Vol. 06, 2019
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.
Tribal warfare: Commensal Neisseria kill pathogen Neisseria gonorrhoeae using its DNA
Magdalene So1 and Maria A. Rendón1
This article comments on work published by Kim et al (Cell Host Microbe, 2019), which adds a new dimension to the concept of commensal protection. It shows that commensal Neisseria kill the closely related pathogen N. gonorrhoeae through an unexpected mechanism, one that involves genetic competence, DNA methylation state and recombination.
Yet another job for the bacterial ribosome
Andrea Origi1,2, Ana Natriashivili1,2, Lara Knüpffer1, Clara Fehrenbach1, Kärt Denks1,2, Rosella Asti1 and Hans-Georg Koch1
This article comments on work published by Knüpffer et al (mBio, 2019), which revealed the intricate interaction of uL23 with yet another essential player in bacteria, the ATPase SecA, which is best known for its role during post-translational secretion of proteins across the bacterial SecYEG translocon
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.
Gut microbial metabolites in depression: understanding the biochemical mechanisms
Giorgia Caspani1, Sidney Kennedy2-5, Jane A. Foster6 and Jonathan Swann1
This article shows how the gut microbiota contributes to the pathophysiology of depression and examines the mechanisms by which microbially-derived molecules may influence depressive behavior, highlighting the potential of dietary interventions as novel therapeutic strategies.
The multiple functions of the numerous Chlamydia trachomatis secreted proteins: the tip of the iceberg
Joana N. Bugalhão1 and Luís Jaime Mota1
CThis article shows an in-depth review on the current knowledge and outstanding questions about secreted proteins from Chlamydia trachomatis, detailing their roles in host cell interaction and immune response evasion.
Forty-five-year evolution of probiotic therapy
Scarlett Puebla-Barragan1,2 and Gregor Reid1,2
The field of probiotics has greatly expanded over the past 45 years, driven by the need for safer alternatives to drugs, interest in natural microbial products, and clinical proof of effectiveness, with scientific formulations increasingly defining the market and promising applications for various health areas expected in the future.
Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release
Alexandre Légiot1, Claire Céré1, Thibaud Dupoiron1, Mohamed Kaabouni1, Nadine Camougrand1 and Stéphen Manon1
This study investigated the role of Mitochondria-Associated Membranes (MAMs) in the regulation of apoptosis by analyzing the localization and function of the pro-apoptotic protein Bax in yeast, finding that disruption of MAMs by deletion of the MDM34 gene affects Bax's mitochondrial localization and the release of cytochrome c.
Chlamydia pneumoniae is present in the dental plaque of periodontitis patients and stimulates an inflammatory response in gingival epithelial cells
Cássio Luiz Coutinho Almeida-da-Silva1, Tamer Alpagot2, Ye Zhu1, Sonho Sierra Lee3,4, Brian P. Roberts5, Shu-Chen Hung1, Norina Tang1,2 and David M. Ojcius1
This study found that Chlamydia pneumoniae is present more frequently in the dental plaque of individuals with periodontal disease, can invade human gingival epithelial cells causing inflammatory responses, and may therefore be a contributing factor to periodontal disease and a potential indicator of risk.
Role of pheromone recognition systems in creating new species of fission yeast
Taisuke Seike1 and Chikashi Shimoda2
This article comments on work published by Seike at al. (PloS Biol., 2019), which demonstrated an “asymmetric” pheromone recognition system in the fission yeast Schizosaccharomyces pombe.
Adaptive bacterial response to low level chlorhexidine exposure and its implications for hand hygiene
Günter Kampf1
This article shows that bacteria can adapt to low levels of Chlorhexidine digluconate (CHG), resulting in increased tolerance and cross-resistance to other antimicrobials, suggesting caution in the widespread use of CHG to minimize avoidable selection pressure for resistance.
Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection
Pedro Pais1,2,#, Mónica Galocha1,2,#, Romeu Viana1,2, Mafalda Cavalheiro1,2, Diana Pereira1,2, Miguel Cacho Teixeira1,2
This review explores how Candida albicans and Candida glabrata, common fungal pathogens resistant to antifungal therapy, adapt and evolve within different environments, aiming to identify stable adaptive mechanisms as potential drug targets.
Adaptive bacterial response to low level chlorhexidine exposure and its implications for hand hygiene
Günter Kampf1
This article shows that bacteria can adapt to low levels of Chlorhexidine digluconate (CHG), resulting in increased tolerance and cross-resistance to other antimicrobials, suggesting caution in the widespread use of CHG to minimize avoidable selection pressure for resistance.
Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection
Pedro Pais1,2,#, Mónica Galocha1,2,#, Romeu Viana1,2, Mafalda Cavalheiro1,2, Diana Pereira1,2, Miguel Cacho Teixeira1,2
This review explores how Candida albicans and Candida glabrata, common fungal pathogens resistant to antifungal therapy, adapt and evolve within different environments, aiming to identify stable adaptive mechanisms as potential drug targets.
The extracellular matrix of mycobacterial biofilms: could we shorten the treatment of mycobacterial infections?
Poushali Chakraborty1 and Ashwani Kumar1, 2
The article discusses the challenges presented by biofilms formed by non-tuberculous mycobacteria (NTM) species, which can lead to persistent infections that are difficult to treat due to phenotypic drug tolerance. The role of various cell wall components in mycobacterial biofilm formation is outlined, with a particular focus on Mycobacterium tuberculosis.
Guidelines for DNA recombination and repair studies: Cellular assays of DNA repair pathways
Hannah L. Klein1, Giedrė Bačinskaja2, Jun Che3, Anais Cheblal4, Rajula Elango5, Anastasiya Epshtein1, Devon M. Fitzgerald6-9, Belén Gómez-González10, Sharik R. Khan11, Sandeep Kumar7, Bryan A. Leland12, Léa Marie13, Qian Mei14, Judith Miné-Hattab16,17, Alicja Piotrowska18, Erica J. Polleys19, Christopher D. Putnam20,21, Elina A. Radchenko19, Anissia Ait Saada22,23, Cynthia J. Sakofsky24, Eun Yong Shim3, Mathew Stracy25, Jun Xia6-9, Zhenxin Yan7, Yi Yin26, Andrés Aguilera10, Juan Lucas Argueso27, Catherine H. Freudenreich19,28, Susan M. Gasser4, Dmitry A. Gordenin24, James E. Haber29, Grzegorz Ira7, Sue Jinks-Robertson30, Megan C. King12, Richard D. Kolodner20, 31-33, Andrei Kuzminov11, Sarah AE Lambert22,23, Sang Eun Lee3, Kyle M. Miller6,15, Sergei M. Mirkin19, Thomas D. Petes26, Susan M. Rosenberg6-9,14, Rodney Rothstein34, Lorraine S. Symington13, Pawel Zawadzki18, Nayun Kim35, Michael Lisby2 and Anna Malkova5
DNA recombination, repair and mutagenesis assays are powerful tools but each comes with its particular advantages and limitations. Here the most commonly used assays are reviewed, discussed, and presented as the guidelines for future studies.
Guidelines for DNA recombination and repair studies: Mechanistic assays of DNA repair processes
Hannah L Klein1, Kenny K.H. Ang2, Michelle R. Arkin2, Emily C. Beckwitt3,4, Yi-Hsuan Chang5, Jun Fan6, Youngho Kwon7,8, Michael J. Morten1, Sucheta Mukherjee9, Oliver J. Pambos6, Hafez el Sayyed6, Elizabeth S. Thrall10, João P. Vieira-da-Rocha9, Quan Wang11, Shuang Wang12,13, Hsin-Yi Yeh5, Julie S. Biteen14, Peter Chi5,15, Wolf-Dietrich Heyer9,16, Achillefs N. Kapanidis6, Joseph J. Loparo10, Terence R. Strick12,13,17, Patrick Sung7,8, Bennett Van Houten3,18,19, Hengyao Niu11 and Eli Rothenberg1
Mechanistic assays of DNA repair processes are a powerful tools but each comes with its particular advantages and limitations. Here the most commonly used assays are reviewed, discussed, and presented as the guidelines for future studies.
Imbalance in gut microbes from babies born to obese mothers increases gut permeability and myeloid cell adaptations that provoke obesity and NAFLD
Taylor K. Soderborg1 and Jacob E. Friedman1,2,3
This article comments on work published by Soderborg et al. (Nat Commun, 2018), which demonstrates a causative role of early life microbiome dysbiosis in infants born to mothers with obesity in novel pathways that promote developmental programming of NAFLD.
Sulfur dioxide resistance in Saccharomyces cerevisiae: beyond SSU1
Estéfani García-Ríos1 and José Manuel Guillamón1
This article discusses the importance of understanding sulfite resistance in Saccharomyces cerevisiae due to its use in winemaking and the potential role of the transcription factor Com2. While the SSU1 gene and its activity have been correlated with sulfite tolerance, the work by Lage et al. (2019) indicates that Com2 might control a large percentage of the genes activated by SO2 and contribute to the yeast's protective response, offering new insights into the molecular factors influencing this oenological trait.
Targeting GATA transcription factors – a novel strategy for anti-aging interventions?
Andreas Zimmermann1, Katharina Kainz1,2, Sebastian J. Hofer1,3, Maria A. Bauer1, Sabrina Schroeder1, Jörn Dengjel4, Federico Pietrocola5, Oliver Kepp6-9, Christoph Ruckenstuhl1, Tobias Eisenberg1,3,10,11, Stephan J. Sigrist12, Frank Madeo1,3,10, Guido Kroemer6-9, 13-15 and Didac Carmona-Gutierrez1
This article comments on work published by Carmona-Gutierrez et al. (Nat Commun., 2019), which identified a natural compound, 4,4'-dimethoxychalcone, inducing autophagy and prolonging lifespan in different organisms through a mechanism that involves GATA transcription factors.
In the beginning was the word: How terminology drives our understanding of endosymbiotic organelles
Miroslav Oborník 1,2
This In the Pit article argues that the naming conventions for biological entities influence research perspectives and methodologies, advocating for mitochondria and plastids to be classified and named as bacteria due to their endosymbiotic origins, with potential implications for our understanding of bacterial prevalence, definitions of the microbiome and multicellularity, and the concept of endosymbiotic domestication.
What’s in a name? How organelles of endosymbiotic origin can be distinguished from endosymbionts
Ansgar Gruber1
This In the Pit article suggests redefining the relationship between hosts and endosymbionts, like mitochondria and plastids, as a single species based on "sexual symbiont integration," the loss of independent speciation, and congruence in genetic recombination and population sizes, rather than solely on historic classifications or structural properties.
Diverse conditions support near-zero growth in yeast: Implications for the study of cell lifespan
August 20, 2019
This review discusses alternative cultivation methods for baker's yeast to study its chronological lifespan, with the aim of better understanding the ageing of non-dividing cells and their potential implications for the lifespan of multicellular eukaryotes such as humans.
Evolution of the bacterial nucleosidase PpnN and its relation to the stringent response
July 16, 2019
This article comments on work published by Zhang et al (Mol Cell, 2019), which discovered an interesting mode of regulation of purine metabolism unique to Proteobacteria.
Integrins in disguise – mechanosensors in Saccharomyces cerevisiae as functional integrin analogues
July 15, 2019
This article shows that although yeast lack integrin-like proteins, they possess WSC- and MID-type mechanosensors that functionally resemble integrins in animal cells, playing a role in sensing external mechanical stimuli and activating the conserved PKC1-SLT1 cell wall integrity pathway, with potential implications for understanding mechanosensing in yeast biology.
Network dynamics of the yeast methyltransferome
July 9, 2019
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.
Bacterial maze runners reveal hidden diversity in chemotactic performance
July 1, 2019
This article comments on work published by Salek et al. (Nat Commun, 2019), which combined microfluidic experiments with mathematical modeling to demonstrate that even in clonal populations, bacteria are individuals with different abilities to climb chemical gradients.
Laundry and textile hygiene in healthcare and beyond
July 1, 2019
This article shows that while institutional laundering is regulated to ensure hygiene, the trend towards energy-efficient washing at lower temperatures raises concerns about the antimicrobial efficacy of domestic laundering, with a focus on addressing microbial contamination in both clinical and home settings.
Bacterial pathogens under high-tension: Staphylococcus aureus adhesion to von Willebrand factor is activated by force
June 11, 2019
This article comments on work published by Viela et al (mBio, 2019), which shows that the bacterial cell surface protein A to the large plasma glycoprotein von Willebrand factor interaction is tightly regulated by mechanical force.
Yeast AP-1 like transcription factors (Yap) and stress response: a current overview
May 28, 2019
This review summarizes current understanding of the eight Yap transcription factors in Saccharomyces cerevisiae, detailing their activation by specific stress conditions and discussing their function and evolution across various fungal species.
Septin clearance from the division site triggers cytokinesis in budding yeast
May 22, 2019
This article comments on work published by Tamborrini et al (Nat Commun., 2019), which shows that septin displacement during splitting is an essential prerequisite for contractile actomyosin ring constriction during mitosis.
Sulfur dioxide resistance in Saccharomyces cerevisiae: beyond SSU1
Estéfani García-Ríos1 and José Manuel Guillamón1
This article discusses the importance of understanding sulfite resistance in Saccharomyces cerevisiae due to its use in winemaking and the potential role of the transcription factor Com2. While the SSU1 gene and its activity have been correlated with sulfite tolerance, the work by Lage et al. (2019) indicates that Com2 might control a large percentage of the genes activated by SO2 and contribute to the yeast's protective response, offering new insights into the molecular factors influencing this oenological trait.