Scientists discover repair mechanism of photolyase in sun damaged DNA

For the first time, researchers in Ohaio State University have observed how the enzyme, called photolyase, functions at the atomic level to repair sun-damaged DNA. They took a series of snapshots using ultrafast light pulses to examine how the enzyme injects a single electron and proton into a damaged strand of DNA; harnessing photons to fix a damaged double helix.

In effect, UV light damages skin by causing chemical bonds to form in the incompatible places along the DNA molecules in our cells. This study has yet revealed that photolyase fix those destructive bonds in certain places to cause the atoms in the DNA to move back into their original positions.

Now that researches know the mechanisms by which this enzyme works, they might use this information to design drugs or lotions that heal sun damage. For example, a sunscreen containing photolyase could potentially heal some of the damage from UV rays; instead of merely reflecting the UV light as current sunscreens are made to do.

For more information, visit:
http://www.scientificamerican.com/blog/post.cfm?id=subatomic-sunscreen-how-light-parti-2010-07-25

Posted by
Takanori Yamamoto
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A gene preventing skin cancer

In the article presented by D. Decraene et al gives an overview of the functions and roles of p53 gene. P53 is a tumor suppressor gene that protects against cancer by regulating cells that are subject to damages. The gene it is located on the short arm of chromosome 17. One of the most important roles of p53 is to protect the human skin from UV light. The gene is activated in the presence of UV light. The experiment is carried out to see the activation of p53 protein by observing the human skin cells when the cells are exposed to stimulated solar radiation. When the skin is not exposed to UV light, the p53 cannot be detected. Once UV light started to radiate onto human skins, an accumulation of p53 protein started to form in the epidermis. The p53 protein appears to be in its highest concentration after 2 hours of exposure to the radiation. The build up of p53 protein plays a pivotal part in protecting skin cells from mutation, DNA damage, growth arrest, DNA repair and apoptosis.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TH0-448BN8N-C&_user=331728&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000016898&_version=1&_urlVersion=0&_userid=331728&md5=bdfa5ca9f53c2e737e2b270688e14f34