Review, Reviews
Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi
Alberto Elías-Villalobos1,2, Dominique Helmlinger2 and José I. Ibeas1
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
Andri Frankl, Muriel Mari and Fulvio Reggiori
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
Kristy L. Hentchel1,2 and Jorge C. Escalante-Semerena1
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
Yun Chen2, Kevin Gozzi1, and Yunrong Chai1
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
Angelica Zhang1, Stephanie M. Rangel1, and Alan R. Hauser1,2
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
Shu-chin Lai# and Rodney J Devenish
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
Valentina Tosato and Carlo V. Bruschi
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
Audrey Bernut1,#, Claudine Belon1, Chantal Soscia2, Sophie Bleves2, Anne-Béatrice Blanc-Potard1
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
Guowu Hu1, Travis McQuiston1, Amélie Bernard2, Yoon-Dong Park1, Jin Qiu1, Ali Vural3, Nannan Zhang1, Scott R. Waterman1, Nathan H. Blewett4, Timothy G. Myers5, John H. Kehrl3, Gulbu Uzel1, Daniel J. Klionsky2 and Peter R. Williamson1
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.
When less is more: hormesis against stress and disease
May 5, 2014
This article condenses the conceptual and potentially therapeutic importance of hormesis by providing a short overview of current evidence in favor of the cytoprotective impact of hormesis, as well as of its underlying molecular mechanisms.
Morphed and moving: TNFα-driven motility promotes cell dissemination through MAP4K4-induced cytoskeleton remodeling
April 24, 2014
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.
Hormesis: a fundamental concept in biology
April 23, 2014
This article addresses the concept of hormetic dose response, which describes the limits to which integrative endpoints can be modulated (i.e., enhanced or diminished) by pharmaceutical, chemical and physical means.
Live longer on MARS: a yeast paradigm of mitochondrial adaptive ROS signaling in aging
April 23, 2014
In this article, the potential relevance of Mitochondrial Adaptive ROS Signaling (MARS) to the human disease Ataxia-Telangiectasia and as a potential anti-aging target is discussed.
Prokaryotic Argonautes – variations on the RNA interference theme
April 15, 2014
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.
Longevity pathways and maintenance of the proteome: the role of autophagy and mitophagy during yeast ageing
April 7, 2014
This review describes recent findings that shed light on how longevity pathways and metabolic status impact maintenance of the proteome in both yeast ageing paradigms. These findings demonstrate that yeast remain a powerful model system for elucidating these relationships and their influence on ageing regulation.
Secondary structures involving the poly(A) tail and other 3’ sequences are major determinants of mRNA isoform stability in yeast
April 5, 2014
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
April 1, 2014
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
April 1, 2014
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?
March 31, 2014
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.