Enzyme kinetics of an alternative splicing isoform of mitochondrial 8-oxoguanine DNA glycosylase, ogg1-1b, and compared with the nuclear ogg1-1a.
J Biochem Mol Toxicol
; 29(2): 49-56, 2015 Feb.
Article
em En
| MEDLINE
| ID: mdl-25196052
ABSTRACT
Eight alternatively spliced isoforms of human 8-oxoguanine DNA glycosylase (OGG1) (OGG1-1a to -1c and -2a to -2e) are registered in the National Center for Biotechnology Information. OGG1(s) in mitochondria have not yet been fully characterized biochemically. In this study, we purified mitochondrial recombinant OGG1-1b protein and compared its activity with nuclear OGG1-1a protein. The reaction rate constant (kg ) of the 7,8-dihydro-8-oxoguanine (8-oxoG) glycosylase activity of OGG1-1b was 8-oxoGC >> 8-oxoGT >> 8-oxoGG > 8-oxoGA (7.96, 0.805, 0.070, and 0.015 min(-1) , respectively) and that of the N-glycosylase/DNA lyase activity (kgl ) of OGG1-1b was 8-oxoGC > 8-oxoGT ≃8-oxoGG >> 8-oxoGA (0.286, 0.079, 0.040, and negligible min(-1) , respectively). These reaction rate constants were similar to those of OGG1-1a except for kgl against 8-oxoGA. APEX nuclease 1 was required to promote DNA strand breakage by OGG1-1b. These results suggest that OGG1-1b is associated with 8-oxoG cleavage in human mitochondria and that the mechanism of this repair is similar to that of nuclear OGG1-1a.
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Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
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Núcleo Celular
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Processamento Alternativo
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Proteínas Mitocondriais
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DNA Glicosilases
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Mitocôndrias
Limite:
Humans
Idioma:
En
Revista:
J Biochem Mol Toxicol
Assunto da revista:
BIOLOGIA MOLECULAR
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BIOQUIMICA
/
TOXICOLOGIA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Japão