Modifications of the respiratory chain of Bacillus licheniformis as an alkalophilic and cyanide-degrading microorganism.

Bacillus licheniformis can use cyanide as a nitrogen source for its growth. However, it can also carry out aerobic respiration in the presence of this compound, a classic inhibitor of mammalian cytochrome c oxidase, indicating that B. licheniformis has a branched respiratory chain with various terminal oxidases.

Sedentary Lifestyles and a Hypercaloric Diets During Middle Age, are Binomial Conducive to Fatal Progression, That is Counteracted by the Hormetic Treatment of Exercise, Metformin, and Tert-Butyl Hydroquinone: An Analysis of Female Middle-Aged Rat Liver Mitochondria.

The world's population continuous to shift towards older, less active and more sedentary lifestyles especially during middle age. In addition consumption of high-caloric diets, increases the risk of metabolic and cardiovascular afflictions. Developing clinical strategies to mitigate those health complications represent a difficult challenge.

Prohibitins, Phb1 and Phb2, function as Atg8 receptors to support yeast mitophagy and also play a negative regulatory role in Atg32 processing.

The prohibitins Phb1 and Phb2 assemble at the mitochondrial inner membrane to form a multi-dimeric complex. These scaffold proteins are highly conserved in eukaryotic cells, from yeast to mammals, and have been implicated in a variety of mitochondrial functions including aging, proliferation, and degenerative and metabolic diseases. In mammals, PHB2 regulates PINK1-PRKN mediated mitophagy by interacting with lipidated MAP1LC3B/LC3B.

Metabolic Changes and Antioxidant Response in Grown in Acetate.

is an important model to study intermediary and mitochondrial metabolism, among other processes. can grow, at very different rates, on glucose, lactate, glycerol, and ethanol as carbon sources. Under nitrogen starvation and glucose as the only carbon source, this fungus synthesizes and accumulates neutral lipids in the form of lipid droplets (LD).

Deletion of the ATP20 gene in Ustilago maydis produces an unstable dimer of FF-ATP synthase associated with a decrease in mitochondrial ATP synthesis and a high HO production.

The FF-ATP synthase uses the energy stored in the electrochemical proton gradient to synthesize ATP. This complex is found in the inner mitochondrial membrane as a monomer and dimer. The dimer shows higher ATPase activity than the monomer and is essential for cristae folding.

The Mitochondrial Alternative Oxidase in Is Not Involved in Response to Oxidative Stress Induced by Paraquat.

It has been shown that the alternative oxidase in mitochondria of fungi and plants has important functions in the response against stress conditions, although their role in some organisms is still unknown. This is the case of . There is no evidence of the participation of the Aox1 in stressful conditions such as desiccation, high or low temperature, and low pH, among others.

Functional Analysis of the Plasma Membrane H-ATPases of .

Plasma membrane H+-ATPases of fungi, yeasts, and plants act as proton pumps to generate an electrochemical gradient, which is essential for secondary transport and intracellular pH maintenance. Saccharomyces cerevisiae has two genes (PMA1 and PMA2) encoding H+-ATPases. In contrast, plants have a larger number of genes for H+-ATPases.

Isolation of Mitochondria from Protoplasts.

, a basidiomycete that infects , is one of the top ten fungal models for studying DNA repair, signal transduction pathways, and dimorphic transitions, among other processes. From a metabolic point of view, lacks fermentative capacity, pointing to mitochondria as a key player in central metabolism. Oxidative phosphorylation, synthesis of heme groups, Krebs cycle, β-oxidation of fatty acids, and synthesis of amino acids are some of the processes that take place in mitochondria.

Carbon and Nitrogen Sources Have No Impact on the Organization and Composition of Respiratory Supercomplexes.

Respiratory supercomplexes are found in mitochondria of eukaryotic cells and some bacteria. A hypothetical role of these supercomplexes is electron channeling, which in principle should increase the respiratory chain efficiency and ATP synthesis. In addition to the four classic respiratory complexes and the ATP synthase, mitochondria contain three type II NADH dehydrogenases (NADH for reduced nicotinamide adenine dinucleotide) and the alternative oxidase.

On the use of n-octyl gallate and salicylhydroxamic acid to study the alternative oxidase role.

The alternative oxidase (AOX) catalyzes the transfer of electrons from ubiquinol to oxygen without the translocation of protons across the inner mitochondrial membrane. This enzyme has been proposed to participate in the regulation of cell growth, sporulation, yeast-mycelium transition, resistance to reactive oxygen species, infection, and production of secondary metabolites. Two approaches have been used to evaluate AOX function: incubation of cells for long periods of time with AOX inhibitors or deletion of AOX gene.

DnmA and FisA Mediate Mitochondria and Peroxisome Fission, and Regulate Mitochondrial Function, ROS Production and Development in .

The dynamin-like protein Drp1 and its receptor Fis-1 are required for mitochondria and peroxisome fission in animal and yeast cells. Here, we show that in the fungus the lack of Drp1 and Fis-1 homologs DnmA and FisA has strong developmental defects, leading to a notable decrease in hyphal growth and asexual and sexual sporulation, with some of these defects being aggravated or partially remediated by different carbon sources. Although both DnmA and FisA, are essential for mitochondrial fission, participate in peroxisomal division and are fully required for HO-induced mitochondrial division, they also appear to play differential functions.

Rapamycin induces morphological and physiological changes without increase in lipid content in Ustilago maydis.

The evolutionarily conserved serine/threonine kinase TOR recruits different subunits to assemble the Target of Rapamycin Complex 1 (TORC1), which is inhibited by rapamycin and regulates ribosome biogenesis, autophagy, and lipid metabolism by regulating the expression of lipogenic genes. In addition, TORC1 participates in the cell cycle, increasing the length of the G2 phase. In the present work, we investigated the effect of rapamycin on cell growth, cell morphology and neutral lipid metabolism in the phytopathogenic fungus Ustilago maydis.

Physiological changes of growth hormone during lactation in pup rats artificially reared.

During the lactation period, rat pups are fed by the dam, and the patterns of mother-pup interaction change during this period. Additionally, there are changes in feeding; first, mother´s milk is the only food needed for sustenance, and later, it is combined with solid food and water. GH serum concentrations depend on both maternal-pup interaction and energy metabolism.

New Insights of Ustilago maydis as Yeast Model for Genetic and Biotechnological Research: A Review.

The basidiomycete Ustilago maydis is a biotrophic organism responsible for corn smut disease. In recent years, it has become one of the most promising models for biochemical and biotechnological research due to advantages, such as rapid growth, and easy genetic manipulation. In some aspects, this yeast is more similar to complex eukaryotes, such as humans, compared to standard laboratory yeast models.

Insight into the Mechanistic Basis of the Hysteretic-Like Kinetic Behavior of Thioredoxin-Glutathione Reductase (TGR).

A kinetic study of thioredoxin-glutathione reductase (TGR) from metacestode (cysticerci) was carried out. The results obtained from both initial velocity and product inhibition experiments suggest the enzyme follows a two-site ping-pong bi bi kinetic mechanism, in which both substrates and products are bound in rapid equilibrium fashion. The substrate GSSG exerts inhibition at moderate or high concentrations, which is concomitant with the observation of hysteretic-like progress curves.

Expression of alternative NADH dehydrogenases (NDH-2) in the phytopathogenic fungus .

Type 2 alternative NADH dehydrogenases (NDH-2) participate indirectly in the generation of the electrochemical proton gradient by transferring electrons from NADH and NADPH into the ubiquinone pool. Due to their structural simplicity, alternative NADH dehydrogenases have been proposed as useful tools for gene therapy of cells with defects in the respiratory complex I. In this work, we report the presence of three open reading frames, which correspond to NDH-2 genes in the genome of .

Differential Functionalization of Presumed and Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions.

arose from an interspecies hybridization (allopolyploidiza-tion), followed by Whole Genome Duplication. Diversification analysis of Alt1/Alt2 indicated that while Alt1 is an alanine transaminase, Alt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP) binding properties of Alt1 and Alt2 indicating functional diversification could have determined loss of Alt2 alanine transaminase activity and thus its role in alanine metabolism.

Lipid Index Determination by Liquid Fluorescence Recovery in the Fungal Pathogen Ustilago Maydis.

The article shows how to implement the LD index assay, which is a sensitive microplate assay to determine the accumulation of triacylglycerols (TAGs) in lipid droplets (LDs). LD index is obtained without lipid extraction. It allows measuring the LDs content in high-throughput experiments under different conditions such as growth in rich or nitrogen depleted media.

Response of Ustilago maydis against the Stress Caused by Three Polycationic Chitin Derivatives.

Chitosan is a stressing molecule that affects the cells walls and plasma membrane of fungi. For chitosan derivatives, the action mode is not clear. In this work, we used the yeast to study the effects of these molecules on the plasma membrane, focusing on physiologic and stress responses to chitosan (CH), oligochitosan (OCH), and glycol-chitosan (GCH).

Structural and kinetics characterization of the FF-ATP synthase dimer. New repercussion of monomer-monomer contact.

Ustilago maydis is an aerobic basidiomycete that fully depends on oxidative phosphorylation for its supply of ATP, pointing to mitochondria as a key player in the energy metabolism of this organism. Mitochondrial FF-ATP synthase occurs in supramolecular structures. In this work, we isolated the monomer (640kDa) and the dimer (1280kDa) and characterized their subunit composition and kinetics of ATP hydrolysis.

Lipid droplets accumulation and other biochemical changes induced in the fungal pathogen Ustilago maydis under nitrogen-starvation.

In many organisms, the growth under nitrogen-deprivation or a poor nitrogen source impacts on the carbon flow distribution and causes accumulation of neutral lipids, which are stored as lipid droplets (LDs). Efforts are in progress to find the mechanism of LDs synthesis and degradation, and new organisms capable of accumulating large amounts of lipids for biotechnological applications. In this context, when Ustilago maydis was cultured in the absence of a nitrogen source, there was a large accumulation of lipid bodies containing mainly triacylglycerols.