Metabolism Can Shape Cells' Destinies

“Those chemical modifications that decorate [histones] and modify gene expression — they’re metabolites, full stop,” said Finley, the cancer biologist. “Chemical modifications themselves are metabolites, and their removal is dependent on metabolites.” Fifteen years ago, when Kathryn Wellen was a postdoc studying cancer cells, she discovered that the epigenetic marks on histones change in response to the presence of nutrients. When food is plentiful, mitochondria make a metabolite called acetyl-CoA. It diffuses into the nucleus, where the genome resides, through large pores. There, enzymes break down the metabolites into epigenetic marks known as acetyl groups and place them on histones to activate one set of genes. However, when the cells are starving, enzymes strip off the acetyl groups. Some of those acetyl groups are turned back into acetyl-CoA and consumed for energy, while others are recycled to activate a different set of genes. Clearly there’s a lot of metabolic activity occur ... Read full article.