Genome complexity: protecting DNA integrity (Introduction)

by David Turell , Friday, December 09, 2016, 15:00 (2689 days ago) @ David Turell

Cells are constantly reproducing themselves as daughters. DNA must be constantly monitored against mistakes, and it is:

http://www.businessinsider.com/breakthrough-prize-winner-dna-research-2016-12

"That DNA tells our cells what to do. When they divide, that information is copied from one cell to another.

"But life is hard on our cells. They become damaged every moment of every day, exposed the radiation of the sun, the heat of our laptops, the chemicals we absorb from air pollution, the alcohol we drink, and more. Aging itself damages them.

"This damage can easily become a harmful mutation, causing cells to replicate in an out of control way, leading to disease and cancer. With the constant assault, it's a wonder this doesn't happen all the time.

"It's only thanks to a mechanism in our cells that can recognize when something has gone wrong that we aren't all riddled with cancer.

"That mechanism, known as the DNA damage response, functions like an individual intelligent agent, able to monitor when things are going wrong and then try to come up with a way to deal with them.

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"Discoveries explaining how that mechanism works are so significant that on December 4, geneticist Stephen Elledge was awarded one of five $3 million Breakthrough Prizes in life sciences.

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"Elledge's research on the DNA damage response certainly fits the bill. While we've thought that cells had some way to respond to damage ever since the 1940s, Elledge has helped reveal the biological components involved in the process.

"'One of the remarkable properties of nature’s most remarkable molecule, DNA, is self-awareness: it can detect information about its own integrity and transmit that information back to itself," Elledge wrote in JAMA after he was awarded a prestigious Lasker award in 2015 for his work.

"When this response detects damaged DNA, it can respond in several ways. It may try to repair the damage, but it may also activate the immune system, cause the cell to destroy itself, or trigger a process known as senescence — which helps prevent tumors but is also largely responsible for aging."

Comment: There is no way life could have continued with a DNA code controlling it, unless such a defense mechanism against mistakes was present at all times. Only a saltation could have produced this result. Not by chance.