DNA-strand breaks limit survival in extreme dryness

Dose, Klaus; Bieger-Dose, A.; Kerz, O.; Gill, Markus

doi:10.1007/bf01809446

Cited by 60 publications

(43 citation statements)

References 17 publications

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“…Like, ionising radiation, the cytotoxicity of desiccation derives from the formation of DSBs (6,14,15). A substantial reduction in the molecular weight of D. radiodurans chromosomal DNA after exposure to a vacuum has been demonstrated (14).…”

Section: Nhej Pathway Protects M Smegmatis Against the Harmful Effecmentioning

confidence: 99%

“…A substantial reduction in the molecular weight of D. radiodurans chromosomal DNA after exposure to a vacuum has been demonstrated (14). Indeed, the extent of chromosomal fragmentation, adjudged to correspond to at least 60 DSBs, in D. radiodurans following desiccation is comparable to exposure to high doses of IR (6).…”

Section: Nhej Pathway Protects M Smegmatis Against the Harmful Effecmentioning

confidence: 99%

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NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation

Pitcher¹,

Green²,

Brzostek³

et al. 2007

DNA Repair

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Abstract:The physiological role of the non homologous end-joining (NHEJ) pathway in the repair of DNA double strand breaks (DSBs) was examined in Mycobacterium smegmatis using DNA repair mutants (∆recA, ∆ku, ∆ligD, ∆ku/ligD, ∆recA/ku/ligD). Wild-type and mutant strains were exposed to a range of doses of ionizing radiation at specific points in their life-cycle. NHEJ mutant strains (∆ku, ∆ligD, ∆ku/ligD) were significantly more sensitive to ionizing radiation (IR) during stationary phase than wild-type M. smegmatis.However, there was little difference in IR sensitivity between NHEJ-mutant and wildtype strains in logarithmic phase. Similarly, NHEJ-mutant strains were more sensitive to prolonged desiccation than wild-type M. smegmatis. A ∆recA mutant strain was more sensitive to desiccation and IR during both stationary and especially in logarithmic phase, compared to wild-type strain, but it was significantly less sensitive to IR than the ∆recA/ku/ligD triple mutant during stationary phase. These data suggest that NHEJ and homologous recombination are the preferred DSB repair pathways employed by M. smegmatis during stationary and logarithmic phases, respectively.

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Section: Nhej Pathway Protects M Smegmatis Against the Harmful Effecmentioning

confidence: 99%

Section: Nhej Pathway Protects M Smegmatis Against the Harmful Effecmentioning

confidence: 99%

NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation

Pitcher¹,

Green²,

Brzostek³

et al. 2007

DNA Repair

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“…It is assumed that DNA double-strand breaks (DSB), which are the most critical damage caused by ionizing radiation (57) and desiccation (9,10,39) in vegetative cells, are also induced in bacterial spores. Spores of B. subtilis contain a single chromosome arranged in a toroidal shape (16,41); therefore, the homologous recombination pathway, which requires at least two homologous chromosomes, cannot operate on DSB during spore germination (55).…”

mentioning

confidence: 99%

“…When typical laboratory vacuum systems are used for simulated extreme desiccation, wild-type spores often exhibit no detectable killing (9,10). A major reason for spore resistance to these processes is protection of spore DNA by SASP.…”

mentioning

confidence: 99%

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

et al. 2007

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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.It has been shown that endospores of gram-positive bacteria can remain viable for at least thousands of years (5, 44, 54; reviewed in reference 31). Bacterial spores persist in a metabolically inactive state, and environmental damage to spore cellular components accumulates unrepaired until germination and outgrowth (32). However, Bacillus subtilis spores are highly resistant to different environmental stresses, such as toxic chemicals and biocidal agents, desiccation, pressure and temperature extremes, and ionizing and UV radiation. The reason for this high resistance to environmental extremes lies partly in the spore structure itself: spores possess thick layers of highly cross-linked coat proteins (13), a modified peptidoglycan spore cortex, and abundant intracellular constituents such as the calcium chelate of dipicolinic acid and small, acidsoluble spore proteins (␣/␤-type SASP), as protectants of spore DNA (46, 50). Binding of ␣/␤-type SASP to spore DNA, coupled with spore core dehydration, appears to change the helical conformation of spore DNA from the B form to an A-like form (34, 48), which in turn alters its UV photochemistry to favor the production of 5-thyminyl-5,6-dihydrothymine, the unique spore-specific spore photoproduct (SP) (8,32,35,50). For the removal of the SP, spores possess an SP-specific repair enzyme called SP lyase, encoded by the splB gene, that monomerizes the SP dimer back to two thymine residues in an adenosyl-radical-dependent reaction (4,28,42).While the UV photochemistry of spore DNA and the repair of UV damage to DNA during germination are well described (12,32,33,47,50), there has been relatively little work on the nature of DNA damage in spores caused by ionizing radiation or extreme dryness and on the occurrence of a specific DNA repair system(s) for repair of this damage. It is assumed that DNA double-strand breaks (DSB), which are the most critical damage caused by ionizing radiation (57) and desiccation (9, 10, 39) in vegetative cells, are also induced in bacterial spores. Spores of B. subtilis contain a single chromosome arranged in a toroidal shape (16, 41); therefore, the homologous recombination pathway, which requires at least two homologous chromosomes, cannot operate on DSB during spore germination (55). An alternative repair pathway for DSB induced in spore DNA, nonhomologous-end joining (NHEJ) (3, 56), is considered here. This pathway as it occurs in eukaryotic cells requires a DNA end-binding component called Ku (Ku70 and Ku80) (58). The fir...

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“…One of the most important issues to be dealt with is the removal of constituent water from DNA molecules during sample evacuation. It has been shown that the subtraction of such water initially leads to damage of the molecules in the form of single (SSB) and double strand breaks (DSB), and eventually complete decomposition of the DNA molecule to its basic building blocks, the nucleotides and nucleosides [78].…”

Section: Preparation Of Dna Films For Vacuum Studies Of Dna Damagementioning

confidence: 99%

Evaluating experimental molecular physics studies of radiation damage in DNA*

Śmiałek

2016

Eur. Phys. J. D

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Abstract. The field of Atomic and Molecular Physics (AMP) is a mature field exploring the spectroscopy, excitation, ionisation of atoms and molecules in all three phases. Understanding of the spectroscopy and collisional dynamics of AMP has been fundamental to the development and application of quantum mechanics and is applied across a broad range of disparate disciplines including atmospheric sciences, astrochemistry, combustion and environmental science, and in central to core technologies such as semiconductor fabrications, nanotechnology and plasma processing. In recent years the molecular physics also started significantly contributing to the area of the radiation damage at molecular level and thus cancer therapy improvement through both experimental and theoretical advances, developing new damage measurement and analysis techniques. It is therefore worth to summarise and highlight the most prominent findings from the AMP community that contribute towards better understanding of the fundamental processes in biologically-relevant systems as well as to comment on the experimental challenges that were met for more complex investigation targets.

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DNA-strand breaks limit survival in extreme dryness

Cited by 60 publications

References 17 publications

NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation

NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation

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

Evaluating experimental molecular physics studies of radiation damage in DNA*

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