Item Type: | Article |
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Title: | Requirement of mammalian DNA polymerase-beta in base-excision repair |
Creators Name: | Sobol, R.W., Horton, J.K., Kühn, R., Gu, H., Singhal, R.K., Prasad, R., Rajewsky, K. and Wilson, S.H. |
Abstract: | Synthesis of DNA by DNA polymerase-beta is distributive on single-stranded DNA templates, but short DNA gaps with a 5' PO4 in the gap are filled processively to completion. In vitro studies have suggested a role of beta-polymerase in different types of DNA repair. However, the significance of these studies to the in vivo role of beta-polymerase has remained unclear. Because genetic studies are essential for determining the physiological role of a gene, we established embryonic fibroblast cell lines homozygous for a deletion mutation in the gene encoding DNA polymerase-beta. Extracts from these cell lines were found to be defective in uracil-initiated base-excision repair. The beta-polymerase-deleted cells are normal in viability and growth characteristics, although they exhibit increased sensitivity to monofunctional DNA-alkylating agents, but not to other DNA-damaging agents. Both the deficiency in base-excision repair and hypersensitivity to DNA-alkylating agents are rescued following stable transfection with a wild-type beta-polymerase minitransgene. These studies demonstrate that beta-polymerase functions specifically in base-excision repair in vivo. |
Keywords: | Cell Division, Cell Line, Cell Survival, DNA Polymerase I, DNA Repair, Gene Deletion, Genetic Complementation Test, Germ-Line Mutation, Phenotype, Restriction Mapping, Transformed Cell Line, Animals, Mice |
Source: | Nature |
ISSN: | 0028-0836 |
Publisher: | Nature Publishing Group |
Volume: | 379 |
Number: | 6561 |
Page Range: | 183-186 |
Date: | 11 January 1996 |
Official Publication: | https://doi.org/10.1038/379183a0 |
PubMed: | View item in PubMed |
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