Monday, September 21, 2009
Scientists have identified how a protein enables sections of
so-called junk DNA to be cut and pasted within genetic code – a finding which
could speed development of gene therapies.
The study by researchers at the University of Edinburgh
sheds light on the process, known as DNA transposition, in which shifted genes
have a significant effect on the behaviour of neighbouring genes. In the human
genome, rearrangement of antibody genes can enable the immune system to target
infection more effectively.
The research identifies how the enzyme is able to cut out a
section of DNA and reinsert it elsewhere in the genome. The study, published in
the journal Cell, was funded by the Wellcome Trust and the Medical Research
Council.
The cut-and-paste property of shifted DNA is now being used
to develop tools for scientific research and medical applications. Learning
more about transposition could help scientists understand how to control the
process and speed the development of gene therapies—which introduce into cells
genes with beneficial properties that, for example, can fight hereditary diseases
or cancer.
Junk DNA, which accounts for almost half of the human
genome, was originally believed to have no purpose. However, it is now emerging
that movement of junk DNA, in a cut-and-paste mechanism, can lead to beneficial
changes in cells.
Dr Julia Richardson of the University's School of Biological
Sciences, who led the study, said: "By
forming a picture of the enzyme that causes DNA to shift, and discovering how
this works, we understand more about how these proteins could be adapted and
controlled. This may one day enable genes to be pasted into cells exactly where
they are needed – which could be of enormous benefit in developing gene
therapies."
University of Edinburgh