Featured Research

from universities, journals, and other organizations

Scientists tie DNA repair to key cell signaling network

Date:
June 15, 2012
Source:
University of Texas Medical Branch at Galveston
Summary:
Researchers have found a surprising connection between a key DNA-repair process and a cellular signaling network linked to aging, heart disease, cancer and other chronic conditions.

University of Texas Medical Branch at Galveston researchers have found a surprising connection between a key DNA-repair process and a cellular signaling network linked to aging, heart disease, cancer and other chronic conditions. The discovery promises to open up an important new area of research -- one that could ultimately yield novel treatments for a wide variety of diseases.

"This is a totally new concept -- it goes against current dogma about the role of DNA repair," said UTMB professor Istvan Boldogh, senior author of a paper on the work now online in the Journal of Biological Chemistry. "We couldn't believe it ourselves, but the data convinced us."

Boldogh and his colleagues came up with the idea of a link between DNA repair and cellular signaling after a close examination of the relationship between DNA damage and cell death produced unexpected results. Conventional DNA-repair dogma holds that a cell's lifespan is determined by the amount of accumulated DNA damage it suffers -- the overall corruption of genetic information stored in sequences of molecules called bases, which form the "rungs" of the DNA double helix. The cells used in Boldogh's study were especially vulnerable to damage because they lacked a key enzyme that repairs the DNA base guanine. According to dogma, this should have shortened the cells' lives; instead, they actually lived longer than expected. This made Boldogh wonder if another factor was involved in reducing the lifespan of normal cells.

"We proposed the hypothesis that instead of the accumulation of damaged guanine in DNA causing ill effects, what is significant is the release of a DNA-repair byproduct that somehow activates processes that shorten the lifespan of cells," Boldogh said.

The researchers knew just where to look to find this hypothetical repair byproduct. The majority of DNA damage is caused by ubiquitous reactive oxygen species, very chemically active molecules created as byproducts of respiration. When DNA meets reactive oxygen species, one of the most common results is the transformation of the DNA base guanine into a molecule called 8-oxoguanine, which can produce mutations in genes.

To protect the integrity of the genetic code, cells remove 8-oxoguanine from their DNA with a repair enzyme called OGG1. OGG1 does its job by attaching to a damaged base, cutting it free from the DNA molecule, and then releasing it. Boldogh and his collaborators found that their key byproduct was being produced just after this repair process was completed. Analyzing test-tube, cell-culture and mouse experimental data, they realized that immediately after being released by OGG1, 8-oxoguanine reunites with the repair enzyme, attaching at a bonding site different from the one used previously. And the resulting 8-oxoguanine-OGG1 complex, they found, has the ability to activate the powerful Ras signaling pathways, some of the most important biochemical networks in the cell.

"Ras family proteins are involved in almost every cell function: metabolism, activation of genes, growth signals, inflammation signals, apoptosis," Boldogh said. "Because it activates Ras pathways, the release of 8-oxoguanine in DNA base repair could be a master regulator of many very basic processes."

According to Boldogh, learning to control this "master regulator," could result in profound consequences for biomedical science and human health. "The ability to regulate 8-oxoguanine excision may give us the ability to prevent the inflammation that's key to a number of chronic diseases -- arthritis, atherosclerosis, Alzheimer's and others," he said. "We believe it may even enable us to extend lifespan, or at least healthy lifespan, which would be a very big achievement. Possibilities like that make us believe that this discovery is going to be very significant."


Story Source:

The above story is based on materials provided by University of Texas Medical Branch at Galveston. Note: Materials may be edited for content and length.


Journal Reference:

  1. I. Boldogh, G. Hajas, L. Aguilera-Aguirre, M. L. Hegde, Z. Radak, A. Bacsi, S. Sur, T. K. Hazra, S. Mitra. Activation of Ras Signaling by 8-oxoguanine DNA glycosylase Bound to Its Excision Product 8-oxoguanine. Journal of Biological Chemistry, 2012; DOI: 10.1074/jbc.C112.364620

Cite This Page:

University of Texas Medical Branch at Galveston. "Scientists tie DNA repair to key cell signaling network." ScienceDaily. ScienceDaily, 15 June 2012. <www.sciencedaily.com/releases/2012/06/120615141720.htm>.
University of Texas Medical Branch at Galveston. (2012, June 15). Scientists tie DNA repair to key cell signaling network. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2012/06/120615141720.htm
University of Texas Medical Branch at Galveston. "Scientists tie DNA repair to key cell signaling network." ScienceDaily. www.sciencedaily.com/releases/2012/06/120615141720.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins