LET-607, a transcription factor in C. elegans, enforces a trade-off between two protein-quality control systems—suppressing cytosolic stress response while promoting endoplasmic reticulum stress response. Removing LET-607 rebalances this allocation, enhancing cytosolic protein quality control and extending lifespan, suggesting that developmental optimization sacrifices longevity potential.
Key Points
- LET-607 deficiency shifts proteostatic resources from ER to cytosol
- Rebalancing activates cytosolic UPR through one-carbon metabolism changes
- Extended lifespan requires cytosolic UPR activation, not ER suppression alone
Longevity Analysis
This research identifies a specific molecular constraint on longevity: the body maintains a proteostatic balance optimized for development and reproduction rather than extended health. The finding demonstrates that the same transcriptional mechanism that allows efficient protein handling during growth actively limits cytosolic protein quality control—a critical capacity for late-life resilience. By revealing how one factor controls allocation between two protein-handling subsystems, the work supports a fundamental principle in aging biology: trade-offs embedded in developmental programming constrain maximum lifespan unless explicitly rebalanced. This has practical relevance for longevity approaches targeting protein homeostasis, suggesting that activating dormant quality-control capacity may be more effective than simply reducing protein damage.
Original published by Wiley Aging Cell, by Haixiang Tong, Wei Li, Pangui Yuan, Feng Li, Qin Liu, Shanshan Pang, Haiqing Tang .