As scientists learn more about the biochemical processes that affect lifespan, they might one day be able to target those processes to reduce the effects of age-related diseases like heart disease or diabetes.
The UW researchers conducted a genome-wide screen of yeast cells to find which genes, and their corresponding proteins, affect lifespan. Two of the proteins, called Tor1 and Sch9, are signaling molecules that are linked to nutrient uptake in many different organisms. Their results suggest that the same proteins, or very similar ones, may be related to both nutrient response and the aging process in humans.
"The idea is to identify pathways in yeast that are involved in aging, and take them to higher organisms like mice and eventually people," explained Brian Kennedy, assistant professor of biochemistry at the UW School of Medicine and one of the study's main authors. He collaborated on the project with Matt Kaeberlein, a postdoctoral researcher in the lab of Stanley Fields, professor of genome sciences at the UW and Howard Hughes Medical Institute investigator.
After finding ten genes that regulate lifespan, the researchers tested two Tor1 and Sch9 to confirm their connection to caloric restriction. One test combined caloric restriction with the genetic mutation to Tor1 that reduced signaling on the TOR pathway. They saw lifespan increases in the resulting yeast cells that were about the same as a cell that had just the Tor1 mutation, indicating that the mutation was doing the same thing as caloric restriction.