- Zou, Ke;
- Rouskin, Silvia;
- Dervishi, Kevin;
- McCormick, Mark A;
- Sasikumar, Arjun;
- Deng, Changhui;
- Chen, Zhibing;
- Kaeberlein, Matt;
- Brem, Rachel B;
- Polymenis, Michael;
- Kennedy, Brian K;
- Weissman, Jonathan S;
- Zheng, Jiashun;
- Ouyang, Qi;
- Li, Hao
Caloric restriction (CR) is known to extend life span across species; however, the molecular mechanisms are not well understood. We investigate the mechanism by which glucose restriction (GR) extends yeast replicative life span, by combining ribosome profiling and RNA-seq with microfluidic-based single-cell analysis. We discovered a cross-talk between glucose sensing and the regulation of intracellular methionine: GR down-regulated the transcription and translation of methionine biosynthetic enzymes and transporters, leading to a decreased intracellular methionine concentration; external supplementation of methionine cancels the life span extension by GR. Furthermore, genetic perturbations that decrease methionine synthesis/uptake extend life span. These observations suggest that intracellular methionine mediates the life span effects of various nutrient and genetic perturbations, and that the glucose-methionine cross-talk is a general mechanism for coordinating the nutrient status and the translation/growth of a cell. Our work also implicates proteasome as a downstream effector of the life span extension by GR.