Cell's Cleaning Mechanism Rebounds after Temporary Stress Episodes
Sunday, May 25, 2014
By: Kevin Hattori

Researchers at the Technion-Israel Institute of Technology have discovered that the proteasome - the "biological machine" that rids the body of damaged proteins - "takes a break" when cells are under harmful oxidative stress. Damaged proteins must be disposed of quickly, or they will accumulate and cause long-term damage. The findings are published this week in Cell Reports.

The team led by Prof. Michael Glickman, of the Technion Faculty of Biology, compares the phenomenon to a person caught in a sandstorm closing their eyes until the storm passes to avoid injury.  They found that experiencing severe stress that may even lead to cell death, proteasomes can get back to work, as long as the stress is temporary.

Professor Michael Glickman

Potential damage to cells comes from a long list of sources, including harmful oxidation that can arise as a side effect of the body’s natural energy production.  Such free radicals (reactive oxidative species) attack the body – including the proteins that make up a large portion of human solid body mass.

Proteasomes remove damaged proteins by recycling them into new proteins. The paradox is that proteasomes themselves are made up of proteins, something that led the researchers to ask: how do proteasomes avoid oxidative stress damage?

“In our experiments, the proteasomes stop working for up to three hours during times of stress, with very minor deleterious effects,” said Prof. Glickman. “In this way, by shielding the protein-recycling mechanism, it reduces potential self-damage during an episode of oxidative stress, and in turn, protects the body from cumulative or unpredictable damage. After such a break, the proteasome can get back to cleaning up the oxidative stress left behind.”

The research was conducted as part of Nurit Livnat-Levanon’s doctoral thesis, in collaboration with Noa Reis, microbiologist and lab manager together with Prof Thorsten Hoppe their partner on a Deutsch-Israelische Projektkooperation (DIP) grant at the University of Cologne, Germany.

The Technion-Israel Institute of Technology is a major source of the innovation and brainpower that drives the Israeli economy, and a key to Israel’s renown as the world’s “Start-Up Nation.” Its three Nobel Prize winners exemplify academic excellence. Technion people, ideas and inventions make immeasurable contributions to the world including life-saving medicine, sustainable energy, computer science, water conservation and nanotechnology. The Joan and Irwin Jacobs Technion-Cornell Innovation Institute is a vital component of Cornell NYC Tech, and a model for graduate applied science education that is expected to transform New York City’s economy.

American Technion Society (ATS) donors provide critical support for the Technion—more than $1.9 billion since its inception in 1940. Based in New York City, the ATS and its network of chapters across the U.S. provide funds for scholarships, fellowships, faculty recruitment and chairs, research, buildings, laboratories, classrooms and dormitories, and more.