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Biochimica Et Biophysica Acta.... Feb 2020Soil fungi play an important role in the environment decomposing dead organic matter and degrading persistent organic pollutants (POP). The presence of hydrophobic POP...
Soil fungi play an important role in the environment decomposing dead organic matter and degrading persistent organic pollutants (POP). The presence of hydrophobic POP in the soil and membrane-lytic substances excreted by competing microorganism to the soil solution is the constant threat to these organisms. To survive in the harsh environment and counteract these hazards the fungal cells have to strictly control the composition of the lipids in their cellular membranes. However, in the case of fungal membranes the correlation between their composition and physical properties is not fully understood. In our studies we applied Langmuir monolayers formed by phospholipids typical to fungal membranes and ergosterol as versatile model membranes. These membranes were characterized by the Langmuir technique, Brewster Angle Microscopy and Grazing Incidence X-ray Diffraction, as well as were exposed to the action of phospholipase A2 treated as a model membrane-lytic protein. We started our studies from the equimolar mixture of phosphatidylethanolamine with phosphatidylcholine and doped this matrix with phosphatidylserine (PS) or phosphatidylinositol (PI). It turned out that the membranes with PS were much more condensed at the mesoscale and periodically organized at the molecular level. Starting from these models we derived two families of model fungal membranes adding to these phospholipid matrices ergosterol. It turned out that the level of ergosterol content is of crucial importance for the model membrane structure and its durability. Changing the ergosterol mole ratio from 0 to 0.5 we defined and described in detail four different 2D crystalline phases.
Topics: Cell Membrane; Ergosterol; Fungi; Phosphatidylcholines; Phosphatidylinositols; Phosphatidylserines; Phospholipases A2; Unilamellar Liposomes
PubMed: 31751523
DOI: 10.1016/j.bbamem.2019.183136 -
Biomolecules Nov 202124-Methylene-cholesterol is a necessary substrate for the biosynthesis of physalin and withanolide, which show promising anticancer activities. It is difficult and...
24-Methylene-cholesterol is a necessary substrate for the biosynthesis of physalin and withanolide, which show promising anticancer activities. It is difficult and costly to prepare 24-methylene-cholesterol via total chemical synthesis. In this study, we engineered the biosynthesis of 24-methylene-cholesterol in by disrupting the two enzymes (i.e., ERG4 and ERG5) in the yeast's native ergosterol pathway, with ERG5 being replaced with the DHCR7 (7-dehydrocholesterol reductase) enzyme. Three versions of DHCR7 originating from different organisms-including the DHCR7 from (PhDHCR7) newly discovered in this study, as well as the previously reported OsDHCR7 from and XlDHCR7 from -were assessed for their ability to produce 24-methylene-cholesterol. XlDHCR7 showed the best performance, producing 178 mg/L of 24-methylene-cholesterol via flask-shake cultivation. The yield could be increased up to 225 mg/L, when one additional copy of the expression cassette was integrated into the yeast genome. The 24-methylene-cholesterol-producing strain obtained in this study could serve as a platform for characterizing the downstream enzymes involved in the biosynthesis of physalin or withanolide, given that 24-methylene-cholesterol is a common precursor of these chemicals.
Topics: Cholesterol; Ergosterol; Metabolic Engineering; Oxidoreductases Acting on CH-CH Group Donors; Saccharomyces cerevisiae
PubMed: 34827708
DOI: 10.3390/biom11111710 -
Journal of Translational Medicine Mar 2008Ayurveda is one of the ancient systems of health care of Indian origin. Roughly translated into "Knowledge of life", it is based on the use of natural herbs and herb... (Review)
Review
Ayurveda is one of the ancient systems of health care of Indian origin. Roughly translated into "Knowledge of life", it is based on the use of natural herbs and herb products for therapeutic measures to boost physical, mental, social and spiritual harmony and improve quality of life. Although sheltered with long history and high trust, ayurveda principles have not entered laboratories and only a handful of studies have identified pure components and molecular pathways for its life-enhancing effects. In the post-genomic era, genome-wide functional screenings for targets for diseases is the most recent and practical approach. We illustrate here the merger of ayurveda and functional genomics in a systems biology scenario that reveals the pathway analysis of crude and active components and inspire ayurveda practice for health benefits, disease prevention and therapeutics.
Topics: Antineoplastic Agents; Biological Assay; Ergosterol; Genomics; Humans; Medicine, Ayurvedic; Molecular Structure; Phytotherapy; Plant Extracts; Systems Biology; Tissue Culture Techniques; Withania; Withanolides
PubMed: 18348714
DOI: 10.1186/1479-5876-6-14 -
Journal of Phycology Aug 2021Animals and fungi produce cholesterol and ergosterol, respectively, while plants produce the phytosterols stigmasterol, campesterol, and β-sitosterol in various...
Animals and fungi produce cholesterol and ergosterol, respectively, while plants produce the phytosterols stigmasterol, campesterol, and β-sitosterol in various combinations. The recent sequencing of many algal genomes allows the detailed reconstruction of the sterol metabolic pathways. Here, we characterized sterol synthesis in two sequenced Chlorella spp., the free-living C. sorokiniana, and symbiotic C. variabilis NC64A. Chlamydomonas reinhardtii was included as an internal control and Coccomyxa subellipsoidea as a plant-like outlier. We found that ergosterol was the major sterol produced by Chlorella spp. and C. reinhardtii, while C. subellipsoidea produced the three phytosterols found in plants. In silico analysis of the C. variabilis NC64A, C. sorokiniana, and C. subellipsoidea genomes identified 22 homologs of sterol biosynthetic genes from Arabidopsis thaliana, Saccharomyces cerevisiae, and C. reinhardtii. The presence of CAS1, CPI1, and HYD1 in the four algal genomes suggests the higher plant cycloartenol branch for sterol biosynthesis, confirming that algae and fungi use different pathways for ergosterol synthesis. Phylogenetic analysis for 40 oxidosqualene cyclases (OSCs) showed that the nine algal OSCs clustered with the cycloartenol cyclases, rather than the lanosterol cyclases, with the OSC for C. subellipsoidea positioned in between the higher plants and the eight other algae. With regard to why C. subellipsoidea produced phytosterols instead of ergosterol, we identified 22 differentially conserved positions where C. subellipsoidea CAS and A. thaliana CAS1 have one amino acid while the three ergosterol producing algae have another. Together, these results emphasize the position of the unicellular algae as an evolutionary transition point for sterols.
Topics: Animals; Chlorella; Computational Biology; Ergosterol; Phylogeny; Phytosterols; Sterols
PubMed: 33713347
DOI: 10.1111/jpy.13164 -
FEMS Microbiology Ecology Oct 2011Bacterial and fungal growth rate measurements are sensitive variables to detect changes in environmental conditions. However, while considerable progress has been made... (Review)
Review
Bacterial and fungal growth rate measurements are sensitive variables to detect changes in environmental conditions. However, while considerable progress has been made in methods to assess the species composition and biomass of fungi and bacteria, information about growth rates remains surprisingly rudimentary. We review the recent history of approaches to assess bacterial and fungal growth rates, leading up to current methods, especially focusing on leucine/thymidine incorporation to estimate bacterial growth and acetate incorporation into ergosterol to estimate fungal growth. We present the underlying assumptions for these methods, compare estimates of turnover times for fungi and bacteria based on them, and discuss issues, including for example elusive conversion factors. We review what the application of fungal and bacterial growth rate methods has revealed regarding the influence of the environmental factors of temperature, moisture (including drying/rewetting), pH, as well as the influence of substrate additions, the presence of plants and toxins. We highlight experiments exploring the competitive and facilitative interaction between bacteria and fungi enabled using growth rate methods. Finally, we predict that growth methods will be an important complement to molecular approaches to elucidate fungal and bacterial ecology, and we identify methodological concerns and how they should be addressed.
Topics: Acetates; Bacteria; Biomass; Desiccation; Ecosystem; Ergosterol; Fungi; Leucine; Soil; Soil Microbiology; Thymidine
PubMed: 21470255
DOI: 10.1111/j.1574-6941.2011.01106.x -
Science Advances Jan 2021Ergosterol-targeting amphotericin B (AmB) is the first line of defense for life-threatening fungal infections. Two models have been proposed to illustrate AmB assembly...
Ergosterol-targeting amphotericin B (AmB) is the first line of defense for life-threatening fungal infections. Two models have been proposed to illustrate AmB assembly in the cell membrane; one is the classical ion channel model in which AmB vertically forms transmembrane tunnel and the other is a recently proposed sterol sponge model where AmB is laterally adsorbed onto the membrane surface. To address this controversy, we use polarization-sensitive stimulated Raman scattering from fingerprint C═C stretching vibration to visualize AmB, ergosterol, and lipid in single fungal cells. Intracellular lipid droplet accumulation in response to AmB treatment is found. AmB is located in membrane and intracellular droplets. In the 16 strains studied, AmB residing inside cell membrane was highly ordered, and its orientation is primarily parallel to phospholipid acyl chains, supporting the ion channel model. Label-free imaging of AmB and chemical contents offers an analytical platform for developing low-toxicity, resistance-refractory antifungal agents.
Topics: Amphotericin B; Candida; Ergosterol; Ion Channels; Spectrum Analysis, Raman
PubMed: 33523971
DOI: 10.1126/sciadv.abd5230 -
Nihon Ishinkin Gakkai Zasshi = Japanese... 2000Cell walls (0.1-0.5 microm in thickness) of dermatophytes, at least Trichophyton mentagrophytes and Epidermophyton floccosum, are built of microfibrils (20 nm in... (Review)
Review
Cell walls (0.1-0.5 microm in thickness) of dermatophytes, at least Trichophyton mentagrophytes and Epidermophyton floccosum, are built of microfibrils (20 nm in diameter) and matrix embedding the fibrils. These fibrils are composed of chitin (70-80%) and a small amount of glucans, and the matrix is composed of beta-1-3, beta1-6 glucan, glucomannan, galactomannan and peptides. Another characteristic structure is the outermost layer (20-50 nm in thickness) of the cell wall, which consists of hydrophobic protein rodlets. Lipids are thought to play important roles in the regulation of dimorphism and virulence in pathogenic fungus. Generally, the ratio of phospholipid/ergosterol is less than 1 in yeast form and 2-20 in mycelial form cells in Candida albicans and Sporothrix schenckii. During the transition from yeast to mycelial forms, phosphatidylinositol and phosphatidylserine are reduced, whereas phosphatidylcholine increases. Phospho-lipase D is activated on this transition. Phospholipase B is now known to be a virulence factor in C. albicans. Polyene antifungal agents bind to ergosterol in membrane to form complexes, which generate pores and destroy the structures and functions of membrane. Azole antifungal agents inhibit the synthesis of ergosterol leading to deficiency in ergosterol content in membrane, and impair the function of membranes in fungal cells. We show the effects of polyenes on the ultrastructure of fungal plasma membrane and impairment of ionomycin-induced calcium influx in T. mentagrophytes, so that we can compare the differences in mode of actions between these two groups of agents.
Topics: Antifungal Agents; Arthrodermataceae; Azoles; Calcium; Cell Wall; Chitin; Ergosterol; Glucans; Lysophospholipase; Membrane Lipids; Polyenes; Virulence
PubMed: 11064317
DOI: No ID Found -
Frontiers in Immunology 2022Animals adjust their lipid metabolism states in response to pathogens infection. However, the underlying molecular mechanisms for how lipid metabolism responds to...
Animals adjust their lipid metabolism states in response to pathogens infection. However, the underlying molecular mechanisms for how lipid metabolism responds to infection remain to be elusive. In this study, we assessed the temporal changes of lipid metabolism profiles during infection by an integrated transcriptomics and lipidomics analysis. Ergosterol is identified to be required for proper host defense to pathogens. Notably, ergosterol level is increased in the hemolymph upon bacterial infection. We show that the increase of ergosterol level by food supplement or genetic depletion of Acsl, a long-chain fatty acid-CoA synthetase, promotes host survival against bacterial challenges. Together, our results suggest a critical role of lipid metabolism adaption in the process of host defense against invading pathogens.
Topics: Animals; Bacterial Infections; Drosophila; Ergosterol; Lipidomics; Transcriptome
PubMed: 35874695
DOI: 10.3389/fimmu.2022.933137 -
Biotechnology Letters Dec 2023The aim was to screen di- and triterpenes as potential biocides against fungal pathogens (Alternaria sp., Fusarium avenaceum, F. sambucinum, Botrytis cinerea, Botryotina...
The aim was to screen di- and triterpenes as potential biocides against fungal pathogens (Alternaria sp., Fusarium avenaceum, F. sambucinum, Botrytis cinerea, Botryotina fuckeliana, Mycocentrospora acerina, Cylindrocarpon sp.) and oomycetes (Phytophthora cactorum, P. fragariae). Results We measured the antifungal activity of terpenes by estimating the growth area, ergosterol content and level of lipid peroxidation. Fungi and oomycetes were grown on solid media in Petri dishes. As a positive control, we used a common synthetic fungicide, fosetyl-Al. Di- and triterpenes showed promising potential as biocides against most of the studied species. The responses of fungi and oomycetes were dependent on the specific type of terpenes and identity of the fungi. Compared to synthetic fungicide, terpenes were equally effective as antifungal agents and even more effective for some species, especially for oomycetes. The terpene mode of action includes inhibition of ergosterol synthesis and increased lipid peroxidation. Conclusions Di- and triterpenes, natural compounds that are very abundant in northern countries, are excellent candidates for biocides.
Topics: Fungicides, Industrial; Triterpenes; Fungi; Antifungal Agents; Diterpenes; Phytophthora; Ergosterol
PubMed: 37910278
DOI: 10.1007/s10529-023-03438-z -
Clinical Microbiology and Infection :... Aug 2017Candida parapsilosis is a healthcare-related fungal pathogen particularly common among immunocompromised patients. Our understanding of antifungal resistance mechanisms...
OBJECTIVES
Candida parapsilosis is a healthcare-related fungal pathogen particularly common among immunocompromised patients. Our understanding of antifungal resistance mechanisms in C. parapsilosis remains very limited. We previously described an azole-resistant strain of C. parapsilosis (BC014R), obtained following exposure in vitro to posaconazole. Resistance was associated with overexpression of ergosterol biosynthetic genes (ERG genes), together with the transcription factors UPC2 (CPAR2-207280) and NDT80 (CPAR2-213640). The aim of this study was to identify the mechanisms underlying posaconazole resistance of the BC014R strain.
METHODS
To identify the causative mutation, we sequenced the genomes of the susceptible (BC014S) and resistant (BC014R) isolates, using Illumina technology. Ergosterol content was assessed in both strains by mass spectrometry. UPC2 and NDT80 genes were deleted in BC014R strain. Mutants were characterized regarding their azole susceptibility profile and ERG gene expression.
RESULTS
One homozygous missense mutation (R135I) was found in ERG3 (CPAR2-105550) in the azole-resistant isolate. We show that Erg3 activity is completely impaired, resulting in a build up of sterol intermediates and a failure to generate ergosterol. Deleting UPC2 and NDT80 in BC014R reduces the expression of ERG genes and restores susceptibility to azole drugs.
CONCLUSIONS
A missense mutation in the ERG3 gene results in azole resistance and up-regulation of ERG genes expression. We propose that this mutation prevents the formation of toxic intermediates when cells are treated with azoles. Resistance can be reversed by deleting Upc2 and Ndt80 transcription factors. UPC2 plays a stronger role in C. parapsilosis azole resistance than does NDT80.
Topics: Antifungal Agents; Azoles; Candida parapsilosis; Drug Resistance, Fungal; Ergosterol; Fungal Proteins; Gene Deletion; Gene Expression Profiling; Mass Spectrometry; Microbial Sensitivity Tests; Mutation, Missense; Oxidoreductases; Provitamins; Transcription Factors; Whole Genome Sequencing
PubMed: 28196695
DOI: 10.1016/j.cmi.2017.02.002