[Oradlist] Radioresistance

[Gibbs, S Julian]

A recent paper in Science that should be of interest, especially to 
basic scientists.
Julian

Science. 2004 Sep 30 [Epub ahead of print]


Accumulation of Mn(II) in Deinococcus radiodurans Facilitates 
Gamma-Radiation Resistance.

Daly MJ, Gaidamakova EK, Matrosova VY, Vasilenko A, Zhai M, 
Venkateswaran A, Hess M, Omelchenko MV, Kostandarithes HM, Makarova 
KS, Wackett LP, Fredrickson JK, Ghosal D.

Uniformed Services University of the Health Sciences, Bethesda, MD 
20814, USA.

ABSTRACT

Deinococcus radiodurans is extremely resistant to ionizing 
radiation. How this bacterium can grow under chronic gammaradiation 
(50 Gy/hour) or recover from acute doses greater than 10 kGy is 
unknown. We show that D. radiodurans accumulates very high 
intracellular manganese and low iron levels compared to radiation 
sensitive bacteria, and resistance exhibits a 
concentration-dependent response to Mn(II). Among the most 
radiation-resistant bacterial groups reported, Deinococcus, 
Enterococcus, Lactobacillus, and cyanobacteria accumulate Mn(II). 
In contrast, Shewanella oneidensis and Pseudomonas putida have high 
Fe but low intracellular Mn concentrations and are very sensitive. 
We propose that Mn(II) accumulation facilitates recovery from 
radiation injury.


***********************************************************
S. Julian Gibbs, DDS, PhD              Office: 615-322-1477
Professor, Emeritus
Dept. of Radiology & Radiological Sciences
Vanderbilt University Medical Center     Home: 615-356-3615
209 Oxford House        Email:s.julian.gibbs at vanderbilt.edu
Nashville TN 37232-4245     or alias:j.gibbs at vanderbilt.edu
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When health is absent
          -Wisdom cannot reveal itself,
          -Art cannot become manifest,
          -Strength cannot fight,
          -Wealth becomes useless and
          -Intelligence cannot be applied.
                          -Herophilus, 325 B.C.
                           Physician to Alexander the Great