Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Resilience through improvisation

21.01.2004


Our cells are resourceful when it comes to copying DNA, even when the DNA is damaged



Billions of cells divide every day in our bodies to replace those that wear out. To be able to do so, their DNA must be copied. A new Weizmann Institute study shows that the molecules in charge of the task of copying DNA -- called DNA polymerases -- are able to improvise in order to achieve this crucially important goal. This new insight into DNA replication and repair could assist in the diagnosis and treatment of diseases in which DNA damage is involved, such as cancer. The surprising findings appear in the December 9 issue of Proceedings of the National Academy of Sciences (PNAS), USA.

DNA polymerases travel along the DNA, producing new "printouts" of it each time the cell divides. In this way, genetic information is passed on in our bodies and from generation to generation. However, problems begin when the DNA is damaged due to factors such as cigarette smoke, radiation and certain reactions in the body. Though our body possesses special enzymes that fix DNA, some damage escapes their notice -- and DNA polymerases must deal with it.


Prof. Zvi Livneh and Ph.D. student Ayelet Maor-Shoshani of the Biological Chemistry Department cut a DNA strand -- from the bacterium E. coli -- and inserted material similar to that which composes crude oil in between both its ends. As expected, the regular DNA polymerase stopped working when it reached the foreign material. Yet to the scientists’ amazement, a specialized DNA polymerase jumped in to rescue the stalled replication process, and continued the copying process, inserting nonexistent genetic components into the "printout" when it encountered the foreign material. This can be compared to a person who forgets some words in a song and makes up new ones to be able to continue to sing.

In other cases, the specialized DNA polymerase skipped over the foreign material or deleted it and thus was able to continue its work as usual. "This shows the remarkable capability of a cell to reproduce," says Livneh. "And it makes one hope that even if extreme types of chemicals are accidentally introduced into our DNA, the body will be able to manage."

True, when DNA polymerase improvises a tune, errors (i.e. mutations) may occur in the new cells’ DNA. Yet Livneh explains that the body cannot feasibly let all cells with damaged DNA die, for there are too many of them. "Only if the DNA contains a very high level of damage will the cell’s machinery ’give up’ and let the cell die."

Prof. Zvi Livneh’s research is supported by the M.D. Moross Institute for Cancer Research, the Levine Institute of Applied Science, the Dr. Josef Cohn Minerva Center for Biomembrane Research, the Dolfi and Lola Ebner Center for Biomedical Research, and the J & R Center for Scientific Research. Prof. Livneh is the incumbent of the Maxwell Ellis Professorial Chair in Biomedical Research.

Alex Smith | EurekAlert!
Further information:
http://www.weizmann.ac.il/

More articles from Life Sciences:

nachricht The dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg

nachricht Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>