scholarly journals Candida auris gene expression: modulation upon caspofungin treatment

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Lysangela Alves ◽  
Rafaela Amatuzzi ◽  
Daniel Zamith-Miranda ◽  
Sharon Martins ◽  
Joshua Nosanchuk

Candida auris has emerged as a serious worldwide threat by causing invasive infections in humans that are frequently resistant to one or more conventional antifungal medications, resulting in high mortality rates. Against this backdrop, health warnings around the world have focused efforts on understanding C. auris fungal biology and effective treatment approaches to combat this fungus. To date, there is little information about C. auris gene expression regulation in response to antifungal treatment. Our integrated analyses focused on the comparative transcriptomics of C. auris in the presence and absence of caspofungin as well as a detailed analysis of the yeast's extracellular vesicle (EV)-RNA composition. The results showed that genes coding oxidative stress response, ribosomal proteins, cell wall, and cell cycle were significantly up-regulated in the presence of caspofungin, whereas transcriptional regulators and proteins related to nucleus were down-regulated. The mRNAs in the EVswere associated with the stress responses induced by caspofungin and the ncRNA content of the EVs shifted during caspofungin treatment. Altogether, the results provide further insights into the fungal response to caspofungin and demonstrate that analyses of C. auris growth under antifungal stress can elucidate resistance and survival mechanisms of this fungus in response to medical therapy.

2020 ◽  
Author(s):  
Daniel Zamith-Miranda ◽  
Rafaela F. Amatuzzi ◽  
Sharon T. Martins ◽  
Alexandre Z. Vieira ◽  
Isadora M. da Rocha ◽  
...  

ABSTRACTCandida auris has emerged as a serious worldwide threat by causing invasive infections in humans that are frequently resistant to one or more conventional antifungal medications, resulting in high mortality rates. Against this backdrop, health warnings around the world have focused efforts on understanding C. auris fungal biology and effective treatment approaches to combat this fungus. To date, there is little information about C. auris gene expression regulation in response to antifungal treatment. Our integrated analyses focused on the comparative transcriptomics of C. auris in the presence and absence of caspofungin as well as a detailed analysis of the yeast’s extracellular vesicle (EV)-RNA composition. The results showed that genes coding oxidative stress response, ribosomal proteins, cell wall, and cell cycle were significantly upregulated in the presence of caspofungin, whereas transcriptional regulators and proteins related to the nucleus were downregulated. The mRNAs in the EVs were associated with stress responses induced by caspofungin and the ncRNA content of the EVs shifted during caspofungin treatment. Altogether, the results provide further insights into the fungal response to caspofungin and demonstrate that analyses of C. auris growth under antifungal stress can elucidate resistance and survival mechanisms of this fungus in response to medical therapy.


2019 ◽  
Vol 20 (23) ◽  
pp. 5869 ◽  
Author(s):  
Rawana Alkhalili ◽  
Joel Wallenius ◽  
Björn Canbäck

The toxin-antitoxin (TA) systems have been attracting attention due to their role in regulating stress responses in prokaryotes and their biotechnological potential. Much recognition has been given to type II TA system of mesophiles, while thermophiles have received merely limited attention. Here, we are presenting the putative type II TA families encoded on the genomes of four Geobacillus strains. We employed the TA finder tool to mine for TA-coding genes and manually curated the results using protein domain analysis tools. We also used the NCBI BLAST, Operon Mapper, ProOpDB, and sequence alignment tools to reveal the geobacilli TA features. We identified 28 putative TA pairs, distributed over eight TA families. Among the identified TAs, 15 represent putative novel toxins and antitoxins, belonging to the MazEF, MNT-HEPN, ParDE, RelBE, and XRE-COG2856 TA families. We also identified a potentially new TA composite, AbrB-ParE. Furthermore, we are suggesting the Geobacillus acetyltransferase TA (GacTA) family, which potentially represents one of the unique TA families with a reverse gene order. Moreover, we are proposing a hypothesis on the xre-cog2856 gene expression regulation, which seems to involve the c-di-AMP. This study aims for highlighting the significance of studying TAs in Geobacillus and facilitating future experimental research.


2019 ◽  
Author(s):  
Jonathan Sandoval-Castillo ◽  
Katie Gates ◽  
Chris J. Brauer ◽  
Steve Smith ◽  
Louis Bernatchez ◽  
...  

AbstractResilience to environmental stressors due to climate warming is influenced by local adaptations, including the capacity for plastic responses. The recent literature has focussed on genomic signatures of climatic adaptation, however little work has been done to address how plastic capacity may be influenced by biogeographic history and evolutionary processes. Here, we investigate phenotypic plasticity as a target of climatic selection, hypothesising that lineages that evolved under warmer climate will exhibit greater plastic adaptive resilience to thermal stress. This was tested using common garden experiments to compare gene expression regulation within and among a temperate, a subtropical and a desert ecotype of Australian rainbowfish. Individuals from each ecotype were subjected to contemporary and projected summer thermal conditions for 2070, and their global patterns of gene expression were characterized using liver transcriptomes. Critical thermal maximums were also determined for each ecotype to assess thermal tolerance. A comparative phylogenetic expression variance and evolution model framework was used to assess plastic and evolved changes in gene expression. Similar changes in both the direction and the magnitude of expressed genes were found within ecotypes. Although most expressed genes were identified in all ecotypes, 532 genes were identified as candidates subject to ecotype-specific directional selection. Twenty-three of those genes showed signal of adaptive (i.e. genetic-based) plastic response to future increases in temperature. Network analyses demonstrated centrality of these genes in thermal response pathways, along with several highly conserved hub genes thought to be integral for heat stress responses. The greatest adaptive resilience to warming was shown by the subtropical ecotype, followed by the desert and temperate ecotypes. Our findings indicate that vulnerability to climate change will be highly influenced by biogeographic factors, and we stress the need for integrative assessments of climatic adaptive traits for accurate estimations of population and ecosystem responses.


2019 ◽  
Vol 20 (6) ◽  
pp. 1309 ◽  
Author(s):  
Ewa Kalemba ◽  
Ewelina Stolarska

Oxidation of methionine to methionine sulfoxide is a type of posttranslational modification reversed by methionine sulfoxide reductases (Msrs), which present an exceptionally high number of gene copies in plants. The side-form general antioxidant function-specific role of each Msr isoform has not been fully studied. Thirty homologous genes of Msr type A (MsrA) and type B (MsrB) that originate from the genomes of Arabidopsis thaliana, Populus trichocarpa, and Oryza sativa were analyzed in silico. From 109 to 201 transcription factors and responsive elements were predicted for each gene. Among the species, 220 and 190 common transcription factors and responsive elements were detected for the MsrA and MsrB isoforms, respectively. In a comparison of 14 MsrA and 16 MsrB genes, 424 transcription factors and responsive elements were reported in both types of genes, with almost ten times fewer unique elements. The transcription factors mainly comprised plant growth and development regulators, transcription factors important in stress responses with significant overrepresentation of the myeloblastosis viral oncogene homolog (MYB) and no apical meristem, Arabidopsis transcription activation factor and cup-shaped cotyledon (NAC) families and responsive elements sensitive to ethylene, jasmonate, sugar, and prolamine. Gene Ontology term-based functional classification revealed that cellular, metabolic, and developmental process terms and the response to stimulus term dominated in the biological process category. Available experimental transcriptomic and proteomic data, in combination with a set of predictions, gave coherent results validating this research. Thus, new manners Msr gene expression regulation, as well as new putative roles of Msrs, are proposed.


2021 ◽  
Author(s):  
Carla Cristina Silva ◽  
Stephanie Karenina Bajay ◽  
Alexandre Hild Aono ◽  
Felipe Roberto Francisco ◽  
Ramir Bavaresco Junior ◽  
...  

Hevea brasiliensis, a tropical tree species from the Amazon rainforest, is the main source of natural rubber worldwide. Due to the high pressure of fungal diseases in hot, humid regions, rubber plantations have been moved to escape areas, which are dryer and have lower temperatures during the winter. Here, we combined gene expression data of a primary (GT1) and a secondary (RRIM600) young rubber tree clones, which present different cold tolerance strategies, to analyze rubber tree gene expression regulation during 24 h of cold exposure (10 degrees Celsius). Together with traditional differential expression approaches, a RNA sequencing (RNA-seq) gene coexpression network (GCN) comprising 27,220 genes was established in which the genes were grouped into 832 clusters. In the GCN, most of the rubber tree molecular responses to cold stress were grouped in 26 clusters, which were divided into three GCN modules: a downregulated group comprising 12 clusters and two upregulated groups comprising eleven and three clusters. Considering the three modules identified, the general Hevea response to short-term cold exposure involved downregulation of gibberellin (GA) signaling, complex regulation of jasmonic acid (JA) stress responses and programmed cell death (PCD) and upregulation of ethylene responsive genes. The hub genes of the cold-responsive modules were subsequently identified and analyzed. As a result of the GCN strategy applied in this study, we could not only access individual DEGs related to the Hevea cold response, but also provide insights into a deeper cascade of associated mechanisms involved in the response to cold stress in young rubber trees. Our results may represent the genetic stress responses of the species, developed during its evolution, since the varieties chosen for this work are genotypes that were selected during the early years of rubber tree domestication. The understanding of H. brasiliensis cold response mechanisms can greatly improve the breeding strategies for this crop, which has a narrow genetic base, is impacted by climate change and is the only source for large-scale rubber production.


2019 ◽  
Vol 70 (19) ◽  
pp. 5355-5374 ◽  
Author(s):  
Dandan Zang ◽  
Jingxin Wang ◽  
Xin Zhang ◽  
Zhujun Liu ◽  
Yucheng Wang

Abstract Plant heat shock transcription factors (HSFs) are involved in heat and other abiotic stress responses. However, their functions in salt tolerance are little known. In this study, we characterized the function of a HSF from Arabidopsis, AtHSFA7b, in salt tolerance. AtHSFA7b is a nuclear protein with transactivation activity. ChIP-seq combined with an RNA-seq assay indicated that AtHSFA7b preferentially binds to a novel cis-acting element, termed the E-box-like motif, to regulate gene expression; it also binds to the heat shock element motif. Under salt conditions, AtHSFA7b regulates its target genes to mediate serial physiological changes, including maintaining cellular ion homeostasis, reducing water loss rate, decreasing reactive oxygen species accumulation, and adjusting osmotic potential, which ultimately leads to improved salt tolerance. Additionally, most cellulose synthase-like (CSL) and cellulose synthase (CESA) family genes were inhibited by AtHSFA7b; some of them were randomly selected for salt tolerance characterization, and they were mainly found to negatively modulate salt tolerance. By contrast, some transcription factors (TFs) were induced by AtHSFA7b; among them, we randomly identified six TFs that positively regulate salt tolerance. Thus, AtHSFA7b serves as a transactivator that positively mediates salinity tolerance mainly through binding to the E-box-like motif to regulate gene expression.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guiomar Martín ◽  
Yamile Márquez ◽  
Federica Mantica ◽  
Paula Duque ◽  
Manuel Irimia

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.


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