Radiation-induced chromosomal rearrangements in dead Deinococcus radiodurans cells: the role of insertion sequences and RecA protein

Cvjetan, Svjetlana (2013) Radiation-induced chromosomal rearrangements in dead Deinococcus radiodurans cells: the role of insertion sequences and RecA protein. Doctoral thesis, Faculty of Science > Department of Biology.

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Abstract

This research was focused on the fundamental cause(s) of cell death in a robust bacterium, Deinococcus radiodurans, known to survive extreme exposures to desiccation, radiation or mutagenic chemicals. The results of this study proved that the key target in cell death is function (proteome) rather than information (genome). Analyzing the fate of the damaged DNA (double-strand breaks and chromosomal rearrangements in surviving and dead cells) and oxydatively damaged (carbonylated) proteins when the “decision“ between survival and death takes place, cell death showed correlation with radiation-induced proteome carbonylation but not with DNA breakage. Cell death is initiated by the progressive loss of vital functions, including DNA repair, caused by increasing levels of the irreversible protein damage. While DNA repair proceeds similarly in dying and surviving cells, the deadly point of no-return is membrane depolarization and permeability - triggered by neo-synthesized oxidized membrane proteins - causing the fatal leakage of metabolites and ions required for all biosynthetic processes. This fatal change in cell membrane is an active process since it depends on de novo transcription and translation in lethally irradiated D. radiodurans cells.

Item Type: Thesis (Doctoral thesis)
Keywords: bacterium Deinococcus radiodurans, cell death, chromosomal rearrangements, RecA protein, insertion sequences, protein carbonylation, DNA repair
Supervisor: Zahradka, Ksenija
Co-supervisor: Radman, Miroslav
Date: 2013
Number of Pages: 132
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Grozdana Sirotic
Date Deposited: 28 Jan 2014 13:31
Last Modified: 24 Sep 2014 11:13
URI: http://digre.pmf.unizg.hr/id/eprint/275

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