Successful adaptation to starvation or cold exposure depends in part on a protein called E2F1 reports a paper online in Nature Cell Biology this week. These findings highlight an important way in which cells cope at the molecular level when exposed to stressful environmental conditions.

Lluis Fajas and colleagues found that mice lacking E2F1 were less susceptible to exercise-induced fatigue and could maintain a higher body temperature following fasting or in cold conditions. These results suggest that E2F1 regulates metabolism. Indeed, the authors found that E2F1 loss increased the expression of genes important for oxidative metabolism, suggesting that E2F1 normally functions to repress this type of metabolism.

The team went on to provide insight into how this function of E2F1 is integrated with its well-established role in cell-cycle progression. These findings support a critical position for E2F1 at the nexus of cell proliferation and metabolism.