Phorbol ester abrogates up-regulation of DNA polymerase beta by DNA-alkylating agents in Chinese hamster ovary cells.


Mammalian DNA polymerase beta (beta-pol), a DNA repair polymerase, is ...
Mammalian DNA polymerase beta (beta-pol), a DNA repair polymerase, is known to be constitutively expressed in cultured cells, but treatment of cells with the DNA-alkylating agents MNNG or methyl methanesulfonate has been shown to up-regulate beta-pol mRNA level. To further characterize this response, we prepared a panel of monoclonal antibodies and used one of them to quantify beta-pol in whole cell extracts by immunoblotting. We found that treatment of Chinese hamster ovary cells with either DNA-alkylating agent up-regulated the beta-pol protein level 5-10-fold. This induction appeared to be secondary to DNA alkylation, as induction was not observed with a genetically altered cell line overexpressing the DNA repair enzyme O6-methylguanine-methyltransferase. We also found that 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of wild type Chinese hamster ovary cells increased expression of beta-pol protein (approximately 10-fold). Any interrelationship between this TPA response and the DNA-alkylation response was studied by treatment with combinations of MNNG and TPA. The beta-pol up-regulation observed with MNNG treatment was abrogated by TPA, and conversely the up-regulation observed with TPA treatment was abrogated by MNNG.




new topics/pols set partial results complete validated


No results available for this paper.

Entry validated by:

Using Polbase tables:


Tables may be sorted by clicking on any of the column titles. A second click reverses the sort order. <Ctrl> + click on the column titles to sort by more than one column (e.g. family then name).


It is also possible to filter the table by typing into the search box above the table. This will instantly hide lines from the table that do not contain your search text.