Phosphoenolpyruvate carboxykinase is a nuclear enzyme in rats and chickens

The presence of phosphoenolpyruvate carboxykinase (PEPCK) in the nuclei of chicken liver cells was confirmed using two experimental designs. PEPCK was found to be enriched in the nuclear fraction of rat liver, a species whose hepatic PEPCK is reported to be predominantly cytosolic. We suggest that PEPCK plays a role in nuclear synthesis of N-acetyl-neuraminic acid.