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.
Functions and regulation of the MRX complex at DNA double-strand breaks
July 27, 2016
DNA double-strand breaks (DSBs) pose a serious threat to genome stability and cell survival. Cells possess mechanisms that recognize DSBs and promote their repair through either homologous recombination (HR) or non-homologous end joining (NHEJ). The present review focuses mainly on recent works in the budding yeast Saccharomyces cerevisiae to highlight structure and regulation of the evolutionary conserved Mre11-Rad50-Xrs2 (MRX) complex as well as its interplays with Tel1.
Syphilis: Re-emergence of an old foe
June 27, 2016
Syphilis is caused by infection with Treponema pallidum subsp. pallidum, a not-yet-cultivable spiral-shaped bacterium that is usually transmitted by sexual contact with an infected partner or by an infected pregnant woman to her fetus. This review provides insights into the etiology, epidemiology, clinical manifestation, diagnosis, treatment and prevention of syphilis.
Trichomoniasis – are we giving the deserved attention to the most common non-viral sexually transmitted disease worldwide?
June 27, 2016
Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in the world. This article contributes to claim the attention of public health policies to control this STD.
Evidence for the hallmarks of human aging in replicatively aging yeast
June 20, 2016
Recently, efforts have been made to characterize the hallmarks that accompany and contribute to the phenomenon of aging, as most relevant for humans. Remarkably, studying the finite lifespan of the single cell eukaryote budding yeast has been paramount for our understanding of aging. Here, we compile observations from literature over the past decades of research on replicatively aging yeast to highlight how the hallmarks of aging in humans are present in yeast.
The molecular and cellular action properties of artemisinins: what has yeast told us?
April 14, 2016
Artemisinin (ART) or Qinghaosu is a natural compound possessing superior anti-malarial activity. Although intensive studies have been done in the medicinal chemistry field to understand the structure-effect relationship, the biological actions of artemisinin are poorly understood and controversial. This review summarizes what we have learned from yeast about the basic biological properties of ARTs, as well as some key unanswered questions.
Chromatin binding and silencing: Two roles of the same protein Lem2
April 4, 2016
This article comments on work published by Barrales et al. (Genes Dev, 2016), which identifies the nuclear envelope protein Lem2, a homolog of metazoan lamin-associated proteins (LAPs), as a relevant factor for heterochromatin silencing and perinuclear localization in the fission yeast Schizosaccharomyces pombe.
Signaling pathways and posttranslational modifications of tau in Alzheimer’s disease: the humanization of yeast cells
March 27, 2016
In the past decade, yeast have been frequently employed to study the molecular mechanisms of human neurodegenerative diseases, generally by means of heterologous expression of genes encoding the relevant hallmark proteins. Substantial posttranslational modifications of many of these proteins are required for the development and progression of potentially disease relevant changes. We give an overview on common modifications as they occur in tau during AD and discuss potential approaches to humanize yeast in order to create modification patterns resembling the situation in mammalian cells.
Histone modifications as regulators of life and death in Saccharomyces cerevisiae
December 31, 2015
The mechanism by which chromosomes restructure during apoptosis is still poorly understood, but it is becoming increasingly clear that altered epigenetic histone modifications are fundamental parameters that influence the chromatin state and the nuclear rearrangements within apoptotic cells. This review highlights recent work on the epigenetic regulation of programmed cell death in budding yeast.
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.