Recent findings in Cockayne syndrome described by researchers from University of Mainz, Institute of Pharmacy
2007 JUL 9 -- Current study results from the report, "Deficiency of the Cockayne syndrome B (CSB) gene aggravates the genomic instability caused by endogenous oxidative DNA base damage in mice," have been published. "The Cockayne syndrome B protein (CSB) has long been known to be involved in the repair of DNA modifications that block the RNA polymerase in transcribed DNA sequences (transcription-coupled repair). Recent evidence suggests that it also has a more general role in the repair of oxidative DNA base modifications such as 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG)," investigators in Mainz, Germany report. "In mammalian cells, 8-oxoG is a substrate of the repair glycosylase OGG1. Mice without this enzyme accumulate 8-oxoG in the genome and have elevated spontaneous mutation rates. To elucidate the role of CSB in the prevention of mutations by oxidative DNA base damage, we have generated mice that are deficient in Csb or Ogg1 or both genes and carry a non-transcribed bacterial lacI gene for mutation analysis (Big Blue mice). Our results indicate that the overall spontaneous mutation frequencies in the livers of Csb(m/m)/Ogg1-/--mice are elevated not only compared with heterozygous control mice (factor 3.3), but also with Ogg1-/--animals (factor 1.6). Sequence analysis revealed that the additional mutations caused by CSB deficiency in an Ogg1-/-background are mostly G:C to T:A transversions and small deletions. For all mouse strains, the background levels of oxidative purine modifications in the livers correlate linearly with the numbers of G:C to T:A transversions observed," wrote C. Trapp and colleagues, University of Mainz, Institute of Pharmacy. The researchers concluded: "The data indicate that CSB is involved in the inhibition of mutations caused by spontaneous oxidative DNA base damage in a non-transcribed gene." Trapp and colleagues published their study in Oncogene (Deficiency of the Cockayne syndrome B (CSB) gene aggravates the genomic instability caused by endogenous oxidative DNA base damage in mice. Oncogene, 2007;26(27):4044-8). For additional information, contact C. Trapp, University of Mainz, Institute of Pharmacy, Mainz, Germany. The publisher of the journal Oncogene can be contacted at: Nature Publishing Group, Macmillan Building, 4 Crinan St., London N1 9XW, England. Keywords: Germany, Mainz, Cockayne Syndrome, DNA, Genetics, Genomics, Neurology. This article was prepared by Pain & Central Nervous System Week editors from staff and other reports. Copyright 2007, Pain & Central Nervous System Week via NewsRx.com.
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