Featured Research

from universities, journals, and other organizations

Researchers Uncover Protection Mechanism Of Radiation-resistant Bacterium

Date:
March 21, 2007
Source:
Uniformed Services University
Summary:
The ability of the bacterium Deinococcus radiodurans to endure and survive enormous levels of ionizing radiation (X-rays and gamma-rays) relies on a powerful mechanism that protects proteins from oxidative damage during irradiation, according to a new study.

Deinococcus radiodurans thrives in radiation levels thousands of times higher than those that would kill most organisms, including humans, and it may prove useful in bioremediation of toxic waste.
Credit: Michael J. Daly, Ph.D., Associate Professor, Uniformed Services University of the Health Sciences

Results of a recent study titled “Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance,” will be published in the March 20 edition of PLoS Biology. The study, headed by Michael J. Daly, Ph.D., associate professor at the Uniformed Services University of the Health Sciences (USU), Department of Pathology, shows that the ability of the bacterium Deinococcus radiodurans to endure and survive enormous levels of ionizing radiation (X-rays and gamma-rays) relies on a powerful mechanism that protects proteins from oxidative damage during irradiation.

Related Articles


The field of radiobiology is built on the premise that radiation is dangerous because of its damaging effects on DNA. Contrary to that view, Daly et al report that the ability of cells to survive radiation is highly dependent on the amount of protein damage caused during irradiation. Surprisingly, a dose of radiation that is sufficient to cause only minor DNA damage in radiation sensitive cells will cause high levels of protein damage compared to resistant cells exposed to the same dose.

This new model of radiation toxicity shifts the emphasis away from DNA damage toward protein damage, where DNA repair-related proteins in sensitive cells are devastated by radiation long before DNA is significantly damaged. In contrast, repair enzymes in extremely resistant cells survive and function with great efficiency after irradiation because they are protected, specifically by a chemical mechanism involving manganese (II) ions.

The new model of extreme radiation resistance reconciles many seemingly conflicting results published over the last two decades, and points directly at the existence of potent manganese-based radioprotectors that prevent protein damage. Daly expects that delivery of purified radioprotective Mn- complexes into sensitive cell-types will make them temporarily radiation resistant.

This possibility opens up new avenues for radioprotection, including approaches to facilitate recovery from short- or long-term exposures to radiation such as cancer therapies, accident- or terror-related nuclear events, and astronauts exposed to cosmic radiation. Furthermore, given that many bacteria with favorable bioremediation functions are extremely sensitive to radiation, the new insight provided by D. radiodurans on how to survive radiation might prove useful in efforts to contain the toxic runoff from the immense radioactive- and heavy metal-contaminated waste sites left over from the Cold War.

The work was funded by the US Department of Energy Office of Science’s Environmental Remediation Science Program (ERSP). DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the nation, manages 10 world-class national laboratories, and builds and operates some of the nation's most advanced R&D user facilities. Its website address is http://www.science.doe.gov.

Citation: Daly MJ, Gaidamakova EK, Matrosova VY, Vasilenko A, Zhai M, et al. (2007) Protein oxidation implicated as the primary determinant of bacterial radioresistance. PLoS Biol 5(4): e92. doi:10.1371/journal.pbio.0050092.


Story Source:

The above story is based on materials provided by Uniformed Services University. Note: Materials may be edited for content and length.


Cite This Page:

Uniformed Services University. "Researchers Uncover Protection Mechanism Of Radiation-resistant Bacterium." ScienceDaily. ScienceDaily, 21 March 2007. <www.sciencedaily.com/releases/2007/03/070320095902.htm>.
Uniformed Services University. (2007, March 21). Researchers Uncover Protection Mechanism Of Radiation-resistant Bacterium. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2007/03/070320095902.htm
Uniformed Services University. "Researchers Uncover Protection Mechanism Of Radiation-resistant Bacterium." ScienceDaily. www.sciencedaily.com/releases/2007/03/070320095902.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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