Research Reports
The translationally controlled tumor protein TCTP is involved in cell cycle progression and heat stress response in the bloodstream form of Trypanosoma brucei
Borka Jojic1, Simona Amodeo1,2 and Torsten Ochsenreiter1
This study reveals the involvement of the translationally controlled tumor protein TCTP in cell cycle regulation and heat stress response in the bloodstream form of Trypanosoma brucei, shedding light on its role in these cellular processes.
Evolution of substrate specificity in the Nucleobase-Ascorbate Transporter (NAT) protein family
Anezia Kourkoulou1,#, Alexandros A. Pittis2,# and George Diallinas1
L-ascorbic acid (vitamin C) is an essential metabolite in animals and plants due to its role as an enzyme co-factor and antioxidant activity. Here, Kourkoulou et al. show further evidence that ascorbate-specific Nucleobase-Ascorbate Transporters (NATs) evolved by optimization of a sub-function of ancestral nucleobase transporters.
Valine biosynthesis in Saccharomyces cerevisiae is regulated by the mitochondrial branched-chain amino acid aminotransferase Bat1
Natthaporn Takpho1, Daisuke Watanabe1 and Hiroshi Takagi1
In Saccharomyces cerevisiae, the yeast, the Bat1 and Bat2 proteins, which are branched-chain amino acid aminotransferases, play distinct roles in valine biosynthesis and cell growth regulation, with Bat1 primarily located in the mitochondria and Bat2 in the cytosol, and the mitochondria being identified as the major site of valine biosynthesis in this yeast.
Microbial competition between Escherichia coli and Candida albicans reveals a soluble fungicidal factor
Damien J. Cabral1, Swathi Penumutchu1, Colby Norris1,2, Jose Ruben Morones-Ramirez3,4 and Peter Belenky1
Localized and systemic fungal infections caused by Candida albicans can lead to significant mortality and morbidity. Here, Cabral et al. show that E. coli produces a soluble factor that kills C. albicans in a magnesium-dependent fashion such that depletion of available magnesium is essential for toxicity.
Impact of F1Fo-ATP-synthase dimer assembly factors on mitochondrial function and organismic aging
Nadia G Rampello1, Maria Stenger2, Benedikt Westermann2, Heinz D Osiewacz1
In aerobic organisms, mitochondrial F1Fo-ATP-synthase is the major site of ATP production. Here, Rampello et al. report on the role of the two dimer assembly factors PaATPE and PaATPG of the aging model Podospora anserina validating a model that links mitochondrial membrane remodeling to aging and identify specific molecular components triggering this process.
Yeast quiescence exit swiftness is influenced by cell volume and chronological age
Damien Laporte1, Laure Jimenez1, Laëtitia Gouleme1, Isabelle Sagot1
Quiescence exit swiftness is crucial not only for micro-organisms in competition for an environmental niche, such as yeast, but also for the maintenance of tissue homeostasis in multicellular species. Here, Laporte et al. explore the effect of replicative and chronological age on Saccharomyces cerevisiae quiescence exit efficiency. Overall, their data illustrate that the quiescent state is a continuum evolving with time, early and deep quiescence being distinguishable by the cell’s proficiency to re-enter the proliferation cycle.
The neuroprotective steroid progesterone promotes mitochondrial uncoupling, reduces cytosolic calcium and augments stress resistance in yeast cells
Slaven Stekovic1,*, Christoph Ruckenstuhl1,*, Philipp Royer1, Christof Winkler-Hermaden1, Didac Carmona-Gutierrez1, Kai-Uwe Fröhlich1, Guido Kroemer3-8, and Frank Madeo1,2
Progesterone, known for its role in the reproductive system, also acts as a neurosteroid and has been suggested to aid recovery from traumatic brain injury; a study using yeast models shows that progesterone can protect against apoptosis, reduce oxidative stress and calcium spikes, and increase mitochondrial function, independent of traditional progesterone receptors or calcium transporters.
A simple microfluidic platform to study age-dependent protein abundance and localization changes in Saccharomyces cerevisiae
Margarita Cabrera1,†, Daniele Novarina1, Irina L. Rempel1, Liesbeth M. Veenhoff1, and Michael Chang1
We have developed a user-friendly microfluidic system paired with a genetic approach to enrich and study ageing mother yeast cells, enabling the monitoring of protein abundance and localization changes during the crucial first half of their replicative lifespan, leading to the discovery of novel age-dependent protein behaviors.
Exogenous folates stimulate growth and budding of Candida glabrata
May 1, 2015
Folate, vitamin B9, is well recognized as being essential for cell growth. The utilization of folate is common to all cells, but the source of it may be quite different. This article reports a novel response of yeast to folates that may increase the utility of yeast as a model to study folate transport and signaling.
Modeling human Coenzyme A synthase mutation in yeast reveals altered mitochondrial function, lipid content and iron metabolism
April 6, 2015
Mutations in nuclear genes associated with defective coenzyme A biosynthesis have been identified as responsible for some forms of neurodegeneration with brain iron accumulation (NBIA), namely PKAN and CoPAN. Yeast expressing a pathogenic mutation exhibited a temperature-sensitive growth defect in the absence of pantothenate and a reduced CoA content. Additional characterization revealed decreased oxygen consumption, reduced activities of mitochondrial respiratory complexes, higher iron content, increased sensitivity to oxidative stress and reduced amount of lipid droplets, thus partially recapitulating the phenotypes found in patients and establishing yeast as a potential model to clarify the pathogenesis underlying PKAN and CoPAN diseases.
Prokaryotic ancestry and gene fusion of a dual localized peroxiredoxin in malaria parasites
January 4, 2015
Horizontal gene transfer has emerged as a crucial driving force for the evolution of eukaryotes. This also includes Plasmodium falciparum and related economically and clinically relevant apicomplexan parasites, whose rather small genomes have been shaped not only by natural selection in different host populations but also by horizontal gene transfer following endosymbiosis. However, there is rather little reliable data on horizontal gene transfer between animal hosts or bacteria and apicomplexan parasites. Here we show that apicomplexan homologues of peroxiredoxin 5 (Prx5) have a prokaryotic ancestry and therefore represent a special subclass of Prx5 isoforms in eukaryotes. Using two different immunobiochemical approaches, we found that...
Two distinct and competitive pathways confer the cellcidal actions of artemisinins
January 1, 2015
The biological actions of artemisinin (ART), an antimalarial drug derived from Artemisia annua, remain poorly understood and controversial. This article concludes that ARTs are endowed with two major and distinct types of properties: a potent and specific mitochondria-dependent reaction and a more general and less specific heme-mediated reaction. The competitive nature of these two actions could be explained by their shared source of the consumable ARTs, so that inhibition of the heme-mediated degradation pathway would enable more ARTs to be available for the mitochondrial action. These properties of ARTs can be used to interpret the divergent antimalarial and anticancer actions of ARTs.
Loss of wobble uridine modification in tRNA anticodons interferes with TOR pathway signaling
November 29, 2014
The herein presented data suggest that proper TOR signaling requires intact tRNA modifications and that loss of U34 modifications impinges on the TOR-sensitive NCR branch via Gln3 misregulation.
Measurement of apoptosis by SCAN©, a system for counting and analysis of fluorescently labelled nuclei
November 26, 2014
This work reports on a system for analyses of apoptosis-like programmed cell death in fungal hyphae that is composed of several modules, which enable automatic quantification of nuclei with chromatin condensation and DNA strand break in large datasets according to nuclei-associated fluorescent markers.
Rewiring yeast acetate metabolism through MPC1 loss of function leads to mitochondrial damage and decreases chronological lifespan
November 18, 2014
This work shows that MPC1-deficient cells make up for their impairment in mitochondrial pyruvate with a metabolic rewiring which involves several intermediates of the mitochondrially localized TCA cycle and the cytosolic glyoxylate shunt but ultimately results in a pro-aging process.
Overexpression of the transcription factor Yap1 modifies intracellular redox conditions and enhances recombinant protein secretion
October 31, 2014
This article investigates the role of Yap1 during the production of recombinant secretory proteins in glucose based growth conditions in Pichia pastoris, and reports a novel role of Yap1 during ER-resident oxidative protein folding.
Functional analysis of lipid metabolism genes in wine yeasts during alcoholic fermentation at low temperature
October 29, 2014
This study confirms the importance of specific genes in growth and fermentation activity of Saccharomyces cerevisiae at low temperature.