Nav: Home

Stress in the powerhouse of the cell

October 18, 2019

Cells need powerhouses known as mitochondria to utilize the energy stored in our food. Most of the proteins required for this powerhouse function are encoded in the nucleus and transported into the mitochondria after they have been synthesized in the cytosol. Signal sequences are needed to allow the protein to enter the mitochondria. Once the protein has arrived there, the signal sequences are, however, removed. Up until now, researchers did not fully understand the importance of this removal of signal sequences. It was also unclear why flawed removal leads to a number of illnesses, such as diseases of the heart or brain. Together with her working group, Dr. Nora Vögtle of the Institute of Biochemistry and Molecular Biology of the University of Freiburg has discovered that errors in the removal of signal sequences lead to an aggregation of these proteins so that they clump together inside the mitochondria. They have presented their findings in the current issue of the scientific journal "Molecular Cell."

The aggregation observed by the researchers could cause the cell powerhouses to stop working, but all organisms require this activity for survival. To counteract these defects the cells execute what the researchers call a protective stress response, which enables mitochondria to maintain their key functions. By means of this stress response, cells such as baker's yeast - the model organism used to carry out the researchers' experiments - survive. Along with doctoral candidate and lead author of the study, Daniel Poveda-Huertes, Vögtle also discovered that the regulation of many different genes is happening in the cell nucleus. What is more, the researchers found out that a transcription factor normally found in the nucleus was surprisingly transported into the mitochondria, where the expression of genetic information was enhanced. Only through this mechanism could the mitochondria ensure cell survival by maintaining generation of energy under these stressful conditions. This completely novel principle in the stress response of cells, explains Vögtle, is probably the earliest reaction that has been detected up until now. She says, "That's the cell's first line of defense when stress appears in its powerhouses."
-end-
The work was carried out in cooperation with the Freiburg-based research groups of Prof. Dr. Chris Meisinger, Prof. Dr. Claudine Kraft, Dr. Ralf Gilsbach, and Prof. Dr. Lutz Hein as well as researchers at the University of Hamburg and Stockholm in Sweden.

Nora Vögtle heads an Emmy Noether group for junior researchers, which is funded by the German Research Foundation (DFG), and is project leader in the Collaborative Research Centre (SFB) "Dynamic Organization of Cellular Protein Machineries" at the University of Freiburg. She is also active within the Freiburg-based cluster of excellence, the Centre for Integrated Biological Signalling Studies, CIBSS.

University of Freiburg

Related Mitochondria Articles:

Unexpected insights into the dynamic structure of mitochondria
As power plants and energy stores, mitochondria are essential components of almost all cells in plants, fungi and animals.
Mitochondria are the 'canary in the coal mine' for cellular stress
Mitochondria, tiny structures present in most cells, are known for their energy-generating machinery.
Master regulator in mitochondria is critical for muscle function and repair
New study identifies how loss of mitochondrial protein MICU1 disrupts calcium balance and causes muscle atrophy and weakness.
Oxygen deficiency rewires mitochondria
Researchers slow the growth of pancreatic tumor cells.
Self-cannibalizing mitochondria may set the stage for ALS development
Northwestern Medicine scientists have discovered a new phenomenon in the brain that could explain the development of early stages of neurodegeneration that is seen in diseases such as ALS, which affects voluntary muscle movement such as walking and talking.  The discovery was so novel, the scientists needed to coin a new term to describe it: mitoautophagy, a collection of self-destructive mitochondria in diseased upper motor neurons of the brain that begin to disintegrate from within at a very early age.
Uncovering the presynaptic distribution and profile of mitochondria
In a recent study published in the Journal of Neuroscience, scientists from the MPFI and the University of Iowa CCOM have provided unprecedented insight into the presynaptic distribution and profile of mitochondria in the developing and mature calyx of Held.
Temple researchers identify new target regulating mitochondria during stress
Like an emergency response team that is called into action to save lives, stress response proteins in the heart are activated during a heart attack to help prevent cell death.
Runaway mitochondria cause telomere damage in cells
Targeted damage to mitochondria produces a 'Chernobyl effect' inside cells, pelting the nucleus with harmful reactive oxygen species and causing chromosomal damage.
Interplay between mitochondria and nucleus may have implications for new treatment
Mitochondria, the 'batteries' that produce our energy, interact with the cell's nucleus in subtle ways previously unseen in humans, according to research published today in the journal Science.
Dissolving protein traffic jam at the entrance of mitochondria
Researchers from Freiburg discovered a novel mechanism that ensures obstacle-free protein traffic into the powerhouse of the cell.
More Mitochondria News and Mitochondria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.