Research, Research Articles
Effect of paraquat-induced oxidative stress on gene expression and aging of the filamentous ascomycete Podospora anserina
Matthias Wiemer and Heinz D. Osiewacz
In this article, paraquat is used to experimentally induce strong cellular oxidative stress in Podospora anserina wild-type cultures of different age, finding that this treatment has profound effects on gene expression, growth and lifespan.
Heat shock protein 90 and calcineurin pathway inhibitors enhance the efficacy of triazoles against Scedosporium prolificans via induction of apoptosis
Fazal Shirazi and Dimitrios P. Kontoyiannis
This article reports for the first time that posaconazole (PCZ) or itraconazolein (ICZ) in combination with the calcineurin inhibitor tacrolimus or the Hsp90 inhibitor 17-demethoxy-17-(2-propenylamino) geldanamycin renders S. prolificans exquisitely sensitive to PCZ or ICZ via apoptosis.
At neutral pH the chronological lifespan of Hansenula polymorpha increases upon enhancing the carbon source concentrations
Adam Kawałek and Ida J. van der Klei
The data presented in this work indicate that in H. polymorpha at neutral pH the chronological lifespan invariably extends upon increasing the carbon source concentration.
Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA
Qiuqiang Gao1, Liang-Chun Liou2, Qun Ren2, Xiaoming Bao3 and Zhaojie Zhang2
In this work, the authors report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ0) and that this damage is related to elevated levels of SCW11 and salt stress-induced reactive oxygen species.
Protein oxidation in the intermembrane space of mitochondria is substrate-specific rather than general
Valentina Peleh1, Jan Riemer2, Andrew Dancis3 and Johannes M. Herrmann1
In this work, the authors suggest that in Saccharomyces cerevisiae, the Mia40-dependent oxidation of proteins in the intermembrane space only takes place in specific proteins and presumably relies on the presence of Mia40-binding sites.
Deletion of AIF1 but not of YCA1/MCA1 protects Saccharomyces cerevisiae and Candida albicans cells from caspofungin-induced programmed cell death
Christopher Chin1,2,#, Faith Donaghey1,#, Katherine Helming1,3,#, Morgan McCarthy1,#, Stephen Rogers1, and Nicanor Austriaco1
This work suggests that deleting AIF1 but not YCA1/MCA1 protects S. cerevisiae and Candida albicans from caspofungin-induced cell death. This is not only the first time that AIF1 has been specifically tied to cell death in Candida but also the first time that caspofungin resistance has been linked to the cell death machinery in yeast.
Reduced TORC1 signaling abolishes mitochondrial dysfunctions and shortened chronological lifespan of Isc1p-deficient cells
Vitor Teixeira1,2, Tânia C. Medeiros1, Rita Vilaça1,2, Pedro Moradas-Ferreira1,2, and Vítor Costa1,2
Overall, this article shows that the TORC1-Sch9p axis is deregulated in Isc1p-deficient Saccharomyces cerevisiae cells, contributing to mitochondrial dysfunction, enhanced oxidative stress sensitivity and premature aging of isc1Δ cells.
Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae.
Maksim I. Sorokin1,3, Dmitry A. Knorre2,3, and Fedor F. Severin2,3
The data preseted herein suggest that retrograde signaling starts to malfunction in relatively young cells, leading to accumulation of heterogeneous mitochondria within one cell. The latter may further contribute to a decline in stress resistances.
Tracking autophagy during proliferation and differentiation of Trypanosoma brucei
William R. Proto1, Nathaniel G. Jones1, Graham H. Coombs2, and Jeremy C. Mottram1
This article provides insights into the function of autophagy, a cellular degradation and recycling pathway, in the protozoan parasite Trypanosoma brucei.
Cellular cholesterol licenses Legionella pneumophila intracellular replication in macrophages
December 6, 2022
Host membranes are inherently critical for niche homeostasis of vacuolar pathogens such as Legionella. One membrane component that is often subverted by vacuolar bacteria is cholesterol. We provide experimental evidence that cellular cholesterol promotes L. pneumophila replication within a membrane bound organelle in infected macrophages.
DadY (PA5303) is required for fitness of Pseudomonas aeruginosa when growth is dependent on alanine catabolism
November 22, 2022
Pseudomonas aeruginosa inhabits diverse environmental niches that can have varying nutrient composition. The ubiquity of this organism is facilitated by a metabolic strategy that preferentially utilizes low-energy, non-fermentable organic acids, such as amino acids, rather than the high-energy sugars preferred by many other microbes. The amino acid alanine is among the preferred substrates of P. aeruginosa. The dad locus encodes the constituents of the alanine catabolic pathway of P. aeruginosa. Physiological roles for DadR (AsnC-type transcriptional activator), DadX (alanine racemase), and DadA (D-amino acid dehydrogenase) have been defined in this pathway. An additional protein, PA5303, is encoded in the dad locus in P. aeruginosa. PA5303 is a member of the ubiquitous Rid protein superfamily and is designated DadY based on the data presented herein. (...)
Multiple genome analysis of Candida glabrata clinical isolates renders new insights into genetic diversity and drug resistance determinants
October 13, 2022
The emergence of drug resistance significantly hampers the treatment of human infections, including those caused by fungal pathogens such as Candida species. Candida glabrata ranks as the second most common cause of candidiasis worldwide, supported by rapid acquisition of resistance to azole and echinocandin antifungals frequently prompted by single nucleotide polymorphisms (SNPs) in resistance associated genes, such as PDR1 (azole resistance) or FKS1/2 (echinocandin resistance). To determine the frequency of polymorphisms and genome rearrangements as the possible genetic basis of C. glabrata drug resistance, we assessed genomic variation across 94 globally distributed isolates with distinct resistance phenotypes, whose sequence is deposited in GenBank. The(...)
Up-regulation of Osh6 boosts an anti-aging membrane trafficking pathway toward vacuoles
July 15, 2022
Members of the family of oxysterol-binding proteins mediate non-vesicular lipid transport between membranes and contribute to longevity in different manners. We previously found that a 2-fold up-regulation of Osh6, one of seven yeast oxysterol-binding proteins, remedies vacuolar morphology defects in mid-aged cells, partly down-regulates the target of rapamycin complex 1 (TORC1), and increases the replicative lifespan. At the molecular level, Osh6 transports phosphatidylserine (PS) and phosphatidylinositol-4-phosphate (PI4P) between the endoplasmic reticulum (ER) and the plasma membrane (PM). To decipher how an ER-PM working protein controls vacuolar morphology, we tested genetic interactions between OSH6 and DRS2, whose protein flips PS from the lumen to the cytosolic side of the Golgi, the organelle between ER and vacuoles in many pathways. Up-regulated (...)
Investigating the role of G-quadruplexes at Saccharomyces cerevisiae telomeres
May 19, 2022
In this study, the authors examine the in vivo relevance of telomeric G-quadruplexes in the budding yeast Saccharomyces cerevisiae by expressing a mutant telomerase RNA subunit (tlc1-tm) that introduces mutant telomeric repeats instead to the distal ends of telomeres. (...)
Air- and dustborne fungi in repositories of the National Archive of the Republic of Cuba
April 1, 2022
This study has as objectives to determine the concentration and diversity of the air- and dustborne mycobiota in seven National Archive of the Republic of Cuba repositories, and to assess the potential risk of biodeterioration that iso-lated taxa may have. In the indoor and outdoor environmental microbiological samplings a SAS biocollector was used and the indoor/outdoor (I/O) ratio was determined for each repository. The settled dust was collected during six months. Sørensen's coefficient of similarity (QS) was calculated to compare the isolated taxa among the three studied niches (indoor air, dust, outdoor air). The biodegradation potential of the isolated taxa was determined by semi-quantitative tests. The concentrations in the air of repositories with natural cross-ventilation ranged from 225.2-750.3 CFU m-3, while in the Map library with air-conditioning (...)
Cleavage-defective Topoisomerase I mutants sharply increase G-quadruplex-associated genomic instability
January 31, 2022
Topoisomerase 1 (Top1) removes transcription-associated helical stress to suppress G4-formation and its induced recombination at genomic loci containing guanine-run containing sequences. Interestingly, Top1 binds tightly to G4 structures, and its inhibition or depletion can cause elevated instability at these genomic loci. Top1 is targeted by the widely used anti-cancer chemotherapeutic camptothecin (CPT) and its derivatives, which stabilize Top1 covalently attached on a DNA nick and prevent the re-ligation step. Here we investigated how CPT-resistance conferring Top1 mutants, which emerge in cancer patients and cells treated with CPT, affect G4-induced genomic instability in S. cerevisiae. We found that Top1 mutants form stable complexes with G4 DNA and that expression of Top1 cleavage-defective mutants but not a DNA-binding-defective (...)
Chromosome-condensed G1 phase yeast cells are tolerant to desiccation stress
November 26, 2021
The budding yeast Saccharomyces cerevisiae is capable of surviving extreme water loss for a long time. However, less is known about the mechanism of its desiccation tolerance. In this study, we revealed that in an exponential culture, all desiccation tolerant yeast cells were in G1 phase and had condensed chromosomes. (...)
Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its first variants in fourplex real-time quantitative reverse transcription-PCR assays
November 25, 2021
The early diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is required to identify and isolate contagious patients to prevent further transmission of SARS-CoV-2. In this study, we present a multitarget real-time TaqMan reverse transcription PCR (rRT-PCR) assay for the quantitative detection of SARS-CoV-2 and some of its circulating variants harboring mutations that give the virus a selective advantage. Seven different primer-probe sets that included probes containing locked nucleic acid (LNA) nucleotides were designed to amplify specific wild-type and mutant sequences in Orf1ab, Envelope (E), Spike (S), and Nucleocapsid (N) genes (...)
Forced association of SARS-CoV-2 proteins with the yeast proteome perturb vesicle trafficking
October 27, 2021
This work demonstrates that the yeast Synthetic Physical Interactions method is a rapid way to identify potential functions of ectopic viral proteins.