Enhanced mitochondrial DNA repair and cellular survival after oxidative stress by targeting the human 8-oxoguanine glycosylase repair enzyme to mitochondria

Allison W. Dobson, Yi Xu, Mark Kelley, Susan P. LeDoux, Glenn L. Wilson

Research output: Contribution to journalArticle

115 Citations (Scopus)

Abstract

Oxidative damage to mitochondrial DNA (mtDNA) has been implicated as a causative factor in many disease processes and in aging. We have recently discovered that different cell types vary in their capacity to repair this damage, and this variability correlates with their ability to withstand oxidative stress. To explore strategies to enhance repair of oxidative lesions in mtDNA, we have constructed a vector containing a mitochondrial transport sequence upstream of the sequence for human 8-oxoguanine DNA glycosylase. This enzyme is the glycosylase/AP lyase that participates in repair of purine lesions, such as 8-oxoguanine. Western blot analysis confirmed float this recombinant protein was targeted to mitochondria. Enzyme activity assays showed that mitochondrial extracts from cells transfected with the construct had increased enzyme activity compared with cells transfected with vector only, whereas nuclear enzyme activity was not changed. Repair assays showed that there was enhanced repair of oxidative lesions in mtDNA. Additional studies revealed that this augmented repair led to enhanced cellular viability as determined by reduction of the tetrazolium compound to formazan, trypan blue dye exclusion, and clonogenic assays. Therefore, targeting of DNA repair enzymes to mitochondria may be a viable approach for the protection of cells against some of the deleterious effects of oxidative stress.

Original languageEnglish
Pages (from-to)37518-37523
Number of pages6
JournalJournal of Biological Chemistry
Volume275
Issue number48
DOIs
StatePublished - Dec 1 2000

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Mitochondria
Oxidative stress
Mitochondrial DNA
DNA Repair
Oxidative Stress
Repair
Survival
Enzyme activity
Enzymes
DNA-(Apurinic or Apyrimidinic Site) Lyase
Formazans
DNA Repair Enzymes
Assays
Cytoprotection
Trypan Blue
Enzyme Assays
Cell Extracts
Recombinant Proteins
Coloring Agents
Western Blotting

ASJC Scopus subject areas

  • Biochemistry

Cite this

Enhanced mitochondrial DNA repair and cellular survival after oxidative stress by targeting the human 8-oxoguanine glycosylase repair enzyme to mitochondria. / Dobson, Allison W.; Xu, Yi; Kelley, Mark; LeDoux, Susan P.; Wilson, Glenn L.

In: Journal of Biological Chemistry, Vol. 275, No. 48, 01.12.2000, p. 37518-37523.

Research output: Contribution to journalArticle

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