Human APE2 protein is mostly localized in the nuclei and to some extent in the mitochondria, while nuclear APE2 is partly associated with proliferating cell nuclear antigen.

@article{Tsuchimoto2001HumanAP,
  title={Human APE2 protein is mostly localized in the nuclei and to some extent in the mitochondria, while nuclear APE2 is partly associated with proliferating cell nuclear antigen.},
  author={Daisuke Tsuchimoto and Yasunari Sakai and Kunihiko Sakumi and Kusuki Nishioka and Michi Sasaki and Tsuyoshi Fujiwara and Yusaku Nakabeppu},
  journal={Nucleic acids research},
  year={2001},
  volume={29 11},
  pages={2349-60}
}
In human cells APE1 is the major AP endonuclease and it has been reported to have no functional mitochondrial targeting sequence (MTS). We found that APE2 protein possesses a putative MTS. When its N-terminal 15 amino acid residues were fused to the N-terminus of green fluorescent protein and transiently expressed in HeLa cells the fusion protein was localized in the mitochondria. By electron microscopic immunocytochemistry we detected authentic APE2 protein in mitochondria from HeLa cells… CONTINUE READING