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 Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>