Microbial eukaryotes have adapted to hypoxia by horizontal acquisitions of a gene involved in rhodoquinone biosynthesis
- Dalhousie University, Canada
- Gonzaga University, United States
Abstract
Under hypoxic conditions, some organisms use an electron transport chain consisting of only complex I and II (CII) to generate the proton gradient essential for ATP production. In these cases, CII functions as a fumarate reductase that accepts electrons from a low electron potential quinol, rhodoquinol (RQ). To clarify the origins of RQ-mediated fumarate reduction in eukaryotes, we investigated the origin and function of rqua, a gene encoding an RQ biosynthetic enzyme. Rqua is very patchily distributed across eukaryotes and bacteria adapted to hypoxia. Phylogenetic analyses suggest lateral gene transfer (LGT) of rqua from bacteria to eukaryotes occurred at least twice and the gene was transferred multiple times amongst protists. We demonstrate that RQUA functions in the mitochondrion-related organelles of the anaerobic protist Pygsuia and is correlated with the presence of RQ. These analyses reveal the role of gene transfer in the evolutionary remodeling of mitochondria in adaptation to hypoxia.
Data availability
All data is available on Dryad DOI: https://doi.org/10.5061/dryad.qp745
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Data from Microbial eukaryotes have adapted to hypoxia by horizontal acquisitions of a gene involved in rhodoquinone biosynthesisAvailable at Dryad Digital Repository under a CC0 Public Domain Dedication.
Article and author information
Author details
Funding
Canadian Institutes of Health Research (MOP 142349)
- Andrew J Roger
National Institutes of Health (1R15GM096398-01)
- Jennifer N Shepherd
Natural Sciences and Engineering Research Council of Canada
- Courtney W Stairs
Killam Trusts
- Courtney W Stairs
Natural Sciences and Engineering Research Council of Canada (RGPIN 05616)
- Graham Dellaire
Canadian Institutes of Health Research (MOP 341174)
- James P Fawcett
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Stairs 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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Microbial eukaryotes have adapted to hypoxia by horizontal acquisitions of a gene involved in rhodoquinone biosynthesis
eLife 7:e34292.
https://doi.org/10.7554/eLife.34292
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