Send to

Choose Destination
Nucleic Acids Res. 2019 Jul 9. pii: gkz575. doi: 10.1093/nar/gkz575. [Epub ahead of print]

Mammalian NSUN2 introduces 5-methylcytidines into mitochondrial tRNAs.

Author information

Department of Chemistry and Biotechnology, Graduate School of Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Faculty of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan.
Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan.
Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012 Japan.
Institute of Resource Development and Analysis, Kumamoto University, Kumamoto 860-0811, Japan.


Post-transcriptional modifications in mitochondrial tRNAs (mt-tRNAs) play critical roles in mitochondrial protein synthesis, which produces respiratory chain complexes. In this study, we took advantage of mass spectrometric analysis to map 5-methylcytidine (m5C) at positions 48-50 in eight mouse and six human mt-tRNAs. We also confirmed the absence of m5C in mt-tRNAs isolated from Nsun2 knockout (KO) mice, as well as from NSUN2 KO human culture cells. In addition, we successfully reconstituted m5C at positions 48-50 of mt-tRNA in vitro with NSUN2 protein in the presence of S-adenosylmethionine. Although NSUN2 is predominantly localized to the nucleus and introduces m5C into cytoplasmic tRNAs and mRNAs, structured illumination microscopy clearly revealed NSUN2 foci inside mitochondria. These observations provide novel insights into the role of NSUN2 in the physiology and pathology of mitochondrial functions.


Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center