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: Mountain near Vegas gains blue butterfly habitat protection

Related Stories

DNA barcoding discloses Antarctic sponge diversity

Jun 25, 2015

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have used DNA barcoding to elucidate the diversity of the sponge fauna found in Antarctic waters. The data provide new insights into the evolution of this poorly ...

A novel DNA damage alarm

Jun 25, 2015

How does our body keep its DNA intact? Researchers at Erasmus MC have just found a new piece of this puzzle. They discovered a novel alarm that cells use to signal DNA damage. "We already knew that DNA damage triggers an ...

What droppings can tell us

Jun 22, 2015

If you want to find out about the shy Eurasian otter, its droppings are a fascinating source of information. By isolating DNA from otter droppings – known as spraint – researchers can not only identify ...

Recommended for you

Why haven't Madagascar's famed lemurs been saved yet?

2 hours ago

Lemurs are cute – there is no denying it. Their big eyes and fluffy faces mean they really are the poster animals of Madagascar, an island known internationally for its unique flora and fauna. But the plight ...

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.