Highly efficient 5' capping of mitochondrial RNA with NAD+ and NADH by yeast and human mitochondrial RNA polymerase.
Jeremy G BirdUrmimala BasuDavid KusterAparna RamachandranEwa Grudzien-NogalskaAtif TowheedDouglas C WallaceMegerditch KiledjianDmitry TemiakovSmita S PatelRichard H EbrightBryce E NickelsPublished in: eLife (2018)
Bacterial and eukaryotic nuclear RNA polymerases (RNAPs) cap RNA with the oxidized and reduced forms of the metabolic effector nicotinamide adenine dinucleotide, NAD+ and NADH, using NAD+ and NADH as non-canonical initiating nucleotides for transcription initiation. Here, we show that mitochondrial RNAPs (mtRNAPs) cap RNA with NAD+ and NADH, and do so more efficiently than nuclear RNAPs. Direct quantitation of NAD+- and NADH-capped RNA demonstrates remarkably high levels of capping in vivo: up to ~60% NAD+ and NADH capping of yeast mitochondrial transcripts, and up to ~15% NAD+ capping of human mitochondrial transcripts. The capping efficiency is determined by promoter sequence at, and upstream of, the transcription start site and, in yeast and human cells, by intracellular NAD+ and NADH levels. Our findings indicate mtRNAPs serve as both sensors and actuators in coupling cellular metabolism to mitochondrial transcriptional outputs, sensing NAD+ and NADH levels and adjusting transcriptional outputs accordingly.
Keyphrases
- oxidative stress
- transcription factor
- highly efficient
- endothelial cells
- gene expression
- dna methylation
- nucleic acid
- mass spectrometry
- ms ms
- saccharomyces cerevisiae
- dendritic cells
- high resolution
- cell wall
- reactive oxygen species
- liquid chromatography tandem mass spectrometry
- ionic liquid
- pluripotent stem cells
- amino acid