Wednesday, October 7, 2015

And this year's Nobel Prize in Chemistry goes to...

Paul Modrich (Duke University School of Medicine), Aziz Sancar (University of North Carolina) and Tomas Lindahl (Francis Crick Institute at Clare Hall Laboratory, Hertfordshire, UK)

They unlocked the secrets of DNA repair, which are molecular tools to ensure DNA is working properly.

Although it is the building block of life, DNA is rather unstable.  Part of the nucleotide cysteine, one of the bases that makes up DNA, tends to degrade over time.  Then it matches up with the wrong nucleotide when the DNA molecule replicates.  One would think why aren't we all dead yet, but Lindahl discovered base excision repair, a process in which the enzyme glycosylase spots the damage, which is then removed (excised) and replaced.  This process also minimizes mistakes when the DNA molecule 'unzips' to be copied.  People who have problems with this repair process might have a higher risk of colon cancer.

DNA can also be damaged by outside influences such as ultraviolet light or chemicals that cause mutation.  Another process, nucleotide excision repair, allows cells to fix those problems.  Sancar discovered enzymes that find UV-damaged DNA and excise the strand.  People who have problems with this repair process might have a higher risk of skin cancer. 

This new work has been relevant for new cancer therapies.


http://news.sciencemag.org/2015/10/cellular-secrets-dna-repair-win-nobel-prize-chemistry?rss=1

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