Translesion DNA synthesis catalyzed by human pol eta and pol kappa across 1,N6-ethenodeoxyadenosine.
1,N(6)-Ethenodeoxyadenosine, a DNA adduct generated by exogenous and endogenous sources, severely blocks DNA synthesis and induces miscoding events in human cells. To probe the mechanism for in vivo translesion DNA synthesis across this adduct, in vitro primer extension studies were conducted using newly identified human DNA polymerases (pol) eta and kappa, which have been shown to catalyze translesion DNA synthesis past several DNA lesions. Steady-state kinetic analyses and analysis of translesion products have revealed that the synthesis is >100-fold more efficient with pol eta than with pol kappa and that both error-free and error-prone syntheses are observed with these enzymes. The miscoding events include both base substitution and frameshift mutations. These results suggest that both polymerases, particularly pol eta, may contribute to the translesion DNA synthesis events observed for 1,N(6)-ethenodeoxyadenosine in human cells.
Levine
R L
RL
Laboratory of Chemical Biology, Department of Pharmacological Sciences, State University of New York, Stony Brook, New York 11794-8651, USA.
Miller
H
H
Grollman
A
A
Ohashi
E
E
Ohmori
H
H
Masutani
C
C
Hanaoka
F
F
Moriya
M
M
D000818:Animals; D020137:Base Pair Mismatch; D001483:Base Sequence; D004247:DNA / Q000096:biosynthesis*; D018736:DNA Adducts / Q000378:metabolism; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D003839:Deoxyadenosines / Q000378:metabolism*; D016368:Frameshift Mutation; D017353:Gene Deletion; D000882:Haplorhini; D006801:Humans; D007700:Kinetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011506:Proteins / Q000378:metabolism*; D000099270:Y-Family DNA Polymerases
D004247:DNA; D018736:DNA Adducts; D004259:DNA-Directed DNA Polymerase; D003839:Deoxyadenosines; D011506:Proteins; C032221:1,N(6)-ethenodeoxyadenosine; C404302:POLK protein, human; D000099270:Y-Family DNA Polymerases; C112338:Rad30 protein