Impaired repair activity of a truncated DNA polymerase beta protein.
DNA polymerase beta (polbeta) is an essential enzyme for gap filling synthesis in damaged DNA template involved in base excision repair pathway. A truncated polbeta protein is expressed in primary colorectal and breast adenocarcinomas. To determine a possible alteration in the functions of the enzyme, a human cell line named HeLapolbetadelta expressing the truncated form of polbeta has been established. These cells revealed a significantly reduced level of repair activity evaluated by gap filling synthesis and polbeta activity. More importantly, the HeLapolbetadelta cells are hypersensitive to MNNG, a DNA alkylating agent. It appears from the responses that the gap filling synthesis of WT cells, a HeLa cell line overexpressing wild-type polbeta protein, was inhibited by HeLapolbetadelta protein.
Bhattacharyya
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N
Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic Foundation, OH 44195, USA.
Banerjee
T
T
Patel
U
U
Banerjee
S
S
D002470:Cell Survival / Q000187:drug effects; D011088:DNA Ligases; D019951:DNA Polymerase beta / Q000378:metabolism*; D004260:DNA Repair; D004305:Dose-Response Relationship, Drug; D006367:HeLa Cells / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D013997:Time Factors
D008769:Methylnitronitrosoguanidine; D019951:DNA Polymerase beta; D011088:DNA Ligases