The Insulin/IGF Signaling Cascade Modulates SUMOylation to Regulate Aging and Proteostasis in C. elegans.

In this project we asked how reducing the activity of the insulin/IGF signaling (IIS) cascade by knocking down the expression of daf-2, affects global protein SUMOylation of C. elegans. We found that among other proteins, IIS reduction lowers the SUMOylation of CAR-1, a protein that negatively regulates the activity of the worm’s notch receptor, GLP-1. Thus, the knockdown of car-1 hyper-activates GLP-1, shortens lifespan and exposes the worm to toxic protein aggregation (proteotoxicity). In contrast, the expression of a SUMOylation resistant CAR-1 (K185R) promotes longevity and protects model nematodes from proteotoxicity.