The riboflavin biosynthetic pathway as a novel target for antifungal drugs against species.

Unlabelled: In recent decades, there has been an increase in the occurrence of fungal infections; yet, the arsenal of drugs available to fight invasive infections remains very limited. The development of new antifungal agents is hindered by the restricted number of molecular targets that can be exploited, given the shared eukaryotic nature of fungi and their hosts which often leads to host toxicity. In this paper, we examine the riboflavin biosynthetic pathway as a potential novel drug target.

Assessment of cAMP-PKA Signaling in Candida glabrata by FRET-Based Biosensors.

Fluorescence or Förster resonance energy transfer (FRET)-based biosensors are used to monitor activity through molecular pathways inside the cell. Binding of secondary metabolites or enzyme-guided modification of protein targets can be assessed by quantifying the rate of energy transfer between two adequate fluorophores. The AKAR3 sensor contains a protein kinase A (PKA) phosphorylation site, which upon phosphorylation interacts with a ligand domain, bringing together FRET donor and acceptor fluorophores and allowing FRET.

The Role of Fatty Acid Metabolites in Vaginal Health and Disease: Application to Candidiasis.

Although the vast majority of women encounters at least one vaginal infection during their life, the amount of microbiome-related research performed in this area lags behind compared to alternative niches such as the intestinal tract. As a result, effective means of diagnosis and treatment, especially of recurrent infections, are limited. The role of the metabolome in vaginal health is largely elusive.

Investigating the Antifungal Mechanism of Action of Polygodial by Phenotypic Screening in .

Polygodial is a "hot" peppery-tasting sesquiterpenoid that was first described for its anti-feedant activity against African armyworms. Using the haploid deletion mutant library of , a genome-wide mutant screen was performed to shed more light on polygodial's antifungal mechanism of action. We identified 66 deletion strains that were hypersensitive and 47 that were highly resistant to polygodial treatment.

Photochromic Fluorophores Enable Imaging of Lowly Expressed Proteins in the Autofluorescent Fungus Candida albicans.

Fluorescence microscopy is a standard research tool in many fields, although collecting reliable images can be difficult in systems characterized by low expression levels and/or high background fluorescence. We present the combination of a photochromic fluorescent protein and stochastic optical fluctuation imaging (SOFI) to deliver suppression of the background fluorescence. This strategy makes it possible to resolve lowly or endogenously expressed proteins, as we demonstrate for Gcn5, a histone acetyltransferase required for complete virulence, and Erg11, the target of the azole antifungal agents in the fungal pathogen We expect that our method can be readily used for sensitive fluorescence measurements in systems characterized by high background fluorescence.

Adhesion of to During Co-Infection Promotes Bacterial Dissemination Through the Host Immune Response.

Interspecies interactions greatly influence the virulence, drug tolerance and ultimately the outcome of polymicrobial biofilm infections. A synergistic interaction is observed between the fungus and the bacterium . These species are both normal commensals of most healthy humans and co-exist in several niches of the host.

Fluorescent toys 'n' tools lighting the way in fungal research.

Although largely overlooked compared to bacterial infections, fungal infections pose a significant threat to the health of humans and other organisms. Many pathogenic fungi, especially Candida species, are extremely versatile and flexible in adapting to various host niches and stressful situations. This leads to high pathogenicity and increasing resistance to existing drugs.

Nutrient sensing and cAMP signaling in yeast: G-protein coupled receptor versus transceptor activation of PKA.

A major signal transduction pathway regulating cell growth and many associated physiological properties as a function of nutrient availability in the yeast is the protein kinase A (PKA) pathway. Glucose activation of PKA is mediated by G-protein coupled receptor (GPCR) Gpr1, and secondary messenger cAMP. Other nutrients, including nitrogen, phosphate and sulfate, activate PKA in accordingly-starved cells through nutrient transceptors, but apparently without cAMP signaling.

The involvement of the trehalase enzymes in stress resistance and gut colonization.

is an opportunistic human fungal pathogen and is frequently present in the human microbiome. It has a high relative resistance to environmental stresses and several antifungal drugs. An important component involved in microbial stress tolerance is trehalose.

Molecular Elucidation of Riboflavin Production and Regulation in Candida albicans, toward a Novel Antifungal Drug Target.

is a major cause of fungal infections, both superficial and invasive. The economic costs as well as consequences for patient welfare are substantial. Only a few treatment options are available due to the high resemblance between fungal targets and host molecules, as both are eukaryotes.

Presenting a codon-optimized palette of fluorescent proteins for use in Candida albicans.

Fluorescent proteins with varying colors are indispensable tools for the life sciences research community. These fluorophores are often developed for use in mammalian systems, with incremental enhancements or new versions published frequently. However, the successful application of these labels in other organisms in the tree of life, such as the fungus Candida albicans, can be difficult to achieve due to the difficulty in engineering constructs for good expression in these organisms.

Transcriptional responses of biofilm cells to fluconazole are modulated by the carbon source.

is an important human fungal pathogen known to trigger serious infections in immune-compromised individuals. Its ability to form biofilms, which exhibit high tolerance to antifungal treatments, has been considered as an important virulence factor. However, the mechanisms involving antifungal resistance in biofilms and the impact of host niche environments on these processes are still poorly defined.

Can Saccharomyces cerevisiae keep up as a model system in fungal azole susceptibility research?

The difficulty of manipulation and limited availability of genetic tools for use in many pathogenic fungi hamper fast and adequate investigation of cellular metabolism and consequent possibilities for antifungal therapies. S. cerevisiae is a model organism that is used to study many eukaryotic systems.

Inhibition of Vesicular Transport Influences Fungal Susceptibility to Fluconazole.

Fungal infections pose a substantial threat to the human population. They can cause either mild and relatively harmless infections or invasive and often lethal diseases in patients with a weakened immune system. The majority of these human fungal infections are caused by species.

Introducing fluorescence resonance energy transfer-based biosensors for the analysis of cAMP-PKA signalling in the fungal pathogen Candida glabrata.

The cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway is central to signal transduction in many organisms. In pathogenic fungi such as Candida albicans, this signalling cascade has proven to be involved in several processes, such as virulence, indicating its potential importance in antifungal drug discovery. Candida glabrata is an upcoming pathogen of the same species, yet information regarding the role of cAMP-PKA signalling in virulence is largely lacking.

The Antifungal Plant Defensin HsAFP1 Is a Phosphatidic Acid-Interacting Peptide Inducing Membrane Permeabilization.

HsAFP1, a plant defensin isolated from coral bells (), is characterized by broad-spectrum antifungal activity. Previous studies indicated that HsAFP1 binds to specific fungal membrane components, which had hitherto not been identified, and induces mitochondrial dysfunction and cell membrane permeabilization. In this study, we show that HsAFP1 reversibly interacts with the membrane phospholipid phosphatidic acid (PA), which is a precursor for the biosynthesis of other phospholipids, and to a lesser extent with various phosphatidyl inositol phosphates (PtdInsP's).

A Bimolecular Fluorescence Complementation Tool for Identification of Protein-Protein Interactions in .

Investigation of protein-protein interactions (PPI) in is essential for understanding the regulation of the signal transduction network that triggers its pathogenic lifestyle. Unique features of , such as its alternative codon usage and incomplete meiosis, have enforced the optimization of standard genetic methods as well as development of novel approaches. Since the existing methods for detection of PPI are limited for direct visualization of the interacting complex , we have established a bimolecular fluorescence complementation (BiFC) assay in , a powerful technique for studying PPI.

Mitochondrial Cochaperone Mge1 Is Involved in Regulating Susceptibility to Fluconazole in and Species.

encodes a yeast chaperone involved in Fe-S cluster metabolism and protein import into the mitochondria. In this study, we identified as a multicopy suppressor of susceptibility to the antifungal fluconazole in the model yeast We demonstrate that this phenomenon is not exclusively dependent on the integrity of the mitochondrial DNA or on the presence of the drug efflux pump Pdr5. Instead, we show that the increased dosage of Mge1 plays a protective role by retaining increased amounts of ergosterol upon fluconazole treatment.

Microbial cell surface proteins and secreted metabolites involved in multispecies biofilms.

A considerable number of infectious diseases involve multiple microbial species coexisting and interacting in a host. Only recently however the impact of these polymicrobial diseases has been appreciated and investigated. Often, the causative microbial species are embedded in an extracellular matrix forming biofilms, a form of existence that offers protection against chemotherapeutic agents and host immune defenses.