Highly efficient 5' capping of mitochondrial RNA with NAD+ and NADH by yeast and human mitochondrial RNA polymerase
- Rutgers University, United States
- Heidelberg University, Germany
- The Children's Hospital of Philadelphia, United States
- University of Pennsylvania, United States
- Thomas Jefferson University, United States
Abstract
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.
Data availability
All data generated or analysed during this study are included in the manuscript.
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Author details
Funding
National Institutes of Health (GM126488)
- Megerditch Kiledjian
American Heart Association (16PRE30400001)
- Urmimala Basu
National Institutes of Health (GM118086)
- Smita S Patel
National Institutes of Health (GM104231)
- Dmitry Temiakov
National Institutes of Health (GM041376)
- Richard H Ebright
National Institutes of Health (GM118059)
- Bryce E Nickels
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Bird et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Highly efficient 5' capping of mitochondrial RNA with NAD+ and NADH by yeast and human mitochondrial RNA polymerase
eLife 7:e42179.
https://doi.org/10.7554/eLife.42179
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