Impaired repair activity of a truncated DNA polymerase beta protein

Life Sci. 2001 Jun 8;69(3):271-80. doi: 10.1016/s0024-3205(01)01120-1.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Survival / drug effects
  • DNA Ligases
  • DNA Polymerase beta / metabolism*
  • DNA Repair*
  • Dose-Response Relationship, Drug
  • HeLa Cells / drug effects
  • HeLa Cells / enzymology
  • Humans
  • Methylnitronitrosoguanidine / pharmacology
  • Time Factors


  • Methylnitronitrosoguanidine
  • DNA Polymerase beta
  • DNA Ligases