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.
Extracellular vesicles: An emerging platform in gram-positive bacteria
October 5, 2020
Extracellular vesicles (EVs) are secreted by both pathogenic and non-pathogenic bacteria to transfer biomolecules and facilitate intercellular communication. While EV secretion in gram-negative bacteria is well understood, less is known about gram-positive bacteria. This review explores the role of EVs involved in bacterial competition, survival, immune evasion, and infection of gram-positive bacteria and compares them to gram-negative counterparts.
Structural insights into the architecture and assembly of eukaryotic flagella
September 21, 2020
Cilia and flagella are key structures in motility and signaling. This review highlights recent findings of cryo-EM studies that have mapped the structure of axonemal microtubules in Chlamydomonas reinhardtii, revealing over 30 associated proteins as well as recent researcht which focused on the trafficking complexes that transport components between the cell body and cilium.
Plant and fungal products that extend lifespan in Caenorhabditis elegans
July 9, 2020
Caenorhabditis elegans' lifespan is extended by plant and fungal extracts activating pathways like autophagy and mitochondrial biogenesis. Low to moderate concentrations promote longevity, while high doses are harmful. This review explores the health benefits of these substances in humans.
From the Uncharacterized Protein Family 0016 to the GDT1 family: Molecular insights into a newly-characterized family of cation secondary transporters
June 15, 2020
This review outlines how the formerly uncharacterized UPF0016 family, now known as the Gdt1 family, plays key roles in cation transport - especially Mn²⁺ - across species from bacteria to humans. These proteins are crucial for processes like glycosylation, photosynthesis, and calcium signaling, with functions linked to their localization in membranes such as the Golgi, chloroplast, and plasma membrane and by that highlighting their evolutionary conservation and physiological relevance, offering insights into their shared and distinct features across organisms.
Regulation of Cdc42 for polarized growth in budding yeast
May 19, 2020
This review highlights how studies in budding yeast have revealed a biphasic mechanism of Cdc42 activation that governs cell polarity establishment, with implications for understanding similar processes in mammalian cells and the role of Cdc42 in aging.
Yeast-based assays for the functional characterization of cancer-associated variants of human DNA repair genes
May 18, 2020
This article highlights how the genetic tractability and conserved DNA repair pathways of yeast make it a powerful system for functionally characterizing human cancer-associated variants in DNA repair genes, aiding in risk assessment and therapeutic decision-making.
Regulation of anti-microbial autophagy by factors of the complement system
March 19, 2020
This review explores emerging evidence that components of the complement system, beyond their traditional immune roles, modulate autophagy - particularly xenophagy - thereby influencing cell-autonomous antimicrobial responses during host-pathogen interactions.
Microfluidic techniques for separation of bacterial cells via taxis
January 15, 2020
Microfluidic tools, ideal for studying microbial motility due to their control over laminar flows at microscopic scales, enable precise analysis of various taxis behaviors and have advanced applications in synthetic biology, directed evolution, and medical microbiology.
Influence of delivery and feeding mode in oral fungi colonization – a systematic review
January 7, 2020
A systematic review of oral fungal colonization in infants found that while breastfeeding did not significantly affect the oral mycobiome, vaginal delivery was associated with higher oral yeast colonization, particularly of Candida albicans.
The role of Lactobacillus species in the control of Candida via biotrophic interactions
November 25, 2019
Microbial communities, including Candida and Lactobacillus species, play a crucial role in human health, particularly in the context of mucosal infections, but our understanding of their interactions and effects is still incomplete due to the variability of species and isolates as well as the complexity of the human host.