Research, Research Articles
The euchromatic histone mark H3K36me3 preserves heterochromatin through sequestration of an acetyltransferase complex in fission yeast
Paula R. Georgescu1, Matías Capella1, Sabine Fischer-Burkart1 and Sigurd Braun1
This study reveals that the loss of heterochromatin silencing in Set2-deficient cells is due to unrestrained Mst2C activity, highlighting the need for spatially restricted chromatin-modifying enzymes to maintain distinct chromatin states.
Depletion of SNAP-23 and Syntaxin 4 alters lipid droplet homeostasis during Chlamydia infection
Tiago Monteiro-Brás1,2,3, Jordan Wesolowski1 and Fabienne Paumet1
This study reveals that the plasma membrane SNARE proteins SNAP-23 and Syntaxin 4 are crucial for Chlamydia trachomatis development by regulating lipid droplet homeostasis and supporting the formation of infectious progeny within host cells.
Yeast can express and assemble bacterial secretins in the mitochondrial outer membrane
Janani Natarajan1, Anasuya Moitra1, Sussanne Zabel1,§, Nidhi Singh2, Samuel Wagner2,3 and Doron Rapaport1
Secretins, essential components of bacterial secretion systems, can be expressed in yeast and show differential dependencies on mitochondrial import and assembly factors for membrane integration, suggesting diverse pathways for their assembly into the bacterial outer membrane.
Metabolic reprogramming of Salmonella infected macrophages and its modulation by iron availability and the mTOR pathway
Julia Telser1,2,#, Chiara Volani1,3,#, Richard Hilbe1,2, Markus Seifert1,2, Natascha Brigo1, Giuseppe Paglia4 and Günter Weiss1,2
This article shows that iron plays a critical role in both the immune response and metabolic reprogramming of macrophages during infection, influencing the TCA cycle and mTOR pathway, with implications for the growth of intracellular bacteria like Salmonella.
Transcriptomic and chemogenomic analyses unveil the essential role of Com2-regulon in response and tolerance of Saccharomyces cerevisiae to stress induced by sulfur dioxide
Patrícia Lage1,2, Belém Sampaio-Marques3,4, Paula Ludovico3,4, Nuno P. Mira5 and Ana Mendes-Ferreira1,2
This article shows that in the presence of sulfur dioxide (SO2), the transcription factor Com2 plays a critical role in the tolerance and response of Saccharomyces cerevisiae, affecting the expression of a majority of SO2-activated genes and contributing to the protection against stress induced by SO2 at an enologically relevant pH.
Network dynamics of the yeast methyltransferome
Guri Giaever1, Elena Lissina1 and Corey Nislow1
This article presents a systematic genetic analysis of methyltransferases (MTases) under normal and stress conditions, uncovering the complex and adaptive nature of the methyltransferome and discovering a potential connection between phospholipid methylation and histone methylation, suggesting interplay between lipid homeostasis and epigenetic regulation.
Functional link between mitochondria and Rnr3, the minor catalytic subunit of yeast ribonucleotide reductase
Isaac Corcoles-Saez1, Jean-Luc Ferat2, Michael Costanzo3, Charles M. Boone3 and Rita S. Cha1
This article shows that the carbon source affects the abundance of ribonucleotide reductase (RNR) subunits in yeast, with a novel Mec1 signaling axis regulating Rnr3 independently of known DNA damage response pathways, and reveals Rnr3's unexpected role in mitochondrial function.
Snf1 cooperates with the CWI MAPK pathway to mediate the degradation of Med13 following oxidative stress
June 25, 2018
This article explores the response of eukaryotic cells to environmental stress, highlighting the role of the conserved cyclin C-Cdk8 kinase in determining pro-survival or pro-death programs. Specifically, it discusses how oxidative stress triggers the destruction of Med13 by the SCFGrr1 ubiquitin ligase, releasing cyclin C to promote mitochondrial fission and cell death in Saccharomyces cerevisiae. Additionally, it reveals that the AMP kinase Snf1 activates a separate degron in Med13, contributing to the complex regulation of Med13 degradation following H2O2 stress through the coordination of the cell wall integrity and MAPK pathways.
Importance of polyphosphate in the Leishmania life cycle
June 22, 2018
This article explores the importance of polyphosphate (polyP) in Leishmania parasites, emphasizing the role of the polyP polymerase VTC4 and its impact on parasite survival at higher temperatures. Additionally, it discusses the effects of VTC4 knockout in mouse infections, noting a delay in lesion formation and strong pathology in L. major VTC4 knockout, without confirmation through complementation and no alteration in L. guyanensis infections in mice with VTC4 knockdown.
Antagonism between salicylate and the cAMP signal controls yeast cell survival and growth recovery from quiescence
March 26, 2018
This article describes the effects of salicylate, the main metabolite of aspirin, on S. cerevisiae cells. It outlines how salicylate influences glucose transport, sugar phosphate biosynthesis, and apoptosis, particularly in MnSOD-deficient cells. Furthermore, it emphasizes the significant impact of salicylate on the exit from a quiescent state, inhibiting growth recovery and viability in long-term stationary phase cells. The passage also discusses the potential therapeutic implications of understanding the antagonistic relationship between cAMP and salicylate in targeting quiescent cancer cells with stem-like properties.
Evolution of substrate specificity in the Nucleobase-Ascorbate Transporter (NAT) protein family
March 22, 2018
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
March 21, 2018
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
March 7, 2018
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.
Spontaneous mutations in CYC8 and MIG1 suppress the short chronological lifespan of budding yeast lacking SNF1/AMPK
February 19, 2018
Chronologically aging yeast cells are prone to adaptive regrowth, whereby mutants with a survival advantage spontaneously appear and re-enter the cell cycle in stationary phase cultures. Here, Magani et al. identified specific downstream SNF1 targets responsible for CLS extension during CR.
Production of poly-β-1,6-N-acetylglucosamine by MatAB is required for hyphal aggregation and hydrophilic surface adhesion by Streptomyces
February 12, 2018
In this article van Dissel et al. describe new insights to allow better control of liquid-culture morphology of streptomycetes, which may be harnessed to improve growth and industrial exploitation of these highly versatile natural product and enzyme producers.
Impact of F1Fo-ATP-synthase dimer assembly factors on mitochondrial function and organismic aging
January 30, 2018
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.