Mitochondrial maintenance under oxidative stress depends on mitochondrially localised α-OGG1.
de Melo Campos, Julliane Tamara Araújo
Radicella, J Pablo
J Cell Sci
The Company of Biologists
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Lia, D., Reyes, A., de Melo Campos, J. T. A., Piolot, T., Baijer, J., Radicella, J. P., & Campalans, A. (2018). Mitochondrial maintenance under oxidative stress depends on mitochondrially localised α-OGG1.. J Cell Sci, 131 (12) https://doi.org/10.1242/jcs.213538
Accumulation of 8-oxoguanine (8-oxoG) in mitochondrial DNA and mitochondrial dysfunction have been observed in cells deficient for the DNA glycosylase OGG1 when exposed to oxidative stress. In human cells, up to eight mRNAs for OGG1 can be generated by alternative splicing and it is still unclear which of them codes for the protein that ensures the repair of 8-oxoG in mitochondria. Here, we show that the α-OGG1 isoform, considered up to now to be exclusively nuclear, has a functional mitochondrial-targeting sequence and is imported into mitochondria. We analyse the sub-mitochondrial localisation of α-OGG1 with unprecedented resolution and show that this DNA glycosylase is associated with DNA in mitochondrial nucleoids. We show that the presence of α-OGG1 inside mitochondria and its enzymatic activity are required to preserve the mitochondrial network in cells exposed to oxidative stress. Altogether, these results unveil a new role of α-OGG1 in the mitochondria and indicate that the same isoform ensures the repair of 8-oxoG in both nuclear and mitochondrial genomes. The activity of α-OGG1 in mitochondria is sufficient for the recovery of organelle function after oxidative stress.
Cell Line, Tumor, Mitochondria, Humans, Reactive Oxygen Species, Guanine, DNA Glycosylases, RNA, Small Interfering, DNA, Mitochondrial, Transfection, Cell Cycle, Oxidative Stress, Mitochondrial Membranes, HEK293 Cells
Medical Research Council (MC_UP_1002/1)
Medical Research Council (MC_UU_00015/8)
External DOI: https://doi.org/10.1242/jcs.213538
This record's URL: https://www.repository.cam.ac.uk/handle/1810/282909