Chromosome glue repairs damaged DNA

Jul 13, 2007

When a strand of DNA breaks in the body's cells, it normally does not take long until it has been repaired. Now researchers at the Swedish medical university Karolinska Institutet have discovered a new mechanism that helps to explain how the cell performs these repairs. The results are presented in Science.

The new results are concerned with a phenomenon called cohesion, whereby two copies of a chromosome in the cell nucleus are held tightly together by a protein complex called cohesin.

Cohesion fulfils an important function during cell division as the newly copied chromosomes, the sister chromatids, have to stay together until the right moment of separation. If the chromatids come apart too early, there is a risk of the daughter cells getting the wrong number of chromosomes, something that is often observed in tumour cells.

Dr Camilla Sjögren and her research team have now shown that the cell also employs cohesion to repair damaged sister chromatids. Their results show that DNA damage can reactivate cohesin, which runs counter to the commonly held view that cohesion only arises during the DNA copying that takes place before cell division.

Scientists have long been fascinated by the way in which the duplicated chromosomes are separated before cell division so that exactly half the copied genetic material ends up in each daughter cell. Another large research question is how cells repair damaged DNA and consequently prevent cancer, for example.

"We have shown that chromosome segregation and DNA repair are partly dealt with by the same machinery. These findings provide new understanding of two fundamental cellular mechanisms and may also be of value to cancer research," says Dr Sjögren.

Source: Karolinska Institutet

Explore further: Biodiversity promotes multitasking in ecosystems

Related Stories

Viral proteins may regulate human embryonic development

8 hours ago

A fertilized human egg may seem like the ultimate blank slate. But within days of fertilization, the growing mass of cells activates not only human genes but also viral DNA lingering in the human genome from ...

Iron-rich rocks could could hold signs of life

4 hours ago

A robotic mission's search for life on Mars may seem worlds away from human scientists wandering around hot springs in Yellowstone National Park. But a study of the Yellowstone hot springs has revealed new ...

Recommended for you

York's anti-malarial plant given Chinese approval

13 hours ago

A new hybrid plant used in anti-malarial drug production, developed by scientists at the University of York's Centre for Novel Agricultural Products (CNAP), is now registered as a new variety in China.

The appeal of being anti-GMO

18 hours ago

A team of Belgian philosophers and plant biotechnologists have turned to cognitive science to explain why opposition to genetically modified organisms (GMOs) has become so widespread, despite positive contributions ...

Micro fingers for arranging single cells

18 hours ago

Functional analysis of a cell, which is the fundamental unit of life, is important for gaining new insights into medical and pharmaceutical fields. For efficiently studying cell functions, it is essential ...

User comments : 0

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.