TY - JOUR
T1 - Cloning and characterization of uracil-DNA glycosylase and the biological consequences of the loss of its function in the nematode Caenorhabditis elegans
AU - Nakamura, Nobuya
AU - Morinaga, Hironobu
AU - Kikuchi, Masahiro
AU - Yonekura, Shin Ichiro
AU - Ishii, Naoaki
AU - Yamamoto, Kazuo
AU - Yonei, Shuji
AU - Zhang, Qiu Mei
PY - 2008/9
Y1 - 2008/9
N2 - Uracil arises in DNA from spontaneous deamination of cytosine and through incorporation of dUMP by DNA polymerase during DNA replication. Excision of uracil by the action of uracil-DNA glycosylase (Ung) initiates the base excision repair pathway to counter the promutagenic base modification. In this study, we cloned a cDNA-encoding Caenorhabditis elegans homologue (CeUng-1) of Escherichia coli Ung. There was 49% identity in amino acid sequence between E.coli Ung and CeUng-1. Purified CeUng-1 removed uracil from both U:G and U:A base pairs in DNA. It also removed uracil from single-stranded oligonucleotide substrate less efficiently than double-stranded oligonucleotide. The CeUng-1 activity was inhibited by Bacillus subtilis Ung inhibitor, indicating that CeUng-1 is a member of the family-1 Ung group. The mutation in the ung-1 gene did not affect development, fertility and lifespan in C.elegans, suggesting the existence of backup enzyme. However, we could not detect residual uracil excision activity in the extract derived from the ung-1 mutant. The present experiments also showed that the ung-1 mutant of C.elegans was more resistant to NaHSO3-inducing cytosine deamination than wild-type strain.
AB - Uracil arises in DNA from spontaneous deamination of cytosine and through incorporation of dUMP by DNA polymerase during DNA replication. Excision of uracil by the action of uracil-DNA glycosylase (Ung) initiates the base excision repair pathway to counter the promutagenic base modification. In this study, we cloned a cDNA-encoding Caenorhabditis elegans homologue (CeUng-1) of Escherichia coli Ung. There was 49% identity in amino acid sequence between E.coli Ung and CeUng-1. Purified CeUng-1 removed uracil from both U:G and U:A base pairs in DNA. It also removed uracil from single-stranded oligonucleotide substrate less efficiently than double-stranded oligonucleotide. The CeUng-1 activity was inhibited by Bacillus subtilis Ung inhibitor, indicating that CeUng-1 is a member of the family-1 Ung group. The mutation in the ung-1 gene did not affect development, fertility and lifespan in C.elegans, suggesting the existence of backup enzyme. However, we could not detect residual uracil excision activity in the extract derived from the ung-1 mutant. The present experiments also showed that the ung-1 mutant of C.elegans was more resistant to NaHSO3-inducing cytosine deamination than wild-type strain.
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U2 - 10.1093/mutage/gen030
DO - 10.1093/mutage/gen030
M3 - Article
C2 - 18524757
AN - SCOPUS:50849101055
VL - 23
SP - 407
EP - 413
JO - Mutagenesis
JF - Mutagenesis
SN - 0267-8357
IS - 5
ER -