogs produces the same metabolic changes seen in dehydrated frogs, demonstrating that dephosphorylation directly regulates glycolytic activity during metabolic depression.

When African clawed frogs experience severe dehydration, their liver and muscle cells produce more RNA copies of pyruvate kinase enzymes, which is part of a metabolic adjustment during reduced energy use.

In African clawed frogs, severe dehydration changes how the liver enzyme pyruvate kinase functions, but does not change how the same enzyme functions in muscle tissue.

In African clawed frogs, dehydration triggers two biochemical changes in liver pyruvate kinase—increased mRNA levels and removal of phosphate groups—that together maintain glycolysis even when overall protein production is reduced.

In severely dehydrated African clawed frogs, liver pyruvate kinase becomes more efficient at using its substrates, resulting in lower energy requirements for enzyme activation and increased ATP production under low-energy conditions.