The rad2 mutation affects the molecular nature of UV and acridine-mustard-induced mutations in the ADE2 gene of Saccharomyces cerevisiae.
We have studied the molecular nature of ade2 mutations induced by UV light and bifunctional acridine-mustard (BAM) in wild-type (RAD) and in excision-deficient (rad2) strains of the yeast, Saccharomyces cerevisiae. In the RAD strain, UV causes 45% GC----AT transitions among all mutations; in the rad2 strain this value is 77%. BAM was shown to be highly specific for frameshift mutagenesis: 60% frameshifts in the RAD strain, and as many as 84% frameshifts in the rad2 strain were induced. Therefore, the rad2 mutation affects the specificity of UV- and BAM-induced mutagenesis in yeast. Experimental data agree with the view that the majority of mutations in the RAD strain are induced by a prereplicative mechanism, whereas mutations in the RAD strain are induced by a prereplicative mechanism, whereas mutations in the rad2 strain are predominantly postreplicative events. Our results also suggest that: cytosine-containing photoproducts are the substances responsible for major premutational damage to cytosine-containing photoproducts are the substances responsible for major premutational damage to DNA; a fraction of the mutations may arise in the course of excision repair of UV photoproducts.
E L
EL
Ivanov
S V
SV
Kovaltzova
G V
GV
Kassinova
L M
LM
Gracheva
V G
VG
Korolev
I A
IA
Zakharov
D000609:Aminoacridines; D004260:DNA Repair; D004261:DNA Replication; D004307:Dose-Response Relationship, Radiation; D005800:Genes, Fungal / Q000187:drug effects / Q000528:radiation effects; D009154:Mutation; D009588:Nitrogen Mustard Compounds / Q000494:pharmacology*; D011836:Radiation Tolerance; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D013489:Suppression, Genetic; D014466:Ultraviolet Rays
D000609:Aminoacridines; D009588:Nitrogen Mustard Compounds; C091910:acridine mustard