scholarly journals DNA Repair: Lessons from the Evolution of Ionizing- Radiation-Resistant Prokaryotes – Fact and Theory

10.5772/22312 ◽  
2011 ◽  
Author(s):  
Haitham Sghaier
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Radiation Resistant

scholarly journals Genome of the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans Viewed from the Perspective of Comparative Genomics

2001 ◽  
Vol 65 (1) ◽  
pp. 44-79 ◽  
Author(s):  
Kira S. Makarova ◽  
L. Aravind ◽  
Yuri I. Wolf ◽  
Roman L. Tatusov ◽  
Kenneth W. Minton ◽  
...  
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Stress Responses ◽  
Deinococcus Radiodurans ◽  
Repetitive Sequences ◽  
Comparative Sequence Analysis ◽  
Phylogenetic Tree Analysis ◽  
Chronic Radiation ◽  
Clusters Of Orthologous Groups ◽  
Radiation Resistant

SUMMARY The bacterium Deinococcus radiodurans shows remarkable resistance to a range of damage caused by ionizing radiation, desiccation, UV radiation, oxidizing agents, and electrophilic mutagens. D. radiodurans is best known for its extreme resistance to ionizing radiation; not only can it grow continuously in the presence of chronic radiation (6 kilorads/h), but also it can survive acute exposures to gamma radiation exceeding 1,500 kilorads without dying or undergoing induced mutation. These characteristics were the impetus for sequencing the genome of D. radiodurans and the ongoing development of its use for bioremediation of radioactive wastes. Although it is known that these multiple resistance phenotypes stem from efficient DNA repair processes, the mechanisms underlying these extraordinary repair capabilities remain poorly understood. In this work we present an extensive comparative sequence analysis of the Deinococcus genome. Deinococcus is the first representative with a completely sequenced genome from a distinct bacterial lineage of extremophiles, the Thermus-Deinococcus group. Phylogenetic tree analysis, combined with the identification of several synapomorphies between Thermus and Deinococcus, supports the hypothesis that it is an ancient group with no clear affinities to any of the other known bacterial lineages. Distinctive features of the Deinococcus genome as well as features shared with other free-living bacteria were revealed by comparison of its proteome to the collection of clusters of orthologous groups of proteins. Analysis of paralogs in Deinococcus has revealed several unique protein families. In addition, specific expansions of several other families including phosphatases, proteases, acyltransferases, and Nudix family pyrophosphohydrolases were detected. Genes that potentially affect DNA repair and recombination and stress responses were investigated in detail. Some proteins appear to have been horizontally transferred from eukaryotes and are not present in other bacteria. For example, three proteins homologous to plant desiccation resistance proteins were identified, and these are particularly interesting because of the correlation between desiccation and radiation resistance. Compared to other bacteria, the D. radiodurans genome is enriched in repetitive sequences, namely, IS-like transposons and small intergenic repeats. In combination, these observations suggest that several different biological mechanisms contribute to the multiple DNA repair-dependent phenotypes of this organism.

scholarly journals Basal DNA repair machinery is subject to positive selection in ionizing-radiation-resistant bacteria

BMC Genomics ◽  
2008 ◽  
Vol 9 (1) ◽  
pp. 297 ◽  
Author(s):  
Haïtham Sghaier ◽  
Kaïs Ghedira ◽  
Alia Benkahla ◽  
Insaf Barkallah
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Positive Selection ◽  
Resistant Bacteria ◽  
Radiation Resistant

scholarly journals PprA Protein Is Involved in Chromosome Segregation via Its Physical and Functional Interaction with DNA Gyrase in Irradiated Deinococcus radiodurans Bacteria

mSphere ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Alice Devigne ◽  
Philippe Guérin ◽  
Johnny Lisboa ◽  
Sophie Quevillon-Cheruel ◽  
Jean Armengaud ◽  
...  
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Chromosome Segregation ◽  
Dna Gyrase ◽  
Specific Protein ◽  
Dna Lesions ◽  
Content Type ◽  
Radiation Resistant ◽  
Radiation Induced

ABSTRACT D. radiodurans is one of the most radiation-resistant organisms known. This bacterium is able to cope with high levels of DNA lesions generated by exposure to extreme doses of ionizing radiation and to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Here, we identified partners of PprA, a radiation-induced Deinococcus-specific protein, previously shown to be required for radioresistance. Our study leads to three main findings: (i) PprA interacts with DNA gyrase after irradiation, (ii) treatment of cells with novobiocin results in defects in chromosome segregation that are aggravated by the absence of PprA, and (iii) PprA stimulates the decatenation activity of DNA gyrase. Our results extend the knowledge of how D. radiodurans cells survive exposure to extreme doses of gamma irradiation and point out the link between DNA repair, chromosome segregation, and DNA gyrase activities in the radioresistant D. radiodurans bacterium. PprA, a radiation-induced Deinococcus-specific protein, was previously shown to be required for cell survival and accurate chromosome segregation after exposure to ionizing radiation. Here, we used an in vivo approach to determine, by shotgun proteomics, putative PprA partners coimmunoprecipitating with PprA when cells were exposed to gamma rays. Among them, we found the two subunits of DNA gyrase and, thus, chose to focus our work on characterizing the activities of the deinococcal DNA gyrase in the presence or absence of PprA. Loss of PprA rendered cells hypersensitive to novobiocin, an inhibitor of the B subunit of DNA gyrase. We showed that treatment of bacteria with novobiocin resulted in induction of the radiation desiccation response (RDR) regulon and in defects in chromosome segregation that were aggravated by the absence of PprA. In vitro, the deinococcal DNA gyrase, like other bacterial DNA gyrases, possesses DNA negative supercoiling and decatenation activities. These two activities are inhibited in vitro by novobiocin and nalidixic acid, whereas PprA specifically stimulates the decatenation activity of DNA gyrase. Together, these results suggest that PprA plays a major role in chromosome decatenation via its interaction with the deinococcal DNA gyrase when D. radiodurans cells are recovering from exposure to ionizing radiation. IMPORTANCE D. radiodurans is one of the most radiation-resistant organisms known. This bacterium is able to cope with high levels of DNA lesions generated by exposure to extreme doses of ionizing radiation and to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Here, we identified partners of PprA, a radiation-induced Deinococcus-specific protein, previously shown to be required for radioresistance. Our study leads to three main findings: (i) PprA interacts with DNA gyrase after irradiation, (ii) treatment of cells with novobiocin results in defects in chromosome segregation that are aggravated by the absence of PprA, and (iii) PprA stimulates the decatenation activity of DNA gyrase. Our results extend the knowledge of how D. radiodurans cells survive exposure to extreme doses of gamma irradiation and point out the link between DNA repair, chromosome segregation, and DNA gyrase activities in the radioresistant D. radiodurans bacterium.

scholarly journals Coexistence of SOS-Dependent and SOS-Independent Regulation of DNA Repair Genes in Radiation-Resistant Deinococcus Bacteria

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 924
Author(s):  
Laurence Blanchard ◽  
Arjan de Groot
Keyword(s):  
Dna Repair ◽  
Deinococcus Radiodurans ◽  
Dna Repair Genes ◽  
Lesion Bypass ◽  
Radiation Resistant ◽  
Radiation Induced ◽  
Induced Mutagenesis ◽  
High Doses ◽  
Translesion Polymerases ◽  
Repair Genes

Deinococcus bacteria are extremely resistant to radiation and able to repair a shattered genome in an essentially error-free manner after exposure to high doses of radiation or prolonged desiccation. An efficient, SOS-independent response mechanism to induce various DNA repair genes such as recA is essential for radiation resistance. This pathway, called radiation/desiccation response, is controlled by metallopeptidase IrrE and repressor DdrO that are highly conserved in Deinococcus. Among various Deinococcus species, Deinococcus radiodurans has been studied most extensively. Its genome encodes classical DNA repair proteins for error-free repair but no error-prone translesion DNA polymerases, which may suggest that absence of mutagenic lesion bypass is crucial for error-free repair of massive DNA damage. However, many other radiation-resistant Deinococcus species do possess translesion polymerases, and radiation-induced mutagenesis has been demonstrated. At least dozens of Deinococcus species contain a mutagenesis cassette, and some even two cassettes, encoding error-prone translesion polymerase DnaE2 and two other proteins, ImuY and ImuB-C, that are probable accessory factors required for DnaE2 activity. Expression of this mutagenesis cassette is under control of the SOS regulators RecA and LexA. In this paper, we review both the RecA/LexA-controlled mutagenesis and the IrrE/DdrO-controlled radiation/desiccation response in Deinococcus.

Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert

2013 ◽  
Vol 55 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Li Zhi-Han Yu ◽  
Xue-Song Luo ◽  
Ming Liu ◽  
Qiaoyun Huang
Keyword(s):  
Ionizing Radiation ◽  
Resistant Bacteria ◽  
Taklimakan Desert ◽  
The Taklimakan Desert ◽  
Radiation Resistant

scholarly journals Genotoxicity and DNA repair indicative in blood cells after occupational exposure to ionizing radiation

10.3823/1992 ◽  
2016 ◽  
Author(s):  
Ronald Gerard Silva ◽  
Marcus Vinícius Oliveira Barros Alencar ◽  
Jadson Silva Teixeira ◽  
Reyca Rodrigues e Silva ◽  
Márcia Fernanda Correia Jardim Paz ◽  
...  
Keyword(s):  
Dna Repair ◽  
Occupational Exposure ◽  
Ionizing Radiation ◽  
Blood Cells

scholarly journals Role of DNA Repair by Nonhomologous-End Joining in Bacillus subtilis Spore Resistance to Extreme Dryness, Mono- and Polychromatic UV, and Ionizing Radiation

2007 ◽  
Vol 189 (8) ◽  
pp. 3306-3311 ◽  
Author(s):  
Ralf Moeller ◽  
Erko Stackebrandt ◽  
Günther Reitz ◽  
Thomas Berger ◽  
Petra Rettberg ◽  
...  
Keyword(s):  
Dna Repair ◽  
Bacillus Subtilis ◽  
Ionizing Radiation ◽  
Ultrahigh Vacuum ◽  
Nonhomologous End Joining ◽  
Wild Type ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Spore Resistance

ABSTRACT The role of DNA repair by nonhomologous-end joining (NHEJ) in spore resistance to UV, ionizing radiation, and ultrahigh vacuum was studied in wild-type and DNA repair mutants (recA, splB, ykoU, ykoV, and ykoU ykoV mutants) of Bacillus subtilis. NHEJ-defective spores with mutations in ykoU, ykoV, and ykoU ykoV were significantly more sensitive to UV, ionizing radiation, and ultrahigh vacuum than wild-type spores, indicating that NHEJ provides an important pathway during spore germination for repair of DNA double-strand breaks.

The ionizing radiation-induced replication protein A phosphorylation response differs between ataxia telangiectasia and normal human cells

1993 ◽  
Vol 13 (12) ◽  
pp. 7222-7231
Author(s):  
V F Liu ◽  
D T Weaver
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Gamma Irradiation ◽  
Ataxia Telangiectasia ◽  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
Inherited Disease ◽  
Dna Replication And Repair ◽  
In Cells

Replication protein A (RPA), the trimeric single-stranded DNA-binding protein complex of eukaryotic cells, is important to DNA replication and repair. Phosphorylation of the p34 subunit of RPA is modulated by the cell cycle, occurring during S and G2 but not during G1. The function of phosphorylated p34 remains unknown. We show that RPA p34 phosphorylation is significantly induced by ionizing radiation. The phosphorylated form, p36, is similar if not identical to the phosphorylated S/G2 form. gamma-Irradiation-induced phosphorylation occurs without new protein synthesis and in cells in G1. Mutation of cdc2-type protein kinase phosphorylation sites in p34 eliminates the ionizing radiation response. The gamma-irradiation-induced phosphorylation of RPA p34 is delayed in cells from ataxia telangiectasia, a human inherited disease conferring DNA repair defects and early-onset tumorigenesis. UV-induced phosphorylation of RPA p34 occurs less rapidly than gamma-irradiation-induced phosphorylation but is kinetically similar between ataxia telangiectasia and normal cells. This is the first time that modification of a repair protein, RPA, has been linked with a DNA damage response and suggests that phosphorylation may play a role in regulating DNA repair pathways.

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