A single mutation in the first transmembrane domain of yeast COX2 enables its allotopic expression
- 16 March 2010
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 107 (11), 5047-5052
- https://doi.org/10.1073/pnas.1000735107
Abstract
During the course of evolution, a massive reduction of the mitochondrial genome content occurred that was associated with transfer of a large number of genes to the nucleus. To further characterize factors that control the mitochondrial gene transfer/retention process, we have investigated the barriers to transfer of yeast COX2, a mitochondrial gene coding for a subunit of cytochrome c oxidase complex. Nuclear-recoded Saccharomyces cerevisiae COX2 fused at the amino terminus to various alternative mitochondrial targeting sequences (MTS) fails to complement the growth defect of a yeast strain with an inactivated mitochondrial COX2 gene, even though it is expressed in cells. Through random mutagenesis of one such hybrid MTS-COX2, we identified a single mutation in the first Cox2 transmembrane domain (W56 → R) that (i) results in the cellular expression of a Cox2 variant with a molecular mass indicative of MTS cleavage, which (ii) supports growth of a cox2 mutant on a nonfermentable carbon source, and that (iii) partially restores cytochrome c oxidase-specific respiration by the mutant mitochondria. COX2W56R can be allotopically expressed with an MTS derived from S. cerevisiae OXA1 or Neurospora crassa SU9, both coding for hydrophobic mitochondrial proteins, but not with an MTS derived from the hydrophilic protein Cox4. In contrast to some other previously transferred genes, allotopic COX2 expression is not enabled or enhanced by a 3′-UTR that localizes mRNA translation to the mitochondria, such as yeast ATP23′-UTR. Application of in vitro evolution strategies to other mitochondrial genes might ultimately lead to yeast entirely lacking the mitochondrial genome, but still possessing functional respiratory capacity.This publication has 32 references indexed in Scilit:
- Translocation of Mitochondrially Synthesized Cox2 Domains from the Matrix to the Intermembrane SpaceMolecular and Cellular Biology, 2007
- Allotopic mRNA Localization to the Mitochondrial Surface Rescues Respiratory Chain Defects in Fibroblasts Harboring Mitochondrial DNA Mutations Affecting Complex I or V SubunitsRejuvenation Research, 2007
- Protein Export across the Inner Membrane of MitochondriaJournal of Biological Chemistry, 2004
- Evolution of mitochondrial gene content: gene loss and transfer to the nucleusMolecular Phylogenetics and Evolution, 2003
- Topogenesis of Cytochrome Oxidase Subunit IIJournal of Biological Chemistry, 1995
- Limitations to in vivo Import of Hydrophobic Proteins into Yeast MitochondriaJBIC Journal of Biological Inorganic Chemistry, 1995
- RNA-mediated transfer of the gene coxII from the mitochondrion to the nucleus during flowering plant evolutionCell, 1991
- Duplication of leader sequence for protein targeting to mitochondria leads to increased import efficiencyFEBS Letters, 1991
- On the Microassembly of Integral Membrane ProteinsAnnual Review of Biophysics and Biophysical Chemistry, 1990
- Why mitochondria need a genomeFEBS Letters, 1986