Microreviews
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.
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.
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.
Helicobacter hepaticus polysaccharide induces an anti-inflammatory response in intestinal macrophages
Camille Danne1 and Fiona Powrie1
In this article, the authors comment on the study "A Large Polysaccharide Produced by Helicobacter hepaticus Induces an Anti-inflammatory Gene Signature in Macrophages. " by Danne et al, (Cell Host Microbe 2017), discussing the interactions between H. hepaticus and intestinal macrophages that promote mutualism.
Endolysosomal pathway activity protects cells from neurotoxic TDP-43
Christine Leibiger1,#, Jana Deisel1,#, Andreas Aufschnaiter2, Stefanie Ambros1, Maria Tereshchenko1, Bert M. Verheijen3,4, Sabrina Büttner2,5, and Ralf J. Braun1
In this article, the authors comment on the study "TDP-43 controls lysosomal pathways thereby determining its own clearance and cytotoxicity" by Leibiger et al. (Hum Mol Genet, 2018), proposing that ameliorating endolysosomal pathway activity enhances cell survival in TDP‑43-associated diseases.
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.
Intracellular phase for an extracellular bacterial pathogen: MgtC shows the way
August 13, 2015
This article discusses the article "A macrophage subversion factor is shared by intracellular and extracellular pathogens" by Belon et al. (PLoS Pathogens 11(6): e1004969, 2015).
The role of transcriptional ‘futile cycles’ in autophagy and microbial pathogenesis
July 30, 2015
Eukaryotic cells utilize macroautophagy (hereafter autophagy) to recycle cellular materials during nutrient stress. Target of rapamycin (Tor) is a central regulator of this process, acting by post-translational mechanisms, phosphorylating preformed autophagy-related (Atg) proteins to repress autophagy during log-phase growth. A role for this regulatory process in fungal virulence was further demonstrated by showing that overexpression of the Dcp2-associated mRNA-binding protein Vad1 in the AIDS-associated pathogen Cryptococcus neoformans results in constitutive repression of autophagy even under starvation conditions as well as attenuated virulence in a mouse model. In summary, Tor-dependent post-transcriptional regulation of autophagy plays a key role in the facilitation of microbial pathogenesis.
Membrane depolarization-triggered responsive diversification leads to antibiotic tolerance
July 24, 2015
In this article, the authors discuss the article "Obg and membrane depolarization are part of a microbial bet-hedging strategy that leads to antibiotic tolerance", Verstraeten et al., Mol. Cell 2015 Jul 2; 59 (1): 9-21.
Evolutionary rewiring of bacterial regulatory networks
July 6, 2015
Bacteria have evolved complex regulatory networks that enable integration of multiple intracellular and extracellular signals to coordinate responses to environmental changes. However, our knowledge of how regulatory systems function and evolve is still relatively limited. There is often extensive homology between components of different networks, due to past cycles of gene duplication, divergence, and horizontal gene transfer, raising the possibility of cross-talk or redundancy. Consequently, evolutionary resilience is built into gene networks – homology between regulators can potentially allow rapid rescue of lost regulatory function across distant regions of the genome. This article discusses Taylor, et al. Science (2015), 347(6225), reporting mutations that facilitate cross-talk between pathways can contribute to gene network evolution, but which come with severe pleiotropic costs. Arising from this work are a number of questions surrounding how this phenomenon occurs.
Handcuffs for bacteria – NDP52 orchestrates xenophagy of intracellular Salmonella
May 21, 2015
This microreview discusses the article "Autophagy Receptor NDP52 Regulates Pathogen-Containing Autophagosome Maturation" by Verlhac et al. (2015), Cell Host Microbe.
Understanding grapevine-microbiome interactions: implications for viticulture industry
May 4, 2015
This microreview discusses the article "The soil microbiome influences grapevine-associated microbiota" by Zarraonaindia et al. (2015), MBio, which reports that the grapevine-associated microbiota depends on the soil microbiome.
Cytokinins beyond plants: synthesis by Mycobacterium tuberculosis
May 4, 2015
This microreview discusses "Proteasomal Control of Cytokinin Synthesis Protects Mycobacterium tuberculosis against Nitric Oxide" by Samanovic et al. (2015), Mol Cell.
Modeling non-hereditary mechanisms of Alzheimer disease during apoptosis in yeast
March 20, 2015
Impaired protein degradation and mitochondrial dysfunction are believed to contribute to neurodegenerative disorders, including Alzheimer disease (AD). This microreview comments on the article "Accumulation of Basic Amino Acids at Mitochondria Dictates the Cytotoxicity of Aberrant Ubiquitin" by Braun et al. (2015), Cell Rep.
New roles for autophagy and spermidine in T cells
March 2, 2015
This microreview discusses the article "Autophagy is a critical regulator of memory CD8+ T cell formation" by Puleston et al. (2014), eLife.
Characterization of the Maf family of polymorphic toxins in pathogenic Neisseria species
March 2, 2015
In addition to harmless commensal species, Neisseria genus encompasses two pathogenic species, N. meningitidis (the meningococcus) and N. gonorrhoeae (the gonococcus), which are responsible for meningitis and genital tract infections, respectively. This microreview comments on the article "A new family of secreted toxins in pathogenic Neisseria species" by Jamet et al. (2015), PLoS Pathog.