Mitochondria can dictate your fate, especially if you’re a stem cell

Redoxoma Highlights | Mitochondria can dictate your fate, especially if you’re a stem cell  Maria F. Forni

by Maria F. Forni*

Known for over a century, mitochondria have become, during the last four decades, an important subject of research within several disciplines. This is mostly due to the fact that this organelle comprises the site of oxidative phosphorylation, the citric acid cycle, fatty acid oxidation, the urea cycle and the biosynthesis of iron-sulphur centres and haem. Moreover, mitochondria are an important redox-signaling node. Indeed, the bioenergetic status of a cell is dependent on the overall quality and relative abundance of the mitochondrial population it harbors. Recent evidence suggests that the control of mitochondrial mass and morphology occurs through the processes of fusion

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Mitochondria-to-nucleus communication controls mitochondrial activity and stress resistance in yeast

Redoxoma Highlights | Mitochondria-to-nucleus communication controls mitochondrial activity and stress resistance in yeast by Fernanda M. Cunha

by Fernanda M. Cunha

Mitochondria are believed to be former free living bacteria that established a successful symbiotic relationship with eukaryotic cells in such a way that today, besides being crucial for the biosynthesis of intermediary metabolites, calcium homeostasis, coordination of apoptosis and ATP synthesis, most mitochondrial proteins are encoded by nuclear rather than mitochondrial DNA. In that scenario, communication pathways that relay signals from the nucleus to mitochondria as well as from mitochondria to the nucleus (the retrograde way) are mandatory to secure energetic and metabolic homeostasis. In yeast, the best characterized retrograde signaling pathway, activated whenever

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Peroxide signaling through thiol switches: chemical and biological aspects.

by Luis E. S. Netto

It is now well accepted that oxidants and other redox intermediates are not only damaging compounds, but also act as signaling molecules. This is especially evident for hydrogen peroxide, whose generation and degradation are finely regulated through multiple enzymatic systems. Proteins whose activities are based on Cysteine (Cys) residues are frequently reported to be oxidized in various biological systems in conditions where hydrogen peroxide is also generated. As the most parsimonious hypothesis, these proteins are frequently assumed to be directly oxidized by hydrogen peroxide, although this is not always supported by chemical data.

For instance, Protein Tyrosine Phosphatases

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A novel ubiquitin-related marker in oxidative stress response

by Marilene Demasi

Protein polyubiquitination was first described as a post-translational modification to direct proteins for degradation. The ubiquitin molecule is covalently bound to the target protein and the polyubiquitin chain is created by successive attachments of ubiquitin through its carboxy-terminal Glycine mainly to Lysine48 (K48) residues of previously conjugated ubiquitin. Proteins tagged with a K48-linked polyubiquitin chain are directed for degradation. However, distinct ubiquitin chains are built up through other Lysine residues from ubiquitin, resulting in distinct structural patterns of ubiquitin complexes, which in most cases are unrelated to target protein degradation.

The

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