Properties and applications of human DNA repair genes

Lawrence H. Thompson

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


The importance of understanding DNA repair processes is discussed in terms of the origins of human cancer. Several human repair genes have been mapped to specific human chromosomes using somatic cell hybrids, It is noteworthy that 3 of these genes lie in the same region of chromosome 19: genes ERCC1 and ERCC2, which are involved in nucleotide excision repair, and XRCC1, which is involved in the repair of strand breaks. The genes XRCC1 and ERCC2 were cloned from cosmid libraries prepared from DNA transformants of the CHO mutants EM9 and UV5, respectively. Analysis of the cDNA sequence of ERCC2 showed that the protein encoded by this gene is highly homologous (73%) to the RAD3 repair protein in the yeast Saccharomyces cerevisiae, Thus, the known properties of RAD3 combined with the high homology provide the first insight about the biochemical role of a human repair protein involved in the incision step of nucleotide excision repair. So far XCRCC1 is the only cloned mammalian gene involved in repairing damage from ionizing radiation. The UV5 mutant line was also applied to problems in environmental mutagenesis by introducing the mouse cytochrome P3450 (P450IA2 subfamily) gene for metabolic activation of aromatic amines. We show in a rapid differential cytotoxicity assay with 2 compounds found in cooked beef (IQ, 2-amino-3-methylimidazo[4,5-f{hook}]quinoline and PhIP, 2-amino-1-methyl-6-phenylimidazo[4,5,-b]pyridine) that this gene is efficiently expressed in the transformed UV5P3 cells. Reversion of the repair deficiency in these cells will give a matched repair of cell lines that are metabolically proficient and repair deficient. Such lines will provide a rapid assay for genotoxic heterocyclic amines requiring activation.

Original languageEnglish (US)
Pages (from-to)213-219
Number of pages7
JournalMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
Issue number2
StatePublished - 1991
Externally publishedYes


  • Cloning repair genes
  • Cytochrome P450
  • Heterocyclic amines
  • Human DNA repair genes
  • Mapping repair genes

ASJC Scopus subject areas

  • Molecular Biology
  • Health, Toxicology and Mutagenesis


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