An RNA-cutting enzyme supports longer life in worms

Reducing DIS-3 activity shortened normal lifespan and reduced lifespan extension from several interventions. A mutation in the gene for DIS-3 eliminated the extra lifespan in two models of dietary restriction. Adding more DIS-3 did not extend lifespan in normal worms. One RNA fragment was essential for lifespan extension from several interventions and slowed protein production by binding to ribosomal proteins, parts of the cell’s protein-making machinery. In human lung connective-tissue cells grown in the lab and engineered to produce telomerase, which maintains chromosome ends, the human enzyme delayed senescence, a state in which cells stop dividing, through a different RNA fragment.