CHEMISTRY NOBEL PRIZE - 2015
Sulekha Rani.R,PGT Chemistry , KV NTPC Kayamkulam
Source& Reference : Nobelprize.org
The Royal Swedish Academy of Sciences has decided (7-10-2015) to award the Nobel Prize in Chemistry
for 2015 to
Tomas Lindahl
Francis Crick Institute and Clare Hall Laboratory, Hertfordshire, UK
Francis Crick Institute and Clare Hall Laboratory, Hertfordshire, UK
Paul Modrich
Howard Hughes Medical Institute and Duke University School of Medicine, Durham, NC, USA
Howard Hughes Medical Institute and Duke University School of Medicine, Durham, NC, USA
Aziz Sancar
University of North Carolina, Chapel Hill, NC, USA
University of North Carolina, Chapel Hill, NC, USA
“for mechanistic
studies of DNA repair"
The Nobel Prize in
Chemistry 2015 is awarded to Tomas Lindahl, Paul Modrich and Aziz Sancar for having mapped,
at a molecular level, how cells repair damaged DNA and safeguard the genetic
information.
Their work has
provided fundamental knowledge of how a living cell functions and is, for
instance, used for the development of new cancer treatments.
Each day our DNA is damaged by UV radiation, free radicals and other carcinogenic substances, but even without such external attacks, a DNA molecule is inherently unstable. Thousands of spontaneous changes to a cell’s genome occur on a daily basis. Furthermore, defects can also arise when DNA is copied during cell division, a process that occurs several million times every day in the human body.
The reason our genetic material does not disintegrate into complete chemical chaos is that a host of molecular systems continuously monitor and repair DNA.
The Nobel Prize in Chemistry 2015 awards three pioneering scientists who have mapped how several of these repair systems function at a detailed molecular level.
In the early 1970s, scientists believed that DNA was an extremely stable molecule, but
Tomas Lindahl demonstrated that DNA decays at a rate that ought to have made
the development of life on Earth impossible. This insight led him to discover a
molecular machinery, base excision repair, which
constantly counteracts the collapse of our DNA.
Aziz Sancar has mapped nucleotide
excision repair, the mechanism that cells use to repair UV damage
to DNA. People born with defects in this repair system will develop skin cancer
if they are exposed to sunlight. The cell also utilises nucleotide excision
repair to correct defects caused by mutagenic substances, among other things.
Paul Modrich has demonstrated how the cell corrects errors that occur when
DNA is replicated during cell division. This mechanism, mismatch
repair, reduces the error frequency during DNA replication by about
a thousandfold. Congenital defects in mismatch repair are known, for example,
to cause a hereditary variant of colon cancer.
Here
is how the committee describe the scientists’ contribution:
From one cell to
another, from one generation to the next. The genetic information that governs
how human beings are shaped has flowed through our bodies for hundreds of
thousands of years. It is constantly subjected to assaults from the
environment, yet it remains surprisingly intact. Tomas Lindahl, Paul Modrich
and Aziz Sancar are awarded the Nobel Prize in Chemistry 2015 for having mapped
and explained how the cell repairs its DNA and safeguards the genetic
information
