Skip to Content
Merck

N6-Deoxyadenosine Methylation in Mammalian Mitochondrial DNA.

Molecular cell (2020-03-19)
Ziyang Hao, Tong Wu, Xiaolong Cui, Pingping Zhu, Caiping Tan, Xiaoyang Dou, Kai-Wen Hsu, Yueh-Te Lin, Pei-Hua Peng, Li-Sheng Zhang, Yawei Gao, Lulu Hu, Hui-Lung Sun, Allen Zhu, Jianzhao Liu, Kou-Juey Wu, Chuan He
ABSTRACT

N6-Methyldeoxyadenosine (6mA) has recently been shown to exist and play regulatory roles in eukaryotic genomic DNA (gDNA). However, the biological functions of 6mA in mammals have yet to be adequately explored, largely due to its low abundance in most mammalian genomes. Here, we report that mammalian mitochondrial DNA (mtDNA) is enriched for 6mA. The level of 6mA in HepG2 mtDNA is at least 1,300-fold higher than that in gDNA under normal growth conditions, corresponding to approximately four 6mA modifications on each mtDNA molecule. METTL4, a putative mammalian methyltransferase, can mediate mtDNA 6mA methylation, which contributes to attenuated mtDNA transcription and a reduced mtDNA copy number. Mechanistically, the presence of 6mA could repress DNA binding and bending by mitochondrial transcription factor (TFAM). Under hypoxia, the 6mA level in mtDNA could be further elevated, suggesting regulatory roles for 6mA in mitochondrial stress response. Our study reveals DNA 6mA as a regulatory mark in mammalian mtDNA.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
LookOut® Mycoplasma PCR Detection Kit, Optimized for use with JumpStart Taq DNA Polymerase, D9307.
Sigma-Aldrich
Magnesium acetate solution, BioUltra, for molecular biology, ~1 M in H2O
Sigma-Aldrich
5-Ethynyl uridine, ≥95%
Sigma-Aldrich
MISSION® esiRNA, targeting human METTL4
Sigma-Aldrich
Anti-METTL4 antibody produced in rabbit, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution
Sigma-Aldrich
Tetramethylrhodamine ethyl ester perchlorate, suitable for fluorescence, ≥90% (HPCE)
Sigma-Aldrich
Phosphodiesterase I from Crotalus adamanteus venom, vial of ≥100 units, Purified