Microreviews
Burkholderia gladioli strain NGJ1 deploys a prophage tail-like protein for mycophagy
Rahul Kumar1, Sunil Kumar Yadav1, Durga Madhab Swain1 and Gopaljee Jha1
In this article, the authors comment on the study "A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi" by Swain et al. (Nature Communications, 2017), discussing that a prophage tail-like protein (Bg_9562) is essential for mycophagy. The protein may help the bacteria to survive in certain ecological niches and, considering its broad-spectrum antifungal activity, may be potentially useful in biotechnological applications to control fungal diseases.
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.
A new role for the nuclear basket network
Paola Gallardo1, Silvia Salas-Pino1 and Rafael R. Daga1
This article comments on work published by Salas-Pino et al. (J Cell Biol, 2017), which describes a novel function of the fission yeast nuclear basket component - the translocated promoter region (TPR) nucleoporin Alm1 - in proper localization of the proteasome to the nuclear envelope.
VAMP8 mucin exocytosis attenuates intestinal pathogenesis by Entamoeba histolytica
Steve Cornick1, France Moreau1, Herbert Y. Gaisano2, Kris Chadee1
This article comments on work published by Cornick et al. (mBio, 2017), which nominates SNARE-mediated exocytosis as the putative mechanism responsible for pathogen-induced mucus secretion from goblet cells.
Shutdown of interferon signaling by a viral-hijacked E3 ubiquitin ligase
Kaitlin A. Davis1 and John T. Patton2
This article comments on work published by Davis et al. (mBio, 2017), which describes molecular requirements that govern NSP1 recognition of β-TrCP, including an essential degron phosphorylation event, and the step-wise incorporation of NSP1 into hijacked cullin-RING E3 ligases (CRLs) that ubiquitinate and tag β-TrCP for degradation.
Breaking the bad: Bacillus blocks fungal virulence factors
François L. Mayer1 and James W. Kronstad1
This article comments on work published by Mayer & Kronstad (mBio, 2017), which identified the soil bacterium, Bacillus safensis as a potent inhibitor of virulence factor production by two major fungal pathogens of humans, Cryptococcus neoformans, and Candida albicans.
Macrophages as drivers of an opportunistic infection
Annette C. Vergunst1, Nazareth Lopez Carranza1, Lili Zhang1,2, Margarida C. Gomes1, Yara Tasrini1,
Annemarie H. Meijer3 and David O’Callaghan1
This article comments on work published by Mesureur et al. (PloS Pathog, 2017), which shows that macrophages are essential for proliferation of B. cenocepacia in the host. This suggests a new paradigm for Bcc infections and urges the development of novel anti-infectious therapies to efficiently disarm these intrinsically antibiotic resistant facultative intracellular pathogens.
Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi
November 4, 2015
Fungi, as every living organism, interact with the external world and have to adapt to its fluctuations. For pathogenic fungi, such interaction involves adapting to the hostile environment of their host. Survival depends on the capacity of fungi to detect and respond to external stimuli, which is achieved through a tight and efficient genetic control. Elías-Villalobos et al. propose that histone acetylation is critical to the proper timing and induction of transcription of the genes encoding factors that coordinate changes in morphology with pathogenesis.
Electron microscopy for ultrastructural analysis and protein localization in Saccharomyces cerevisiae
October 12, 2015
The yeast Saccharomyces cerevisiae is a key model system for studying of a multitude of cellular processes because of its amenability to genetics, molecular biology and biochemical procedures. The goal of this review is to guide researchers that want to investigate a particular process at the ultrastructural level in yeast by aiding in the selection of the most appropriate approach to visualize a specific structure or subcellular compartment.
Complex regulation of the sirtuin-dependent reversible lysine acetylation system of Salmonella enterica
October 12, 2015
The extensive involvement of the reversible lysine acylation (RLA) system in metabolism has attracted the attention of investigators interested in understanding the fundamentals of prokaryotic and eukaryotic cell function. Here the authors discuss the implications of recently reported work performed in the enteropathogen Salmonella enterica (mBio (2015) 6(4):e00891-15), which provided the first insights into the integration of the transcriptional regulation of genes encoding the RLA system with the acs gene encoding the central metabolic enzyme acetyl-CoA synthetase (Acs).
A bacterial volatile signal for biofilm formation
September 23, 2015
Bacteria constantly monitor the environment they reside in and respond to potential changes in the environment through a variety of signal sensing and transduction mechanisms in a timely fashion. In their recent study (Chen, et al. mBio (2015), 6: e00392-15), the authors demonstrated that the soil bacterium Bacillus subtilis uses acetic acid as a volatile signal to coordinate the timing of biofilm formation within physically separated cells in the community. They also showed that the bacterium possesses an intertwined gene network to produce, secrete, sense, and respond to acetic acid, in stimulating biofilm formation.
The great escape: Pseudomonas breaks out of the lung
September 23, 2015
The Gram-negative bacterium Pseudomonas aeruginosa is a major cause of hospital-acquired infections and the focus of much attention due to its resistance to many conventional antibiotics. This article discusses the potential mechanisms by which these processes occur as well as the novel techniques used to study ExoS function in vivo.
Peering into the ‘black box’ of pathogen recognition by cellular autophagy systems
August 22, 2015
Autophagy is an intracellular process that plays an important role in protecting eukaryotic cells and maintaining intracellular homeostasis. This review summarises the available evidence regarding the specific recognition of invading pathogens by which they are targeted into host autophagy pathways.
Per aspera ad astra: When harmful chromosomal translocations become a plus value in genetic evolution. Lessons from Saccharomyces cerevisiae
August 20, 2015
This review will focus on chromosomal translocations (either spontaneous or induced) in budding yeast. Indeed, very few organisms tolerate so well aneuploidy like Saccharomyces, allowing in depth studies on chromosomal numerical aberrations. The phenomenon of post-translocational adaptation (PTA) is discussed, providing some new unpublished data and proposing the hypothesis that translocations may drive evolution through adaptive genetic selection.
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.
The many facets of homologous recombination at telomeres
July 30, 2015
The ends of linear chromosomes are capped by nucleoprotein structures called telomeres. A dysfunctional telomere may resemble a DNA double-strand break (DSB), which is a severe form of DNA damage. The presence of one DSB is sufficient to drive cell cycle arrest and cell death. Therefore cells have evolved mechanisms to repair DSBs such as homologous recombination (HR). HR-mediated repair of telomeres can lead to genome instability, a hallmark of cancer cells, which is why such repair is normally inhibited. However, some HR-mediated processes are required for proper telomere function. The need for some recombination activities at telomeres but not others necessitates careful and complex regulation, defects in which can lead to catastrophic consequences. Furthermore, some cell types can maintain telomeres via telomerase-independent, recombination-mediated mechanisms. In humans, these mechanisms...