Unstable proteins can cause premature ageing

August 6, 2009

(PhysOrg.com) -- The normal ageing process has long been linked to problems with cell respiration, the process through which the cells extract energy from nutrients. Researchers at the Swedish medical university Karolinska Institutet have now shown how certain proteins that are synthesised in the cellular mitochondria - popularly known as the cells' power plants - become unstable and disintegrate, which in turn can impair cell respiration and cause premature ageing.

Every time we inhale, the blood transports the oxygen from our lungs to our cells' mitochondria, where it is used to convert the nutrients in our food into a form of energy that the body can use. Problems with this process, called cell respiration, have been linked to numerous conditions, from rare to diabetes, cancer, Parkinson's disease and the normal ageing process.

For cell respiration to function properly, it needs proteins synthesised outside and then imported into the mitochondria, and proteins synthesised within the mitochondria themselves from their own (mtDNA). It has long been known that an accumulation of harmful mutations of mtDNA can cause premature ageing, but just how this happens has remained something of a mystery.

Scientists at Karolinska Institutet in Stockholm have now shown through studies on mice that changes in mtDNA can cause ageing by introducing errors into the proteins manufactured by the . The amount of is normal, but the proteins are rendered unstable and quickly disintegrate, leading eventually to the breakdown of cell respiration.

"Our results show that premature ageing is caused by point mutations in the mtDNA, which cause the mitochondrial proteins to become unstable and disintegrate," says Aleksandra Trifunovic, one of the scientists involved in the study.

According to the team, the study, which is presented in the scientific journal , provides a better understanding of the interaction between mitochondrial function and the ageing process, and improves the chances of one day finding an efficacious treatment for mitochondrial disorders, something that is currently lacking.

More information: "Random Point Mutations with Major Effects on Protein-Coding Genes Are the Driving Force behind Premature Aging in mtDNA Mutator Mice", Daniel Edgar, Irina Shabalina, Yolanda Camara, Anna Wredenberg, Maria Antoinette Calvaruso, Leo Nijtmans, Jan Nedergaard, Barbara Cannon, Nils-Göran Larsson and Aleksandra Trifunovic, Cell Metabolism, 6 August 2009.

Source: Karolinska Institutet (news : web)

Explore further: A new brake on cellular energy production discovered

Related Stories

A new brake on cellular energy production discovered

July 27, 2007

A condition that has to be met for the body to be able to keep warm, move and even survive is that the mitochondria - the cells' power stations - release the right amounts of energy. Scientists at Karolinska Institutet have ...

Immune cells kill foes by disrupting mitochondria 2 ways

May 15, 2008

When killer T cells of the immune system encounter virus-infected or cancer cells, they unload a lethal mix of toxic proteins that trigger the target cells to self-destruct. A new study shows T cells can initiate cellular ...

Key protein in cellular respiration discovered

April 8, 2009

Many diseases derive from problems with cellular respiration, the process through which cells extract energy from nutrients. Researchers at the Swedish medical university Karolinska Institutet have now discovered a new function ...

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Birger
not rated yet Aug 06, 2009
A team in Canada has reported successful treatments of mitochondria-related disease (including some cancers) by using dichloracetate. It would be interesting to test if it is useful here, possibly by inducing apoptosis of the malfunctioning mitochondria.
E_L_Earnhardt
not rated yet Aug 07, 2009
Only one of the inter-cellular tubels terminates in the mitochondria to my limited knowledge. Other tubels maintain the cell's electrolite and protein covering. Mitochondria maintains a store of active electrons to be released when mitosis is desired.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.