Abstract
We developed a system for tracing DNA adducts in targeted mutagenesis (TATAM) and investigated the prevalence and types of consequent mutations. Targeted mutagenesis methods site-specifically replace endogenous DNA bases with bases carrying synthetic adducts using targeting vectors. The TATAM system was enabled by introduction of site-specific DNA double strand breaks (DSB), which strongly enhanced targeting efficiency through homologous recombination (HR), and a new polymerase chain reaction-based technique, which gives high yields of the target vectors carrying DNA adducts. Human lymphoblastoid TSCER122 cells are compound heterozygous for the thymidine kinase gene (TK-/-), and have a homing endonuclease I-SceI site in intron 4 of the TK gene. The TATAM system enabled targeting of the TK- allele with the I-SceI site using a synthetic TK+ allele containing an 8-oxo-7,8-dihydroguanine (8-oxoG) adduct, a typical product of oxidative DNA damage. The targeted clones (TK+/-) were then isolated by drug selection. Site-specific HR for DSB induced by I-SceI improved targeted integration of the synthetic allele by five orders of magnitude (from 10 -7 to 10 -2 ). Subsequent analyses of approximately 800 target clones revealed that 8-oxoG was restored to G in 86% clones, probably reflecting base excision repair or translesion synthesis without mutation. Lesions of the remaining clones (14%) were associated with mutations. The mutation spectrum corresponded closely with that of oxidative DNA damage inducers reported, in which G:C to T:A transversions (5.9%) were predominant. Over-expression of MutY homologs in cells, which prevents G:C to T:A transversions by removing 8-oxoG:A mispairing, significantly decreased the frequency of mutations to 2.6%, indicating that the 8-oxoG adducts introduced by the TATAM system are processed in the same manner as those generated by oxidative DNA damage.
| Original language | English |
|---|---|
| Pages (from-to) | 11-20 |
| Number of pages | 10 |
| Journal | DNA Repair |
| Volume | 15 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2014 Mar 1 |
| Externally published | Yes |
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Keywords
- 8-Oxoguanine (8-oxoG)
- DNA adducts
- Gene targeting
- Mutagenesis
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology
Cite this
Tracing the fates of site-specifically introduced DNA adducts in the human genome. / Yasui, Manabu; Kanemaru, Yuki; Kamoshita, Nagisa; Suzuki, Tetsuya; Arakawa, Toshiya; Honma, Masamitsu.
In: DNA Repair, Vol. 15, No. 1, 01.03.2014, p. 11-20.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Tracing the fates of site-specifically introduced DNA adducts in the human genome
AU - Yasui, Manabu
AU - Kanemaru, Yuki
AU - Kamoshita, Nagisa
AU - Suzuki, Tetsuya
AU - Arakawa, Toshiya
AU - Honma, Masamitsu
PY - 2014/3/1
Y1 - 2014/3/1
N2 - We developed a system for tracing DNA adducts in targeted mutagenesis (TATAM) and investigated the prevalence and types of consequent mutations. Targeted mutagenesis methods site-specifically replace endogenous DNA bases with bases carrying synthetic adducts using targeting vectors. The TATAM system was enabled by introduction of site-specific DNA double strand breaks (DSB), which strongly enhanced targeting efficiency through homologous recombination (HR), and a new polymerase chain reaction-based technique, which gives high yields of the target vectors carrying DNA adducts. Human lymphoblastoid TSCER122 cells are compound heterozygous for the thymidine kinase gene (TK-/-), and have a homing endonuclease I-SceI site in intron 4 of the TK gene. The TATAM system enabled targeting of the TK- allele with the I-SceI site using a synthetic TK+ allele containing an 8-oxo-7,8-dihydroguanine (8-oxoG) adduct, a typical product of oxidative DNA damage. The targeted clones (TK+/-) were then isolated by drug selection. Site-specific HR for DSB induced by I-SceI improved targeted integration of the synthetic allele by five orders of magnitude (from 10 -7 to 10 -2 ). Subsequent analyses of approximately 800 target clones revealed that 8-oxoG was restored to G in 86% clones, probably reflecting base excision repair or translesion synthesis without mutation. Lesions of the remaining clones (14%) were associated with mutations. The mutation spectrum corresponded closely with that of oxidative DNA damage inducers reported, in which G:C to T:A transversions (5.9%) were predominant. Over-expression of MutY homologs in cells, which prevents G:C to T:A transversions by removing 8-oxoG:A mispairing, significantly decreased the frequency of mutations to 2.6%, indicating that the 8-oxoG adducts introduced by the TATAM system are processed in the same manner as those generated by oxidative DNA damage.
AB - We developed a system for tracing DNA adducts in targeted mutagenesis (TATAM) and investigated the prevalence and types of consequent mutations. Targeted mutagenesis methods site-specifically replace endogenous DNA bases with bases carrying synthetic adducts using targeting vectors. The TATAM system was enabled by introduction of site-specific DNA double strand breaks (DSB), which strongly enhanced targeting efficiency through homologous recombination (HR), and a new polymerase chain reaction-based technique, which gives high yields of the target vectors carrying DNA adducts. Human lymphoblastoid TSCER122 cells are compound heterozygous for the thymidine kinase gene (TK-/-), and have a homing endonuclease I-SceI site in intron 4 of the TK gene. The TATAM system enabled targeting of the TK- allele with the I-SceI site using a synthetic TK+ allele containing an 8-oxo-7,8-dihydroguanine (8-oxoG) adduct, a typical product of oxidative DNA damage. The targeted clones (TK+/-) were then isolated by drug selection. Site-specific HR for DSB induced by I-SceI improved targeted integration of the synthetic allele by five orders of magnitude (from 10 -7 to 10 -2 ). Subsequent analyses of approximately 800 target clones revealed that 8-oxoG was restored to G in 86% clones, probably reflecting base excision repair or translesion synthesis without mutation. Lesions of the remaining clones (14%) were associated with mutations. The mutation spectrum corresponded closely with that of oxidative DNA damage inducers reported, in which G:C to T:A transversions (5.9%) were predominant. Over-expression of MutY homologs in cells, which prevents G:C to T:A transversions by removing 8-oxoG:A mispairing, significantly decreased the frequency of mutations to 2.6%, indicating that the 8-oxoG adducts introduced by the TATAM system are processed in the same manner as those generated by oxidative DNA damage.
KW - 8-Oxoguanine (8-oxoG)
KW - DNA adducts
KW - Gene targeting
KW - Mutagenesis
UR - http://www.scopus.com/inward/record.url?scp=84893721705&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893721705&partnerID=8YFLogxK
U2 - 10.1016/j.dnarep.2014.01.003
DO - 10.1016/j.dnarep.2014.01.003
M3 - Article
C2 - 24559511
AN - SCOPUS:84893721705
VL - 15
SP - 11
EP - 20
JO - DNA Repair
JF - DNA Repair
SN - 1568-7864
IS - 1
ER -