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Published on: January 7, 2022
The emerging picture of the mitochondrial protein import complexes of Amoebozoa supergroup
Małgorzata Wojtkowska1, Dorota Buczek2,3, Yutaka Suzuki4
1Laboratory of Bioenergetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland. woytek@amu.edu.pl.
Background:
The existence of mitochondria-related organelles (MROs) is proposed for eukaryotic organisms. The Amoebozoa includes some organisms that are known to have mitosomes but also organisms that have aerobic mitochondria. However, the mitochondrial protein apparatus of this supergroup remains largely unsampled, except for the mitochondrial outer membrane import complexes studied recently. Therefore, in this study we investigated the mitochondrial inner membrane and intermembrane space complexes, using the available genome and transcriptome sequences.
Results:
When compared with the canonical cognate complexes described for the yeast Saccharomyces cerevisiae, amoebozoans with aerobic mitochondria, display lower differences in the number of subunits predicted for these complexes than the mitochondrial outer membrane complexes, although the predicted subunits appear to display different levels of diversity in regard to phylogenetic position and isoform numbers. For the putative mitosome-bearing amoebozoans, the number of predicted subunits suggests the complex elimination distinctly more pronounced than in the case of the outer membrane ones.
Conclusion:
The results concern the problem of mitochondrial and mitosome protein import machinery structural variability and the reduction of their complexity within the currently defined supergroup of Amoebozoa. This results are crucial for better understanding of the Amoebozoa taxa of both biomedical and evolutionary importance.
Insights
This study reveals significant variability in mitochondrial protein import complexes across Amoebozoa. Organisms with aerobic mitochondria show fewer differences, while mitosome-bearing species exhibit more pronounced complex reduction.
Area of Science:
- Cell Biology
- Evolutionary Biology
- Biochemistry
Background:
- Mitochondria-related organelles (MROs) are proposed for eukaryotes.
- Amoebozoa possess either aerobic mitochondria or mitosomes.
- Mitochondrial protein import machinery in Amoebozoa is largely uncharacterized.
Purpose of the Study:
- Investigate the mitochondrial inner membrane and intermembrane space complexes in Amoebozoa.
- Analyze the structural variability and complexity reduction of these complexes.
- Enhance understanding of Amoebozoa taxa.
Main Methods:
- Comparative analysis of available genome and transcriptome sequences.
- Prediction of subunits for mitochondrial inner membrane and intermembrane space complexes.
- Phylogenetic analysis of predicted subunits.
Main Results:
- Amoebozoans with aerobic mitochondria show fewer subunit differences compared to yeast, but with phylogenetic diversity.
- Mitosome-bearing amoebozoans display more significant reduction in complex subunits than previously observed for outer membrane complexes.
- Predicted subunits exhibit varying levels of diversity and isoform numbers across phylogenetic positions.
Conclusions:
- The study addresses the structural variability and complexity reduction of mitochondrial and mitosome protein import machinery in Amoebozoa.
- Findings are crucial for understanding the evolutionary trajectory of these organelles within the supergroup.
- Results contribute to the biomedical and evolutionary significance of Amoebozoa taxa.
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