Vol. 05, 2018

A versatile plasmid system for reconstitution and analysis of mammalian ubiquitination cascades in yeast

Rossella Avagliano Trezza1,#, Janny van den Burg1, Nico van den Oever1 and Ben Distel1,2

In this article Avagliano Trezza et al. describe a versatile vector system that allows the reconstitution of specific ubiquitination cascades in the model eukaryote Saccharomyces cerevisae (baker’s yeast) that provides a versatile tool to study complex post-translational modifications in a cellular setting.

Alcohols enhance the rate of acetic acid diffusion in S. cerevisiae : biophysical mechanisms and implications for acetic acid tolerance

Lina Lindahl1, Samuel Genheden2, Fábio Faria-Oliveira1, Stefan Allard3, Leif A. Eriksson2, Lisbeth Olsson1, Maurizio Bettiga1,4

Microbial cell factories with the ability to maintain high productivity in the presence of weak organic acids, such as acetic acid, are required in many industrial processes. This study demonstrates that the rate of acetic acid diffusion can be strongly affected by compounds that partition into the cell membrane, and highlights the need for considering interaction effects between compounds in the design of microbial processes.

Untargeted metabolomics confirms and extends the understanding of the impact of aminoimidazole carboxamide ribotide (AICAR) in the metabolic network of Salmonella enterica

Jannell V. Bazurto1, Stephen P. Dearth2, Eric D. Tague2, Shawn R. Campagna2 and Diana M. Downs1

In Salmonella enterica, aminoimidazole carboxamide ribotide (AICAR) is a purine biosynthetic intermediate and a substrate of the AICAR transformylase/IMP cyclohydrolase (PurH) enzyme. Data herein describe the use of metabolomics to identify the metabolic state of mutant strains and probe the underlying mechanisms used by AICAR to inhibit thiamine synthesis. The results obtained provide a cautionary tale of using metabolite concentrations as the only data to define the physiological state of a bacterial cell.

The cytosolic glyoxalases of Plasmodium falciparum are dispensable during asexual blood-stage development

Cletus A. Wezena1, Romy Alisch1, Alexandra Golzmann2, Linda Liedgens1, Verena Staudacher1,3, Gabriele Pradel2 and Marcel Deponte1,3

In this study the authors demonstrate that, PfGlo1 and PfcGlo2 are dispensable during asexual blood-stage development while the loss of PfcGlo2 may induce the formation of transmissible gametocytes. These combined data show that PfGlo1 and PfcGlo2 are most likely not suited as targets for selective drug development against the malaria parasite Plasmodium falciparum.

Previous

A versatile plasmid system for reconstitution and analysis of mammalian ubiquitination cascades in yeast

Rossella Avagliano Trezza1,#, Janny van den Burg1, Nico van den Oever1 and Ben Distel1,2

In this article Avagliano Trezza et al. describe a versatile vector system that allows the reconstitution of specific ubiquitination cascades in the model eukaryote Saccharomyces cerevisae (baker’s yeast) that provides a versatile tool to study complex post-translational modifications in a cellular setting.

Alcohols enhance the rate of acetic acid diffusion in S. cerevisiae : biophysical mechanisms and implications for acetic acid tolerance

Lina Lindahl1, Samuel Genheden2, Fábio Faria-Oliveira1, Stefan Allard3, Leif A. Eriksson2, Lisbeth Olsson1, Maurizio Bettiga1,4

Microbial cell factories with the ability to maintain high productivity in the presence of weak organic acids, such as acetic acid, are required in many industrial processes. This study demonstrates that the rate of acetic acid diffusion can be strongly affected by compounds that partition into the cell membrane, and highlights the need for considering interaction effects between compounds in the design of microbial processes.

Untargeted metabolomics confirms and extends the understanding of the impact of aminoimidazole carboxamide ribotide (AICAR) in the metabolic network of Salmonella enterica

Jannell V. Bazurto1, Stephen P. Dearth2, Eric D. Tague2, Shawn R. Campagna2 and Diana M. Downs1

In Salmonella enterica, aminoimidazole carboxamide ribotide (AICAR) is a purine biosynthetic intermediate and a substrate of the AICAR transformylase/IMP cyclohydrolase (PurH) enzyme. Data herein describe the use of metabolomics to identify the metabolic state of mutant strains and probe the underlying mechanisms used by AICAR to inhibit thiamine synthesis. The results obtained provide a cautionary tale of using metabolite concentrations as the only data to define the physiological state of a bacterial cell.

The cytosolic glyoxalases of Plasmodium falciparum are dispensable during asexual blood-stage development

Cletus A. Wezena1, Romy Alisch1, Alexandra Golzmann2, Linda Liedgens1, Verena Staudacher1,3, Gabriele Pradel2 and Marcel Deponte1,3

In this study the authors demonstrate that, PfGlo1 and PfcGlo2 are dispensable during asexual blood-stage development while the loss of PfcGlo2 may induce the formation of transmissible gametocytes. These combined data show that PfGlo1 and PfcGlo2 are most likely not suited as targets for selective drug development against the malaria parasite Plasmodium falciparum.

Previous

Toxin release mediated by the novel autolysin Cwp19 in Clostridium difficile

Imane El Meouche1 and Johann Peltier2,3

In this article, the authors comment on the study "Cwp19 is a novel lytic transglycosylase involved in stationary-phase autolysis resulting in toxin release in Clostridium difficile" by Wydau-Dematteis (MBio, 2018) that characterizes a novel peptidoglycan hydrolase, Cwp19, in Clostridioides difficile, highlighting its glucose-dependent mediation of toxins secretion and suggesting a potential role in the pathogenesis of this bacterium, contributing to the understanding of these enzymes in C. difficile and their implication in pathogenicity.

Escherichia coli hijack Caspr1 receptor to invade cerebral vascular and neuronal hosts

Wei-Dong Zhao1, Dong-Xin Liu1, Yu-Hua Chen1

In this article, the authors comment on the study "Caspr1 is a host receptor for meningitis-causing Escherichia coli" by Zhao et al. (Nat Commun, 2ß18) that identified Caspr1 as a key host receptor for E. coli virulence factor IbeA, facilitating E. coli penetration through the blood-brain barrier (BBB). The research demonstrated that targeting the interaction between IbeA and Caspr1 could potentially neutralize E. coli virulence and prevented meningitis, shedding light on the mechanisms of bacterial invasion into brain endothelial cells and hippocampal neurons.

A global view of substrate phosphorylation and dephosphorylation during budding yeast mitotic exit

Sandra A. Touati1 and Frank Uhlmann1

In this article, the authors comment on the study "Phosphoproteome dynamics during mitotic exit in budding yeast" by Touati (EMBO J, 2018) that described a time-resolved global phosphoproteome analysis during a cell cycle phase known as mitotic exit in budding yeast revealed the principles of phosphoregulation governing the ordered sequence of events such as spindle elongation, chromosome decondensation, and completion of cell division.

Gammaretroviruses tether to mitotic chromatin by directly binding nucleosomal histone proteins

Madushi Wanaguru1 and Kate N. Bishop1

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.

Methodologies for in vitro and in vivo evaluation of efficacy of antifungal and antibiofilm agents and surface coatings against fungal biofilms

Patrick Van Dijck1,2,‡, Jelmer Sjollema3,‡, Bruno P.A. Cammue4,5, Katrien Lagrou6,7, Judith Berman8, Christophe d’Enfert9, David R. Andes10,11, Maiken C. Arendrup12-14, Axel A. Brakhage15, Richard Calderone16, Emilia Cantón17, Tom Coenye18,19, Paul Cos20, Leah E. Cowen21, Mira Edgerton22, Ana Espinel-Ingroff23, Scott G. Filler24, Mahmoud Ghannoum25, Neil A.R. Gow26, Hubertus Haas27, Mary Ann Jabra-Rizk28, Elizabeth M. Johnson29, Shawn R. Lockhart30, Jose L. Lopez-Ribot31, Johan Maertens32, Carol A. Munro26, Jeniel E. Nett33, Clarissa J. Nobile34, Michael A. Pfaller35,36, Gordon Ramage19,37, Dominique Sanglard38, Maurizio Sanguinetti39, Isabel Spriet40, Paul E. Verweij41, Adilia Warris42, Joost Wauters43, Michael R. Yeaman44, Sebastian A.J. Zaat45, Karin Thevissen4,*

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

Gabriele A. Fontana1, Julia K. Reinert1,2, Nicolas H. Thomä1, Ulrich Rass1

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

Jesús García-Martínez1, Rafael D. Maldonado1, Noemí M. Guzmán1 and Francisco J. M. Mojica1,2

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.

A novel mechanism for regulation of the type I IFN response by herpesvirus deconjugases

Soham Gupta1, Päivi Ylä-Anttila1, Maria G. Masucci1

In this article, the authors comment on the study "Herpesvirus deconjugases inhibit the IFN response by promoting TRIM25 autoubiquitination and functional inactivation of the RIG-I signalosome" by Gupta et al. (PLoS Pathog, 2018), discussing the finding of a novel mechanism for regulation of the type I IFN response by herpesvirus deconjugases.

Metabolic disharmony and sibling conflict mediated by T6SS

Vera Troselj1 and Daniel Wall1

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.

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.

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.

A novel mechanism for regulation of the type I IFN response by herpesvirus deconjugases

April 11, 2018

In this article, the authors comment on the study "Herpesvirus deconjugases inhibit the IFN response by promoting TRIM25 autoubiquitination and functional inactivation of the RIG-I signalosome" by Gupta et al. (PLoS Pathog, 2018), discussing the finding of a novel mechanism for regulation of the type I IFN response by herpesvirus deconjugases.

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.