scholarly journals Telomeric and Sub-Telomeric Structure and Implications in Fungal Opportunistic Pathogens

2021 ◽  
Vol 9 (7) ◽  
pp. 1405
Author(s):  
Raffaella Diotti ◽  
Michelle Esposito ◽  
Chang Hui Shen
Keyword(s):  
Fungal Pathogens ◽  
Functional Abilities ◽  
Opportunistic Pathogens ◽  
Telomeric Sequences ◽  
Coding Regions ◽  
Telomeric Structure ◽  
Linear Chromosomes ◽  
Dna Ends ◽  
Telomere Structure

Telomeres are long non-coding regions found at the ends of eukaryotic linear chromosomes. Although they have traditionally been associated with the protection of linear DNA ends to avoid gene losses during each round of DNA replication, recent studies have demonstrated that the role of these sequences and their adjacent regions go beyond just protecting chromosomal ends. Regions nearby to telomeric sequences have now been identified as having increased variability in the form of duplications and rearrangements that result in new functional abilities and biodiversity. Furthermore, unique fungal telomeric and chromatin structures have now extended clinical capabilities and understanding of pathogenicity levels. In this review, telomere structure, as well as functional implications, will be examined in opportunistic fungal pathogens, including Aspergillus fumigatus, Candida albicans, Candida glabrata, and Pneumocystis jirovecii.

scholarly journals Telomere Structure Regulates the Heritability of Repressed Subtelomeric Chromatin in Saccharomyces cerevisiae

Genetics ◽  
2000 ◽  
Vol 154 (2) ◽  
pp. 587-598 ◽  
Author(s):  
Yangsuk Park ◽  
Arthur J Lustig
Keyword(s):  
Position Effect ◽  
Dna Structures ◽  
Telomeric Structure ◽  
Pol Iii ◽  
Linear Chromosomes ◽  
In Cis ◽  
Telomere Structure ◽  
Predominant Effect ◽  
Subtelomeric Regions

Abstract Telomeres, the protein-DNA structures present at the termini of linear chromosomes, are capable of conferring a reversible repression of Pol II- and Pol III-transcribed genes positioned in adjacent subtelomeric regions. This phenomenon, termed telomeric silencing, is likely to be the consequence of a more global telomere position effect at the level of chromatin structure. To understand the role of telomere structure in this position effect, we have developed an assay to distinguish between the heritability of transcriptionally repressed and derepressed states in yeast. We have previously demonstrated that an elongated telomeric tract leads to hyperrepression of telomere-adjacent genes. We show here that the predominant effect of elongated telomeres is to increase the inheritance of the repressed state in cis. Interestingly, the presence of elongated telomeres overcomes the partial requirement of yCAF-1 in silencing. We propose that the formation of a specific telomeric structure is necessary for the heritability of repressed subtelomeric chromatin.

scholarly journals Chromosome End Maintenance by Telomerase

2009 ◽  
Vol 284 (24) ◽  
pp. 16061-16065 ◽  
Author(s):  
Jennifer L. Osterhage ◽  
Katherine L. Friedman
Keyword(s):  
Genome Stability ◽  
Chromosomal Abnormalities ◽  
Human Aging ◽  
Dna Complexes ◽  
Telomeric Sequences ◽  
Telomere Elongation ◽  
Telomere Function ◽  
Multiple Levels ◽  
Linear Chromosomes

Telomeres, protein-DNA complexes at the ends of eukaryotic linear chromosomes, are essential for genome stability. The accumulation of chromosomal abnormalities in the absence of proper telomere function is implicated in human aging and cancer. Repetitive telomeric sequences are maintained by telomerase, a ribonucleoprotein complex containing a reverse transcriptase subunit, a template RNA, and accessory components. Telomere elongation is regulated at multiple levels, including assembly of the telomerase holoenzyme, recruitment of telomerase to the chromosome terminus, and telomere accessibility. This minireview provides an overview of telomerase structure, function, and regulation and the role of telomerase in human disease.

scholarly journals Production of Phytotoxic Metabolites by Botryosphaeriaceae in Naturally Infected and Artificially Inoculated Grapevines

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 802
Author(s):  
Pierluigi Reveglia ◽  
Regina Billones-Baaijens ◽  
Jennifer Millera Millera Niem ◽  
Marco Masi ◽  
Alessio Cimmino ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Protocatechuic Acid ◽  
Physiological Factors ◽  
Diplodia Seriata ◽  
Grapevine Trunk Diseases ◽  
Botryosphaeria Dieback ◽  
Trunk Diseases ◽  
One Year ◽  
Pathogen Dna

Grapevine trunk diseases (GTDs) are considered a serious problem to viticulture worldwide. Several GTD fungal pathogens produce phytotoxic metabolites (PMs) that were hypothesized to migrate to the foliage where they cause distinct symptoms. The role of PMs in the expression of Botryosphaeria dieback (BD) symptoms in naturally infected and artificially inoculated wood using molecular and analytical chemistry techniques was investigated. Wood samples from field vines naturally infected with BD and one-year-old vines inoculated with Diplodia seriata, Spencermartinsia viticola and Dothiorella vidmadera were analysed by cultural isolations, quantitative PCR (qPCR) and targeted LC-MS/MS to detect three PMs: (R)-mellein, protocatechuic acid and spencertoxin. (R)-mellein was detected in symptomatic naturally infected wood and vines artificially inoculated with D. seriata but was absent in all non-symptomatic wood. The amount of (R)-mellein detected was correlated with the amount of pathogen DNA detected by qPCR. Protocatechuic acid and spencertoxin were absent in all inoculated wood samples. (R)-mellein may be produced by the pathogen during infection to break down the wood, however it was not translocated into other parts of the vine. The foliar symptoms previously reported in vineyards may be due to a combination of PMs produced and climatic and physiological factors that require further investigation.

scholarly journals Post-Translational Modifications Drive Success and Failure of Fungal–Host Interactions

2021 ◽  
Vol 7 (2) ◽  
pp. 124
Author(s):  
Charmaine Retanal ◽  
Brianna Ball ◽  
Jennifer Geddes-McAlister
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Treatment Options ◽  
Global Scale ◽  
Host Cells ◽  
Candida Spp ◽  
Post Translational Modifications ◽  
Fungal Host ◽  
Resistant Species

Post-translational modifications (PTMs) change the structure and function of proteins and regulate a diverse array of biological processes. Fungal pathogens rely on PTMs to modulate protein production and activity during infection, manipulate the host response, and ultimately, promote fungal survival. Given the high mortality rates of fungal infections on a global scale, along with the emergence of antifungal-resistant species, identifying new treatment options is critical. In this review, we focus on the role of PTMs (e.g., phosphorylation, acetylation, ubiquitination, glycosylation, and methylation) among the highly prevalent and medically relevant fungal pathogens, Candida spp., Aspergillus spp., and Cryptococcus spp. We explore the role of PTMs in fungal stress response and host adaptation, the use of PTMs to manipulate host cells and the immune system upon fungal invasion, and the importance of PTMs in conferring antifungal resistance. We also provide a critical view on the current knowledgebase, pose questions key to our understanding of the intricate roles of PTMs within fungal pathogens, and provide research opportunities to uncover new therapeutic strategies.

scholarly journals Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens

2017 ◽  
Vol 8 ◽  
Author(s):  
Soledad R. Ordonez ◽  
Edwin J. A. Veldhuizen ◽  
Martin van Eijk ◽  
Henk P. Haagsman
Keyword(s):  
Fungal Pathogens ◽  
Effector Molecules ◽  
Innate Effector

scholarly journals Genetic Separation of Sae2 Nuclease Activity from Mre11 Nuclease Functions in Budding Yeast

2017 ◽  
Vol 37 (24) ◽  
Author(s):  
Sucheta Arora ◽  
Rajashree A. Deshpande ◽  
Martin Budd ◽  
Judy Campbell ◽  
America Revere ◽  
...  
Keyword(s):  
Nuclease Activity ◽  
Double Strand Breaks ◽  
Endonuclease Activity ◽  
Dna Double Strand Breaks ◽  
Dna Breaks ◽  
Content Type ◽  
Strand Breaks ◽  
Dna Ends

ABSTRACT Sae2 promotes the repair of DNA double-strand breaks in Saccharomyces cerevisiae. The role of Sae2 is linked to the Mre11/Rad50/Xrs2 (MRX) complex, which is important for the processing of DNA ends into single-stranded substrates for homologous recombination. Sae2 has intrinsic endonuclease activity, but the role of this activity has not been assessed independently from its functions in promoting Mre11 nuclease activity. Here we identify and characterize separation-of-function mutants that lack intrinsic nuclease activity or the ability to promote Mre11 endonucleolytic activity. We find that the ability of Sae2 to promote MRX nuclease functions is important for DNA damage survival, particularly in the absence of Dna2 nuclease activity. In contrast, Sae2 nuclease activity is essential for DNA repair when the Mre11 nuclease is compromised. Resection of DNA breaks is impaired when either Sae2 activity is blocked, suggesting roles for both Mre11 and Sae2 nuclease activities in promoting the processing of DNA ends in vivo. Finally, both activities of Sae2 are important for sporulation, indicating that the processing of meiotic breaks requires both Mre11 and Sae2 nuclease activities.

scholarly journals ON THE QUESTION OF THE PATHOGENESIS OF HIV-INFECTION: THE ROLE OF IMMUNE ACTIVATION IN PROGRESSION OF DISEASE

2012 ◽  
Vol 17 (3) ◽  
pp. 47-52
Author(s):  
G. R. Khasanova ◽  
I. G. Mustafin ◽  
V. A. Anokhin
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Hiv Infection ◽  
Immune Activation ◽  
Opportunistic Pathogens ◽  
Rate Of Progression ◽  
Progression Of Disease ◽  
Modern Knowledge

Hyperactivaion of immme system is considered by most investigators as importantfactor, contributing to progression of HIV-infection and development ofAIDS. In the review modern knowledge about mechanisms and results of activation of immune system during HIV-infection are presented. HIV itself, opportunistic pathogens and components of gut microbiota, first of all, endotoxins ofgram-negative bacteria are considered as probable "activators" of immune system. High levels of endotoxin and markers of immune activation are associated with an even greater rate of progression of HIV-infection.

scholarly journals Comparison of different extraction kits to isolate microRNA fromGalleria mellonella(wax moth) larvae infected withMetarhizium brunneum(ARSEF4556)

2019 ◽  
Author(s):  
Muneefah A. Alenezi ◽  
Tariq M. Butt ◽  
Daniel C. Eastwood
Keyword(s):  
Fungal Pathogens ◽  
High Throughput Sequencing ◽  
Galleria Mellonella ◽  
Host Tissue ◽  
Tissue Cultures ◽  
Complex Environments ◽  
Infected Insect ◽  
Sequencing And Expression ◽  
Wax Moth

ABSTRACTMicroRNAs (miRNAs) play an important role in regulating gene expression and are involved in developmental processes in animals, plants and fungi. To understand the role of miRNAs in a biological system, it is important to optimise the extraction procedures to obtain high quality and quantity nucleic acid that enable high throughput sequencing and expression analysis. Numerous kit-based miRNA extraction protocols have been optimised generally to single cell or tissue cultures. Fungi, however, often occupy physically and chemically complex environments which miRNA make extraction challenging, such as fungal pathogens interacting within plant or animal host tissue. We used aGalleria mellonella(wax moth) larvae and entomopathogenic fungusMetarhizium brunneum ARSEF 4556host/pathogen model to compare commercially available miRNA extraction kits (Invitrogen PureLink™ miRNA Isolation Kit, Ambion mirVana™miRNA Isolation Kit and Norgen microRNA purification Kit). Our results showed reproducible and significant differences in miRNAs extraction between the kits, with the Invitrogen PureLink™ miRNA Isolation protocol demonstrating the best performance in terms of miRNA quantity, quality and integrity isolated from fungus-infected insect tissue.

scholarly journals Iron metabolismin conditions of infection. Review

2020 ◽  
pp. 90-99
Author(s):  
Yuriy P. Orlov ◽  
N. V Govorova ◽  
V. N Lukach ◽  
G. A Baitugaeva ◽  
A. V Klementyev ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Medical Literature ◽  
Bacterial Flora ◽  
Medical Community ◽  
Therapeutic Approaches ◽  
Iron Supply ◽  
Review Analysis ◽  
The Relationship ◽  
Iron Exchange

The purpose of writing the review. Analysis of publications on the role of iron metabolism in the manifestation of the septic process and the dependence of bacterial flora activity on the conditions of their access to iron. Methods. More than 200 publications in pubmed, Medline, EMBASE medical literature databases were analyzed between 2000 and 2018 using the search words: iron and infection, iron and sepsis, iron exchange, iron and bacteria - including and available works in domestic (e-library) literature. Results. The review uses materials from 61 publications that meet the challenges of the search and reflect both the relationship between iron exchange and the development of the septic process and the importance for the medical community of understanding the identified relationships in the search for future therapeutic approaches. Conclusion. The review provides evidence of direct iron involvement in the manifestation of the septic process caused by various bacterial (q/-) and fungal flora. Introduction of iron-hesing agents and ciderophon - conjugate drugs to infected patients today seems to be a biologically acceptable approach as an auxiliary therapy in the treatment of septic process caused by pathogens dependent on iron supply (many bacterial and fungal pathogens), but the problem that is being raised certainly requires further experimental and clinical research.

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