Genetic Control or Repair and Adaptive Response to Low-Level DNA Damage

Technical Report · Mon Oct 05 04:00:00 EDT 2009

DOI:https://doi.org/10.2172/965273· OSTI ID:965273

Haber, J E ^[1]

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1. Brandeis University

Research was focused on how a single double-strand break - a model of low-dose ionizing radiation-induced DNA damage - could be studied in a simple model system, budding yeast. Breaks were induced in several different ways. We used the site-specific HO endonuclease to create a single DSB in all cells of the population so that its fate could be extensively analyzed genetically and molecularly. We also used two heterologous systems, the plant DS element and the Rag1/Rag2 proteins, to generate different types of DSBs, these containing hairpin ends that needed to be cleaved open before end-joining could take place. All three approaches yielded important new findings. We also extended our analysis of the Mre11 protein that plays key roles in both NHEJ and in homologous recombination. Finally we analyzed the poorly understood recombination events that were independent of the key recombination protein, Rad52. This line of inquiry was strongly motivated by the fact that vertebrate cells do not rely strongly on Rad52 for homologous recombination, so that some clues about alternative mechanisms could be gained by understanding how Rad52-independent recombination occurred. We found that the Mre11 complex was the most important element in Rad52-independent recombination.

• Research Organization: Brandeis University
• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-01ER63229
• OSTI ID: 965273
• Report Number(s): DOE/ER/63229
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DNA DAMAGES
ENDONUCLEASES
GENETIC CONTROL
IONIZING RADIATIONS
LOW DOSE IRRADIATION
PROTEINS
RECOMBINATION
REPAIR
VERTEBRATES
YEASTS