
Expression of theE.colifpg gene in mammalian cells reduces the mutagenicity of γ-rays
Author(s) -
Françoise Laval
Publication year - 1994
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/22.23.4943
Subject(s) - transfection , biology , chinese hamster ovary cell , microbiology and biotechnology , gene , dna glycosylase , dna , cell culture , chinese hamster , dna repair , biochemistry , genetics
The E. coli fpg gene encodes the formamido-pyrimidine-DNA-glycosylase (FPG protein) which specifically removes the formamido-pyrimidine and C8-oxoGuanine residues from gamma-irradiated DNA. The fpg gene was ligated in the psV2 vector and transfected into the Chinese hamster CHO and V-79 cells. The transfected cells expressed a formamido-pyrimidine-DNA-glycosylase activity 30 to 40-fold over the constitutive level. The resistance of CHO and V-79 cells to the lethal effect of gamma-rays was similar in control and transfected cells. Furthermore CHO cells expressing the fpg gene had the same resistance to the lethal effect of hydrogen peroxide as control cells. However, the sensitivity to the mutagenic effect of gamma-rays, measured as 6-thioguanine resistance, decreased both in CHO and V-79 transfected cells. Since the lethal effect of gamma-rays was not modified in cells overproducing the FPG protein, the results suggest that this protein protects the cells against the mutagenic lesions formed by ionizing radiations, and among them C8-oxoguanine.