UV-induced mutations of supF gene on a shuttle vector plasmid in p53-deficient mouse cells are qualitatively different from those in wild-type cells.
To verify the genetic instability of p53-deficient cells, UV-induced mutation of the supF gene on a shuttle vector was analyzed. UV-irradiated or non-irradiated shuttle vector plasmid carrying the supF gene as a target of mutation (pYZ289) was introduced into p53-deficient and p53-proficient mouse embryonic fibroblasts, and then the plasmid DNA replicated in mouse cells was recovered. Survival of UV-irradiated plasmid was almost equivalent in both p53-deficient and p53-proficient cells. The frequencies of UV-induced mutation of the supF gene were also the same in both types of cells. However, the distributions of base change mutations in the supF sequence were different between p53-deficient and p53-proficient cells; especially the locations of tandem CpC to TpT changes exhibited a marked difference. Since DNA repair activities of these two types of cell were almost the same, these qualitative differences in UV-induced mutations were probably caused by as yet unidentified differences in other than DNA repair activity.
Ishizaki
K
K
Laboratory of Experimental Radiology, Aichi Cancer Center Research Institute, Nagoya, Japan.
Nishizawa
K
K
Mimaki
S
S
Aizawa
S
S
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004622:Embryo, Mammalian; D004926:Escherichia coli / Q000235:genetics; D005347:Fibroblasts; D005798:Genes, Bacterial / Q000528:radiation effects; D016153:Genes, Suppressor / Q000528:radiation effects*; D016158:Genes, p53; D005822:Genetic Vectors; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010957:Plasmids / Q000528:radiation effects; D012343:RNA, Transfer / Q000096:biosynthesis* / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency* / Q000235:genetics; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D016159:Tumor Suppressor Protein p53; C096275:supF tRNA; D012343:RNA, Transfer