Lysine modification links cell metabolism to gene activity

Cells use chemical marks on proteins to regulate functions. One of the best known is acetylation: the addition of an acetyl group to the amino acid lysine. That process is well studied. But a related modification, lysine acetoacetylation (Kacac), has long remained poorly understood. Researchers knew it existed, but its precise workings were unclear.

A new team developed a chemical-immunological method to reliably detect Kacac in cells. Using this approach, the researchers mapped which proteins carry this modification and which enzymes add or remove it. The results show that Kacac is present on a broad range of proteins, including histones: the spool-like structures around which DNA winds and which play a key role in gene regulation.

The link with energy metabolism

Acetoacetate, the molecule underlying this modification, is a ketone body. Ketone bodies are produced when cells have little glucose available, for example during fasting or a low-carbohydrate diet. That makes Kacac particularly notable: it places a direct link between the cell’s energy status and gene activity.

This mechanism provides a molecular explanation for something researchers had long suspected: that how cells use energy directly influences which genes are active. This connection is relevant to aging, in which both energy metabolism and epigenetic regulation (the switching of genes on and off without changes to DNA) are altered.

Significance for future research

The study also identifies which enzymes are responsible for adding and removing Kacac. That opens the door to targeted intervention. If specific Kacac patterns contribute to disease or aging, inhibitors of those enzymes could in principle be therapeutically interesting. For now these are foundational findings, but they lay solid groundwork for further research.

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