Research, Research Articles
A humanized yeast-based toolkit for monitoring phosphatidylinositol 3-kinase activity at both single cell and population levels
Julia María Coronas-Serna1, Teresa Fernández-Acero1, María Molina1 and Víctor J. Cid1
In this study, a humanized yeast system for functional studies on higher eukaryotic Phosphatidylinositol 3-kinase (PI3K) was developed by restricting PI3K activity in yeast to specific plasma membrane microdomains, utilizing engineered reporters to monitor activity at a single-cell level and employing novel tools to study the performance of yeast plasma membrane (PM) microdomain-directed PI3K, revealing location-specific effects on yeast growth and endocytosis.
A chemical genetic screen reveals a role for proteostasis in capsule and biofilm formation by Cryptococcus neoformans
François L. Mayer1, Eddy Sánchez-León1, James W. Kronstad1
This study demonstrates that the bipolar disorder drug lithium inhibits the formation of key virulence factors, biofilm, and polysaccharide capsule, in Cryptococcus neoformans by dysregulating the ubiquitin/proteasome system, shedding light on the impact of lithium and providing insights into potential alternative pharmaceutical approaches for combating this fungal pathogen.
Nutritional and meiotic induction of transiently heritable stress resistant states in budding yeast
Heldder Gutierrez1, Bakhtiyar Taghizada1, and Marc D. Meneghini1
This study demonstrates that transient exposures to environmental stresses induce persistent states of elevated stress resistance in yeast cells, termed cellular memory, suggesting a form of epigenetic inheritance, and shows that this phenomenon occurs not only in meiotically produced spores but also in haploid cells subjected to glucose withdrawal, adding new insights into the developmentally and nutritionally induced cellular memory.
Specific mutations in the permease domain of septal protein SepJ differentially affect functions related to multicellularity in the filamentous cyanobacterium Anabaena
Félix Ramos-León1, Sergio Arévalo1, Vicente Mariscal1 and Enrique Flores1
In this study, the multifunctional roles of the SepJ protein in the multicellular function of the Anabaena filament were investigated, revealing that specific amino acids and stretches within the protein are essential for the formation of long filaments, heterocyst differentiation, and intercellular communication, shedding light on the structure and diverse functions of SepJ in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.
Trehalose-6-phosphate promotes fermentation and glucose repression in Saccharomyces cerevisiae
Rebeca L. Vicente1,2, Lucie Spina1, Jose P.L. Gómez1, Sebastien Dejean3, Jean-Luc Parrou1 and Jean Marie François1,4
This study examined the capability of trehalose-6-phosphate synthase (TPS1) homologues from various species to complement the phenotypic defects of a Saccharomyces cerevisiae tps1 mutant, resulting in the classification of complementation into different groups based on metabolic patterns and fermentation capacity, shedding light on the role of TPS1 and trehalose-6-phosphate (T6P) as critical factors in sugar fermentation and glucose repression.
The translationally controlled tumor protein TCTP is involved in cell cycle progression and heat stress response in the bloodstream form of Trypanosoma brucei
Borka Jojic1, Simona Amodeo1,2 and Torsten Ochsenreiter1
This study reveals the involvement of the translationally controlled tumor protein TCTP in cell cycle regulation and heat stress response in the bloodstream form of Trypanosoma brucei, shedding light on its role in these cellular processes.
Single telomere length analysis in Ustilago maydis, a high-resolution tool for examining fungal telomere length distribution and C-strand 5’-end processing
Ganduri Swapna1, Eun Young Yu1 and Neal F. Lue1, 2
This article introduces the development of single telomere length analysis (STELA) for Ustilago maydis, a basidiomycete fungus, enabling the precise measurement of telomere lengths and distributions. The study demonstrates STELA's utility in revealing the existence of relatively short telomeres in wild-type cells, preferential loss of long telomeres in a mutant defective in telomere replication, and the characterization of telomere C-strand 5’ ends, highlighting U. maydis as a strong model for telomere research.
Temporal analysis of the autophagic and apoptotic phenotypes in Leishmania parasites
Louise Basmaciyan1, Laurence Berry2, Julie Gros3, Nadine Azas3 and Magali Casanova3
This article details a comprehensive analysis of miltefosine-induced cell death and autophagy in Leishmania major, providing criteria for clear identification of apoptotic and autophagic cells, demonstrating the sequential nature of autophagy followed by apoptosis in nutrient-deprived conditions, and cautioning against using the generic kinase inhibitor staurosporine as a Leishmania apoptosis inducer, with the aim of improving the understanding of these processes and their targeting for new anti-leishmanial drugs.
Snf1 cooperates with the CWI MAPK pathway to mediate the degradation of Med13 following oxidative stress
Stephen D. Willis1, David C. Stieg1, Kai Li Ong2, Ravina Shah1,3, Alexandra K. Strich1,4, Julianne H. Grose2 and Katrina F. Cooper1
This article explores the response of eukaryotic cells to environmental stress, highlighting the role of the conserved cyclin C-Cdk8 kinase in determining pro-survival or pro-death programs. Specifically, it discusses how oxidative stress triggers the destruction of Med13 by the SCFGrr1 ubiquitin ligase, releasing cyclin C to promote mitochondrial fission and cell death in Saccharomyces cerevisiae. Additionally, it reveals that the AMP kinase Snf1 activates a separate degron in Med13, contributing to the complex regulation of Med13 degradation following H2O2 stress through the coordination of the cell wall integrity and MAPK pathways.
Transcriptomic and chemogenomic analyses unveil the essential role of Com2-regulon in response and tolerance of Saccharomyces cerevisiae to stress induced by sulfur dioxide
September 30, 2019
This article shows that in the presence of sulfur dioxide (SO2), the transcription factor Com2 plays a critical role in the tolerance and response of Saccharomyces cerevisiae, affecting the expression of a majority of SO2-activated genes and contributing to the protection against stress induced by SO2 at an enologically relevant pH.
Network dynamics of the yeast methyltransferome
July 9, 2019
This article presents a systematic genetic analysis of methyltransferases (MTases) under normal and stress conditions, uncovering the complex and adaptive nature of the methyltransferome and discovering a potential connection between phospholipid methylation and histone methylation, suggesting interplay between lipid homeostasis and epigenetic regulation.
Functional link between mitochondria and Rnr3, the minor catalytic subunit of yeast ribonucleotide reductase
May 20, 2019
This article shows that the carbon source affects the abundance of ribonucleotide reductase (RNR) subunits in yeast, with a novel Mec1 signaling axis regulating Rnr3 independently of known DNA damage response pathways, and reveals Rnr3's unexpected role in mitochondrial function.
Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release
March 15, 2019
This study investigated the role of Mitochondria-Associated Membranes (MAMs) in the regulation of apoptosis by analyzing the localization and function of the pro-apoptotic protein Bax in yeast, finding that disruption of MAMs by deletion of the MDM34 gene affects Bax's mitochondrial localization and the release of cytochrome c.
Chlamydia pneumoniae is present in the dental plaque of periodontitis patients and stimulates an inflammatory response in gingival epithelial cells
March 11, 2019
This study found that Chlamydia pneumoniae is present more frequently in the dental plaque of individuals with periodontal disease, can invade human gingival epithelial cells causing inflammatory responses, and may therefore be a contributing factor to periodontal disease and a potential indicator of risk.
Simultaneous profiling of sexually transmitted bacterial pathogens, microbiome, and concordant host response in cervical samples using whole transcriptome sequencing analysis
January 24, 2019
This study used total RNA sequencing to analyze cervical samples from women at high risk for STIs, revealing that host transcriptional profiles can be linked to microbiome composition and STI infections, with implications for advancing our understanding of PID and identifying potential biomarkers.
Genome-wide analysis of yeast expression data based on a priori generated co-regulation cliques
January 22, 2019
The study demonstrates the use of predefined genome-wide expression cliques, derived from extensive microarray data, to effectively analyze and visualize the complete gene expression response across various cellular conditions in yeast.
A humanized yeast-based toolkit for monitoring phosphatidylinositol 3-kinase activity at both single cell and population levels
November 12, 2018
In this study, a humanized yeast system for functional studies on higher eukaryotic Phosphatidylinositol 3-kinase (PI3K) was developed by restricting PI3K activity in yeast to specific plasma membrane microdomains, utilizing engineered reporters to monitor activity at a single-cell level and employing novel tools to study the performance of yeast plasma membrane (PM) microdomain-directed PI3K, revealing location-specific effects on yeast growth and endocytosis.
A chemical genetic screen reveals a role for proteostasis in capsule and biofilm formation by Cryptococcus neoformans
October 31, 2018
This study demonstrates that the bipolar disorder drug lithium inhibits the formation of key virulence factors, biofilm, and polysaccharide capsule, in Cryptococcus neoformans by dysregulating the ubiquitin/proteasome system, shedding light on the impact of lithium and providing insights into potential alternative pharmaceutical approaches for combating this fungal pathogen.