TY - JOUR
T1 - A functional analysis of the DNA glycosylase activity of mouse MUTYH protein excising 2-hydroxyadenine opposite guanine in DNA
AU - Ushijima, Yasuhiro
AU - Tominaga, Yohei
AU - Miura, Tomofumi
AU - Tsuchimoto, Daisuke
AU - Sakumi, Kunihiko
AU - Nakabeppu, Yusaku
N1 - Funding Information:
We thank Drs Masato Furuichi and Yoshimichi Nakatsu for their helpful discussions; Akemi Matsuyama, Naomi Adachi, Setsuko Kitamura and Keiko Aiura for their technical assistance; Dr Hiroshi Honda for providing us with the opportunity to conduct this study; and Dr B. Quinn for comments on the manuscript. This work was supported by grants from CREST, Japan Science and Technology Agency, the Ministry of Education, Culture, Sports, Science, and Technology of Japan (grant number 16012248), and Japan Society for the Promotion of Science (grant numbers 15590347 and 16390119). Funding to pay the Open Access publication charges for this article was provided by Japan Society for Promotion of Science.
PY - 2005
Y1 - 2005
N2 - 2-Hydroxy-2-deoxyadenosine triphosphate (2-OH-dATP), generated by the oxidation of dATP, can be misincorporated by DNA polymerases opposite guanine in template DNA during DNA replication, thus causing spontaneous mutagenesis. We demonstrated that mouse MUTYH (mMUTYH) has a DNA glycosylase activity excising not only adenine opposite 8-oxoguanine (8-oxoG) but also 2-hydroxyadenine (2-OH-A) opposite guanine, using purified recombinant thioredoxin-mMUTYH fusion protein. mMUTYH formed a stable complex with duplex oligonucleotides containing an adenine: 8-oxoG pair, but the binding of mMUTYH to oligonucleotides containing a 2-OH-A:guanine pair was barely detectable, thus suggesting that mMUTYH recognizes and interacts with these two substrates in a different manner which may reflect the difference in the base excision repair process foreach substrate. Mutant mMUTYH with G365D amino acid substitution, corresponding to a G382D germline mutation of human MUTYH found in familial adenomatous polyposis patients, almost completely retained its DNA glycosylase activity excising adenine opposite 8-oxoG; however, it possessed 1.5% of the wild-type activity excising 2-OH-A opposite guanine. Our results imply that the reduced repair capacity of the mutant hMUTYH(G382D), which inefficiently excises 2-OH-A opposite guanine, results in an increased occurrence of somatic G:C to T:A transversion mutations in the APC gene as well as tumorigenesis in the colon.
AB - 2-Hydroxy-2-deoxyadenosine triphosphate (2-OH-dATP), generated by the oxidation of dATP, can be misincorporated by DNA polymerases opposite guanine in template DNA during DNA replication, thus causing spontaneous mutagenesis. We demonstrated that mouse MUTYH (mMUTYH) has a DNA glycosylase activity excising not only adenine opposite 8-oxoguanine (8-oxoG) but also 2-hydroxyadenine (2-OH-A) opposite guanine, using purified recombinant thioredoxin-mMUTYH fusion protein. mMUTYH formed a stable complex with duplex oligonucleotides containing an adenine: 8-oxoG pair, but the binding of mMUTYH to oligonucleotides containing a 2-OH-A:guanine pair was barely detectable, thus suggesting that mMUTYH recognizes and interacts with these two substrates in a different manner which may reflect the difference in the base excision repair process foreach substrate. Mutant mMUTYH with G365D amino acid substitution, corresponding to a G382D germline mutation of human MUTYH found in familial adenomatous polyposis patients, almost completely retained its DNA glycosylase activity excising adenine opposite 8-oxoG; however, it possessed 1.5% of the wild-type activity excising 2-OH-A opposite guanine. Our results imply that the reduced repair capacity of the mutant hMUTYH(G382D), which inefficiently excises 2-OH-A opposite guanine, results in an increased occurrence of somatic G:C to T:A transversion mutations in the APC gene as well as tumorigenesis in the colon.
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U2 - 10.1093/nar/gki214
DO - 10.1093/nar/gki214
M3 - Article
C2 - 15681617
AN - SCOPUS:13844313936
VL - 33
SP - 672
EP - 682
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 2
ER -