Vol. 05, 2018
Two distinct penicillin binding proteins promote cell division in different Salmonella lifestyles
Sónia Castanheira1, Juan J. Cestero1, Francisco García-del Portillo1, M. Graciela Pucciarelli1,2,3
In this article, the authors comment on the study "A Specialized Peptidoglycan Synthase Promotes Salmonella Cell Division inside Host Cells" by Castanheira et al. (mBio, 2017), discussing insights in two distinct penicillin binding proteins that promote cell division in different Salmonella lifestyles.
Production of poly-β-1,6-N-acetylglucosamine by MatAB is required for hyphal aggregation and hydrophilic surface adhesion by Streptomyces
Dino van Dissel1, Joost Willemse1, Boris Zacchetti1, Dennis Claessen1, Gerald B. Pier2, Gilles P. van Wezel1
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
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.
Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry yeast production
Esther Gamero-Sandemetrio1, Lucía Payá-Tormo1, Rocío Gómez-Pastor1,3, Agustín Aranda1,2 and Emilia Matallana1,2
Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. Here, Gamero-Sandemetrio et al. present findings that non-canonical regulation of glutathione and trehalose biosynthesis could cause poor fermentative performance after active dry yeast (ADY) production, as it corroborates the corrective effect of antioxidant treatments, during biomass propagation, with both pure chemicals and food-grade argan oil.
New perspectives from South-Y-East, not all about deathA report of the 12th lnternational Meeting on Yeast Apoptosis in Bari, Italy, May 14th-18th, 2017
Nicoletta Guaragnella1,#, Mariarita Stirpe2,#, William Burhans3, Manuela Côrte-Real4, Campbell Gourlay5, Paula Ludovico6,7, Frank Madeo8,9, Dina Petranovic10, Joris Winderickx11, Cristina Mazzoni2 and Sergio Giannattasio1
In this article Guaragnella et al. report on the 12th International Meeting on Yeast Apoptosis (IMYA12), which was held in Bari, Italy from May 14th to 18th, 2017, where more than 100 participants, among which senior and young scientists from Europe, USA, North Africa and Japan, had an intense and open exchange of achievements and ideas in the field of yeast regulated cell death (RCD).
Molecular signature of the imprintosome complex at the mating-type locus in fission yeast
Célia Raimondi1, Bernd Jagla2, Caroline Proux3, Hervé Waxin4, Serge Gangloff1, Benoit Arcangioli1
Genetic and molecular studies have indicated that an epigenetic imprint at mat1, the sexual locus of fission yeast, initiates mating type switching. Here, Raimondi et al. characterized the recruitment of early players of mating type switching at the mat1 region and suggest a nucleoprotein protective structure defined as imprintosome.
A novel system to monitor mitochondrial translation in yeast
Tamara Suhm1, Lukas Habernig2, Magdalena Rzepka1, Jayasankar Mohanakrishnan Kaimal3, Claes Andréasson3, Sabrina Büttner2,3 and Martin Ott1
In this study Suhm et al. present a novel system to monitor mitochondrial translation by detection of mitochondrial GFP-translation through fluorescence microscopy and flow cytometry in functional mitochondria. This novel tool allows the investigation of the function and regulation of mitochondrial translation during stress signaling, aging and mitochondrial biogenesis.
Retroviral integration site selection: a running Gag?
Paul Lesbats1,2,3 and Vincent Parissi1,2,3
In this article, the authors comment on the study "Structural basis for spumavirus GAG tethering to chromatin" by Lesbats et al. (Proc Natl Acad Sci, 2018) that revealed that the Gag protein of the spumaretrovirus prototype foamy virus (PFV) directly interacts with the nucleosome acidic patch, acting as a chromatin tether, and its disruption leads to delocalization of viral particles and integration sites, shedding light on the importance of retroviral structural proteins in the selection of integration sites.
A humanized yeast-based toolkit for monitoring phosphatidylinositol 3-kinase activity at both single cell and population levels
Julia María Coronas-Serna1, Teresa Fernández-Acero1, María Molina1 and Víctor J. Cid1
In this study, a humanized yeast system for functional studies on higher eukaryotic Phosphatidylinositol 3-kinase (PI3K) was developed by restricting PI3K activity in yeast to specific plasma membrane microdomains, utilizing engineered reporters to monitor activity at a single-cell level and employing novel tools to study the performance of yeast plasma membrane (PM) microdomain-directed PI3K, revealing location-specific effects on yeast growth and endocytosis.
Insights into the host-pathogen interaction: C. albicans manipulation of macrophage pyroptosis
Teresa R. O’Meara1 and Leah E. Cowen1
In this article, the authors comment on the study "High-Throughput Screening Identifies Genes Required for Candida albicans Induction of Macrophage Pyroptosis" by O’Meara et al. (MBio, 2018) that provides a comprehensive analysis of the genetic circuitry in both Candida albicans and host macrophages that leads to pyroptosis, revealing the impact of altered pyroptosis on infection, the role of pyroptosis in facilitating neutrophil accumulation at the site of C. albicans infection, and the decoupling of inflammasome priming and activation in the response to C. albicans infection, thus shedding new light on the factors governing the outcomes of this interaction.
A chemical genetic screen reveals a role for proteostasis in capsule and biofilm formation by Cryptococcus neoformans
François L. Mayer1, Eddy Sánchez-León1, James W. Kronstad1
This study demonstrates that the bipolar disorder drug lithium inhibits the formation of key virulence factors, biofilm, and polysaccharide capsule, in Cryptococcus neoformans by dysregulating the ubiquitin/proteasome system, shedding light on the impact of lithium and providing insights into potential alternative pharmaceutical approaches for combating this fungal pathogen.
A comparative approach to decipher intestinal animal-microbe associations
Keisuke Nakashima1
In this article, the authors comment on the study "Chitin-based barrier immunity and its loss predated mucus-colonization by indigenous gut microbiota" by Nakashima et al. (Nat Commun, 2018) that used comparative analyses of chordates to investigate the development of animal-microbe associations, suggesting that microbial colonization of the mucus layer over mammalian gastrointestinal epithelium was established upon the loss of ancestral chitin-based barrier immunity, providing insights into the establishment of these associations in an evolutionary context.
Nutritional and meiotic induction of transiently heritable stress resistant states in budding yeast
Heldder Gutierrez1, Bakhtiyar Taghizada1, and Marc D. Meneghini1
This study demonstrates that transient exposures to environmental stresses induce persistent states of elevated stress resistance in yeast cells, termed cellular memory, suggesting a form of epigenetic inheritance, and shows that this phenomenon occurs not only in meiotically produced spores but also in haploid cells subjected to glucose withdrawal, adding new insights into the developmentally and nutritionally induced cellular memory.
A novel basolateral type IV secretion model for the CagA oncoprotein of Helicobacter pylori
Silja Wessler1 and Steffen Backert2
In this article, the authors comment on the study "Helicobacter pylori Employs a Unique Basolateral Type IV Secretion Mechanism for CagA Delivery" by Tegtmeyer et al. (Cell Host Microbe, 2017), discussing that the finding of a T4SS receptor suggests the presence of a sophisticated control mechanism for the injection of CagA and the possible impact of this novel signaling cascade on pathogenesis during infection with Helicobacter pylori.
Exploring the mechanism of amebic trogocytosis: the role of amebic lysosomes
Allissia A. Gilmartin1 and William A. Petri, Jr1,2,3
In this article, the authors comment on the study "Inhibition of Amebic Lysosomal Acidification Blocks Amebic Trogocytosis and Cell Killing" by Gilmartin et al. (MBio, 2017), discussing the the role of amebic lysosomes in Trogocytosis, the intracellular transfer of fragments of cell material.
Gammaretroviruses tether to mitotic chromatin by directly binding nucleosomal histone proteins
July 24, 2018
In this article, the authors comment on the study "Murine leukemia virus p12 tethers the capsid-containing pre-integration complex to chromatin by binding directly to host nucleosomes in mitosis" by Wanaguruet al. (PLoS Pathog, 2018) that highlights the essential role of the gammaretroviral gag cleavage product, p12, at both early and late stages of the virus life cycle, particularly in the integration of the viral DNA into the host cell chromatin to form a provirus. It also emphasizes the recent findings regarding the N- and C-terminal domains of p12, revealing their direct binding to the viral capsid lattice and nucleosomal histone proteins, respectively, thus elucidating the mechanism by which p12 links the viral pre-integration complex to mitotic chromatin.
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.
Methodologies for in vitro and in vivo evaluation of efficacy of antifungal and antibiofilm agents and surface coatings against fungal biofilms
June 14, 2018
This article highlights the critical importance of accurate susceptibility testing methods and the discovery of novel antifungal and antibiofilm agents in combating invasive fungal infections associated with biofilm formation on medical devices, thereby emphasizing the need for advancements in medical mycology research to address these complex diseases.
Shepherding DNA ends: Rif1 protects telomeres and chromosome breaks
May 17, 2018
This review discusses the conserved mechanisms cells have evolved to protect DNA ends at chromosomal termini and DNA double-strand breaks (DSBs), focusing on the protein Rif1’s roles in telomere homeostasis and DSB repair in eukaryotes. It highlights the intriguing connection between Rif1's involvement in both telomere maintenance and DSB repair, and suggests that excluding end-processing factors may underlie Rif1's diverse biological functions at telomeres and chromosome breaks.
The CRISPR conundrum: evolve and maybe die, or survive and risk stagnation
May 16, 2018
In this article García-Martínez et al. cover how the model bacterium Escherichia coli deals with CRISPR-Cas to tackle the major dilemma of evolution versus survival.
Microbial wars: competition in ecological niches and within the microbiome
May 7, 2018
In this Editorial Bauer et al. provide a brief overview on microbial competition and discuss some of its roles and consequences that directly affect humans.
Metabolic disharmony and sibling conflict mediated by T6SS
April 4, 2018
In this article, the authors comment on the study "Physiological Heterogeneity Triggers Sibling Conflict Mediated by the Type VI Secretion System in an Aggregative Multicellular Bacterium" by Troselj et al. (MBio, 2018) discussing that M. xanthus uses T6SS to eliminate less fit cells from their population and identified toxic effector and cognate immunity protein (TsxEI) that mediates this sibling antagonism.
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.
Microbial wars: competition in ecological niches and within the microbiome
Maria A. Bauer1, Katharina Kainz1, Didac Carmona-Gutierrez1 and Frank Madeo1,2
In this Editorial Bauer et al. provide a brief overview on microbial competition and discuss some of its roles and consequences that directly affect humans.