Review, Reviews
The many facets of homologous recombination at telomeres
Clémence Claussin and Michael Chang
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...
From the baker to the bedside: yeast models of Parkinson’s disease
Regina Menezes1,2, Sandra Tenreiro3,5, Diana Macedo2, Cláudia N. Santos1,2, Tiago Fleming Outeiro4,5,6
The baker’s yeast Saccharomyces cerevisiae has been extensively explored for our understanding of fundamental cell biology processes highly conserved in the eukaryotic kingdom. This review provides a brief historical perspective on the emergence of yeast as an experimental model and on how the field evolved to exploit the potential of the model for tackling the intricacies of various human diseases. In particular, the authors focus on existing yeast models of the molecular underpinnings of Parkinson’s disease (PD), focusing primarily on the central role of protein quality control systems.
Why are essential genes essential? – The essentiality of Saccharomyces genes
Zhaojie Zhang and Qun Ren
Essential genes are defined as required for the survival of an organism or a cell. This article reviews and analyzes the levels of essentiality of the Saccharomyces cerevisiae genes and groups the genes into four categories: (1) Conditional essential: essential only under certain circumstances or growth conditions; (2) Essential: required for survival under optimal growth conditions; (3) Redundant essential: synthetic lethal due to redundant pathways or gene duplication; and (4) Absolute essential: the minimal genes required for maintaining a cellular life under a stress-free environment. The essential and non-essential functions of the essential genes are further analyzed.
Membrane depolarization-triggered responsive diversification leads to antibiotic tolerance
Natalie Verstraeten, Wouter Joris Knapen, Maarten Fauvart, Jan Michiels
In this article, the authors discuss the article "Obg and membrane depolarization are part of a microbial bet-hedging strategy that leads to antibiotic tolerance", Verstraeten et al., Mol. Cell 2015 Jul 2; 59 (1): 9-21.
Evolutionary rewiring of bacterial regulatory networks
Tiffany B. Taylor1,*, Geraldine Mulley1, Liam J. McGuffin1, Louise J. Johnson1, Michael A. Brockhurst2, Tanya Arseneault1,3, Mark W. Silby4 and Robert W. Jackson1,5
Bacteria have evolved complex regulatory networks that enable integration of multiple intracellular and extracellular signals to coordinate responses to environmental changes. However, our knowledge of how regulatory systems function and evolve is still relatively limited. There is often extensive homology between components of different networks, due to past cycles of gene duplication, divergence, and horizontal gene transfer, raising the possibility of cross-talk or redundancy. Consequently, evolutionary resilience is built into gene networks – homology between regulators can potentially allow rapid rescue of lost regulatory function across distant regions of the genome. This article discusses Taylor, et al. Science (2015), 347(6225), reporting mutations that facilitate cross-talk between pathways can contribute to gene network evolution, but which come with severe pleiotropic costs. Arising from this work are a number of questions surrounding how this phenomenon occurs.
Wanted Plasmodium falciparum, dead or alive
Fatimata Sow1, Mary Nyonda1, Anne-Lise Bienvenu1, 2, Stephane Picot1, 2
In this article, mechanisms of cell death in unicellular parasites are discussed, focussing on “programmed cell death” in Plasmodium.
Yeast as a tool to explore cathepsin D function
H. Pereira1, C.S.F. Oliveira1,2, L. Castro1, A. Preto1, S. R. Chaves1,#, M. Côrte-Real1,#
Cathepsin D has garnered increased attention in recent years, mainly since it has been associated with several human pathologies. This review summarizes how cathepsin D can have both anti- and pro-survival functions depending on its proteolytic activity, cellular context and stress stimulus.
Coordinate responses to alkaline pH stress in budding yeast
Albert Serra-Cardona, David Canadell and Joaquín Ariño
This review summarizes the modulation of a substantial number of signaling pathways whose participate in the alkaline response in yeast. These regulatory inputs involve not only the conserved Rim101/PacC pathway, but also the calcium-activated phosphatase calcineurin, the Wsc1-Pkc1-Slt2 MAP kinase, the Snf1 and PKA kinases and oxidative stress-response pathways.
Handcuffs for bacteria – NDP52 orchestrates xenophagy of intracellular Salmonella
Pauline Verlhac1,2,3,4,5, Christophe Viret1,2,3,4,5 and Mathias Faure1,2,3,4,5
This microreview discusses the article "Autophagy Receptor NDP52 Regulates Pathogen-Containing Autophagosome Maturation" by Verlhac et al. (2015), Cell Host Microbe.
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.