Hungry yeast live longer

Caloric restriction (CR) is known to extend life-span in many species, and is thought to work by slowing metabolism and thus the generation of toxic reactive oxygen species. In the 22 September Science Lin et al. report that yeast also grow longer under conditions of CR (Science 2000, 289:2126-2128). Yeast on low-glucose plates, or with a defect in the glucose-activated protein kinase A (PKA) pathway, divide for more generations before senescing. The histone deacetylase and silencing protein Sir2p is known to affect aging, and is required for the CR effect. Maintenance of silencing may be critical to longevity in many species, either by repressing genomic instability or by preventing inappropriate gene expression.