Reviews
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 The phenomenon of post-translocational adaptation (PTA) is discussed, providing some new unpublished data and proposing the hypothesis that translocations may drive evolution through adaptive genetic selection.
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.
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.
Yeast as a model system to study metabolic impact of selenium compounds
Enrique Herrero1,* and Ralf Erik Wellinger2
Inorganic Se forms such as selenate or selenite (the two more abundant forms in nature) can be toxic in Saccharomyces cerevisiae cells, which constitute an adequate model to study such toxicity at the molecular level and the functions participating in protection against Se compounds. In this article, the authors propose that yeast may be used to improve our knowledge on the impact of Se on metal homeostasis, the identification of Se-targets at the DNA and protein levels, and to gain more insights into the mechanism of Se-mediated apoptosis.
Occurrence and potential mechanism of holin-mediated non-lytic protein translocation in bacteria
September 23, 2022
Holins are generally believed to generate large membrane lesions that permit the passage of endolysins across the cytoplasmic membrane of prokaryotes, ultimately resulting in cell wall degradation and cell lysis. However, there are more and more examples known for non-lytic holin-dependent secretion of proteins by bacteria, indicating that holins somehow can transport proteins without causing large membrane lesions. Phage-derived holins can be used for a non-lytic endolysin translocation to permeabilize the cell wall for the passage of secreted proteins. In addition, clostridia, which do not possess the Tat pathway for transport of folded proteins, most likely employ non-lytic holin-mediated transport also for secretion of toxins and bacteriocins that are incompatible with the general Sec pathway. The mechanism for non-lytic holin-mediated transport is (...)
Pirates of the haemoglobin
February 18, 2022
Not all treasure is silver and gold; for pathogenic bacteria, iron is the most precious and the most pillaged of metallic elements. Iron is essential for the survival and growth of all life; however free iron is scarce for bacteria inside human hosts. As a mechanism of defence, humans have evolved ways to store iron so as to render it inaccessible for invading pathogens, such as keeping the metal bound to iron-carrying proteins. For bacteria to survive within humans, they must therefore evolve counters to this defence to compete with these proteins for iron binding, or directly steal iron from them. (...)
Endomembrane remodeling and dynamics in Salmonella infection
December 27, 2021
Salmonellae are bacteria that cause moderate to severe infections in humans, depending on the strain and the immune status of the infected host. These pathogens have the particularity of residing in the cells of the infected host. They are usually found in a vacuolar compartment that the bacteria shape with the help of effector proteins. Following invasion of a eukaryotic cell, the bacterial vacuole undergoes maturation characterized by changes in localization, composition and morphology. In particular, membrane tubules stretching over the microtubule cytoskeleton are formed from the bacterial vacuole. Although these tubules do not occur in all infected cells, they are functionally important and promote intracellular replication. This review focuses on the role and significance of membrane compartment remodeling observed in infected cells and the bacterial and host cell pathways involved.
Lipid and fatty acid metabolism in trypanosomatids
October 6, 2021
This work reviews specific aspects of lipid and fatty acid metabolism in the protozoan parasites T. brucei, T. cruzi, and Leishmania spp., as well as the pathways that have been explored for the development of new chemotherapies.
Understanding the pathogenesis of infectious diseases by single-cell RNA sequencing
August 4, 2021
This work highlights recent remarkable advances in single-cell RNA sequencing technologies and their applications in the investigation of host-pathogen interactions. Current challenges and potential prospects for disease treatment are discussed as well.
Exploring absent protein function in yeast: assaying post translational modification and human genetic variation
July 2, 2021
This review discusses the applicability of yeast systems to investigate absent human protein function with a specific focus on the impact of protein variation on protein-protein interaction modulation.
Mechanisms underlying lactic acid tolerance and its influence on lactic acid production in Saccharomyces cerevisiae
April 14, 2021
This article reviews the manner in which Saccharomyces cerevisiae deals with the accumulation of lactic acid as a singular stress factor as well as in combination with other stresses. In addition, different methods to improve lactic acid tolerance in S. cerevisiae using targeted and non-targeted engineering methods are discussed.
Biofilms by bacterial human pathogens: Clinical relevance – development, composition and regulation – therapeutical strategies
February 1, 2021
This review focuses on bacterial biofilms formed by human pathogens, highlights their relevance for diverse diseases and discusses therapeutical intervention strategies targeting biofilms.
Milestones in Bacillus subtilis sporulation research
November 27, 2020
In this review, the foundational discoveries that shaped the sporulation field are discussed, from its origins to the present day, tracing a chronology that spans more than one hundred eighty years.