Scientists have discovered the biochemical equivalent of a cellular dimmer switch to control metabolism.
It's well known that genes can be turned on and off to allow cells to respond to different metabolic demands. And, in recent years, scientists have also discovered that the levels at which genes are expressed (turned on) can also be controlled to further tweak the sensitivity of the system.
But now scientists have discovered that the proteins, including enzymes, that drive the metabolic pathways inside cells can also be manipulated to make them more or less active. Writing in Science, Fudan University, Shanghai, scientist Shimin Zhao and colleagues show, using liver cells, that a chemical moiety called an acetyl group (a chain of two carbon atoms) can be added to lysine, one of the amino acid building blocks that makes up proteins.
This modification occurs in response to certain chemicals and also to changes in a cell's immediate environment, which can have the effect of altering - and in some cases doubling - the activity of the protein.
This means that there is a whole new layer of complexity to the way cells respond to local conditions and signals such as hormones or even glucose levels. Understanding how this works in detail will inevitably lead to new drugs for old diseases, and a better understanding of many pathological and physiological processes.