By Mary Elizabeth Dallas, HealthDay Reporter
THURSDAY, Sept. 11, 2014 (HealthDay News) -- A team of researchers has uncovered a key way
that cells respond to stress.
As
they explain it, cells produce more than 25,000 different proteins with
specific 3-D shapes, but when stressed, they can make mistakes and produce
misshapen proteins that are unfolded or misfolded.
Duke
University researchers found, however, that cells are able to recognize this
build-up of misshapen proteins and respond by temporarily slowing down
production or shutting it off entirely.
The
researchers suggested that their findings, published Sept. 11 in the journal Cell,
could help scientists gain a better understanding of diseases like Alzheimer's,
Lou Gehrig's disease (ALS), Huntington's, Parkinson's and type 2 diabetes,
which involve the accumulation of misfolded proteins.
"We
have identified an entirely new mechanism for how the cell responds to
stress," study author Christopher V. Nicchitta, a professor of cell
biology at Duke University School of Medicine, said in a university news
release. "Essentially, the cell remodels the organization of its protein
production machinery in order to compartmentalize the tasks at hand."
Cells
work like a factory, making protein on a production line: each cell has a DNA
blueprint, which is first transcribed into messenger RNA or mRNA, which then
travels to the outer part of the cell and is translated into proteins.
When
a cell gets stressed from overheating or starvation, however, its proteins do
not fold properly. These unfolded proteins trigger an alarm that causes the
cell to slow down its production line and clean up the misshapen proteins. This
reaction is known as the unfolded protein response, the researchers explained.
"You
can slow down protein production, but sometimes slowing down the workflow is
not enough," explained Nicchitta. "You can activate genes to help
chew up the misfolded proteins, but sometimes they are accumulating too
quickly. Here we have discovered a mechanism that does one better -- it
effectively puts everything on hold. Once things get back to normal, the mRNAs
are released from the holding pattern."
Nicchitta
said he was now looking for the factors that determine which mechanism cells
employ during a stress response.
More
information
The
U.S. National Institute of Mental Health has more on the health effects
of stress.
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