The proteasome stops working temporarily, until the oxidative stress passes
The Technion researchers discovered that the proteasome - the mechanism that removes damaged proteins - "goes on hiatus" until the oxidative stress passes. This is what the scientific journal "Cell Reports" publishes in its latest issue. The research was conducted as part of Nurit Levant-Levanon's doctoral thesis, under the direction of Professor Michael Glickman from the Faculty of Biology, with the participation of the laboratory director Naa Reiss and researchers from the University of Cologne in Germany.
"Our cells are exposed to damage, including oxidative damage during the breathing process," explains Professor Glickman. "Active oxygen molecules ('free radicals') attack the substances in the body, including proteins. The damaged proteins need to be eliminated quickly, otherwise they will accumulate and cause long-term damage."
A "biological machine" (the proteasome) is responsible for removing the damaged proteins. It removes them by recycling them into new proteins. The paradox is that the proteasome itself is also made of proteins and the Technion researchers asked themselves how the machine itself avoids the damage, or alternatively - how does it continue to work after it has already been damaged?
"We discovered that the proteasome temporarily stops working during stress (in our experiments - up to three hours)," says Professor Glickman. "In this way, he reduces the damage, because if he continues to work when he himself is injured - he will not recycle the proteins well and thus cumulative or unexpected damage will be caused to the body. After the stoppage of work - there is a good chance that the oxidative damage has passed in the meantime."
Technion researchers compare the surprising discovery to a person caught in a sandstorm. He closes his eyes until the storm passes and thus prevents damage. "As proof of the tremendous efficiency of the phenomenon, even after extremely acute damage (supposed to kill cells), the proteasome returned to normal work, as long as the damage was temporary," they emphasize.
