TY - JOUR
T1 - Extracellular dGMP Enhances Deinococcus radiodurans Tolerance to Oxidative Stress
AU - Li, Mingfeng
AU - Sun, Hongxing
AU - Feng, Qiong
AU - Lu, Huiming
AU - Zhao, Ye
AU - Zhang, Hui
AU - Xu, Xin
AU - Jiao, Jiandong
AU - Wang, Liangyan
AU - Hua, Yuejin
PY - 2013/1/30
Y1 - 2013/1/30
N2 - Free extracellular DNA provides nutrition to bacteria and promotes bacterial evolution by inducing excessive mutagenesis of the genome. To understand the influence of extracellular DNA fragments on D. radiodurans, we investigated cell growth and survival after extracellular DNA or dNMPs treatment. The results showed that the extracellular DNA fragments inhibited the growth of D. radiodurans. Interestingly, dGMP, a DNA component, enhanced D. radiodurans tolerance to H2O2 and gamma-radiation significantly. Further experiments indicated that extracellular dGMP stimulated the activity of one catalase (KatA, DR1998), and induced gene transcription including the extracellular nuclease (drb0067). When this only extracellular nuclease gene (drb0067) in D. radiodurans was deleted, the mutant strain showed more sensitive to H2O2 and gamma-radiation than the wild type strain. These results suggest that DRB0067 plays an important role in oxidative stress resistance. Taken together, we proposed a new anti-oxidation mechanism in D. radiodurans. This mechanism acts to increase expression levels of DRB0067 which then secretes active nuclease to degrade extracellular DNA fragments. The extracellular nuclease has a two-fold benefit, creating more free dNTPs for further cell protection and the removal of extracellular DNA fragments.
AB - Free extracellular DNA provides nutrition to bacteria and promotes bacterial evolution by inducing excessive mutagenesis of the genome. To understand the influence of extracellular DNA fragments on D. radiodurans, we investigated cell growth and survival after extracellular DNA or dNMPs treatment. The results showed that the extracellular DNA fragments inhibited the growth of D. radiodurans. Interestingly, dGMP, a DNA component, enhanced D. radiodurans tolerance to H2O2 and gamma-radiation significantly. Further experiments indicated that extracellular dGMP stimulated the activity of one catalase (KatA, DR1998), and induced gene transcription including the extracellular nuclease (drb0067). When this only extracellular nuclease gene (drb0067) in D. radiodurans was deleted, the mutant strain showed more sensitive to H2O2 and gamma-radiation than the wild type strain. These results suggest that DRB0067 plays an important role in oxidative stress resistance. Taken together, we proposed a new anti-oxidation mechanism in D. radiodurans. This mechanism acts to increase expression levels of DRB0067 which then secretes active nuclease to degrade extracellular DNA fragments. The extracellular nuclease has a two-fold benefit, creating more free dNTPs for further cell protection and the removal of extracellular DNA fragments.
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U2 - 10.1371/journal.pone.0054420
DO - 10.1371/journal.pone.0054420
M3 - Article
C2 - 23365666
AN - SCOPUS:84872870856
SN - 1932-6203
VL - 8
JO - PloS one
JF - PloS one
IS - 1
M1 - e54420
ER -