The C-terminal alphaO helix of human Ogg1 is essential for 8-oxoguanine DNA glycosylase activity: the mitochondrial beta-Ogg1 lacks this domain and does not have glycosylase activity.

ABSTRACT: The human Ogg1 glycosylase is responsible for repairing 8-oxo-7,8-dihydroguanine (8-oxoG) in both nuclear and mitochondrial DNA. Two distinct Ogg1 isoforms are present; alpha-Ogg1, which mainly localizes to the nucleus and beta-Ogg1, which localizes only to mitochondria. We recently showed that mitochondria from rho(0) cells, which lack mitochondrial DNA, have similar 8-oxoG DNA glycosylase activity to that of wild-type cells. Here, we show that beta-Ogg1 protein levels are approximately 80% reduced in rho(0) cells, suggesting beta-Ogg1 is not responsible for 8-oxoG incision in mitochondria. Thus, we characterized the biochemical properties of recombinant beta-Ogg1. Surprisingly, recombinant beta-Ogg1 did not show any significant 8-oxoG DNA glycosylase activity in vitro. Since beta-Ogg1 la

SUBMITTER: Hashiguchi K 

PROVIDER: S-EPMC524278 | biostudies-literature | 2004

REPOSITORIES: biostudies-literature