scholarly journals SUMOylation in Human Pathogenic Fungi: Role in Physiology and Virulence

2020 ◽  
Vol 6 (1) ◽  
pp. 32
Author(s):  
Mahima Sagar Sahu ◽  
Sandip Patra ◽  
Kundan Kumar ◽  
Rupinder Kaur
Keyword(s):  
Protein Modification ◽  
Sequence Similarity ◽  
In Silico Analysis ◽  
Pathogenic Fungi ◽  
Mammalian Host ◽  
Nuclear Pore ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pathogenic Yeast ◽  
Sumo Conjugation

The small ubiquitin-related modifier (SUMO) protein is an important component of the post-translational protein modification systems in eukaryotic cells. It is known to modify hundreds of proteins involved in diverse cellular processes, ranging from nuclear pore dynamics to signal transduction pathways. Owing to its reversible nature, the SUMO-conjugation of proteins (SUMOylation) holds a prominent place among mechanisms that regulate the functions of a wide array of cellular proteins. The dysfunctional SUMOylation system has been associated with many human diseases, including neurodegenerative and autoimmune disorders. Furthermore, the non-pathogenic yeast Saccharomyces cerevisiae has served as an excellent model to advance our understanding of enzymes involved in SUMOylation and proteins modified by SUMOylation. Taking advantage of the tools and knowledge obtained from the S. cerevisiae SUMOylation system, research on fungal SUMOylation is beginning to gather pace, and new insights into the role of SUMOylation in the pathobiology of medically important fungi are emerging. Here, we summarize the known information on components of the SUMOylation machinery, and consequences of overexpression or deletion of these components in the human pathogenic fungi, with major focus on two prevalent Candida bloodstream pathogens, C. albicans and C. glabrata. Additionally, we have identified SUMOylation components, through in silico analysis, in four medically relevant fungi, and compared their sequence similarity with S. cerevisiae counterparts. SUMOylation modulates the virulence of C. albicans and C. glabrata, while it is required for conidia production in Aspergillus nidulans and A. flavus. In addition to highlighting these recent developments, we discuss how SUMOylation fine tunes the expression of virulence factors, and influences survival of fungal cells under diverse stresses in vitro and in the mammalian host.

scholarly journals Tomatinase from Fusarium oxysporum f. sp. lycopersici Is Required for Full Virulence on Tomato Plants

2008 ◽  
Vol 21 (6) ◽  
pp. 728-736 ◽  
Author(s):  
Yolanda Pareja-Jaime ◽  
M. Isabel G. Roncero ◽  
M. Carmen Ruiz-Roldán
Keyword(s):  
Fusarium Oxysporum ◽  
Hydrolysis Product ◽  
Disease Process ◽  
In Silico Analysis ◽  
Pathogenic Fungi ◽  
Infection Process ◽  
Detoxification Enzymes ◽  
Glycosyl Hydrolases ◽  
Tomato Plants

Saponin detoxification enzymes from pathogenic fungi are involved in the infection process of their host plants. Fusarium oxysporum f. sp lycopersici, a tomato pathogen, produces the tomatinase enzyme Tom1, which degrades α-tomatine to less toxic derivates. To study the role of the tom1 gene in the virulence of F. oxysporum, we performed targeted disruption and overexpression of the gene. The infection process of tomato plants inoculated with transformants constitutively producing Tom1 resulted in an increase of symptom development. By contrast, tomato plants infected with the knockout mutants showed a delay in the disease process, indicating that Tom1, although not essential for pathogenicity, is required for the full virulence of F. oxysporum. Total tomatinase activity in the disrupted strains was reduced only 25%, leading to β2-tomatine as the main hydrolysis product of the saponin in vitro. In silico analysis of the F. oxysporum genome revealed the existence of four additional putative tomatinase genes with identities to tomatinases from family 3 of glycosyl hydrolases. These might be responsible for the remaining tomatinase activity in the Δtom1 mutants. Our results indicate that detoxification of α-tomatine in F. oxysporum is carried out by several tomatinase activities, suggesting the importance of these enzymes during the infection process.

scholarly journals Candida albicans Cyclin Clb4 Carries S-Phase Cyclin Activity

2010 ◽  
Vol 9 (9) ◽  
pp. 1311-1319 ◽  
Author(s):  
Ayala Ofir ◽  
Daniel Kornitzer
Keyword(s):  
Cell Cycle ◽  
Candida Albicans ◽  
Cell Cycle Progression ◽  
Sequence Similarity ◽  
Eukaryotic Cell ◽  
S Phase ◽  
Pathogenic Yeast ◽  
Content Type

ABSTRACT Cyclin-dependent kinases (CDKs) are key regulators of eukaryotic cell cycle progression. The cyclin subunit activates the CDK and also imparts to the complex, at least in some cases, substrate specificity. Saccharomyces cerevisiae, an organism in which the roles of individual cyclins are best studied, contains nine cyclins (three G1 cyclins and six B-type cyclins) capable of activating the main cell cycle CDK, Cdc28. Analysis of the genome of the pathogenic yeast Candida albicans revealed only two sequences corresponding to B-type cyclins, C. albicans Clb2 (CaClb2) and CaClb4. Notably, no homolog of the S. cerevisiae S-phase-specific cyclins, Clb5/Clb6, could be detected. Here, we performed an in vitro analysis of the activity of CaClb2 and CaClb4 and of three G1 cyclins, as well as an analysis of the phenotype of S. cerevisiae cells expressing CaClb2 or CaClb4 instead of Clb5. Remarkably, replacement of CLB5 by CaCLB4 caused rapid diploidization of S. cerevisiae. In addition, both in vivo and in vitro analyses indicate that, in spite of the higher sequence similarity of CaClb2 to Clb5/Clb6, CaClb4 is the functional homolog of Clb5/Clb6. The activity of a CaClb2/CaClb4 cyclin hybrid suggests that the cyclin box domain of CaClb4 carries the functional specificity of the protein. These results have implications for our understanding of the evolution of specificity of the cell cycle cyclins.

scholarly journals Yeast Los1p Has Properties of an Exportin-Like Nucleocytoplasmic Transport Factor for tRNA

1998 ◽  
Vol 18 (11) ◽  
pp. 6374-6386 ◽  
Author(s):  
Klaus Hellmuth ◽  
Denise M. Lau ◽  
F. Ralf Bischoff ◽  
Markus Künzler ◽  
Ed Hurt ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Sequence Similarity ◽  
Nucleocytoplasmic Transport ◽  
Dominant Negative ◽  
Nuclear Pore ◽  
Negative Effects ◽  
Nuclear Pore Protein ◽  
Vitro Binding ◽  
The Family

ABSTRACT Saccharomyces cerevisiae Los1p, which is genetically linked to the nuclear pore protein Nsp1p and several tRNA biogenesis factors, was recently grouped into the family of importin/karyopherin-β-like proteins on the basis of its sequence similarity. In a two-hybrid screen, we identified Nup2p as a nucleoporin interacting with Los1p. Subsequent purification of Los1p from yeast demonstrates its physical association not only with Nup2p but also with Nsp1p. By the use of the Gsp1p-G21V mutant, Los1p was shown to preferentially bind to the GTP-bound form of yeast Ran. Furthermore, overexpression of full-length or N-terminally truncated Los1p was shown to have dominant-negative effects on cell growth and different nuclear export pathways. Finally, Los1p could interact with Gsp1p-GTP, but only in the presence of tRNA, as revealed in an indirect in vitro binding assay. These data confirm the homology between Los1p and the recently identified human exportin for tRNA and reinforce the possibility of a role for Los1p in nuclear export of tRNA in yeast.

scholarly journals Comparison of the RNA Content of Extracellular Vesicles Derived from Paracoccidioides brasiliensis and Paracoccidioides lutzii

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 765 ◽  
Author(s):  
Roberta Peres da Silva ◽  
Larissa G. V. Longo ◽  
Julia P. C. da Cunha ◽  
Tiago J. P. Sobreira ◽  
Marcio L. Rodrigues ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Protein Modification ◽  
Paracoccidioides Brasiliensis ◽  
Pathogenic Fungi ◽  
In Vitro Translation ◽  
Rna Seq ◽  
Rna Content ◽  
Oxidation Reduction ◽  
Culture Supernatants

Paracoccidioides brasiliensis and P. lutzii cause human paracoccidioidomycosis. We have previously characterized the <200-nt RNA sub-populations contained in fungal extracellular vesicles (EVs) from P. brasiliensis Pb18 and other pathogenic fungi. We have presently used the RNA-seq strategy to compare the <200- and >200-nt RNA fractions contained in EVs isolated from culture supernatants of P. brasiliensis Pb18, Pb3, and P. lutzii Pb01. Shared mRNA sequences were related to protein modification, translation, and DNA metabolism/biogenesis, while those related to transport and oxidation-reduction were exclusive to Pb01. The presence of functional full-length mRNAs was validated by in vitro translation. Among small non-coding (nc)RNA, 15 were common to all samples; small nucleolar (sno)RNAs were enriched in P. brasiliensis EVs, whereas for P. lutzii there were similar proportions of snoRNA, rRNA, and tRNA. Putative exonic sRNAs were highly abundant in Pb18 EVs. We also found sRNA sequences bearing incomplete microRNA structures mapping to exons. RNA-seq data suggest that extracellular fractions containing Pb18 EVs can modulate the transcriptome of murine monocyte-derived dendritic cells in a transwell system. Considering that sRNA classes are involved in transcription/translation modulation, our general results may indicate that differences in virulence among fungal isolates can be related to their distinct EV-RNA content.

scholarly journals In Vitro Phenotypic Activity and In Silico Analysis of Natural Products from Brazilian Biodiversity on Trypanosoma cruzi

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5676
Author(s):  
Raiza B. Peres ◽  
Ludmila F. de A. Fiuza ◽  
Patrícia B. da Silva ◽  
Marcos M. Batista ◽  
Flávia da C. Camillo ◽  
...  
Keyword(s):  
Natural Products ◽  
Trypanosoma Cruzi ◽  
In Silico ◽  
In Silico Analysis ◽  
Mammalian Host ◽  
Reference Drug ◽  
Wide Range ◽  
Pure Compounds ◽  
Silico Analysis

Chagas disease (CD) affects more than 6 million people worldwide. The available treatment is far from ideal, creating a demand for new alternative therapies. Botanical diversity provides a wide range of novel potential therapeutic scaffolds. Presently, our aim was to evaluate the mammalian host toxicity and anti-Trypanosoma cruzi activity of botanic natural products including extracts, fractions and purified compounds obtained from Brazilian flora. In this study, 36 samples of extracts and fractions and eight pure compounds obtained from seven plant species were evaluated. The fraction dichloromethane from Aureliana fasciculata var. fasciculata (AFfPD) and the crude extract of Piper tectoniifolium (PTFrE) showed promising trypanosomicidal activity. AFfPD and PTFrE presented EC50 values 10.7 ± 2.8 μg/mL and 12.85 ± 1.52 μg/mL against intracellular forms (Tulahuen strain), respectively. Additionally, both were active upon bloodstream trypomastigotes (Y strain), exhibiting EC50 2.2 ± 1.0 μg/mL and 38.8 ± 2.1 μg/mL for AFfPD and PTFrE, respectively. Importantly, AFfPD is about five-fold more potent than Benznidazole (Bz), the reference drug for CD, also reaching lower EC90 value (7.92 ± 2.2 μg/mL) as compared to Bz (23.3 ± 0.6 μg/mL). Besides, anti-parasitic effect of eight purified botanic substances was also investigated. Aurelianolide A and B (compounds 1 and 2) from A. fasciculata and compound 8 from P. tuberculatum displayed the best trypanosomicidal effect. Compounds 1, 2 and 8 showed EC50 of 4.6 ± 1.3 μM, 1.6 ± 0.4 μM and 8.1 ± 0.9 μM, respectively against intracellular forms. In addition, in silico analysis of these three biomolecules was performed to predict parameters of absorption, distribution, metabolism and excretion. The studied compounds presented similar ADMET profile as Bz, without presenting mutagenicity and hepatotoxicity aspects as predicted for Bz. Our findings indicate that these natural products have promising anti-T. cruzi effect and may represent new scaffolds for future lead optimization.

scholarly journals Yeast Hsl7 (histone synthetic lethal 7) catalyses the in vitro formation of ω-NG-monomethylarginine in calf thymus histone H2A

2006 ◽  
Vol 395 (3) ◽  
pp. 563-570 ◽  
Author(s):  
Tina Branscombe Miranda ◽  
Joyce Sayegh ◽  
Adam Frankel ◽  
Jonathan E. Katz ◽  
Mark Miranda ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Protein ◽  
Sequence Similarity ◽  
Arginine Methylation ◽  
Histone H2a ◽  
Yeast Saccharomyces Cerevisiae ◽  
Synthetic Lethal ◽  
Calf Thymus

The HSL7 (histone synthetic lethal 7) gene in the yeast Saccharomyces cerevisiae encodes a protein with close sequence similarity to the mammalian PRMT5 protein, a member of the class of protein arginine methyltransferases that catalyses the formation of ω-NG-monomethylarginine and symmetric ω-NG,N′G-dimethylarginine residues in a number of methyl-accepting species. A full-length HSL7 construct was expressed as a FLAG-tagged protein in Saccharomyces cerevisiae. We found that FLAG-tagged Hsl7 effectively catalyses the transfer of methyl groups from S-adenosyl-[methyl-3H]-L-methionine to calf thymus histone H2A. When the acid-hydrolysed radiolabelled protein products were separated by high-resolution cation-exchange chromatography, we were able to detect one tritiated species that co-migrated with an ω-NG-monomethylarginine standard. No radioactivity was observed that co-migrated with either the asymmetric or symmetric dimethylated derivatives. In control experiments, no methylation of histone H2A was found with two mutant constructs of Hsl7. Surprisingly, FLAG–Hsl7 does not appear to effectively catalyse the in vitro methylation of a GST (glutathione S-transferase)–GAR [glycine- and arginine-rich human fibrillarin-(1–148) peptide] fusion protein or bovine brain myelin basic protein, both good methyl-accepting substrates for the human homologue PRMT5. Additionally, FLAG–Hsl7 demonstrates no activity on purified calf thymus histones H1, H2B, H3 or H4. GST–Rmt1, the GST-fusion protein of the major yeast protein arginine methyltransferase, was also found to methylate calf thymus histone H2A. Although we detected Rmt1-dependent arginine methylation in vivo in purified yeast histones H2A, H2B, H3 and H4, we found no evidence for Hsl7-dependent methylation of endogenous yeast histones. The physiological substrates of the Hsl7 enzyme remain to be identified.

The Formation, Structure, Distribution and Frequency of Nuclear Pores

1971 ◽  
Vol 29 ◽  
pp. 518-519
Author(s):  
G. G. Maul
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Membrane ◽  
Dynamic Structure ◽  
Nuclear Pore ◽  
Nuclear Pores ◽  
Filter Function ◽  
Etching Technique ◽  
Selective Filter ◽  
Membranous Part

The chromatin of eukaryotic cells is separated from the cytoplasm by a double membrane. One obvious structural specialization of the nuclear membrane is the presence of pores which have been implicated to facilitate the selective nucleocytoplasmic exchange of a variety of large molecules. Thus, the function of nuclear pores has mainly been regarded to be a passive one. Non-membranous diaphragms, radiating fibers, central rings, and other pore-associated structures were thought to play a role in the selective filter function of the nuclear pore complex. Evidence will be presented that suggests that the nuclear pore is a dynamic structure which is non-randomly distributed and can be formed during interphase, and that a close relationship exists between chromatin and the membranous part of the nuclear pore complex.Octagonality of the nuclear pore complex has been confirmed by a variety of techniques. Using the freeze-etching technique, it was possible to show that the membranous part of the pore complex has an eight-sided outline in human melanoma cells in vitro. Fibers which traverse the pore proper at its corners are continuous and indistinguishable from chromatin at the nucleoplasmic side, as seen in conventionally fixed and sectioned material. Chromatin can be seen in octagonal outline if serial sections are analyzed which are parallel but do not include nuclear membranes (Fig. 1). It is concluded that the shape of the pore rim is due to fibrous material traversing the pore, and may not have any functional significance. In many pores one can recognize a central ring with eight fibers radiating to the corners of the pore rim. Such a structural arrangement is also found to connect eight ribosomes at the nuclear membrane.

A Comparison of the Effect of Decorsin and Two Disintegrins, Albolabrin and Eristostatin, on Platelet Function

1995 ◽  
Vol 74 (05) ◽  
pp. 1316-1322 ◽  
Author(s):  
Mary Ann McLane ◽  
Jagadeesh Gabbeta ◽  
A Koneti Rao ◽  
Lucia Beviglia ◽  
Robert A Lazarus ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Sequence Similarity ◽  
Platelet Aggregation Inhibitors ◽  
Antiplatelet Drug ◽  
Rgd Sequence ◽  
Fibrinogen Receptor ◽  
Activated Platelets

SummaryNaturally-occurring fibrinogen receptor antagonists and platelet aggregation inhibitors that are found in snake venom (disintegrins) and leeches share many common features, including an RGD sequence, high cysteine content, and low molecular weight. There are, however, significant selectivity and potency differences. We compared the effect of three proteins on platelet function: albolabrin, a 7.5 kDa disintegrin, eristostatin, a 5.4 kDa disintegrin in which part of the disintegrin domain is deleted, and decorsin, a 4.5 kDa non-disintegrin derived from the leech Macrobdella decora, which has very little sequence similarity with either disintegrin. Decorsin was about two times less potent than albolabrin and six times less potent than eristostatin in inhibiting ADP- induced human platelet aggregation. It had a different pattern of interaction with glycoprotein IIb/IIIa as compared to the two disintegrins. Decorsin bound with a low affinity to resting platelets (409 nM) and to ADP-activated platelets (270 nM), and with high affinity to thrombin- activated platelets (74 nM). At concentrations up to 685 nM, it did not cause expression of a ligand-induced binding site epitope on the (β3 subunit of the GPIIb/IIIa complex. It did not significantly inhibit isolated GPIIb/IIIa binding to immobilized von Willebrand Factor. At low doses (1.5-3.0 μg/mouse), decorsin protected mice against death from pulmonary thromboembolism, showing an effect similar to eristostatin. This suggested that decorsin is a much more potent inhibitor of platelet aggregation in vivo than in vitro, and it may have potential as an antiplatelet drug.

Improved Production of Two Anti-Candida Lipopeptide Homologues Co- Produced by the Wild-Type Bacillus subtilis RLID 12.1 under Optimized Conditions

2020 ◽  
Vol 21 (5) ◽  
pp. 438-450
Author(s):  
Ramya Ramchandran ◽  
Swetha Ramesh ◽  
Anviksha A ◽  
RamLal Thakur ◽  
Arunaloke Chakrabarti ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pathogenic Fungi ◽  
Fold Increase ◽  
Production Yield ◽  
Yield Enhancement ◽  
Bioactive Metabolites ◽  
Candida Auris ◽  
Media Formulation ◽  
Static Conditions

Background:: Antifungal cyclic lipopeptides, bioactive metabolites produced by many species of the genus Bacillus, are promising alternatives to synthetic fungicides and antibiotics for the biocontrol of human pathogenic fungi. In a previous study, the co- production of five antifungal lipopeptides homologues (designated as AF1, AF2, AF3, AF4 and AF5) by the producer strain Bacillus subtilis RLID 12.1 using unoptimized medium was reported; though the two homologues AF3 and AF5 differed by 14 Da and in fatty acid chain length were found effective in antifungal action, the production/ yield rate of these two lipopeptides determined by High-Performance Liquid Chromatography was less in the unoptimized media. Methods:: In this study, the production/yield enhancement of the two compounds AF3 and AF5 was specifically targeted. Following the statistical optimization (Plackett-Burman and Box-Behnken designs) of media formulation, temperature and growth conditions, the production of AF3 and AF5 was improved by about 25.8- and 7.4-folds, respectively under static conditions. Results:: To boost the production of these two homologous lipopeptides in the optimized media, heat-inactivated Candida albicans cells were used as a supplement resulting in 34- and 14-fold increase of AF3 and AF5, respectively. Four clinical Candida auris isolates had AF3 and AF5 MICs (100 % inhibition) ranging between 4 and 16 μg/ml indicating the lipopeptide’s clinical potential. To determine the in vitro pharmacodynamic potential of AF3 and AF5, time-kill assays were conducted which showed that AF3 (at 4X and 8X concentrations) at 48h exhibited mean log reductions of 2.31 and 3.14 CFU/ml of C. albicans SC 5314, respectively whereas AF5 at 8X concentration showed a mean log reduction of 2.14 CFU/ml. Conclusion:: With the increasing threat of multidrug-resistant yeasts and fungi, these antifungal lipopeptides produced by optimized method promise to aid in the development of novel antifungal that targets disease-causing fungi with improved efficacy.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli
Keyword(s):  
Drug Targets ◽  
Redox Homeostasis ◽  
Cost Effective ◽  
Structural Features ◽  
Mammalian Host ◽  
Neglected Diseases ◽  
Nitrogen Compounds ◽  
Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

Sign in / Sign up

Export Citation Format

Share Document