Microreviews
Divide and conquer: processive transport enables multidrug transporters to tackle challenging drugs
Nir Fluman and Eitan Bibi
This article comments on work published by Fluman et al. (Nat Comm, 2014), which describes the ability of bacterial multidrug transporters to move long molecules through the membrane in a processive manner.
Combinatorial stress responses: direct coupling of two major stress responses in Escherichia coli
Daniel R. Brown, Geraint Barton, Zhensheng Pan, Martin Buck and Sivaramesh Wigneshweraraj
This article comments on work published by Brown et al. (Nat Comm, 2014), which showed that the transcription of relA is activated by NtrC during nitrogen starvation, revealing that in E. coli and related bacteria, NtrC functions in combinatorial stress and serves to couple two major stress responses, the Ntr response and stringent response.
The replication timing program in the hands of two HDACs
Kazumasa Yoshida1,2, Armelle Lengronne1 and Philippe Pasero1
This article comments on work published by Yoshida et al. (Mol Cell, 2014), which performed a systematic analysis of the role of histone deacetylases (HDACs) in the regulation of origin activity in budding yeast, finding that the epigenetic regulation of repetitive sequences is a key determinant of the DNA replication program.
Increased Trypanosoma brucei cathepsin-L activity inhibits human serum-mediated trypanolysis
Sam Alsford
This article comments on work published by Alsford et al. (PLoS Pathogens, 2014), which identified a Trypanosoma brucei lysosomal cathepsin with an inhibitory effect on human serum’s trypanolytic action.
A novel role of centrin in flagellar motility: stabilizing an inner-arm dynein motor in the flagellar axoneme
Ziyin Li
This article comments on work published by Wei et al. (Nat Comm, 2014), which discovered that centrin maintains the stability of an inner-arm dynein in the flagellar axoneme in Trypanosoma brucei.
A non-proteolytic function of ubiquitin in transcription repression
Ada Ndoja and Tingting Yao
This article comments on work published by Ndoja et al. (Mol Cell, 2014), which demonstrates that monoubiquitination of some transcription activators can inhibit transcription by recruiting the AAA+ ATPase Cdc48 (also known in metazoans as p97 or VCP), which then extracts the ubiquitinated activator from DNA.
Mutagenesis by host antimicrobial peptides: insights into microbial evolution during chronic infections
Dominique H. Limoli and Daniel J. Wozniak
This article comments on work published by Limoli et al. ((PLoS Pathogens, 2014), which provides evidence that at subinhibitory levels, AMPs promote mutations in bacterial DNA, which enhance bacterial survival.
Where antibiotic resistance mutations meet quorum-sensing
Rok Krašovec1, Roman V. Belavkin2, John A.D. Aston3, Alastair Channon4, Elizabeth Aston4, Bharat M. Rash1, Manikandan Kadirvel5,6, Sarah Forbes6, and Christopher G. Knight1
This article comments on work published by Krašovec et al. (Nat Comm, 2014), which found that the modulation of de novo mutation to promote antibiotic resistance depends on the density of the bacterial population and cell-cell interactions (rather than, for instance, the level of stress).
Genome evolution in yeast reveals connections between rare mutations in human cancer
Xinchen Teng1,2 and J. Marie Hardwick2
This article comments on work published by Teng et al. (Mol Cell, 2013), which, using the yeast knockout collections, provides hard evidence that single gene deletions/mutations in most non-essential genes can drive the selection for cancer-like mutations.
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...