The three scientists, from Sweden, the US and Turkey respectively, received an equal share of the prestigious 8m Swedish kronor (£631,000) award for “mechanistic studies of DNA repair”. Their research mapped and explained how the cell repairs its DNA in order to prevent errors occurring in genetic information. Lindahl, Modrich and Sancar worked out how cells repair faults that inevitably creep in when DNA is copied time and time again, and mutations that arise under a barrage of environmental factors such as UV rays in sunlight.
When an egg is fertilised it begins to divide; with two cells becoming four and four becoming eight. After a span of one week a human embryo consists of 128 cells, each with its own set of genetic material. But many billions more divisions take place as we make our way to adulthood, until we possess enough DNA in our trillions of cells to reach the sun and back, 250 times over. The most remarkable feat is how the genetic information is copied so faithfully. “From a chemical perspective, this ought to be impossible,” the Nobel committee said. “All chemical processes are prone to random errors. Additionally, your DNA is subjected on a daily basis to damaging radiation and reactive molecules. In fact, you ought to have been a chemical chaos long before you even developed into a foetus,” they added.
Together, the repair mechanisms discovered by the scientists, fix thousands of DNA faults caused by UV rays, cigarette smoke and other toxic substances. They are constantly at work to repair copying errors as cells divide. Without these repair mechanisms, the genomes would be riddled with errors, and cancer would be rife.
“Their systematic work has made a decisive contribution to the understanding of how the living cell functions, as well as providing knowledge about the molecular causes of several hereditary diseases and about mechanisms behind both cancer development and ageing,” the committee said.
Source and details: http://www.theguardian.com/science/2015/oct/07/lindahl-modrich-and-sancar-win-nobel-chemistry-prize-for-dna-research