Microreviews
Decoding the biosynthesis and function of diphthamide, an enigmatic modification of translation elongation factor 2 (EF2)
Raffael Schaffrath and Michael J. R. Stark
This article comments on work published by Uthman et al. (PLoS Genet, 2013), which suggests that Dph5 has a novel role as an EF2 inhibitor that affects cell growth when diphthamide synthesis is blocked or incomplete and shows that diphthamide promotes the accuracy of EF2 performance during translation.
Autophagy extends lifespan via vacuolar acidification
Christoph Ruckenstuhl1, Christine Netzberger1, Iryna Entfellner1, Didac Carmona-Gutierrez1, Thomas Kickenweiz1, Slaven Stekovic1, Christina Gleixner1, Christian Schmid1, Lisa Klug1, Ivan Hajnal1, Alice G. Sorgo1, Tobias Eisenberg1, Sabrina Büttner1, Guillermo Marin͂o2-4, Rafal Koziel5, Christoph Magnes6, Frank Sinner6,7, Thomas R. Pieber6,7, Pidder Jansen-Dürr5, Kai-Uwe Fröhlich1, Guido Kroemer2,3,8-11, and Frank Madeo1
This article comments on work published by Ruckenstuhl et al. (PLoS Genet, 2014), which uses Saccharomyces cerevisiae to show that autophagy promotes lifespan extension upon MetR and requires the subsequent stimulation of vacuolar acidification, while it is epistatic to the equally autophagy-dependent anti-aging pathway triggered by TOR1 inhibition or deletion.
Morphed and moving: TNFα-driven motility promotes cell dissemination through MAP4K4-induced cytoskeleton remodeling
Min Ma1,2 and Martin Baumgartner1
This article comments on work published by Ma and Baumgartner (PLoS Patho, 2014), which investigated Theileria parasite control of host cell motile properties in the context of inflammatory signaling.
Prokaryotic Argonautes – variations on the RNA interference theme
John van der Oost1, Daan C. Swarts1, Matthijs M. Jore1,2
This article comments on work published by Swarts et al. (Nature, 2014), which demonstrates that Argonaute family protein of the bacterium Thermus thermophilus acts as a barrier for the uptake and propagation of foreign DNA.
Secondary structures involving the poly(A) tail and other 3’ sequences are major determinants of mRNA isoform stability in yeast
Zarmik Moqtaderi#, Joseph V. Geisberg# and Kevin Struhl
This article comments on work published by Geisberg et al. (Cell (2014), which points to an important role for mRNA structure at 3’ termini in governing transcript stability, likely by reducing the interaction of the mRNA with the degradation apparatus.
De novo peroxisome biogenesis revisited
Marten Veenhuis and Ida J. van der Klei
This article comments on work published by Knoops et al. (JCB, 2014), which describes an alternative peroxisome formation pathway in yeast pex3 and pex19 cells, which relies on the existence of small peroxisomal remnants that are present in these cells.
Transcriptional and genomic mayhem due to aging-induced nucleosome loss in budding yeast
Zheng Hu1, Kaifu Chen2, Wei Li2 and Jessica K. Tyler2
This article comments on work published by Zheng et al. (Genes and Development, 2014), which investigated a loss of histones during replicative aging in budding yeast, which was also accompanied by a significantly-increased frequency of genomic instability including DNA breaks, chromosomal translocations, retrotransposition, and transfer of mitochondrial DNA into the nuclear genome.
The Parkinson’s disease-associated protein α-synuclein disrupts stress signaling – a possible implication for methamphetamine use?
Shaoxiao Wang1 and Stephan N. Witt1,2
This article comments on work published by Wang et al. (PNAS, 2012), which reported that human α-syn, at high expression levels, disrupts stress-activated signal transduction pathways in both yeast and human neuroblastoma cells. Disruption of these signaling pathways ultimately leads to vulnerability to stress and to cell death.
Massive gene swamping among cheese-making Penicillium fungi
Jeanne Ropars1,2, Gabriela Aguileta1,2,3, Damien M. de Vienne4,5 and Tatiana Giraud1,2
This article comments on work published by Cheeseman et al. (Nat Comm, 2014), which indicates that horizontal gene transfer is a crucial mechanism of rapid adaptation, even among eukaryotes.
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...