Research, Research Articles

Acetate modulates the inhibitory effect of Lactobacillus gasseri against the pathogenic yeasts Candida albicans and Candida glabrata

Nuno A. Pedro1,2, Gabriela Fontebasso1,2, Sandra N. Pinto1,2, Marta Alves3 and Nuno P. Mira1,2

The results herein described advance the design of new anti-Candida therapies based on probiotics, in particular, those based on vaginal lactobacilli species, helping to reduce the significant burden that infections caused by Candida have today in human health.

D-Serine reduces the expression of the cytopathic genotoxin colibactin

D-Serine reduces the expression of the cytopathic genotoxin colibactin

Jennifer C. Hallam1,#, Sofia Sandalli1,#, Iris Floria1, Natasha C. A. Turner1, Min Tang-Fichaux2, Eric Oswald2,3, Nicky O’Boyle1,4 and Andrew J. Roe1

Sensing and responding to environmental cues and signalling molecules is crucial for bacterial survival. In this study we have identified a D-amino acid that has a strong regulatory effect on the pks genomic island which encodes for biosynthesis genes for the genotoxic compound colibactin.

A modular cloning (MoClo) toolkit for reliable intracellular protein targeting in the yeast Saccharomyces cerevisiae

Pavel Simakin1,#, Christian Koch1,# and Johannes M. Herrmann1

In this study, we describe an advanced Molecular cloning toolkit that is designed for the baker’s yeast Saccharomyces cerevisiae and optimized for the targeting of proteins of interest to specific cellular compartments.

The role of invariant surface glycoprotein 75 in xenobiotic acquisition by African trypanosomes

Alexandr Makarov1, Jakub Began2,†, Ileana Corvo Mautone1,3, Erika Pinto1, Liam Ferguson1, Martin Zoltner1,4, Sebastian Zoll2 and Mark C. Field1,5

By CRISPR/Cas9 knockout and biophysical analysis, we show here that the invariant surface glycoprotein 75 directly binds the the century-old drug suramin and mediates uptake of additional naphthol-related compounds, making this glycoprotein a conduit for entry of at least one structural class of trypanocidal compounds.

The first taxonomic and functional characterization of human CAVD-associated microbiota

Lavinia Curini1,#, Brunilda Alushi2,#, Mary Roxana Christopher3, Simone Baldi1, Leandro Di Gloria4, Pierluigi Stefano5, Anna Laganà5, Luisa Iannone5, Herko Grubitzsch6, Ulf Landmesser7, Matteo Ramazzotti4, Elena Niccolai1,§, Alexander Lauten2,§ and Amedeo Amedei1,8,§

Calcific aortic valve disease (CAVD) is the most common heart valve disorder, defined by a remodeling multistep process. In this study, we aimed to investigate and characterize the presence of valvular microbiota and the associated immune response in human CAV samples originating from two European populations.

Cellular cholesterol licenses <i>Legionella pneumophila</i> intracellular replication in macrophages

Cellular cholesterol licenses Legionella pneumophila intracellular replication in macrophages

Edna Ondari1,#, Ashley Wilkins1,#, Brian Latimer3, Ana-Maria Dragoi2,3 and Stanimir S. Ivanov1

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

Ronnie L. Fulton1 and Diana M. Downs1

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

Pedro Pais1,2,3,#, Mónica Galocha1,2,3,#, Azusa Takahashi-Nakaguchi4, Hiroji Chibana4 and Miguel C. Teixeira1,2,3

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(...)

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A cobalt concentration sensitive Btu-like system facilitates cobalamin uptake in Anabaena sp. PCC 7120

February 20, 2024

Metal homeostasis is central to all forms of life, as metals are essential micronutrients with toxic effects at elevated levels. Our results provide novel information on the uptake of cobalamin and the regulation of the cellular cobalt content in cyanobacteria.

Predictable regulation of survival by intratumoral microbe-immune crosstalk in patients with lung adenocarcinoma

February 19, 2024

Intratumoral microbiota can regulate the tumor immune microenvironment (TIME) and mediate tumor prognosis by promoting inflammatory response or inhibiting anti-tumor effects. Our study demonstrated that intratumoral microbiota-immune crosstalk was strongly associated with prognosis in LUAD patients, which would provide new targets for the development of precise therapeutic strategies.

Two TonB-dependent outer membrane transporters involved in heme uptake in Anabaena sp. PCC 7120

January 9, 2024

Low availability of micronutrients such as iron has enforced the evolution of uptake systems in all kingdoms of life. In our study, we conclude that heme transport might not be restricted to Anabaena, but at the same time is not specific to a cyanobacterial order and thus might be related to the habitat of origin, a notion which needs to be challenged in the future.

The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit

January 5, 2024

FurE is a H+ symporter specific for the cellular uptake of uric acid, allantoin, uracil, and toxic nucleobase analogues in the fungus Aspergillus nidulans. Being member of the NCS1 protein family, FurE is structurally related to the APC-superfamily of transporters.

Extracellular DNA secreted in yeast cultures is metabolism-specific and inhibits cell proliferation

November 23, 2023

Our study demonstrates that extracellular DNA released by living cells can impact the growth rate of Saccharomyces cerevisiae cultures, showing similarities to extrachromosomal circular DNA and leading to cell cycle arrest in the S phase, suggesting potential new functional roles of exDNA.

Basal level of ppGpp coordinates Escherichia coli cell heterogeneity and ampicillin resistance and persistence

October 25, 2023

The universal stringent response alarmone ppGpp (guanosine penta and tetra phosphates) plays a crucial role in various aspects of fundamental cell physiology (e.g., cell growth rate, cell size) and thus bacterial tolerance to and survival of external stresses, including antibiotics. In tihs study, we discuss the fundamental role of basal level of ppGpp in regulating cell homogeneity and ampicillin persistence.

Investigation of the acetic acid stress response in Saccharomyces cerevisiae with mutated H3 residues

August 18, 2023

Yeast cells respond to acetic acid in diverse ways. Here, we have elucidated the deleterious effects of acetic acid on different histone mutants

The coenzyme B12 precursor 5,6-dimethylbenzimidazole is a flavin antagonist in Salmonella

August 17, 2023

Here we investigated why 5,6-dimethylbenzimidazole (DMB) inhibits in S. Typhimurium. Briefly, we determined that the structural similarities of the substituted benzene ring of DMB with the isoalloxazine moiety of flavins is responsible for the deleterious effects of this CoB12 precursor.

Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2

August 8, 2023

We show here that apart from its effector role for Elongator-dependent tRNA modification in yeast, Kti13 alias Dph8 also operates in step one of the diphthamide modification pathway.

Caspase 3 exhibits a yeast metacaspase proteostasis function that protects mitochondria from toxic TDP43 aggregates

July 10, 2023

Caspase 3 activation is a hallmark of cell death and there is a strong correlation between elevated protease activity and evolving pathology in neurodegenerative disease, such as amyotrophic lateral sclerosis (ALS). These results suggest that caspase 3 is not inherently pathogenic, but may act as a compensatory proteostasis factor, to limit TDP-43 protein inclusions and protect organelle function in aggregation related degenerative disease.

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