@article {135859, title = {Novel regulators of mitochondrial genome integrity.}, journal = {J Biosci}, volume = {48}, year = {2023}, month = {2023}, abstract = {

Mitochondrial genomes are unusual in that they have very low mutation rates in coding sequences when compared with animals, yeast, and bacteria. It has been proposed that the mitochondrial (mt) DNA damage is preferentially repaired by homologous recombination (HR). In this short review, we summarize and discuss the well-established and recently identified pathways that help in maintaining the integrity of plant mitochondrial genomes.

}, keywords = {Animals, DNA, Mitochondrial, Genome, Mitochondrial, Genome, Plant, Homologous Recombination, Mitochondria, Plants, Saccharomyces cerevisiae}, issn = {0973-7138}, author = {Nair, Ashwin and Shivaprasad, P V} } @article {122345, title = {Structural heterogeneity of the Rieske iron-sulfur protein in a yeast complex III.}, journal = {IUCrJ}, volume = {10}, year = {2023}, month = {2023 Jan 01}, pages = {1-3}, abstract = {

Cryo-EM has been used to analyze the positions of the hydrophilic domain of the Rieske iron{\textendash}sulfur protein in a yeast complex III under various redox and substrate/inhibitor conditions.

}, keywords = {Electron Transport Complex III, Iron-Sulfur Proteins, Mitochondrial Membranes, Saccharomyces cerevisiae}, issn = {2052-2525}, doi = {10.1107/S2052252522012003}, author = {Vinothkumar, Kutti R} } @article {113552, title = {Genome doubling enabled the expansion of yeast vesicle traffic pathways.}, journal = {Sci Rep}, volume = {12}, year = {2022}, month = {2022 Jul 02}, pages = {11213}, abstract = {

Vesicle budding and fusion in eukaryotes depend on a suite of protein types, such as Arfs, Rabs, coats and SNAREs. Distinct paralogs of these proteins act at distinct intracellular locations, suggesting a link between gene duplication and the expansion of vesicle traffic pathways. Genome doubling, a common source of paralogous genes in fungi, provides an ideal setting in which to explore this link. Here we trace the fates of paralog doublets derived from the 100-Ma-old hybridization event that gave rise to the whole genome duplication clade of budding yeast. We find that paralog doublets involved in specific vesicle traffic functions and pathways are convergently retained across the entire clade. Vesicle coats and adaptors involved in secretory and early-endocytic pathways are retained as doublets, at rates several-fold higher than expected by chance. Proteins involved in later endocytic steps and intra-Golgi traffic, including the entire set of multi-subunit and coiled-coil tethers, have reverted to singletons. These patterns demonstrate that selection has acted to expand and diversify the yeast vesicle traffic apparatus, across species and time.

}, keywords = {Blister, Gene Duplication, Golgi Apparatus, Saccharomyces cerevisiae, Saccharomycetales}, issn = {2045-2322}, doi = {10.1038/s41598-022-15419-9}, author = {Purkanti, Ramya and Thattai, Mukund} } @article {854, title = {Ancient dynamin segments capture early stages of host-mitochondrial integration.}, journal = {Proc Natl Acad Sci U S A}, volume = {112}, year = {2015}, month = {2015 Mar 3}, pages = {2800-5}, abstract = {

Eukaryotic cells use dynamins-mechano-chemical GTPases--to drive the division of endosymbiotic organelles. Here we probe early steps of mitochondrial and chloroplast endosymbiosis by tracing the evolution of dynamins. We develop a parsimony-based phylogenetic method for protein sequence reconstruction, with deep time resolution. Using this, we demonstrate that dynamins diversify through the punctuated transformation of sequence segments on the scale of secondary-structural elements. We find examples of segments that have remained essentially unchanged from the 1.8-billion-y-old last eukaryotic common ancestor to the present day. Stitching these together, we reconstruct three ancestral dynamins: The first is nearly identical to the ubiquitous mitochondrial division dynamins of extant eukaryotes, the second is partially preserved in the myxovirus-resistance--like dynamins of metazoans, and the third gives rise to the cytokinetic dynamins of amoebozoans and plants and to chloroplast division dynamins. The reconstructed sequences, combined with evolutionary models and published functional data, suggest that the ancestral mitochondrial division dynamin also mediated vesicle scission. This bifunctional protein duplicated into specialized mitochondrial and vesicle variants at least three independent times--in alveolates, green algae, and the ancestor of fungi and metazoans-accompanied by the loss of the ancient prokaryotic mitochondrial division protein FtsZ. Remarkably, many extant species that retain FtsZ also retain the predicted ancestral bifunctional dynamin. The mitochondrial division apparatus of such organisms, including amoebozoans, red algae, and stramenopiles, seems preserved in a near-primordial form.

}, keywords = {Animals, Arabidopsis, Caenorhabditis elegans, Chloroplasts, Dictyostelium, Drosophila melanogaster, Dynamins, Evolution, Molecular, Humans, Mitochondria, Mitochondrial Dynamics, Saccharomyces cerevisiae, Schizosaccharomyces}, issn = {1091-6490}, doi = {10.1073/pnas.1407163112}, author = {Purkanti, Ramya and Thattai, Mukund} }