Ras pathways help buffer biological timekeeping against metabolic perturbations.

Circadian clocks need to be buffered against changes in conditions that could affect their rate and disrupt their timekeeping function. The circadian period of the fungus Neurospora is compensated across a range of nutritional conditions. Several gene products are implicated in the mechanism, but a complete picture is lacking. Sárkány et al. report that a Ras pathway linked to cAMP is required to maintain a constant period under low glucose conditions. They extend this work to a human cell line showing similar effects of the homologous Ras pathway, pointing toward potential conservation of compensation pathways across eukaryotes.