RT Journal Article
SR Electronic
T1 Mammalian NSUN2 introduces 5-methylcytidines into mitochondrial tRNAs
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 624932
DO 10.1101/624932
A1 Saori Shinoda
A1 Sho Kitagawa
A1 Shinichi Nakagawa
A1 Fan-Yan Wei
A1 Kazuhito Tomizawa
A1 Kimi Araki
A1 Masatake Araki
A1 Takeo Suzuki
A1 Tsutomu Suzuki
YR 2019
UL http://biorxiv.org/content/early/2019/05/02/624932.abstract
AB Post-transcriptional modifications in mitochondrial tRNAs (mt-tRNAs) play critical roles in mitochondrial protein synthesis, which produces respiratory chain complexes. In this study, we used 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 (SAM). Although NSUN2 is predominantly localized to the nucleus and introduces m5C into cytoplasmic tRNAs and mRNAs, structured illumination microscopy (SIM) clearly revealed NSUN2 foci inside mitochondria. These observations provide novel insights into the role of NSUN2 in the physiology and pathology of mitochondrial functions.